Streptococcus agalactiae infections in non-pregnant adults: single center experience of a growing clinical problem.

Background: Group B beta-hemolytic streptococcus (Streptococcus agalactiae) has been traditionally considered a major pathogen in neonates and pregnant women. However, there is accumulating concern about its significance in non-pregnant adults too.

Material/methods: To study Streptococcus agalactiae infections in non-pregnant adults in a 354-bed general tertiary center in Athens, Greece, we analyzed retrospectively collected data from patients with Streptococcus agalactiae isolates during a 5-year period.

Results: Sixty-nine strains were isolated from specimens of 65 non-pregnant adults (42 women and 23 men). Thirty-four of them were managed as inpatients and 31 as outpatients. Mean age of the 34 inpatients was 57.7 (range 18-84) years. Nineteen (17 women and 2 men) of the 34 inpatients had the organism isolated from urine. Thirteen of these 19 (68.4%) patients had clinical evidence of urinary tract infection (UTI). Streptococcus agalactiae infections were diagnosed in 26 of 34 inpatients. Besides the 13 inpatients with an UTI, 2 had bacteremia of unknown origin, 2 pneumonia, 2 erysipelas, 1 spondylodiscitis, 1 peritonitis, 2 prostatitis, 1 perirectal abscess, 1 testicular abscess, and 1 diabetic foot infection. Underlying conditions of the 26 inpatients possibly predisposing to infections were neoplasia, diabetes mellitus, heart disease, splenectomy, and corticosteroid treatment.

Conclusions: In keeping with results from other recent studies Streptococcus agalactiae was isolated more frequently than previously believed from non-pregnant adults in our study. In addition, our data suggest that Streptococcus agalactiae may be an underestimated cause of UTI in non-pregnant women.