The Polio Vaccination Status of Non-polio Acute Flaccid Paralysis Cases in the Far North Region of Cameroon: A Five-Year Retrospective Study From 2015 to 2019

Abstract

Background: The Expanded Program on Immunization (EPI) of Cameroon contributes to the reduction of polio, but the rate of non-polio acute flaccid paralysis (NPAFP) is still high. The aim of this study was to describe the immunization profile of NPAFP cases and the performance of polio surveillance in the Far North Region of Cameroon between 2015 and 2019. Methods: A retrospective secondary data analysis was conducted using the national EPI and regional AFP surveillance case-based database from 2015 to 2019. Analyses were carried out using Epi-Info statistical software (version 7) (Centers for Disease Control and Prevention, Atlanta, GA). Results: The surveillance network of the region reported 848 cases of NPAFP between 2015 and 2019. The sex distribution of the AFP cases revealed that 43.3% were females and 56.7% were males. Cases with AFP aged less than five years accounted for the largest proportion of cases (67.2%). Overall, 733/848 (86.4%) of the AFP cases received at least three doses of the oral polio vaccine (OPV). The AFP detection rate substantially increased in the region after the introduction of community-based surveillance in 2016. The mean NPAFP level during the study period was 7.3/100,000 children aged less than 15 years. The mean proportion of AFP cases with two adequate stools was 668/848 (78.7%), and the mean proportion of stools to the national reference laboratory within three days was 466/848 (54.9%). Conclusion: Only 86.4% of AFP cases received three or more doses of OPV required for immunization. The stool specimen management indices were not good enough to confirm that no case of poliovirus was missed in the laboratory. To strengthen the country’s polio-free status, surveillance should be strengthened in least-performing health districts to improve the quality of AFP case investigations after detection.