Seroprevalence of Rift Valley fever virus infection in camels (dromedaries) in northern Tanzania

Rift Valley fever (RVF) is an arthropod-borne viral zoonotic disease that affects a wide range of animals including sheep, goats, cattle, camels and humans. Camels have only recently been introduced into Tanzania and, as a result, there is no credible diseases status information concerning this population, estimated to be in the low hundreds. As part of a broader study on camel diseases in different localities of northern Tanzania, serum samples (n = 109) were collected from apparently healthy, non-vaccinated camels during the period June to August 2010 and tested for antibodies specific to RVF virus (RVFV) using the inhibition enzyme-linked immunosorbent assay (ELISA). Overall, herd and individual camel IgG seroprevalence was 78.5 % (11/14) and 27.5 % (30/109), respectively. IgG was found to be most prevalent in camels from Kilindi and Hai districts (45 %, each) and in introduced camels from other areas (37.1 %). The relationship between age and seropositivity showed that the seroprevalence was the highest (84.6 %) in age group of ≥10 years and lowest (11.9 %) in age group of ≤5 years.