Experience and findings from surveillance peer review in Nigeria, August 2017-May 2019.

Introduction: acute flaccid paralysis (AFP) surveillance is the gold standard of the Global Polio Eradication Initiative (GPEI) for detecting cases of poliomyelitis and tracking poliovirus transmission. Nigeria's AFP surveillance performance indicators are among the highest in countries of the World Health Organization (WHO) African Region. The primary AFP surveillance performance indicators are the rate of non-polio AFP among children and the proportion of timely, adequate specimen collection. The surveillance working group of the National Emergency Operations Centre assessed the quality of AFP surveillance data in some reportedly high-performing states. Methods: we conducted a retrospective review of AFP surveillance performance indicators in Nigeria for 2010-2019. We also reviewed data in reports from four groups of surveillance peer reviews and validation visits (conducted by in-country GPEI partners) during August 2017-May 2019 in 16 states with high primary AFP surveillance indicators; the validation visits reviewed clinical information and the dates of specimen collection and onset of paralysis with caretakers. Results: there were consistently increasing AFP surveillance primary performance indicators during 2010-2016, followed by declines during 2017-2019. From the data for 16 states with peer reviews conducted from August 2017-May 2019, overall concordance of reported and "true" (validated) AFP indicator data in peer review investigations was highly variable. True AFP concordance ranged from 58%-100%, and stool timeliness concordance ranged from 56%-95%. The most common clinical causes of reported AFP cases that were not true AFP were spastic paralysis, malaria, sickle cell disease, and malnutrition. All the states that participated in peer reviews developed surveillance improvement plans based on the gaps identified. Conclusion: Nigeria has highly sensitive AFP surveillance according to reported primary AFP performance indicators. The findings of peer reviews indicate that the AFP surveillance system needs to be strengthened and well-supervised to enhance data quality.

Targeting the last polio sanctuaries with Directly Observed Oral Polio Vaccination (DOPV) in northern Nigeria, (2014-2016).

BACKGROUND: The declaration of poliomyelitis eradication as a programmatic emergency for global public health by the 65th World Health Assembly in 2012 necessitated innovations and strategies to achieve results. Review of the confirmed polio cases in 2013 showed that most of the cases were from non-compliant households, where parents connived with vaccinators to finger mark the children without actually vaccinating the children with oral polio vaccine or children were absent from home at the time of the visit of vaccinators. METHODS: We used pre-post design to quantify the outcomes of directly observed vaccination in 90 local government areas from 12 northern Nigeria states at very high risk of polio transmission. The strategy is an intervention, vaccinating children under the direct supervision of an independent supervisor to ensure compliance. Attractive incentives (pluses) were used to make parents willingly submit their children for vaccination or directly attract children to the vaccination teams or post as part of this strategy. RESULTS: There was a steady increase in population immunity in all the 90 DOPV implementing LGAs since the introduction of DOPV in 2013. The number of states in which > 90% of children received > 4 OPV doses increased from 7 in 2013 to 11 states by July 2016. Yobe state reported the highest proportional increase from 75 to 99% by July 2016 (22% increase), while Kano state reported 17% increase, from 82 to 99% by July 2016. CONCLUSION: Directly observed polio vaccination strategy improved uptake of polio vaccines and population immunity in high-risk areas for polio transmission.