The role of livestock keeping in human brucellosis trends in livestock keeping communities in Tanzania

A cross-sectional survey was carried out in Karatu and Ngorongoro districts in Arusha region and Babati, Hanang and Mbulu districts in Manyara region involving 20 agro-pastoral and 9 pastoral villages, to establish the magnitude of human brucellosis in relation to livestock brucellosis. A multistage random sampling was used to select villages, sub-village administrative units, ten cell leadership units and animal keeping households. A total of 460 humans from 90 families (19 pastoral and 71 agro-pastoral families) and 2723 domestic ruminants from 90 livestock households were sampled and bled to obtain serum samples for analysis. A competitive enzyme linked-immunosorbent assay (c-ELISA) was used to analyse these samples to detect Brucellacirculating antibodies. The overall livestock seroprevalence was 5.7% with 32.2% of livestock households being seropositive whereas, human seropositivity was 8.3% with 28% family households being seropositive. The highest proportion of seropositive families was observed in Ngorongoro district (46%) and the lowest in Babati district with no seropositive family household. Family members in seropositive livestock households were 3.3 (OR) times more likely to be seropositive than those with seronegative livestock households. However; 25% of seronegative family households had seropositive livestock households and 48% seropositive family households had seronegative livestock households. Therefore, Brucellainfection is widespread in the human populations and their livestock in the northern Tanzania and thus humans may acquire infection from their own animals or from other sources thus prompted public health awareness creation in such communities.