PCR ON CEREBROSPINAL-FLUID TO SHOW INFLUENZA-ASSOCIATED ACUTE ENCEPHALOPATHY OR ENCEPHALITIS

Background Except for Reye's syndrome, influenza-associated acute ence phalopathy or encephalitis is not universally recognised. We did a mul ticentre study of laboratory and clinical data for patients with influ enza-associated acute encephalopathy or encephalitis. Methods In Nagoy a, Japan, ten patients with acute encephalopathy or encephalitis assoc iated with influenza-like illness were admitted to our hospitals betwe en April, 1996, and March, 1997. We collected clinical, laboratory and serological data and assessed cerebrospinal fluid samples by PCR for influenza A and B. Findings Seven patients, aged 22 months to 4 years, had evidence of recent influenza infection, six with type-A/Hong Kong (H3N2) and one with type B. The first sign in the central nervous sys tem appeared within 2 days of fever in all but one patient. The first sign of involvement of the central nervous system was generalised conv ulsions in all patients. Two patients died, one had sequelae, and four survived without sequelae. PCR for influenza type A was positive for five patients. Interpretation The results of PCR suggest that at least part of the influenza type A genome existed in the central nervous sy stem. influenza-associated acute encephalopathy or encephalitis in you ng children deserves wider recognition.