How can non-polio enteroviruses cause paralytic illness and how can labs differentiate?

• A. EVs such as EV-A71 or EV-D68 can cause AFP or meningitis; labs differentiate using RT-PCR typing and sequencing to identify serotypes
• B. Non-polio enteroviruses cannot cause paralysis
• C. All AFP is caused by polio
• D. Clinical symptoms alone differentiate

Answer: (A)

Non-polio enteroviruses can invade the nervous system and cause paralytic illness such as acute flaccid paralysis or meningitis. Viruses like EV-A71 and EV-D68 are well known for producing AFP and associated CNS symptoms in outbreaks, sometimes with severe outcomes.

Because the clinical picture alone isn’t specific to a particular virus, laboratories identify the exact serotype to determine the cause and distinguish these from poliovirus. The standard approach is molecular: first, real-time RT-PCR to detect enterovirus RNA in specimens (such as stool, throat swab, or CSF). If enterovirus RNA is found, typing by sequencing—usually of the VP1 region—determines the serotype (for example EV-A71 or EV-D68) and confirms whether the virus is a non-polio enterovirus.

This serotype identification is crucial for surveillance, outbreak characterization, and distinguishing non-polio enteroviruses from poliovirus in polio-free settings. Clinical symptoms alone cannot reliably differentiate these viruses, and it’s false to claim that non-polio enteroviruses cannot cause paralysis or that all AFP is polio.