Clinical characteristics of group B streptococcus bacteremia in non-pregnant adults

Group B streptococcus (GBS) [Streptococcus agalactiae] is an emerging cause of disease in non-pregnant adults with underlying diseases. This retrospective study analyzed 90 episodes of GBS bacteremia in adults occurring over a 4-year period.

Basic and clinical data were collected by reviewing medical charts of patients. Blood cultures were performed on admission of patients suspected of bacteremia. Presence of underlying diseases, such as liver disease, heart disease, urinary tract disorders, and female-specific cancers, as well as possible portals of entry of infection was analyzed.

In 56 episodes (62.2%), patients were aged 60 years or older and 40 (44.4%) episodes occurred in males. Skin and soft tissue were the most common sources of GBS bacteremia (22/90, 24.4%). GBS bacteremia was classified as primary in 50% of the episodes (45 patients). Liver diseases were more common in males, while malignancy was more common in females. Portals of entry with a significant gender predominance included skin and soft tissue in women (p=0.018), bone and joint in women (p=0.016), and urinary tract in men (p=0.042). The overall mortality rate was 18.9% and the attributable mortality rate was 7.8%.

Elderly people and those with underlying diseases are particularly susceptible to GBS infections. Preventive strategies, including GBS vaccine and skin care, are likely to be particularly important in these high-risk groups.