Virological and Serological Studies of Neurological Complications of Acute Hemorrhagic Conjunctivitis in Thailand

An extensive outbreak of acute hemorrhagic conjunctivitis (AHC) occurred from September to December 1974 in Thailand. At least 29 patients with polio-like motor paralysis that complicated AHC were hospitalized in Bangkok. Paired or triplicate samples of serum from 16 patients were tested for neutralizing antibody to enterovirus type 70 (EV70). A significant rise in titer of antibody was found for two patients, and the other 14 had neutralizing antibody titers ranging from 1:8 to 1:512 without an increasf larger than or equal to 1:16, a level which is considered to be diagnostically significant. Neutralizing antibody to EV70 was detected in 19S fractions of nine sera examined, but neutralizing antibody to three types of poliovirus was confined to 7S fractions. EV70 was isolated from one of seven stool specimens collected on day 37 after the onset of AHC and none of 10 samples of cerebrospinal fluid. These results and additional clinical and epidemiologic findings gave further support to the hypothesis that EV70 infection can cause polio-like motor paralysis as a complication of AHC.