Armstrong – Table of Contents

on the WEE studies, Dr. L. L. Lumsden, a member of the Public Health Service team in
St. Louis, postulated a mosquito vector, likely one of the Culex varieties, either C. pipiens
or possibly C. quinquefasciatus both of which were indigenous and prevalent in the St.
Louis area. The mosquito as a vector, however, was not proven at the time of the ongoing
1933 investigation. Later, in 1941 Hammon et al. (16) isolated from Culex tarsalis both
WEE and St. Louis encephalitis, Hess and Holden in1958 and Brody and Browning in
1960 both isolated St. Louis encephalitis from C. pipiens and C. quinquefasciatus
establishing them as vectors for the virus (16). Thus, by 1958 Lumsden’s accuracy of
observation and conclusions about the mosquito as vector were proven (17).
In 1933, however, as part of the epidemiological studies (3B, 13), the Public
Health service under the direction of Surgeon L. L. Williams was carrying out insect
transmission studies, particularly with mosquitoes. Also participating with Williams were
Drs. James P. Leake and Bruce Mayne all of whom offered themselves as experimental
volunteers in the manner of Walter Reed’s yellow fever investigations in Cuba during the
Spanish-American War. In 1933 Major James S. Simmons, Director of Laboratories,
Army Medical School and Major V. H. Cornell, Curator of the Army Medical Museum at
Washington, DC were also directing mosquito studies simultaneously. Major Kelser of
the United States Army (see above) proved that the “sleepy death” of horses in the San
Joachin Valley could go from guinea pig to guinea pig via the bites of stegomaia (species
of Aedes aegypti) mosquitoes; however, these were not present in the San Joachin Valley.
Thousands of these special mosquitoes were shipped from Memphis, Tennessee, where
Major Kelser was stationed, allowed to feed on patients in St. Louis, and then
investigators fed them initially on monkeys. When the monkeys did not become ill, Drs.