RELAPSING INVASIVE GROUP-B STREPTOCOCCAL INFECTION IN ADULTS

Objective: To study recurrent group B streptococcal infection in adult s. Design: Patients with more than one reported group B streptococcal infection were identified through active surveillance for this infecti on. Sterile-site group B streptococcal isolates were evaluated for ser otype and molecular subtyping using restriction endonuclease analysis of chromosomal DNA (REAC). Setting: All acute-care hospitals in Maryla nd. Patients: Nonpregnant residents of Maryland 18 years of age or old er. Results: 22 adults had at least two group B streptococcal episodes that were separated by 2 to 95 weeks (mean, 24 weeks). Of 395 patient s with invasive group B streptococcal infection who survived the first episode and were followed for at least 1 year, 17 (4.3% [95% CI, 2.6% to 6.9%]) had more than one episode. Several patients were found to h ave endocarditis or osteomyelitis during the second episode. Group B s treptococcal isolates from both episodes were obtained from 18 of 22 p atients. Of the 18 isolate pairs, 13 (72% [CI, 46% to 90%]) had identi cal REAC patterns; the probability that at least 13 matches would be f ound by chance alone was less than 0.00001. Among patients with recurr ent infection caused by the same strain, the interval between episodes was shorter (mean, 14 weeks) than that among patients with recurrent infection caused by another strain (mean, 43 weeks; P = 0.05). Conclus ions: Recurrent group B streptococcal infection is common among adults and in most cases appears to be caused by relapse. The optimal manage ment of adults with a first episode of group B streptococcal infection needs to be further defined to minimize the likelihood of recurrent d isease.