Wild polio virus surveillance in the sewage system of selected communities at the risk of poliomyelitis in southwest Nigeria.

Twenty two sewage samples collected from eleven locations among communities at risk of poliomyelitis in the southwestern part of Nigeria were screened for the presence of polio virus. The virus was isolated from seven of the samples. All the isolates were type 1 wild polio virus, an indication that all the isolates were from human contamination and that the wild polio virus is still very much in circulation in Nigeria many years after the Expanded Programme on Immunisation was introduced. It can be concluded from this study that polio immunisation campaign has not been successful in Nigeria considering the number of wild polio virus isolated from the sewage samples since virological examination of sewage has been used to document the effect of vaccination campaigns.