Increasing incidence of neonatal septicemia: causative organism and predisposing risk factors.

The incidence of neonatal septicemia in the referral area of St. Göran's Children's Hospital in Stockholm has been studied during a ten-year period (1969-1978). An increase was noticed during the period 1974-1978 in comparison with the preceding five-year period. The incidence per 1 000 live births was 1.4 and 3.1, respectively. The incidence of osteoarthritis increased from 0.21 to 0.41 per 1 000. Mortality rate from neonatal septicemia remained unchanged. Gram-negative organisms as an etiologic factor seemed to be decreasing while staphylococcal infections have increased. Group B streptococcal infection occurred with the same frequency during the whole period. The low incidence of enteric organisms might be related to the common practice of feeding the babies with milk from their own mothers. Perinatal risk factors were equally common in both five-year periods. The observed increase of the prevalence of neonatal septicemia caused by Staphylococcus aureus may be explained by a higher rate of survival of highly susceptible low-birthweight infants and other sick neonates treated in the neonatal intensive care unit.