Accession Number : AD0784990

Title :   Tick-borne Pathogens with Special Reference to a Possible Extra-Human Cycle of Epidemic Typhus Infection.

Descriptive Note : Final rept.,


Personal Author(s) : Wisseman,Charles L. , Jr. ; McDade,Joseph E.

Report Date : 30 SEP 1973

Pagination or Media Count : 34

Abstract : The studies undertaken are fully counter to the recent and much quoted contention that ticks and domestic animals play a significant role in the ecology of epidemic typhus and, instead, strongly suggest that the serological data that had been presented in support of such a hypothesis are based upon artifacts. Thus, out of 861 Ethiopian livestock sera and 2,849 sera from Egyptian domestic animals tested by complement fixation (CF) in the program, none of the samples contained antibodies specific for rickettsiae of either epidemic typhus or murine typhus. Moreover, 821 of 822 sera from Egyptian donkeys were anticomplementary and therefore nonspecifically positive in CF tests. The identical or a similar anticomplementary substance, identified as IgM, accounted for the results reported as 'positive' by earlier workers. These results indicate that such domestic animals could not serve as a reservoir or source of infection of ticks with R. prowazeki in nature. (Modified author abstract)

Descriptors :   *Ticks, *Typhus, *Rickettsia, Antigen antibody reactions, Disease vectors, Humans, Pathogenic microorganisms, Epidemiology, Ecology, Infectious diseases, Serology, Ethiopia, Egypt, Life cycles, Livestock

Subject Categories : Microbiology

Distribution Statement : APPROVED FOR PUBLIC RELEASE