Non-Polio Enteroviruses in Acute Flaccid Paralysis: Analysis of Surveillance in Iraq from 2018 to 2024

Background: Acute flaccid paralysis surveillance, forms the basis for poliovirus eradication efforts and provides useful data on non-polio enteroviruses, which are significant causes of acute flaccid paralysis in polio-free countries. Non polio enteroviruses were the most common isolates from acute flaccid paralysis cases at this time, indicating sensitivity of surveillance and continued circulation of enteroviruses. Objectives: This study aimed to determine the prevalence, epidemiologic trends and clinical features of non- polio enteroviruses among children with acute flaccid paralysis in Iraq, from 2018 to 2024, for improving surveillance sensitivity and complementary evidence-based public health measures. Methods: The data was gathered from the acute flaccid paralysis surveillance system in Iraq. Stool specimens were analyzed at the National Polio Laboratory according to the World Health Organization guidelines. Suspensions of stool were prepared and inoculated into the Rhabdomyosarcoma cell line and genetically modified mouse L cells expressing the human poliovirus receptor. Isolates were subjected for real-time polymerase chain reaction, whereas cultures were checked for cytopathic effect. Isolates negative for poliovirus but positive in Rhabdomyosarcoma cells were classified as non-polio enteroviruses. Demographics and clinical findings were analyzed using appropriate statistical tests. Results: Non-polio enteroviruses were reported in 10.5% of the cases; the prevalence being highest in children 1 to 2 years. They appeared to be two peaks; one in January and another in May, and cases were particularly low in September. Non-polio enteroviruses were associated with residual weakness and lower mortality. Conclusions: Non-polio enteroviruses detection declined during 2020–2023 with recovery in 2024. Positivity was significantly higher in younger children, and demonstrated clear seasonal peaks. Non-polio enteroviruses infection was associated with residual weakness but not with gender, fever, or mortality.