Acute flaccid paralysis surveillance system evaluation-Enugu state, Nigeria 2015–2018

Abstract

Background: Nigeria is one of the three polio-endemic countries worldwide. Wild polio virus was reported last in Nigeria by August 2016 although pockets of circulating vaccine derived viruses’ infection and vaccine associated paralytic polio still occur. As part of the polio endgame strategy Nigeria targets to achieve and sustain optimum surveillance performance indicators in all States by December 2018. We evaluated the acute flaccid paralysis (AFP) surveillance system in Enugu State to assess if the target for these indicators are being met. Methods and materials: We used an adapted US CDC Updated Guidelines for Evaluating Public Health Surveillance Systems. We reviewed of AFP surveillance data collected 2015–2018. We conducted key informant interviews and focus group discussion with purposively selected stakeholders. We collected data from 30 randomly selected AFP Surveillance officers in the state using an adapted questionnaire and recorded frequencies and proportions of key indicators. Results: One compatible poliovirus case was identified in 2015 among the 1211 AFP cases recorded. The case definition of AFP and tools for reporting are simple. The system is mainly funded by foreign partners although the main challenge is sustainability. The system is unstable as there are few trained staff who are regularly assigned other duties or transferred to other departments other than AFP surveillance. The system is flexible, and accepted by all stakeholders. The sensitivity of the system measured by the annualized Non-Polio AFP (NPAFP) rate is 15.1 ± 2.7 (target of ≥2/100,000 population). The mean data quality was 94%, SD: 2.8 (target ≥90). Mean stool adequacy and timeliness of reporting were 83.9 ± 14.3% and 91.0 ± 8.6% respectively both having target of ≥80%. Case investigations done in ≤48 h: Mean 89 ± 7.4, non-polio enterovirus isolation rate: Mean 39.5 ± 19.4, target >10% and 60 days follow up Mean 85.2 SD (17.0). Conclusion: Enugu State AFP surveillance is meeting most of its target although stability of the system is suboptimal. We recommended that Enugu state government train a pool of health officers on AFP surveillance and reduce staff mobility. Enugu state government should also plan to have a budget line for surveillance of AFP, and take ownership of the surveillance structure.