Acute Flaccid Paralysis Surveillance system Evaluation, Oyo state, Nigeria; 2008-2014

Maureen Anyanwu


ObjectiveWe evaluated the AFP surveillance system in Oyo State to assessits attributes and determine if it was meeting its set objectives.IntroductionIn September, 2015, Nigeria was delisted from the list of polioendemic countries globally. To be certified polio free, the countrymust attain and maintain certification standard Acute Flaccid Paralysis(AFP) surveillance for additional two-years. In Oyo State, no case ofWild Polio Virus (WPV) has been reported since February, 2009.MethodsWe used the Centre for Disease Control and Prevention updatedguidelines for evaluating public health surveillance system.We conducted a retrospective review of AFP surveillance databetween 1stJanuary, 2008 and 31stDecember, 2014. We conductedin-depth interviews with identified stakeholders. Semi-structuredquestionnaires were administered to Disease Surveillance andNotification Officers (DSNOs) and AFP focal persons. Univariateanalysis was performed by calculating frequencies, means andproportions using Microsoft Excel 2010.ResultsThe case definition of AFP and the tools for reporting are simple.Of the 897 AFP cases detected during the period under review(2008-2014), 20 (2.2%) were laboratory confirmed WPV. Thesensitivity of the system between 2008 and 2014 measured by theAnnualized Non-Polio AFP (NPAFP) rate was consistently abovethe target. of≥2/100,000 population(Mean=3.96, Standard deviation(SD): 0.48). The mean NPAFP rate for underperforming LGAs duringthe review period was 1.6, SD: 0.31. The mean Stool adequacy andTimeliness were 91.43% (SD: 18.3) and 91.3% (SD: 20.3) abovethe target of≥80% respectively. The mean Data quality was 90%(target is≥90; SD: 3.8). Positive Predictive Value (PVP) was 2%(2008 -2009), and 0% in 2010-2014.ConclusionsThe Oyo State AFP surveillance system is simple, flexible,sensitive and meeting its set objectives. However, PVP was low andthe system’s operating conditions are not stable. All the LGAs, at onepoint during the period under review did not meet the NPAFP andNPENT rates. We recommended that more logistic support shouldbe provided for non-performing LGAs to improve case reporting,investigation, and response. DSNOs should be re -sensitized onreverse cold chain, so as to improve the NPENT rate

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Online Journal of Public Health Informatics * ISSN 1947-2579 *