Salmonella reservoirs in animals as sources of human infection

Abstract

Salmonellosis is a cosmopolitan zoonotic disease of considerable importance. In Kenya, salmonellosis may be more significant in terms of number of infections and mortality than typhoid fever and cholera. Animals and animal products have been regularly incriminated as sources of human infections for most salmonella serotypes except the anthropophilic ones. These reservoirs also serve·as sources of SalQonella infections in domestic aniQals. An attempt has been Qade to define these reservoirs through a Survey of domestic animals and rodents in the Nairobi area. Forty nine salmonella strains were isolated from a variety of sources, comprising 32 serotypes. The hIghest carrier rate' (7.3~) was found in wild rodents, m3.inly 3.attus rattus. The high carrier rate and the tendency of this species to invade houses indicate that these rodents play an important role in the epidemiology of salmonellosis, both in man and animals. The serotype most commonly recovered in this species was S. enteritidis which was also the second most prevalent serotype from human patients at Kenyatta National Hospital during the period 1974 - 1979. This observation further supports the, view that wild rodents are of major importance as sources of infection. In addition to the standard slide agglutination method for typing Salmonella strains, the Staphylococcus coagglutination method according to Kronvall was used in parallel. Complete agreement was found between the two methods, but the coagglutination method was more rapid and far more economical in terms of reagents than the slide test.