Trend of neonatal group B streptococcal infection during the last 15 years

BACKGROUND: The survey was designed to determine the trend of group B streptococcal (GBS) infection during the last 15 years, as well as update the reality of this disease. METHODS: Questionnaires were administered every 5 years towards neonatal intensive care unit-equipped hospitals. The first survey was made from 1983 to 1987, the second one from 1988 to 1992 and the third one from 1993 to 1997. The 15-year questionnaire survey included a total of 831 patients. The changes in number of patients, the ages at onset, the diagnosis, the serotypes of causative agents, the presence or absence of complicated delivery and the prognosis were analyzed. RESULTS: It seems that the increasing trend of the number of patients has stopped in the period from 1993 to 1997 (third survey). The most common causative subtype was type III GBS, regardless of early onset type or late onset type. As to perinatal abnormality, approximately 40% of the early onset cases were free from risk factors. Concerning the prognosis, 22.6% of early onset cases and 38.7% of late onset cases died or had sequelae. CONCLUSIONS: The number of GBS-infected cases has stopped increasing, but it is still necessary to carry out screenings of pregnant women for the purpose of decreasing the onset of the disease.