CHAPTER VIII
Rubella
Joseph Stokes, Jr., M. D.
HISTORICAL NOTE 1
Rubella (German measles) has been of considerably greater significance than chickenpox in the armed services but has not approached measles or mumps in importance. Whereas in World War I, the noneffective rate for chickenpox was 0.02 per 1,000; the same rate for rubella was 0.14 per 1,000; for measles, 1.25; and for mumps, 2.58. The total number of primary admissions for rubella was 17,378, or a rate of 4.21 per 1,000 per annum, while the similar figures for chickenpox were 1,757 and 0.43 respectively.
CONTROL MEASURES
During World War I, no method of control had been developed nor has any conclusive evidence been obtained during or after World War II that the disease can be prevented. An exception to this is the suggestive recent evidence that gamma globulin in certain batches prepared in the United States from the American Red Cross plasma pools and in Australia from convalescent plasma may modify the disease when injected during the incubation period. However, the evidence on passive immunization is still scant and inconclusive. No method of active immunization has been developed. There is no conclusive evidence that the virus has been transmitted to the embryonated hen's egg, although Habel 2 has reported the infection of the monkey (Macaca mulatta) with the virus. Many further studies should be conducted both among the armed services and civilian groups for the purpose of determining the possible value of both types of gamma globulin mentioned. Such passive immunization may be urgent for aggregations in strategic places.
INCIDENCE
The hospital and quarters admission rates in the United States per 1,000 per annum for the 5 years 1941-45 are 21.7 (enlisted men only and including Alaska), 5.5. 17.1, 3.1, and 3.4 respectively. During the winter and early
1 (1) The Medical Department of the United States in the World War. Statistics. Washington: Government Printing Office, 1925, vol. XV, pt. 2, p. 238. (2) The Medical Department of the United States in the World War. Communicable and Other Diseases. Washington: U. S. Government Printing, Office, 1928, vol. IX, pp. 387, 463.
2 Habel, K.:Transmission of Rubella to Macacus Mulatta Monkeys. Pub.Health Rep. 57: 1126-1139, 31July1942.
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spring, incidence rates were highest. On occasion in certain of theservice commands, incidencerates reached from 100 to 132 per 1,000 strength, during January,February, March, and April ofthese 5 years.
When one separates the incidence of the disease in accordance with the various areas for the years 1942 through 1945 (table 26), it is obvious that this childhood disease follows the usual history of such diseases in wars; namely, that the incidence is relatively high during and shortly after the period when the rate of induction is high and relatively low during the period when the rate of induction is low.
Table 26 indicates such a separation. The difference between the years 1942 and 1945 would have been considerably greater had not the incidence in the Latin American area remained elevated. This apparently resulted from the high rate of induction of Puerto Ricans, since most of the cases were among Puerto Rican soldiers. The recruitments from Puerto Rico were high during the last half of 1941 and the first 6 months of 1942. Thereafter, they declined and remained low until 1944 when they began to rise and continued to accelerate until well into 1945. Such active recruitment and the absence of an influx of
TABLE26.-Incidenceof rubella(German measles) in the U. S. Army, by area and year,1942-45
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continental units after 1942 would account for the fact that most ofthe cases were among PuertoRican soldiers and that the rates were relatively high.
?It was also of interest that a comparatively high incidence of rubella occurred aboard transports. This could well be caused by the movement and crowding of troops into the staging area, the port of embarkation, and the transport itself.Close contact and possibly the change of environment may have been causative factors.