Evaluation of a protocol for rapid diagnosis of enterovirus associated with acute flaccid paralysis cases

The virological surveillance of acute flaccid paralysis (AFP) is a critical component of the initiative of the World Health Organization (WHO) to eradicate poliomyelitis worldwide. Furthermore rapid methods are needed either to detect or rule out the presence of polioviruses during the late stages of eradication, especially in polio-free areas.

The aim of this study was to evaluate a fast protocol combining one passage (5 days) in cell culture followed by RT-PCR and molecular typing in order to detect and type poliovirus (PV) and other enteroviruses associated with AFP cases.

A total of 216 fecal suspensions from AFP suspected cases were tested by using this approach and compared with the WHO gold standard.

Using the WHO protocol enterovirus was detected in 12 out of the 216 AFP samples (5.55%) while with the proposed protocol enterovirus was detected in 15 out of the 216 AFP samples (6.94%). The additional positive samples detected by the proposed method were classified as non-polio enteroviruses (NPEV).

The proposed protocol showed higher sensitivity than the WHO gold standard, reducing the entire process of identification and typing of the isolates from the typically 14-21 days to only approximately 6-8 days.