137
Part II. Experience in South Atlantic Command29
Because the areas in the South Atlantic involve different latitudes, altitudes, and especially different vectors, these subjects will be discussed under separate commands and subdivisions.
EXTENT OF COMMAND
The South Atlantic Command was activated on 24 November 1942. It included Brazil, Paraguay, and Uruguay, and extended from Amapá, Brazil,
29 See footnote 6, p. 122. This document, covering medical activities in the South Atlantic, has been used widely as a source for this section.
138
to Montevideo, Uruguay; that is, from 20º north latitude to 35º south latitude. The most westerly point was Asuncion, Paraguay, the most easterly Ascension Island, Great Britain, 1,437 miles east of Natal. There were no U.S. Army facilities south of Rio de Janeiro.
Nine stations were established. These were located at Amapá, Belém, Sâo Luis, Fortaleza, Natal, Recife, Bahia, Fernando de Noronha (Brazilian Penal Settlement), and Ascension. Belém and Natal (together with Ascension), were the principal bases in connection with the ferrying route. There were no tropical disease problems at Ascension Island, but at all other stations, serious hazards existed, malaria among them.
PREVALENCE OF MALARIA ON BRAZILIAN COAST
In 1940, malaria had ranked third as a cause of death in Pernambuco, where it caused 4.5percent of all deaths. U.S. Army surveys of native populations disclosedindices of parasitemia, ranging from 0.26 to 8.4 percent. Vivax infections outnumbered falciparum infections five to one. Civilian effortsat control were somewhat hindered by lack of funds. Also, division of responsibility between the Brazilian National Malaria Service, the Servico Nacional deFebre Amarela (Yellow Fever), and various local health agencies sometimesmade concerted action difficult.
Malaria was endemic in the vicinity of all U.S. Army installations in Brazil but was particularly prevalent around the airbases at Belém, Natal, and Recife. The average annual rainfall along the coastal area is given as 60 to 70 inches, theaverage temperature as 87º F.
Because of the great importance of keeping men and materiel moving to North Africa, the small service force in the South Atlantic had to be maintained in a high state ofhealth and efficiency, and rigid malaria control measures at all bases becamea necessity.
A malaria control training program was instituted early in the history of the South Atlantic Command. Because of the possibility of transfers, malaria discipline was taught at well-sanitated bases as well as elsewhere. Flight surgeons were required to brief transient crews on malaria and its control. Antimalaria posters were distributed, and a circular letter was used to instruct transient personnel. Film strips were used for instruction, and the malaria training film, TF 8-953, issued in 1943, was shown at movie theaters. Some of these theaters, it should be mentioned, were of the open-air type, but no cases of malaria were ever traced to them. Strategic spraying of movie areas at Recife by the 202d MSD (Malaria Survey Detachment) was doubtless a desirable precaution. It is to the credit of all concerned that no significant disability among the troops from malaria ever existed and that serious cases of malaria within the Command were very few. All evacuations of patients, between June 1943 and 12 October 1945, included only nine cases of tertian malaria--four in 1943, four in 1944, and one in 1945.
139
Protection, by suppressive medication only, gave reasonably satisfactory results under some conditions. 30 For the duration of the war, Brazilian troops were stationed in various towns and villages along the coast in the State of SâoPaulo, where malaria is always endemic. Both mepacrine (Atabrine) and metoquine (quinacrine hydrochloride) were used. Heavy dosage for 5 days was followed by continued weekly administration. During the 3-year period concerned, only 37 of 4,112 officers and men contracted malaria, a figure equivalent to 0.9 percent. A much higher malaria rate prevailed in nearby cantonments where drug prophylaxis was not in force.
Since many A. tarsimaculatus (A. aquasalis) and A. albitarsis were collected in the barracks and 11,142 cases of malaria were recorded from the civilian population with which the soldiers were associated, the general good health of these particular troops may be said to have depended upon the suppressive medication program.
SUMMARY OF ADMINISTRATIVE HISTORY (MEDICAL)
Earliest medical reports from this theater of operations were informal communications from two officers of the Army Air Corps Ferrying Command. Capt. Fred A. Heimstra, MC, who was stationed at Natal, in April 1942, and Lt. Francis M. Dougherty, MC, who assumed duties at Belém in May 1942. Malaria was pointedout as a major medical problem.
With the activation of the new command on 24 November 1942, Wing Headquarters were established at Natal. Brazil had entered the war as an ally on 22 August 1942. Lt.Col. (later Col.) George E. Leone, MC, became surgeon, with Capt. (laterMaj.) Millard E. Smith, SnC, as sanitary engineer and malaria control officer. On 2 December 1942, Maj. Harold F. Funsch, MC, assumed the duties of Wing Surgeon. Colonel Leone continued to plan the development of the theatermedical service. Brazilian Armed Forces were available for home defense,so that the main function of the U.S. Army forces in that country thenceforthwas to provide logistic support to the activities of the Air Transport Command.
Recife (Pernambuco) was selected as the site for concentration of medical activities. For malaria control in the environs of Recife, the services of the Division of Health and Sanitation of the Office of the Coordinator of Inter-American Affairs in Rio de Janeiro were requested and obtained. This group had already accomplished good results around the U.S. Army Air Force installations at Belém.
Recife also became the site of general headquarters for the USAFSA (U.S. Army Forces, South Atlantic). Brig. Gen. (later Maj. Gen.) Robert L. Walsh, previously in command of the South Atlantic Wing, took over the additional duties of commanderof the USAFSA. To avoid confusion of
30 Coda, D.: Expériences sur la chimioprophylaxie du paludisme au Brésil. Bull. Soc. path. exot. 42: 168-172, 1949. Abstr. Trop. Dis. Bull. 47: 207, March 1950.
140
responsibility in medical matters,General Walsh utilized the theater surgeon, Colonel Leone, in the added capacity of surgeon for the Air Transport Command. Colonel Leone became qualified for this dual function by attendance at the course in aviation medicine at Randolph Field, Tex.
This arrangement continued in effect until May 1945. Redeployment of U.S. Army forces had by then greatly increased aviation medical problems, and the Air Transport Command, in executing the "Green" and "White" projects,31 once again began to operate its medical service without reference to theaterheadquarters. On 25 July 1945, Lt. Col. Joseph Nagle, MC, was designatedas Division Surgeon, South Atlantic Transport Division, Air Transport Command.The theater surgeon temporarily retained responsibility for theater medicalproblems not strictly related to aviation. After the defeat of Japan inAugust 1945, steps were taken which resulted in the transference of allmedical responsibilities to the Air Transport Command by the date of closeoutfor the South Atlantic theater. This took place on 31 October 1945.
The table of organization for Headquarters, Medical Section, USAFSA, was approved by War Department letter, dated 21 September 1943 (chart 7). As of 31 December 1943, thestaff included Capt. (later Maj.) Gus R. Herzik, Jr., SnC, Sanitary Engineerand Assistant Medical Inspector; Capt. Millard E. Smith, SnC (duty statusfrom South Atlantic Wing, Air Transport Command), in charge of malaria control work; Capt. Jacob M. Benson, MC, Theater Malariologist, in charge of disinsectization of aircraft and liaison officer with the Brazilian Port Health Service; and Capt. Sylvanis N. Landis, MC, in charge of the theater laboratory. Of this group, only Captain Herzik remained to be listed as of 31 December 1944.Captain Landis was replaced during the year by Capt. (later Maj.) Benjamin Al. Kagan, MC, who served as liaison officer as well as theater laboratory officer and epidemiologist. Major Herzik was replaced by Maj. John E. Vogt, SnC, on 27 March 1945.
ORGANIZATION
Malariologists
The special malaria control organization of the Medical Department of the Army was established in 1942.32 A chief malariologist was appointed for each theater of operations in which malaria was a problem. Capt. (later Lt.Col.) Everett W. Ryan, MC, served as theater medical inspector for theSouth Atlantic, until the appointment of Capt. Jacob M. Benson, MC, in 1943.These malariologists both planned and supervised the control program for
31 The "Green Plan" provided for the redeployment of troops from Europe to the UnitedStates by air. Provision was made to transport approximately 50,000 troopsper month, of which half would travel the South Atlantic Route. The "'WhitePlan" pertained to the return of aircraft.
32 MalariaControl Overseas (News and Comment). Bull. U.S. Army M. Dept. 4: 501-503,November 1945.
141
CHART7.- Table of organization, Headquarters, Medical Section, U.S. Army Forces,South Atlantic
142
their respective areas and served as liaison officers between field units and higher headquarters. Effective function in the field dates from February 1943. The total personnel specifically designated for malaria control overseas, by the end of the war, included approximately 345 officers and 2,350 enlisted men.
Sanitary Corps Activities
Sanitary Corps officers were used as sanitary engineers, malaria control officers, assistant medical inspectors, laboratory officers, and administrative assistants. All these functions, especially the first four, related more or less intimately to the malaria problem. The services performed by 2d Lt. (later Capt.) Irving E. Linderman, SnC, Commanding Officer, 57th MCD (Malaria Control Detachment), may be cited as an example. This officer, with his detachment, reported to Headquarters, USAFSA, at Recife on 3 December 1943. Because the greatest problem in malaria control existed in the Belém area, he and his unit were assigned to that station. The unit engaged in malaria control activity at Belém, Amapá. and Sâo Luis. Inasmuch as Captain Linderman was trained as a sanitary engineer, it was decided to utilize him as a consultant in this field whenever his duties in malaria control work might permit. In this connection, Captain Linderman was appointed assistant base medical inspector at Belém, 17 February 1945.
A request had been submitted to the War Department on 17 November 1943 for the services of a malaria survey unit On 15 April 1944. 2d Lt. (later Capt.) Herbert T. Dalmat, SnC, and 2d Lt. (later 1st Lt.) Aran S. Johnson, SnC, reported to headquarters. Since the principal anxiety in the matter of malaria control related tothe possible reintroduction of A. gambiae into Brazil, LieutenantDalmat was assigned to Natal, as aircraft disinsectization officer, to assistthe Brazilian authorities in the treatment of airplanes arriving from Africa. Lieutenant Johnson, an entomologist, was retained at Recife, until the arrival of the 202d Malaria Survey (later designated the 202d Malaria Survey Detachment) on 3 July 1944. He was then sent to Belém and was attached to the57th Malaria Control Unit which was doing survey as well as control workand could well utilize his services.
The activities at Natal were very important from the standpoint of Brazilian-U.S relations. It became necessary to make the officer in charge directly responsibleto the Commanding General, USAFSA.
History of Malaria Survey and Control Units
202d Malaria Survey Detachment . - The 202d MSD was activated at Camp Ellis, Ill., on 10 December 1943, in accordance with General Orders 85, Headquarters, Camp Ellis. Enlistedpersonnel were drawn from various casual detachments at the camp, exceptfor three laboratory technicians who were assigned from Fort Sam Houston,Tex. Capt. Rupert L. Wenzel, SnC, and 2d Lt. (later Capt.) Leon Jacobs, SnC,joined the organization on
143
13 and 17 January 1944, respectively. Captain Wenzel left the unit on 24 October 1944, and Captain Jacobs assumed command.
The unit received some preliminary training in Camp Ellis and then proceeded to Camp Plauche, La., where it received specialized malaria training from 1 March to 20April 1944, and arrived in Recife on 3 July 1944.
After 10 days of quarantine, the detachments enlisted personnel were attached to the 200th Station Hospital for rations and quarters, while the officers were quartered with Headquarters, USAFSA, officers.
The 202d MSD, like the 57th MCD, was assigned a theater function, and came under Headquarters, USAFSA, for the major part of its administration, only minor details being subordinated to the base command. In addition to the theater function of malaria survey work, it was charged with malaria control responsibilityin the Recife military area, mainly routine larviciding, ditching, and ditch maintenance. However, when opportunity permitted, it performed some permanent filling operations. It managed its own survey work entirely. The laboratory staff did mosquito identifications and blood surveys. In its theater survey function, it performed malaria surveys at Amapá. and Fortaleza and assisted in survey work at Natal and Belém. It performed experimental work on DDT as a mosquito larvicide and on an A-24 airplane fitted for spraying DDT. Personnel of the unit also performed fly survey and control work on Ascension Island. The unit was inactivated on 21 September 1945.
57th MalariaControl Detachment. - The 57th MCD was officially activated in the springof 1943 at Camp Plauche, which was then the New Orleans staging area. Personnel to make up the organization were assigned from various medical replacement centers and pools. The unit embarked at the New Orleans Port of Embarkation early in 1944 and arrived at Belém on 8 February 1944. Personnel were attached to the 193d Station Hospital for rations and quarters.
The Detachment was charged with malaria control at the bases of Belém, Amapá, and Sâo Luis. Usually two men were sufficient to handle routine control operations at Amapá, and the rest remained working at Belém. It was only necessary to send a man to Sâo Luis occasionally, because of good control effected there by the Brazilian National Malaria Service. At first the unit confined itself to control work, obtaining its surveyinformation from the SESP (Serviço Especial de Sáude Pública).Later, in September 1944, with the aid of Lieutenant Johnson, who remainedon temporary duty with the detachment from September to December 1944, alarva survey team was set up. The unit borrowed a microscope and did itsown mosquito identification, although it still received daily reports fromSESP. Enlisted men of the 202d MSD were placed on detached service with the57th MCD in September and October 1944, one at Belém and one at Amapá, to aid in survey work.
The chief activity of the 57th MCD was carrying out temporary and semipermanent control measures. Larviciding, wherever larvae were found,
144
was performed regularly, and stream training, construction of new ditches, and the maintenance of old oneswere also carried on. This work occupied the efforts of 40 to 60 Brazilianworkers who were employed by the post engineer and supervised by the 57thMCD.
ACTIVITIES AT VARIOUS BASES
Housing
Inspection in July 1942 disclosed that no provision had been made for mosquitoproofing of buildings to be occupied by troops. Especially to be criticized were the loosely laid tiles which formed the roofs of the one-story mortar, tile, and brick structures being erected by Brazilian contractors. The very satisfactory screened wooden buildings, on concrete supports, used in British Guiana, could not be duplicated in Brazil, because of lack of lumber and other technical difficulties. Repeated protests and considerable correspondence resulted in commitment of mosquitoproofing either by cementing the tile or by copper screening the ceilings. There was a shortage of material, however, and troops arrived before the quarters were completed. It was therefore necessary to house some of them in tents.
Transient personnel for whom transportation could not be immediately provided were housed in tents at Natal, and a "Tent City" was established at Recife to give temporary shelter to transients, to overflow personnel, to prisoners of war, and to survivors of disasters at sea. Most of these persons remained only a short period, but 140 permanently assigned individuals lived there for considerable time.
Tent City was within a malaria zone, and the tents were not in any way mosquitoproof. Infected natives lived within flight range of the area, and suitable vector species were present. Repellents and mosquito nets constituted the only protection, and it is remarkable that only nine cases of malaria were determined as originating there. Since requested construction of mosquito-proof barracks did not materialize, these troops were moved into existing barracks regardless of the crowding which resulted. It would appear that malaria discipline among the permanently stationed personnel of the South Atlantic Command was usually satisfactory. Educational efforts to this end on the part of the theater surgeon werenot lacking. Number five of the seven "health precautions," set forth bya War Department poster distributed throughout the command in November 1943,read as follows: "Use mosquito bed net every night. Use protective clothingand mosquito repellents if on out-door night duty."
General Health Measures
Data on the number of malaria cases among U.S. Army troops in Brazil in 1942 are inaccurate. Some figures will be presented in the sections on the individual bases.Malaria attacks among command personnel in the South
145
Atlantic theater during the year 1943 totaled 133 cases, with 20 of these recurrences. During 1944, there were 75 cases of which 22 were recurrences. From January through August 1945, therewere 39 cases of which 17 were recurrences. These figures include all casesoriginating in permanent personnel regardless of whether the disease wascontracted outside the theater. The breakdown of these cases per month ispresented in table 17.
Since particular problems existed at the various bases, further data appear on each one,individually, as follows:
Be1ém.- Val de Cans Field was situated 6 miles outside ot the city ot Belém on the south side of the Rio do Pará (Guajar á Bay). The airbase bordered this river and the Val de Cans River.
Close to the Rio do Pará. in the low areas, there is much marsh and swamp, whilethe higher ground is covered by dense tropical rain forest. The proximityof the base to the flood plane, together with intense humidity and a climate which is never dry and which has a prolonged season of heavy rains, all aidedin producing optimum mosquito-breeding conditions. Rainfall averages 112inches per annum, of which 75 percent falls during the first 6 months ofthe year. Brackish waters of the Pará River infiltrating in areas closeto the shore produce conditions suitable for the breeding of A. aquasalis , while seepage and storm waters collecting in unshaded depressions produce foci of the mosquito second only to A. gambiae as a malaria vector, A. darlingi.
A report by Colonel Leone revealed poor malaria conditions at Belém in July 1942. Though malaria registers were not kept, the local medical officer reported atleast 30 cases of malaria within the preceding 2 months, among a
146
base population of 6 officers and 105 enlisted men. There was no way of ascertaining how many of the 25 to 50 transients per day who were passing through the field acquired malaria during thattime. One-half mile northeast of the closest U.S. Army barracks, there waslocated a Brazilian Army post where no precautions against malaria were taken,with the consequence that the malaria rate (new cases only) among the Brazilian troops for the period April through July 1942 was 506 per 1,000 per annum, and for April only, always a month of high incidence, 910 per 1,000 perannum. At the U.S. Army installation, meager control measures were beingeffected by the base personnel. These consisted of oiling stagnant waterson the base with crude oil, and some minor drainage. Control was limitedbecause of lack of adequate supervision and equipment. All personnel wererequired to sleep under mosquito netting, and head nets, gloves, and mosquitoboots were worn by guards at night.. Malaria prophylaxis, consisting ofquinine sulfate- 7½ grains daily--or of Atabrine--6 grains (4 tablets) weekly--was required.
Even during thedry season (from August to November) of 1942, cases of malaria occurred among the small troop complement stationed at Belém. Three cases of malaria occurred in August, and the malaria incidence was still high with 12 cases in October. Action was initiated by the Office of the Surgeon, USAFSA, to mosquitoproof all buildings at the base at Belém and to insure the proper construction of any additional barracks. Arrangements were also made with Serviço Especial de Sáude Pública to carry on a treatment program of all known cases of malaria among the neighboring natives. Further recommendations included extension of the drainage system. In the absence of screening, cloth was to be used for mosquitoproofing buildings; however, not much of this work was accomplished. Fortunately, not much jungle was cleared. In those places where this work was accomplished, at the ends of the runways--not for malaria control but as a necessary measure in the construction of the airfield--innumerable pools of water were exposed to direct sunlight, providing an ideal environment for the breeding of A. darlingi , the worst vector of malaria in the area.
Factors peculiar to the military situation contributed to a high rate of malaria in Belém. It was necessary for airplanes remaining overnight to be guarded by military personnel of the command. These. men were exposed to malaria-infected mosquitoes, which abounded in the grassy areas of the field where the planes were parked. Head nets, mosquito boots, and repellent were not always available forthese guards; so undoubtedly many cases of malaria could be attributed tonight activity.
The SESP, a joint health project of the Brazilian Government and the Coordinator of Inter-American Affairs organized during 1942 at Belém, set up a program of permanent and temporary malaria control measures. The permanent measures consisted of a vast drainage system and the installation of tide gates at the mouth of small streams emptying into the Rio do Pará. Larvicidal measures were directed principally against A. darlingi, the most
147
important vector in Belém and secondarily against A. aquasalis. The vastness of the permanent control program caused slow progress, but the effects of the larviciding became evident much sooner. In a report to the chief surgeon, 2 December 1942, Capt. Millard E. Smith described the larvicidal work of SESP as excellent. Paris green(copper acetoarsenite) larvicide (50-50 paris green and kerosene, dilutedwith water at the site of application and dispersed by knapsack sprayers) was used twice a week on the breeding areas. It was anticipated, however, that larviciding without drainage would be inadequate at the height of the rainy season.
By May 1943, animprovement had been effected in the malaria situation. Most of the livingquarters were completely screened and mosquitoproofed. Others were beingrepaired. The malaria rate was kept relatively low, in comparison with 1942,because of the larviciding activities of SESP and the improved living conditions.The observance of individual malaria discipline was lax, however, and caseswere being acquired needlessly.
The malaria incidence in Belém during 1943 was ameliorated, too, by the establishmentof a sanitary detail supervised by the sanitary inspector and composed of2 enlisted men and 40 natives employed by the Air Port Development Project. This detail accomplished such antimalaria measures as drainage and filling of stagnant pools in borrow pits, cleaning streams of debris and vegetation, and clearing underbrush around the field.
No figures are available for the number of malaria cases contracted at Belém during the months of February through April 1943. However, it is estimated on the basis of vague statements in the monthly sanitary reports that 1 to 3 cases occurred per month, of which some may have been recurrences. (In January, only one recurrent case was reported.) The incidence of the disease rose slightly duringthe months of May and June 1943, when 5 and 6 cases were reported respectively,giving rates per annum of 76 and 103. This was a considerable improvementover 1942. During the rest of the year, only five more cases of malaria appearedin the command at Belém--two in July, two in September, and one inDecember.
At the beginning of December 1943, Lieutenant Linderman arrived in the theater. The 57thMCD had been requisitioned for service at Belém, and air transportation had been requested for its commanding officer so that it would be possible for him to orient himself with the situation before the arrival of hisunit. The enlisted men of the detachment arrived on 8 February 1944, butthe organizational equipment, due to transportation difficulties, was notdelivered until 29 April 1944. Until arrival of the supplies, the unit didits best with borrowed equipment and took over the malaria control procedureson the base.
In November andDecember 1943, reports were received that Eighth Air Force combat crews ferriedthrough the South Atlantic had incurred many cases of malignant tertian malaria. The striking power of the Eighth Air Force had been materially reduced as a result of malaria, with 17 percent of
148
a group of combat personnel becoming ill with the disease upon arrival at their oversea destination. The complaint from Headquarters, Eighth Air Force, referred to the first week of November as the time when this incidence of malaria was encountered. The rates in the South Atlantic Command had fallen off sharply in the second half of1943. Moreover, the predominant infection among permanent troops was alwayscaused by P. vivax. (In the entire history of the command, only five falciparum infections were incurred.)
Consequently, it was not considered likely that the aircrews had become infected in Brazil. The record spoke for itself, and except for the more rigid enforcementof malaria discipline at Belém, no major changes in the malaria control program had to be effected. Directives on the control of malaria had been published for the entire command, and the importance of malaria was reiterated in additional letters. Col. Paul C. Gilliland, MC, Air Transport Command Surgeon, made a special inspection of Belém and Natal in regard to malaria. Suppressive treatment for malaria was directed by Colonel Gilliland for transient combat crews using the South Atlantic route.
After the arrival of the 57th MCD, Belém showed considerable improvement over 1943, with only 17 cases throughout the year 1944. Some of these cases were contracted at remote outposts, such as Clevelandia, where it was impracticable tocarry on control. Most of the 17 cases occurred during the period from Aprilthrough June 1944, with 4 cases in April, 8 in May, and 3 in June. Of thesecases, one in April, two in May, and two in June were recurrences.
The 57th MCD inherited the original Air Port Development. Project Sanitation Squad and augmented it to include from 50 to 60 native laborers, who were employed regularly under the supervision of enlisted personnel of the organization. These employees were divided into various crews for larviciding, barracks spraying, ditching and maintenance, and survey work. The activities formerly performed by SESP came under the control of the 57th MCD. However, since the control detachment was not equipped for survey work, SESP continued to make surveys and perform identifications. Liaison between SESP and the 57th MCD was maintained closely during the entire year, and it was therefore possible to perform effective spot oiling for the elimination of foci of A. darlingi.
The native larva survey team mentioned previously was established with the help of a sanitary technician on detached service with the 57th MCD from the 202d MSD in Recife. In accordance with theater policy on the use of malaria control personnel, the 202d MSD had detailed men to Belém and Amapá to aid in survey work. Also, from August 1944 to January 1945, Captain Linderman had the assistance of Lieutenant Johnson, who aided in the administration ofthe unit and in the establishment of survey procedures.
From July 1944 until August 1945, only five cases of malaria were charged against Belém. Of these, two in June 1945 were in recently assigned personnel who arrived at the base within the incubation time of the disease. This record
149
is enviable, considering the high incidence of malaria during the early history of the base. During the rainy season of 1945, DDT was used very successfully for the first time in Belém as a larvicide, and this may account for the excellent malaria control during this particularly difficult portion of the year. (Previous to April 1945, sufficient DDT was available for residual spraying, which had been accomplished routinely in the Army dwellings.)
Natal. - ParnamirimField, the most important airbase of the U.S. Army in Brazil, was locatedabout 8 miles from the city of Natal, which is at 5º 50' south latitude and 38º 5', west longitude. The airfield,at an elevation of 133 feet above sea level, was surrounded by hilly, generally well drained terrain, although there were a number of small fresh waterlakes. Except for a small lake adjacent to the area of the field, no bodiesof water exist in a radius of 2 1/2 miles of the area. The surroundingcountry is dry, with sandy soil, rapid drainage and a covering of low brush,"catinga." In the south, there are two streams, the Rio Cajupiranga and theRiacho Cajupiranginha, joining in an area which was about 2 1/2miles directly below the base. Further east, the combined stream unites withthe Rio Pitimbu to form the Rio Pirangi which empties into the sea southeastof area in which the field was located. The Rio Pitimbu has its origin westof this area, makes a circuit around it to the north, and then descends southto its confluence with the Rio Cajupiranga, over 2 miles from the area ofParnamirim Field.
The borders of these streams are cut by irrigation ditches which are required for cultivation along the river valleys. Sometimes these are abandoned and become covered with grass which protects numerous foci of Anopheles mosquitoes.In addition, there are low banks, cutoffs and meanders along the pathsof these waters which are well vegetated and serve for mosquito breeding.
The climate is good with an average daytime temperature of 86º F., and an annual rainfall of approximately 55 inches, most of which falls during the months of April to July. There is a constant wind blowing from the south or southeast.
Because of the favorable topography of the area and the distance of the base from mosquito-breeding foci, malaria was not considered as a serious health problem at Parnamirim Field. Most of the control activities were in the hands of the Brazilian National Malaria Service. The activities of the Brazilians included stream training, brush clearing, minor drainage and ditch maintenance, and somelarvicidal work using paris green. Their service, because of lack of funds,was not adequate, as evidenced by an epidemic of malaria which broke outin June 1943 in villages along the Pirangi Valley. The favorable situationof Parnamirim Field is evidenced by the fact that only a few cases of malariaoccurred among base personnel during the period of the epidemic in the nearbyvalley.
During the entire history of the airbase at Natal, most of the cases of malaria could betraced to off-base activities. A radio range situated about 5 miles fromthe base was the site of many infections that were incurred, and
150
emphasis frequently had to be placed on the use of individual protective measures. Soldiers required to attend the warning lights, situated between the base and the Rio Cajupiranga,also became infected. The city of Natal itself was not free of malaria,and soldiers visiting the city at night or wandering around the native habitationsnear the base despite "off-limits" orders were exposed to bites of Anopheles . Occasional cases of malaria among permanent personnel were incurred, although, on the base proper, mosquitoes were seen rarely.
In April 1944, a malaria control officer, Lieutenant Dalmat, was assigned to Parnamirim Field. This officer had the double duty of aiding the Brazilian Government in the disinsectization of aircraft arriving from Africa and of supervising whatever malaria control activities were required at the field. To supplement the work of the Brazilian National Malaria Service in the Parnamirim area, this officer set up a system of survey and control work on and around the base. Routine checks were made of all water deposits on the base and within a radius of 4 miles around it. Barracks and other buildings were searched every day for adult mosquitoes, and inspections were made of screening defects. A mosquito light trap was kept in operation near the Army outdoor theater as a further check on adult mosquitoes. Control measures consisted of weekly oiling all water deposits on the base and 1 mile around with a mixture of waste oil and kerosene. When areas outside of a 1-mile radius were found to harbor mosquitolarvae, the Brazilian National Malaria Service was notified.
From 1 May 1944to 31 December 1944, only five A. albitarsis adults were found onthe base. All of these were dissected, and none was found to harbor sporozoites of the malaria plasmodia. These adults were found in unscreened buildings of the base laundry and in buildings on the Navy side of the base. Themosquito light trap situated near the outdoor movie theater was operatedcontinually for 14 days, and only one culicine was found.
Despite these results of vigilant survey work, which indicated a fairly safe situation on the base, malaria cases appeared among permanent personnel during May, June, and July. In May, one case of malaria was incurred by a soldier who gave no history of having been outside the geographic limits of the base for over 3 weeks before the onset of the disease. Moreover, five cases of malaria developed among U.S. Navy personnel of whom one man stated he had not left the field for considerable time.
In June 1944, seven cases of malaria were hospitalized at the 194th Station Hospital. Of these cases, however, only one was a "new" infection in permanent personnel. The others were either relapses or transients. In July, two more cases were reported in permanent base personnel. The occurrence of these cases of malaria, although few, still led to a reiteration of the need for malaria discipline. Except for one more new case of malaria which developed in August in a soldier who visited off-base areas in his work, no malaria cases directly attributable to Parnamirim Field were encountered during the rest
151
of the year. During the entire year of 1944, there were only 19 cases of malaria treated in the 194th Station Hospital, including permanent and transient personnel and recurrences.
The use of DDT as a residual spray, both for the control of malaria and for the elimination of bedbugs, was instituted in Parnamirim Field in September 1944. Thereafter, barracks were sprayed regularly every 3 or 4 weeks or slightly less frequently. Its effect against bedbugs was easily judged, in that a previously ever-present pest was entirely eliminated. Its effect against mosquitoes could notbe judged because of the small number of these insects found on the base.It was incorporated into the control program as an adjunct to the otherantimalaria measures in force.
During the year1945, malaria was somewhat more of a concern at Parnamirim Field than inprevious years. One of the most important factors influencing this was arainy season that exceeded in intensity and duration the precipitation thathad been experienced in the 12 years preceding. Another factor was the crowdingof the base under the Green Project and the appearance of malaria among menassigned to the base as "Green Support" after having served in Africa andItaly. Some of these men either had suffered previous malaria attacks orhad been taking suppressive Atabrine therapy. A number of these individualshad to be hospitalized for malaria during the year. Moreover, the malariarates for the city of Natal as well as for the small villages near the airbasewere higher this year than for many years in the past. The personnel of ParnamirimField were allowed to visit the city, and some of them worked in outlyingareas.
Routine survey work was maintained in order to provide protection of troops against malaria. In addition, after an upsurge of malaria occurred on the base in May, aspecial survey team from the 202d MSD in Recife was sent to Natal to aidin the survey work. Despite vigilant searches, no Anopheles mosquitoeswere found on the base. However, control measures were carried on as follows:
To control malaria on Parnamirim Field and for 2½ miles around it, the malaria survey and control teams were increased in size from two to four men, and an additional vehicle was furnished for their use. Spraying of DDT as a residual spray wasinstituted in native houses within a 2-mile radius of the base. For this purpose,a gasoline-driven compressor improvised by the 202d MSD was used with a paintspray gun. All barracks on the base were routinely sprayed with DDT asusual. Larviciding activities were also performed, with all water depositswithin a radius of 2½ miles of the base receiving a weekly treatmentof 2.5 percent DDT in oil. Screening was installed in Army buildings situatedoff the base, such as the radio range and the market center.
During the month of August 1945, DDT treatment of larval breeding areas beyond the 2½ mile control zone was accomplished thoroughly by means of airplane spraying. An A-24 airplane equipped with a venturi spray apparatus and an 80-gallon tank was used, and enlisted men of the 202d MSD
152
in Recife were detailed to Natal to aid in performing the work and in evaluating the results.
The malaria record at Parnamirim Field showed 16 new cases among permanent military personnel during 1945. Of these 16 cases, 8 were recently assigned from Italy and Africa where they had been receiving suppressive Atabrine therapy; the other 8 cases possibly contracted the disease on the base area. Of these latter individuals, most had left the base and had spent some time in town, butthe actual place where the disease was incurred could not be definitely established. Because no anopheline larvae or adults could be found on or within 2½ miles of the base, it was difficult to understand how 8 cases could possibly be contracted there. It was surmised that mosquitoes flew in (with the air of prevailing winds) from the Rio Cajupiranga in the south. Surveys of this area uncovered very few larvae or adults; yet to cause eight cases (six of the men becoming ill at approximately the same time), large numbers of A. albitarsis would have to be present. In endemic regions near Parnamirim Field, less than 1 percent of the A. albitarsis were ever found infected. It is believed that most of these cases were contracted awayfrom Parnamirim Field, where the number of mosquitoes was great enough toallow easy malaria transmission.
Recife.-Ibura Field, Brazil, established about 6 miles south of the city of Recifeon an area of level ground about 33 feet above sea level, was surroundedby the populous villages of Ibura, Imbiribeira, Boa Viagem, Prazeres, andPiedade. The terrain around the field consisted of a low narrow coastal plain,bounded on the west by a range of low hills. Much of the terrain near theshore was dune country, with irregular rises of sand above a soft soil consistinglargely of decayed vegetation. The hills to the west had poor natural drainageand an impervious subsoil resulting in the formation of many springs. Because of the dune formations and because a large amount of the land was only slightly higher than sea level, drainage was poor and the water table was high.The streams, which form at the western hills, are sluggish and meandering and enter into salt marshes near the outskirts of the city of Recife, or into a vast swamp about 2 miles south of the area of the field. A long tidaldrainage ditch, running parallel to the beach and about 100 yards inland,joined the salt marshes to the north and south. The rainfall per year variesbetween 60 and 100 inches, the greater portion (93 percent) of which occursduring the months of April to September with as much as 33 percent fallingduring the month of May or June.
The saline waters along the shore provided excellent breeding conditions for A. aquasalis, the most important malaria vector in the area. The fresh springs and deposits of rainwater in the valleys to the west provided foci for A. albitarsis, of secondary importance in malaria transmission. The natural water deposits were supplemented by many manmade collections of water. The natives cultivated the soil by forming little hillocks at the base of which seepage and rainwater collected and was impounded. When these were abandoned,
153
the high grass obscured numerous small pools which were the producers of many mosquitoes. The natives, in searching for crabs, also excavated small holes at the borders of the tidal marsh; these holes became filled with water and remained unaffected by the fluctuation of the tides, furnishing ideal situations for larvae of A. aquasalis. Among the other anophelines found in the vicinity were Anopheles argyritarsis, Anopheles peryassui, A. triannulatus, A. pessoai, and A. noroestensis, none of which is incriminated as a malaria vector.
In October 1942, a sanitary survey of the Recife base was made by SESP at the request of Colonel Leone. Dr. Oswaldo Silva, malariologist, and Mr. C. Heard Field,sanitary engineer, arrived in Recife on 11 October 1942 and spent severaldays in a survey of the malaria situation. As a result of their work, SESPcontemplated performing drainage and filling operations and stream trainingaround Ibura Field and the use of larvicides on breeding areas. The U.S.Army was to furnish a preliminary topographical survey and construct linedditches to connect with the drainage system to be installed by the civilagency. It was recommended that all living quarters be mosquitoproofed andbe sprayed regularly and, also, that mosquito netting be used and that chemicalprophylaxis be instituted for night guards.
The Serviço Especial de Sáude Pública was organized especially for work in the Amazon and Rio Doce Valleys. In a question of jurisdiction, theBrazilian National Malaria Service was assigned control responsibility aroundU.S. Army bases in other localities. The Brazilian National Malaria Servicewas very helpful in furnishing data to the U.S. Army authorities throughoutthe war and also performed malaria control activities in conjunction withthe U.S. Army. Around Recife, close liaison was always maintained with Dr.Durval T. Lucena, laboratory chief of the region.
From the Brazilian National Malaria Service, the following data on malaria among the natives around Ibura Field in 1942 were obtained: The village of Boa Viagem showed 11.2 percent of 3,026 persons with malaria; Prazeres 41.2 percent of 1,835 persons; Piedade 32.4 percent of 377 persons; Imbiribeira 32.2 percentof 986 persons. Adjacent villages of Venda Grande and Candeias showed 27.9 percent of 340 persons and 17.6 percent of 319 persons as malaria carriers. Obviously, the malaria control problem around Ibura Field required considerable attention. The incidence of malaria among Brazilian troops stationed on the base was 30 percent during the months of July and August 1942, and 10 percent of a small detachment of U.S. Marines had malaria during the same period.
At the request of the Commanding General, South Atlantic Wing, Air Transport Command, the sum of $15,000 was made available for malaria control at Recife. Colonel Leone had requested a sanitary engineer officer in early July 1942. This officer, Lt. Millard E. Smith, arrived on 14 November 1942 and took over the duties of theater malaria control and sanitary engineering around the Recife area.
154
A barracks-spraying detail, organized in late 1942, functioned under the supervision of the base surgeon, performing routine spraying of all living quarters every 48 hours. No larviciding, however, was done either by the Brazilian National Malaria Service or the Army until February 1943. At that time, the Brazilian National Malaria Service used paris green to a small extent because their supplies were always limited. Most emphasis was placed on drainage of the area. The Brazilian National Malaria Service had constructed a series ofditches in the tidal areas and was working on excavation of a drainage systemin a fresh water swamp west of the base. The Air Port Development Projecthad eliminated some mosquito foci on the base by filling or drainage but,on the other hand, had created additional breeding places by the excavationof topsoil in swampy ground, leaving large borrow pits.
The manner in which the engineering projects were planned apparently took no cognizance of the malaria control problems involved in the area. Difficulties such as those encountered at Belém in regard to mosquitoproofing of buildings were met, and the situation had to be remedied by the grouting-in of the loose tile roofing. The most important difficulty encountered was the lack ofaction on drainage required for malaria control. A swamp on the southeasterly side of Ibura Field was the subject of much correspondence and was still not drained or filled a year after the first recommendation. Even in 1945, swampy areas between the runways on Ibura Field required larviciding regularly.
It soon became apparent that the facilities of the Brazilian National Malaria Service were not sufficient to provide adequate protection against malaria for U.S. Army personnelstationed at Ibura Field. Between 27 February and 23 March 1943, 21 casesof malaria appeared among Army personnel on the field. In the several monthsprevious to this outbreak, only six cases had been reported. The unseasonalincrease was probably due to the rains which fall during the early partof the year and are called chuvas de caju by the Brazilians. Itwas necessary to discontinue the showing of outdoor movies and to reinstructpersonnel in malaria discipline, which had become lax during the dry season.Consequent to this outbreak, a larviciding squad of Brazilian employeeswas established for the control of mosquito breeding around the area, andanother crew of natives was organized to do ditching and maintenance work.These two crews, in addition to the barracks spraying detail, came underthe supervision of the base surgeon and of the malaria control officer, USAFSA,who acted in an advisory capacity. Routine oiling was performed of all waterswithin a 1-mile radius of the base. The larviciding and ditching crews wereplaced under the direct charge of three enlisted men of the base complement,and the spraying crew was supervised by men of the office of the base surgeon.
As a result of the efforts of these antimalaria details, no further serious malaria outbreaks occurred during the year. The rainy season passed with three cases inApril, one in May, one in July, and two in September. November
155
and December showed an increase, with five cases and one case, respectively, indicating that some malaria transmission occurred, even during the height of the dry season.
In April 1943, a survey was made of mosquito-breeding areas in the vicinity of Ibura Field by the Wing sanitary officer, Capt. Millard E. Smith, Dr. Mario Pinotti , Director of the Brazilian National Malaria Service, and Maj. BenjaminGause, SnC, of the Office of the Coordinator of Inter-American Affairs.The object of this survey was to determine the feasibility and practicabilityof permanent malaria control measures around the base. It was Captain Smith'sopinion that permanent ditch lining would not be feasible because the typeof soil would render even lined ditches unstable and subject to shift ingrade and alignment and because of the scarcity of materials and high cost.He believed that tide gates would serve no useful purpose, and that larvicidingwould be the cheapest method of control even over a 5- to 10-year period.However, he considered that help should be given the Brazilian NationalMalaria Service in the construction and maintenance of the system of unlinedmalaria control ditches around the field.
The antimalariasquads continued functioning in the same manner, under the supervision ofthe base surgeon, Ibura Field, and later of the medical inspector under theCommanding Officer, 200th Station Hospital, throughout 1943 and part of 1944.With the expansion of Ibura Field into its two subposts and the establishmentof the hospital area, in the spring of 1943, it was necessary to includea. larger amount of terrain in the control program. The squads were graduallyexpanded to include approximately 40 Brazilian laborers, exclusive of thebarracks spraying crew.
In April 1944, two malaria survey officers arrived, Lieutenant Dalmat and Lieutenant Johnson. These officers performed some malaria survey work around Ibura Field and its two subposts. They found anopheline breeding in areas to the northof Ibura Field and to the south of the hospital and recommended controlin these areas. Lieutenant Dalmat was transferred, on 22 April 1944, toNatal to take charge of the disinsectization of airplanes and of malariacontrol there. Lieutenant Johnson was left in charge of malaria controlin the Recife area.
In May and June1944, a small outbreak of malaria, occurred among troops quartered in tentsin an area between the USAPSA headquarters and the 200th Station Hospital.Fifteen cases occurred among a command of 140 men during these 2 months.The tents were unscreened, and malaria discipline was apparently poor. Theneed for reemphasizing malaria discipline and control measures during therainy season was pointed out by the malaria control officer, USAFSA, in variousletters in May 1944. It was also recommended that the tents in the area concerned be screened or that permanent type barracks be provided for the personnel involved. The men were moved to permanent type barracks elsewhere in the area during the latter part of June 1944.
156
However, one more case of malaria from this group of men was admitted to the hospital in early July.
One additional case of malaria among 87 transient officers and men was traced to the Tent City area where these troops were quartered between 3 July and 28 July 1944. In addition, one other new malaria case was contracted in late July elsewhere in the Recife area (admitted to hospital 6 August 1944). These were the last new cases of malaria to originate in the command up until September 1945.
Among the troops billeted at Tent City, during the month of July 1944, was the 202d MSD. The unit was relieved from quarantine on 14 July 1944 and after settingup headquarters and laboratory at the 200th Station Hospital assumed theduties of malaria control in the Recife military area, on 1 August 1944.
One of the first preoccupations of the detachment was the source of the malaria outbreak in the Tent City area. It was clear that the same source could menace the hospital and USAFSA establishments, only one-quarter of a mile away on either side. A physical survey of the area was made, and the terrain was rezoned to follow ridge lines and easily identifiable boundaries. Adult collecting stations consisting of groups of native houses, numbered by the unit foridentification, were established throughout the area. An adult collectingcrew was established to investigate these stations routinely. A larva surveyteam of Brazilians supervised by sanitary technicians of the detachment performedroutine survey work around the area, and the oiling crew was regularly employed,as in the past, to cover all zones. The rest of the laborers were used inditch maintenance and construction, and, in addition, attempts were madeto perform some permanent control work.
The tidal drainage ditch, in the area between the hospital and USAFSA headquarters, was incriminated many times as the source of A. aquasalis mosquitoes. The malaria control officer, USAFSA, had earlier, in December 1943, negated a proposal by the U.S. Engineer Department to fill in areas adjacent to this canal,considering that cutting through the spoil bank would be all that would benecessary. The 202d MSD, however, found these areas too low to be drainedby laterals, as the soil along the margins of the ditch was very boggy andthe water level lower than in the canal itself. They hauled a total of 90,000cubic feet of earth to fill and grade the sides of the canal and produceda permanent improvement.
The 202d MSD took advantage of the dry months to prepare for the intensive malaria control program which would be required during the rainy season in 1945. In contrast to the earlier malaria control work by the U.S. Army in the area, advantage was taken of time and equipment to do small amounts of permanent control work, although large projects were not feasible, When idle engineering equipment was available, it was borrowed by the detachment from the post engineer and used for filling low areas and eliminating small swamps.
157
The 202d MSD performed blood survey work in addition to its mosquito surveys, in an effort toevaluate the malaria reservoir in the native population. When DDT becameavailable in sufficient quantity, the houses of infected natives were sprayedwith DDT residual spray. Later, this method of control was extended to allnative habitations. DDT was also employed routinely as a larvicide, withthe inception of the rainy season. It was possible, by the use of this insecticide,to economize on the use of oil by means of a spot-oiling technique in theless dangerous zones.
In addition to malaria control around the Recife military area and survey work elsewhere in the theater, the 202d MSD performed studies on the larvicidal effect of DDT in collaboration with the Brazilian National Malaria Service. It also performed fly control work on Ascension Island and fitted an A-24 airplane for the spraying of DDT. The airplane was used at Natal, and later at Belém in an attempt to eliminate A. darlingi from the environs of the airbase and the city. The 202d MSD thus was engaged in considerable experimental workin addition to its routine duties. No new cases of malaria were contracted in the Recife military area after the assumption of malaria control by the detachment.
Amapá - Amapá Air Base was situated on a stretch of level grassy terrain about 6 miles from the village of Amapá and about 60 miles inland at 2o 8' north latitude and 50º49' west longitude. The altitude was 32 feet above sea level. The country surrounding the base was an undulating series of knolls, producing a roiling type of landscape. Beneath a 3-foot clay soil there was a hard bedrock, which inhibited absorption of storm water and caused the formation of swampy areas in the depressions between the knolls. During the dry season, the nearest surface water wasabout 1 mile away from the base, but during the rainy season there were manyswamps close by. Rainfall during the rainy season of 1942 (January to July)measured 92.78 inches, while 6.15 inches fell during the rest of the year.
The airport wasdeveloped first by the Air Port Development Project during 1942. During thedry season, about 25 Americans and 500 local Brazilian employees were engagedin construction work. During the intense rainy season, only a skeleton forceof about 6 Americans and 100 Brazilians was maintained, since constructionwork could not be prosecuted effectively because of the heavy rains.
Soon after the onset of the 1942 dry season, malaria appeared and reached epidemic proportions. Over 300 natives had to be returned to their homes because of malaria,and 7 of the 25 Americans were stricken. Because of the lack of oral quinine or Atabrine, treatment was effected by intramuscular injection of quinine, or quinine plus methylene blue intravenously.
A medical officer of the Air Transport Command at Belém was sent to Amapá.to render whatever assistance possible. This officer aided in the evacuation of many laborers who were too ill to work. He brought supplies of quinine and Atabrine, ordered prophylactic treatment of all Americans, also investigated the mosquito population, and performed blood examinations.
158
The vector of malaria was identified as A. darlingi. Blood smears indicated a predominance of Plasmodium falciparum. The small number of Americans who became ill is probably attributable to the use of screened barracks and bed nets.
Two medical officers of the Trinidad Sector and Base Command were sent to Amapá fromthe U.S. Engineer Department Hospital, Trinidad District, to help out inthe epidemic. At the time of their arrival, 28 November 1942, the epidemicwas already subsiding. They provided additional quinine and Atabrine fortreatment, placed all local civilian employees on chemical pro prophylaxis,5 grains quinine daily, and recommended that prophylaxis could be omittedafter the period of heavy mosquito breeding, depending on the findings ofthe station medical officer.
No further reports on malaria control at Amapá are available until the first monthly sanitary report from the base was submitted on 1 September 1943. Apparently no control measures against a reoccurrence of malaria had been undertaken by the Air Port Development Project, and the only control measure in effect was the spraying of barracks and tents by six workers of the Serviço Especial de Sáude Pública. All the native workers were removed from the confines of the post to a distance of about 1 mile, and theirshacks were burned and their wells filled. The medical officer recommendedsome drainage measures on the post to reduce the number of mosquito-breeding foci. A request was also made for a malaria control officer.
Some larvicidaloiling was undertaken by a sanitary squad under the supervision of the basesurgeon. The medical officer noted that the number of mosquitoes presenton the base was far less than at Amapá village or the barge landingon the Rio Amapá Grande, about 55 miles from the post. Personnel employedat the docks on the river, or on barges unloading ships lying off the island of Maracá were required frequently to work at night, because the shipping was dependent on tides. These personnel were given malaria control lectures, and individual protective measures were enforced among them.
In late July and early August 1943, a visit was made to Amapá by the theater malariologist, USAFSA. Because of the small size of the base, extensive permanent control measures were not indicated. However, some drainage of swamps on the base was recommended. Emphasis was to be placed on larviciding and on the rigid enforcement of malaria discipline.
Larvicidal measures against mosquitoes were prosecuted vigorously by the sanitary squad. Native laborers were employed for hand oiling, using waste engine oil and kerosene, and an improvised power sprayer and drip oilers were used wherever possible. In addition, the routine spraying of barracks was performed once nightly by the crew of SESP workers. One case of malaria occurred in December 1943, in an enlisted man who worked at night at the docks. This was the onlycase of malaria acquired among U.S. Army personnel at Amapá AirBase after it was taken over by the Air Transport Command. A few casesoccurred among Navy and civilian personnel.
159
The barracks spraying detail of SESP became unsatisfactory due to lack of control by the Army. At the end of March 1944, the medical officer at the base was informedthat SESP would discontinue this work. The barracks spraying and the larviciding operations were taken over by two enlisted technicians of the 57th MCD, in June 1944. The commanding officer of this unit had visited Amapá in January 1944 and had made some recommendations regarding control there, and, in the interim between the cessation of work by SESP and the arrival of the enlisted technicians, the barracks spraying was accomplished by other base personnel.
In August 1944,one enlisted man of the 202d MSD was sent to Amapá to aid in surveywork around the base. The work of this man was intended to supplement thecontrol activities of the men of the 57th MCD, providing knowledge of theextent and location of the breeding places of Anopheles and of theeffectiveness of control measures. The need for such work had been broughtout in an earlier report.
Captain Linderman modified the larviciding program at Amapá by using only crews of native laborers with knapsack sprayers. Drip oilers, in use previously,were removed because they were found to be an ineffective method of control.Spraying of barracks could be reduced, because of good larvicidal work,to three times weekly. Concentration was placed on larviciding, althoughsome attempt was made to effect malaria control by clearing swamp areasclose to the cantonment, by burning grass in low areas during the dry season,and by the drainage of swamps and the filling of small pits. Malaria controlwas enhanced to some extent by spraying native huts, starting in February1945, after a case of malaria had been incurred in an enlisted man of theU.S. Navy. Residual spraying with DDT was instituted in April 1945, afterthe arrival of a sufficient quantity.
In September 1944, a parasite survey was made by the 202d MSD of the native population living around the airbase at Amapá. This was done to determine the size of the malaria reservoir. Surprisingly, only 2 cases of P. vivax infection were discovered among 769 natives examined. This extremely lowindex may have been due to the fact that the survey was performed duringthe dry season. The results do not, of course, reflect the earlier epidemicin 1942, when P. falciparum was reported to be the malaria parasiteinvolved. This is to be expected, because, although P. falciparum produces the most acute disease, it is, probably because of this characteristic, the least likely to cause relapses. The low index of P. vivax infections was also due, probably, to the fact that the natives investigated lived ina small settlement around the base and well within the control zone covered by the larviciding crew. Moreover, all cases of malaria which had occurred in this native population had been treated by the base surgeon or the Brazilian Red Cross nurse on duty there.
Mosquito collections made by the 57th MCD and the 202d MSD also showed the malaria hazard to be low at the time, with only one A. darlingi
160
found outside the controlled area,and A. peryassui and A. pessoai, neither of which are malariavectors, predominating.
On the basis ofthese data, it was stated that the airbase at Amapá fortuitously hadbeen located in a good area, from the standpoint of malaria control. Thiswas said despite earlier remarks by the base surgeon that a worse area could not have been selected. Actually, considering its position in the Amazon basin, the location of the base 6 miles from Amapá village and about the same distance from the tidal marshes made the problem of control much simpler than would have been the case otherwise. As soon as control measures were instituted, the incidence of malaria was maintained at a minimum.
Sâo Luís .- In the entire history of the U.S. Army airbase at Sâo Lu í s, only one case of malaria was reported to have been incurred among Army personnel stationed there. The malaria situation was never serious at the base, and the routine control measures under the supervision of the base surgeon were ample to maintain malaria at a minimum.
The airbase of Tirirical Field was situated about 5½ miles southeast of the city of Sâo Luís in the State of Maranhâo, at 2º 35' south latitude and 44º 14'west longitude. Its altitude was about 174 feet above sea level. The cityand the airbase were on a large island, lying in the mouth of an extensive river system, separated from the mainland by the Baía de Sâo Marcos and the Baía de Sâo José. Rainfall varies between 40 to 90 inches per year with most of the precipitation occurring between February and October. However, droughts do occur during which time the totalrainfall per year remains less than 40 inches. Despite the proximity tothe Equator, the climate is good, with a mean annual temperature of 83 º F., and relative humidity of 80 percent.
The relatively high altitude of the base and a terrain affording good drainage lessened the possible malaria hazard. Anopheles mosquitoes of the species A. darlingi and A. aquasalis are prevalent in the low country of the mainland but not in the interior of the island. That malaria vectors were present near the shore of the island, however, was evidenced by a report of seven cases of malaria in one English family living on the beach and of the finding of many anophelines in that area.
An early sanitary survey of the base revealed little malaria potential. A few anophelines (unidentified) were found breeding in a ditch on the post and one adult Anopheles was captured. The use of mosquito bars and the mosquitoproofing of buildings were recommended. These were the only antimosquito measures applied until October 1943.
During that month, a large number of Culex mosquitoes appeared which were found tobe breeding in overgrown ditches on the post. These ditches were oiled and later filled, and the number of mosquitoes soon diminished.
Sâo Luís was visited by the commanding officer of the 57th MCD, in November 1943 and in January 1944. This officer recommended the continued use of bed nets during the rainy season, emphasized the need for main-
161
tenance of screening, the use of larvicidal measures against mosquitoes during the rainy part of the year, and the routine spraying of barracks twice weekly during the rainy season.
Larvicidal measures were put into effect by employing two natives to do occasional oilingwhen necessary and another small crew of Brazilians to operate a portablegasoline engine-driven spray apparatus. After the appearance of the caseof malaria at Sao Luis, an additional survey was made by the commandingofficer and two enlisted men of the 57th MCD. One of the enlisted men remainedto supervise the malaria control program, consisting of larviciding, ditchclearing, and insecticide spraying, with very satisfactory results.
Fortaleza. - Adjacento Field was situated on rolling sandy terrain about 5 miles south of the city of Fortaleza. No malaria has ever been contracted there among U.S. Army personnel. This situation was due mainly to the fortuitous location of the base inland, away from the breeding places of A. aquasalis. Although considerable water existed during the rainy season in depressions around the airfield, these ponds and swamps afforded breeding only for innocuous anophelines, A. argyritarsis, A. pessoai, Anopheles strodei, and A. albitarsis. While A. albitarsis is an important malariavector in the Natal area, its zoophilic habit makes it unimportant in malariacontrol in the State of Ceará.
Precautionary measures against malaria at Adjacento Field consisted of the use of mosquito bars, mosquitoproofing of barracks, and the use of non-residual sprays. These measures were directed not only against malaria but also against pest insects as well. The base was always well sanitated.
Bahia.- Ipitanga Field was located about 24 miles southeast of the city of Sâo Salvador in the State of Bahia, Brazil, at about 12º south latitude and 38º west longitude. The field was several miles from the coastline, separated from it by a series of dunelike hills running alongthe south and east. The Rio Ipitanga partially bounded the landing field,while swamps existed on nearly all sides of the base. Prevailing winds blewover the field from the southeast and east. Temperature ranges from 70º to 90º with an average of 77 º. Precipitation totals about 77 inches per year with a rainy season similarto that in Recife.
The field was surrounded by depressions which became filled with water during the rainy season and served as mosquito-breeding foci. The field was also adjacent to a native village of several thousand population in which malaria was endemic. The Brazilian National Malaria Service conducted some survey and larvicidal work around the airfield in 1943, when the base was under construction, but this work was apparently not extensive.
Because of U.S.Navy administration and of the small number of Army personnel on the base,control measures by the U.S. Army against malaria could not be made definitive.Recommendations for malaria control in 1943 included drainage or fillingof swampy areas on the base, larviciding operations with
162
diesel oil, barracks spraying and mosquitoproofing, the use of the indoor movie theater, and the use of bed nets and of other individual protective measures for individuals required to work outside at night.
The U.S. Engineer Department employed a small squad of Brazilian laborers and also set up a series of drip oilers for larviciding standing waters. No further action was taken by the U.S. Army because the base was mainly under U.S. Navy control and the U.S. Army Medical Department had no activities there after November 1943. In August 1943, the Area Medical Inspector, South Atlantic Transport Division, Air Transport Command, accompanied a general staff officer of that Headquarters to Bahia on an inspection tour. These officers concluded that malaria was not a serious problem at the base and made recommendations for control similar to those made previously by the malaria control officer, USAFSA. In May 1944, a request was received from the commanding officerof USAF, at Bahia, for a malaria survey of the base. It was determined that a Navy entomologist was supervising malaria control at Ipitanga Field, and to avoid duplication of effort, no action was taken by this Headquarters.
After the U.S. Navy vacated Ipitanga Field in early 1945 and the U.S. Army took it over as a subpost of the Recife military area, attention was again given to malaria control. The base surgeon established liaison with the Brazilian National Malaria Service, and 10 Brazilian laborers were employed by the base engineer to work with this agency on the base and in adjacent areas, performing larviciding and semipermanent control. Repairs were also made to buildings to make them mosquitoproof, and barracks spraying and the use of bed nets were resumed.
In the history of U.S. Army occupation of Ipitanga Field, no cases of malaria were incurred among Army personnel. Records show four cases in civilians in the months of April through October 1943, and no cases after July 1954. No figuresare available on the malaria incidence in Navy personnel, although somecases are known to have occurred.
Theater MedicalLaboratory
On 6 January 1943, Captain Landis of the Air Transport Command was given the responsibility of establishing and supervising the Wing and area laboratory. This waslater merged with the laboratory of the 200th Station Hospital at Recife.On 24 April 1944, Captain Kagan became chief of laboratory service andepidemiologist.
The laboratory had by this time become the theater medical laboratory and histopathology center. In June 1944, this laboratory was reorganized to include an Epidemiology Section, of which Entomology and Parasitology were subdivisions. On 14July 1944, the 202d Malaria Survey Unit was given space in the laboratoryand took complete charge of the Entomology Section. The unit also assistedthe Parasitology Section in certain aspects of its work. Dur-
163
ing 1944, a total of 36,437 procedures were accomplished in the laboratory, of which 684 had to do with entomology and 5,730 with parasitology. In 1945, the number of procedures totaled31,324, of which 5,901 related to parasitology, 2,032 being malaria smears.Only 62 insect identifications were performed, the medically important anthropods of the area having been largely recognized the previous year.
Achievements
In June 1945, the strength of the Command (USAFSA) reached 10,000. The "Green" Project (return of troops from Europe) was then in full swing. Although this represented the greatest number exposed to tropical health hazards in the history of the USAFSA, the incidence of malaria was close to the lowest for the entire period (table 18).33
TABLE18.- Malaria in U.S. Army Forces, South Atlantic, 1943-45
The commanding general, Maj. Gen. Ralph H. Wooten was able to report, in July 1945, that through intensive application of permanent control measures, extracantonment sanitation in cooperation with Brazilian health agencies, and enforcement of malaria discipline, malaria had been practically eliminated from U.S. Army bases in Brazil.
EXTRAMILITARY RELATIONS
Liaison with various Brazilian agencies involved cooperative activity along the following lines:
1. Assistance in malaria control activities in areas adjacent to U.S.Army bases.
2. DDT made available both for control purposes and for experimental work.
3. Demonstrations in use of DDT.
Of the several Brazilian agencies involved in medical liaison with the USAFSA, three were especially important in relation to malaria:
1. The Brazilian National Malaria Service (Dr. Mario Pinotti).
33 See footnote 5, p.121
164
2. The Port Health Service (Dr. F. Carneiro de Mendonca). This agencyhad to do with disinsectization and foreign quarantine.
3. Serviço Especial de Sáude Pública.
Close contacts were of course maintained with the Medical Departments of the Brazilian Army, Navy, and Air Force.
Insofar as malaria is concerned, the Division of Health and Sanitation of the Office of the Coordinator of Inter-American Affairs was perhaps the most important cooperating agency. Considerable aid was furnished the U.S. Army in malaria controlwork both at Belém and at Fortaleza.
The Brazilian National Malaria Service was especially helpful in areas where the Office of the Coordinator of Inter-American Affairs did not operate. At Sâo Luís, Fortaleza, Natal, Recife, and Bahia, this agency furnished data to the malaria control officer, as well as to base surgeons. Control work by the U.S. Army in these areas was then coordinated with Brazilian activities. At Recife, the 202d MSD carried on joint experiments with Dr. Lucena, of the Brazilian National Malaria Service, concerning the use of DDT as a larvicide. Likewise, a "guarda" was loaned by this agency to the 202d MSD to collect epidemiological data. The data furnished by the Detachment were made the basis for treatment of infected natives by the Brazilian National Malaria Service. The 202d MSDalso assisted this agency in planning residual spray experiments (with DDT)for the control of adult anophelines.
The SESP, at anearly date, set up a program of permanent and temporary control measuresaround Belém and of barracks spraying at Amapá. Although controlprocedures at these points were later taken over by the 57th MCD, the SESPcontinued to furnish survey information of vital importance to the work ofthis group. The SESP also cooperated in two surveys at Ibura Field. In 1945,this agency invited the theater sanitary engineer, USAFSA, to conduct aninspection of their facilities in the Amazon Valley.
The most important achievement of a cooperative nature was the establishment, in January1944, of an efficient system for disinsectization of aircraft coming fromAfrica. Brazilian national health authorities, Brazilian port sanitarypersonnel, the Rockefeller Foundation representatives in Rio de Janeiro,and the U.S. Army were jointly involved.
In 1944-45, important work was accomplished outside of military command under the auspices of the Inter-American Cooperative Public Health Services in Latin Americancountries. 34 Anopheles pseudopunctipennis was shownto occur on the west coast of South America from sea level to 11,000 feet.Its range was confirmed as including Bolivia, Chile, Colombia, Peru, andEcuador, as well as parts of Mexico and most of Central America. Anophelesdarlingi was identified from Bolivia, Brazil, Colombia, Guatemala,
34 (i) Yeager, C. H: Mosquito work in the Other Americas. Proc. N. J. Mosq. Extermin.Ass. 32: 134-142, 1943. (2) Bishopp, F. C., and Stage, H. H. A Review ofMosquito Work in a World at War in 1944. Proc. N. J. Mosq. Extermin. Ass.32: 13-25, 1945.
165
Honduras, British Honduras, the Guatemalan boundary of Mexico, eastern Peru, and Venezuela. Anopheles albitarsis was listed from Brazil, Bolivia, Colombia, Trinidad, British Guiana, Venezuela, and Paraguay. Anopheles albimanus was confirmed forEcuador, Venezuela, Colombia, Panama, Costa Rica, Nicaragua, El Salvador,Honduras, Guatemala, Mexico, Cuba, Haiti, and the Dominican Republic.Cuba and the British Colonies were not included in these particular investigations.
Permanent drainage projects were carried out in Guatemala, El Salvador, honduras, Nicaragua, and Costa Rica.35 While these were underway, temporary control measures included larviciding with paris green, diesel oil, and DDT, also DDT spraying in houses.
South American Countries
An informative account of malaria control work in most Central and South American countries during the war years has been prepared by Gabaldon.36 Administrative organization, antiparasitic measures, and antianopheline measures are discussed. Budgets are compared for the years 1939 to 1943. Facts and figures appear to justify future emphasis on anopheline reduction or eradication. Exclusion and interception measures (spraying inside houses) are reported as veryeffective. Such information may be of great potential importance in possiblefuture military operations, as well as in relation to various activitiesof a commercial and industrial nature, on which the continued prosperityof the Americas depend.?
