Invasive Group B Streptococcal disease in non-pregnant adults, New Mexico, 2004 – 2008

Background: Group B Streptococcus (GBS), a well-known cause of neonatal sepsis, is also an increasing cause of morbidity and mortality in non-pregnant adults. Five years (2004 - 2008) of New Mexico (NM) population-based surveillance data were examined to identify disease trends. Methods: The NM Emerging Infections Program's Active Bacterial Core surveillance component conducts statewide invasive GBS disease surveillance. A case was defined as GBS isolation from a sterile site in non-pregnant New Mexico residents age 18 and over. Demographic and clinical information was abstracted from medical records. Results: Five hundred-four sterile site GBS infections were identified in non-pregnant NM adults during 2004 – 2008; a five-year average incidence rate of 7 cases per 100,000 persons. Adults aged 65 and over (17 cases/100,000) and Native Americans (15 cases/100,000) had highest disease rates. Eleven percent of infections with a known outcome were fatal. Most common clinical syndromes were: bacteremia without focus, skin and/or soft-tissue infection, and pneumonia. Eighty-one percent of cases had at least one underlying condition, 52% had more than one condition. Diabetes was present in 46% of cases. Isolates were available for 53%. Conclusions: NM GBS disease and fatality rates were similar to national estimates; however, Native Americans in NM have higher rates than the overall population. Diabetes is a substantial underlying condition which may predispose an individual to skin and soft-tissue infection, one of the most frequently-reported clinical syndromes.