Group B streptococcus, a major cause of serious infections, declined about 25 percent among infants younger than 7 days from 1999 to 2005, but increased nearly 50 percent among persons 15 to 64 years old, according to a study in the May 7 issue of JAMA, the Journal of the American Medical Association.
In the 1970s, group B streptococcus emerged as the leading cause of sepsis and meningitis in the first week of life. Subsequent prevention strategies resulted in substantial declines in disease in infants younger than 7 days (also known as early-onset disease). Guidelines for prevention of this disease near the time of birth were revised in 2002. Disease trends following the release of these guidelines have not yet been well studied.
In addition to illness in the first week of life, group B streptococcus also causes invasive disease in older infants, pregnant women, children and young adults with underlying medical conditions and older adults. "The epidemiology of group B streptococcal disease is dynamic, and continued surveillance to monitor trends across age groups is necessary. For example, an increase in disease incidence among nonpregnant adults has been documented in past decades, but whether that trend has continued is unknown," the authors write. In the United States in 2005, group B streptococcus caused an estimated 21,500 cases of invasive disease and 1,700 deaths, according to information in the article.
Christina R. Phares, Ph.D., of the Centers for Disease Control and Prevention, Atlanta, and colleagues evaluated trends and characteristics over a recent period among cases of laboratory-confirmed invasive group B streptococcal disease identified by population-based surveillance in 10 states participating in the Active Bacterial Core surveillance/Emerging Infections Program Network.