Acute flaccid paralysis (AFP) surveillance intensification for polio certification in Kaduna state, Nigeria: lessons learnt, 2015-2016.

Background: Nigeria has made remarkable progress in its current efforts to interrupt wild poliovirus transmission despite the re-emergence of wild poliovirus in 2016. The gains made in Nigeria have been achieved through concerted efforts by governments at all levels, traditional leaders, health workers, caregivers, and development partners. The efforts have involved an elaborate plan, coordination, and effective implementation of routine immunization services, supplemental immunization activities, and acute flaccid paralysis (AFP) surveillance.
Methods: We conducted the following activities to strengthen AFP surveillance in Kaduna state: a monetary reward for all AFP cases reported by health workers or community informants and verified as "true" AFP by a World Health Organization (WHO) cluster coordinator; training and sensitization of surveillance officers, clinicians, and community informants; recruitment of more personnel and expansion of the surveillance network; and the involvement of special populations (nomadic, hard-to-reach, and border communities) and caregivers in stool sample collection. The paired t test was used to evaluate the impact of the different initiatives implemented in Kaduna state to intensify AFP surveillance in 2016.
Results: There was increased annualized non-polio AFP rate (ANPAFPR) in 21 out of 23 Local Government Areas (LGAs) of Kaduna state 6 months after implementation of different initiatives to intensify AFP surveillance. The AFP reported by the special population increased in 15 out of 23 LGAs. Statistical analyses of mean scores of ANPAFPR before and after the interventions using the paired t test revealed a significant difference in mean scores: mean = 19.7 (standard deviation (SD) = 16.1) per 100,000 < 15 years old in July-December 2015, compared with 38.0 (SD = 21.6) per 100,000 < 15 years old in January-June 2016 (p < 0.05). Likewise, analysis of silent wards using the paired t test showed a significant difference in mean scores: mean = 4.0 (SD = 2.1) in July-December 2015 compared with 2.4 (SD = 1.8) in January-June 2016 (p < 0.05).
Conclusion: The different initiatives implemented in 23 LGAs of Kaduna state to intensify AFP surveillance may be responsible for the significant improvement in the AFP surveillance performance indicators in 2016.