Recurrent Late-Onset Neonatal Group B Streptococcal Disease Transmitted Through Breast Milk: A Case Report

Background: Group B Streptococcus is the most frequent cause of neonatal invasive disease. Recurrent GBS infections are infrequent, with reported incidences ranging from 1% to 6%. Recurrent GBS infections usually represent persistent mucosal colonization, but occasionally reinfection occurs. Treatment for recurrent infection is suggested to be continued for one week longer than the usual course, but there are no data to indicate efficacy of this recommendation.

Case presentation: A healthy neonate, delivered by caesarian section who developed recurrent late onset GBS infection. Workup includes positive blood cultures.

We cultured the breast milk of the mother and discovered GBS, the culture was verified twice. We had the mother stop breastfeeding and switch to formula. The neonate was treated with Ampicillin for 14 days and preventive Amoxicillin for 2 more months.

Discussion: Breast milk can be a route for neonatal contamination by pathogenic microorganisms. To the best of our knowledge, forty-eight cases of GBS late onset sepsis transmitted by breast milk were reported in the literature. Two main mechanisms of acquisition have been proposed. The first, based on recent studies in animal models suggest that bacteria from the maternal digestive tract may also colonize the breast. In the second, maternal milk ducts are generally assumed to be infected during breast feeding by bacteria that colonize the neonate`s oropharyngeal mucosa in the perinatal period, the neonate is then re-infected as the concentration of bacteria increased in the breast milk.

Conclusions: We suggest culturing breast milk for GBS in mothers whose children have recurrent late onset GBS infection.