Seroprevalence of Leptospira antibodies in rodents and shrews of Kibondo and Kakonko Districts, Kigoma region, Tanzania

Abstract

Leptospirosis is a worldwide neglected bacterial zoonotic disease caused by pathogenic species of the genus Leptospira. Humans get  leptospirosis through contact with an environment contaminated with bacteria from reservoir hosts, which are mainly rodents. A cross- sectional epidemiological study was carried out in Kibondo and Kakonko districts of Kigoma region, Tanzania, to determine the seroprevalence of Leptospira species in rodents and shrews. Blood sera were collected from rodents and shrews (n = 582) and tested for  leptospiral antibodies using the Microscopic Agglutination Test (MAT) against five live serovars with titers ranging from 1:20 to 1:160 and  a cut-off point of 1:160. The overall prevalence of leptospira antibodies was 11.9% with rodents showing 11.6% (95% CI 9.1% to 14.3%) and  shrews having 0.3% (95% CI 0.1% to 1.1%). Number and prevalence per species (in brackets) were as follows; Aethomys kaiseri 16  (2.7%), Arvicanthis niloticus 1 (0.2%), Lemniscomys rosalia 2 (0.3%), Lemniscomys striatus 10 (1.7%), Lophuromys flavopunctatus 2 (0.3%),  Mastomys natalensis 30 (5.2%), Rattus rattus 6 (1.0%) and Crocidura tansaniana 2 (0.3%). No antibodies were revealed in Grammomys  dolichurus, Mus musculus, Praomys delectorum, and Tatera indica. In terms of prevalence, there was no significant variation with regard  to sex or between rodents and shrews, but it was found across species (P<0.05). The most prevalent Leptospira serovar and titer were  Lora (4%) and titer 1:40 respectively. Kakonko had a prevalence of 18 (3.1%) compared to Kibondo, 51 (8.8%). Fallow land was leading in  the prevalence of leptospira antibodies in its captured rodents and shrews with a prevalence of 36 (6.2%), followed by farmland 16 (2.7%),  indoor 11 (1.9%), grassland 4 (0.7%), forest 1 (0.2%) and wetland 1 (0.2%). The findings of this study denote a potential public health risk  among the people of Kigoma region, Tanzania, and hence the need to raise awareness of the disease among the study population and   the country as a whole.