Non-polio enteroviruses among healthy children aged zero to five (0-5) years old in the Philippines

Background One of the indicators of a properly functioning Acute Flaccid Paralysis (AFP) surveillance is the proportion of stool samples in which non-polio enteroviruses (NPEV) are detected. Typically, this proportion is expected to be above 10% in tropical countries, however, the Philippines only averages 6.5% NPEV isolation rate. With continued threat of possible importation of wild poliovirus, the current NPEV rate prompted concerns about the quality of the AFP surveillance, in particular, stool sample management and transportation being performed in the field. To know whether the low NPEV rates gathered from AFP cases is a reflection of the true prevalence in the Philippines, a stool survey of healthy children 0-5 years old from three urban communities was conducted in 2015.Methods Two stool samples were collected from three hundred sixty healthy children. Virus isolation and Polymerase Chain Reaction was performed to identify enteroviruses in the samples. The results were compared to the prevalence and isolation rate among AFP cases the same year.Results Results show a prevalence of 24.7% which is higher than 12.4% prevalence rate among AFP cases the similar year. However, analysis of AFP cases between 0-5 years old showed prevalence of 20.8% (p-value 0.33) which is not significantly different when compared to the study.Conclusion This study supports the idea that the observed low NPEV rate in the country may be due to low number of NPEV prevalence. However, further investigations on all possible data sources for NPEV such as among hand, foot, and mouth disease (HFMD), and aseptic meningitis cases, may be necessary to fully understand the occurrence of NPEVs in the country.