A NEWBORN BABY OUTBREAK OF ECHOVIRUS-TYPE-33 INFECTION

Objectives: in 1994, an outbreak of echovirus type 33 (EV33) infection occurred in a maternity hospital in Japan. Nine new-born babies were infected, some presenting symptoms of encephalitis or disseminated int ravascular coagulopathy. EV33 was isolated from the faeces or cerebros pinal fluid of all seven of the patients sampled, and serum antibody t itres against EV33 were significantly elevated in the convalescence ph ase sera in all cases. Subjects and Methods: to study what public heal th situations EV33 may become a serious pathogen for new born babies, serum EV33 antibody positivity in the general population was examined. Sera were obtained 649 samples before the outbreak, and 344 samples a fter the outbreak from aged 7 days to 65 years old. Results: the avera ge positive rate was 12.0% and the rate increased depending on age. Co mparison of positive rates before and after this outbreak showed no in crease in any age group. However, the positive rate was found to avera ge only 5.6% in persons aged 16-30 years old, including pregnant women . This low positive rate in young adults would result in a lack or onl y a low level of antibodies in newborn babies. Conclusions: in conclus ion, our findings suggest that EV33 infection in the new-born baby wit h no or low level of maternal neutralizing antibody may cause serious symptoms.