Prevalence and Genotyping of Echinococcus Species from Livestock in Kajiado County, Kenya

Abstract

Cystic Echinococcosis (CE) is a widespread neglected zoonotic disease and is caused by the larval stage of the dog tapeworm Echinococcus granulosus sensu lato. CE is more frequent in livestock-rearing areas and where people live a nomadic or seminomadic lifestyle such as in Kajiado County, Kenya. There is limited data on CE disease situation in the county of Maasailand; the present study, therefore, reports on the prevalence of CE in cattle, sheep, and goats and their relative importance in CE transmission in Kajiado County. In total, 1,486 livestock (388 cattle, 625 sheep, and 473 goats) slaughtered in two abattoirs were examined for the presence of hydatid cysts in various organs. Cyst isolates were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) of the NADH dehydrogenase subunit 1 gene (nad1). The overall prevalence of CE was 14.8% (220/1486), while prevalence per livestock species was 15.2% (72/473) in goats, 14.9% (93/625) in sheep, and 14.2% (55/388) in cattle. Out of the 421 cysts isolated, 389 cysts were successfully characterized to be either E. granulosus sensu stricto (s. s.), 356/389 (91.5%), E. canadensis (G6/7), 26/389 (6.7%), or E. ortleppi, 7/389 (1.8%). This record confirms predominance of E. granulosus s. s. in Maasailand and other parts of Kenya, while the importance of E. ortleppi and E. canadensis (G6/7) to the general CE burden in Maasailand might be higher than previously thought. More so, a higher infection pressure for humans by E. granulosus s. s. based on its abundance could be speculated. The study sheds significant light on CE situation in livestock in the nomadic/seminomadic society of the Maasai in Kajiado County and provides good bases to investigate human CE in the area.