Maina, Alice N.Jiang, JuOmulo, S.A.Cutler, Sally J.Ade, FredrickOgola, EricFeikin, Daniel R.Njenga, M. KariukiCleaveland, SarahMpoke, SolomonNg’ang’a, ZipporahBreiman, Robert F.Knobel, Darryn LeslieRichards, Allen L.2014-12-122014-12-122014Maina, AN, Jiang, J, Omulo, SA, Cutler, SJ, Ade, F, Ogola, E, Feikin, DR, Njenga, MK, Cleaveland, S, Mpoke, S, Ng'ang'a, Z, Breiman, RF, Knobel, DL & Richards, AL 2014, 'High prevalence of Rickettsia africae variants in Amblyomma variegatum ticks from domestic mammals in rural Western Kenya : implications for human health', Vector Borne and Zoonotic Diseases, vol. 14, no. 10, pp. 695-702.1530-3667 (print)1557-7759 (online)10.1089/vbz.2014.1578O-7057-20140000-0002-0425-37996602518021http://hdl.handle.net/2263/42953Tick-borne spotted fever group (SFG) rickettsioses are emerging human diseases caused by obligate intracellular Gram-negative bacteria of the genus Rickettsia. Despite being important causes of systemic febrile illnesses in travelers returning from sub-Saharan Africa, little is known about the reservoir hosts of these pathogens. We conducted surveys for rickettsiae in domestic animals and ticks in a rural setting in western Kenya. Of the 100 serum specimens tested from each species of domestic ruminant 43% of goats, 23% of sheep, and 1% of cattle had immunoglobulin G (IgG) antibodies to the SFG rickettsiae. None of these sera were positive for IgG against typhus group rickettsiae. We detected Rickettsia africae–genotype DNA in 92.6% of adult Amblyomma variegatum ticks collected from domestic ruminants, but found no evidence of the pathogen in blood specimens from cattle, goats, or sheep. Sequencing of a subset of 21 rickettsia-positive ticks revealed R. africae variants in 95.2% (20/21) of ticks tested. Our findings show a high prevalence of R. africae variants in A. variegatum ticks in western Kenya, which may represent a low disease risk for humans. This may provide a possible explanation for the lack of African tick-bite fever cases among febrile patients in Kenya.en© Mary Ann Liebert, Inc.Amblyomma variegatumRickettsia africaeAfrican tick-bite feverTick-borne Spotted Fever GroupSFGArticle