The Enteroviruses: Problems in Need of Treatments

Specific antiviral therapy is currently not available for enterovirus (EV) infections. Poliomyelitis, EV 71 neurologic disease, and neonatal EV disease are three manifestations of EV infections that exemplify the importance of developing antivirals for EV infections. Despite tremendous strides in the effort to eradicate polio through vaccination, challenges remain, including the potential for transmission of neurovirulent vaccine-derived polioviruses which have genetically reverted from live-attenuated, oral poliovirus vaccine virus. EV 71 emerged in the late 1990 s in eastern Asia as a neurovirulent virus that causes large outbreaks of hand-foot-mouth disease, herpangina, and fever, and, in some children, meningitis, acute flaccid paralysis, and brainstem encephalitis complicated by pulmonary edema and cardiopulmonary collapse. EV infections in neonates can cause severe disease characterized by meningoencephalitis, myocarditis, pneumonitis, and/or hepatitis and coagulopathy. Prototypic agents for specific therapy of EV infections that act upon numerous potential viral targets exist. Three candidate compounds are currently in development: pleconaril (active against many EVs), V-073 (anti-poliovirus), and BTA-798 (active against many rhinoviruses and EVs). The three conditions described illustrate why development of antiviral medications for EV infections is a medically important need.