A sero-survey of XXXX in nomadic pastoral systems in central and southern Somalia from 2002 to 2003, using a spatially integrated random sampling approach.

@entity281 @entity291 @entity72329
A cross-sectional sero-survey, using a two-stage cluster sampling design, was conducted between 2002 and 2003 in ten administrative regions of central and southern Somalia, to estimate the seroprevalence and geographic distribution of @entity72329 ( @entity72329 ) in the study area, as well as to identify potential risk factors for the observed seroprevalence distribution. The study was also used to test the feasibility of the spatially integrated investigation technique in nomadic and semi-nomadic pastoral systems. In the absence of a systematic list of livestock holdings, the primary sampling units were selected by generating random map coordinates. A total of 9,216 serum samples were collected from @entity291 aged 12 to 36 months at 562 sampling sites. Two apparent clusters of @entity72329 seroprevalence were detected. Four potential risk factors associated with the observed seroprevalence were identified: the mobility of @entity291 herds, the @entity291 population density, the proximity of @entity291 herds to @entity291 trade routes and @entity291 herd size. Risk maps were then generated to assist in designing more targeted surveillance strategies. The observed seroprevalence in these areas declined over time. In subsequent years, similar seroprevalence studies in neighbouring areas of Kenya and Ethiopia also showed a very low seroprevalence of @entity72329 or the absence of antibodies against @entity72329 . The progressive decline in @entity72329 antibody prevalence is consistent with virus extinction. Verification of freedom from @entity281 in the Somali ecosystem is currently in progress.
