Distribution Pattern of the Non Polio Enterovirus (NPEV) Rate in Children with Acute Flaccid Paralysis Reported to the Surveillance System in Nigeria 2010-2015

Abstract

Objective: This study focuses on the reverse cold chain system of stool sample management from cases reported to the AFP surveillance system between 2010 and 2015. Through the distribution of their NPEV isolation rates, we identify lapses in the reverse cold chain management and provide recommendations that should help improve the reverse cold chain system and the AFP surveillance system in general as Nigeria once again matches towards a polio free certification. Methods: A descriptive retrospective study was conducted using AFP surveillance data routinely collected between January 2010 and December 2015 by the Disease Surveillance and Notification Officers (DSNOs) in Nigeria and the WHO accredited Polio Laboratories. All AFP cases reported to the Disease Surveillance network during this period from all the states were included in the study. EPIINFO—veritable customized software was used to run queries on the access database and obtain the specific data sets required. Results: A total of 52,879 AFP cases were reported from 2010-2015, in which 7288 non-polio enteroviruses were isolated. NPEV isolation rate ranged from 10.8% in the southeast to 20.3% in the northeast with the states in the northern geopolitical zones having higher NPEV rates in comparison to the states in the southern geopolitical zones. The WHO Polio laboratory in Ibadan serves twenty-seven states in the country; the average non-polio AFP rate among states served by this laboratory is 11.7% from a total of 4012 AFP cases recorded. The WHO Polio laboratory in Maiduguri recorded 3276 with an average non-polio AFP rate of 19.2%. Conclusion: Though the country’s NPEV isolation rate remain slightly higher above the 10% recommended by WHO, steps should be taken to enhance the reverse cold-chain system particularly in the southern states. This would increase confidence in the AFP surveillance system in Nigeria as she proceeds once again towards complete polio eradication and meeting certification standards.