Echovirus 7 associated encephalomyelitis

Hand, foot, and mouth disease (HFMD) is endemic in Malaysia. In 1997, a large outbreak of enterovirus 71 (EV-71) associated HFMD resulted in 41 deaths due to severe left ventricular dysfunction and central nervous system infection with extensive damage to the medulla and pons. The clinical presentation in all these patients were rapid cardio-respiratory decompensation leading to cardiac arrest. Another large outbreak of HFMD with 55 fatal cases and a similar clinical picture was reported in Taiwan in 1998. In 2000, an outbreak of HFMD resulted in the deaths of three children who had rapid cardio-respiratory decompensation and one child who survived a central nervous system infection.

We set out to study the etiologic agent and mechanism involved in three children who presented to our hospital, two of whom died and one survived a central nervous system infection.

The clinical course of the disease was described. Throat, rectal swab and cerebrospinal fluid samples were subjected to viral isolation and viral isolates were identified by immunofluorescence, micro-neutralisation using human rhabdomyosarcoma (RD) cells, and reverse transcritpase polymerase chain reaction. Magnetic resonance imaging was performed on two of the patients.

Echovirus 7 was the sole pathogen isolated from three cases of acute encephalomyelitis, two of which were fatal due to severe left ventricular dysfunction resistant to inotropic support. The survivor had residual bulbar palsy, but is considered to have had a good neurological outcome.

Echovirus 7 infection associated with encephalomyelitis could be fatal due to indirect involvement of the heart resulting in severe left ventricular dysfunction. In addition one of the children presented with hand, foot, and mouth disease, a syndrome that has not been previously associated with echovirus 7 infection.