FRIDAY, May 9, 2008 (HealthDay News) -- Instances of Group B streptococcus, a major cause of serious infections, have dropped by about 25 percent among week-old infants, but rose by almost 50 percent among most adults during a recent six-year period, according to a new study.
Group B strep is the leading cause of sepsis and meningitis in the first week of life. Prevention strategies put in place during the 1970s have helped quell the condition, called early-onset disease. However, an estimated 21,500 cases of invasive disease and 1,700 deaths were traced to the disease during 2005, according to the study, published in the May 7 issue of Journal of American Medical Association.
Group B streptococcus can also cause invasive disease in older infants, pregnant women, children and young adults with underlying medical conditions and older adults. An increase in disease incidence among non-pregnant adults has been previously documented in past decades.
The new study, which examines data on laboratory-confirmed invasive group B streptococcal disease in 10 states from 1999 to 2005, found 14,573 cases of the disease overall. Of those, 1,232 cases where early-onset disease.
Incidence decreased among week-old infants by 27 percent after the early-onset disease prevention guidelines were revised in 2002. Incidence remained flat among babies aged 7 days to 89 days and pregnant women.
Among those age 15 to 64 years, Group B strep increased 48 percent. Occurrence of the disease increased by 20 percent among those aged 65 years or older.
The proportion of patients who died was highest in the oldest age groups.
All strains of Group B strep tested were vulnerable to the antibiotics penicillin, ampicillin, and vancomycin, but 32 percent and 15 percent were resistant to erythromycin and clindamycin, respectively.
The study's authors concluded that group B streptococcus vaccination trials for mothers should become a priority, followed by vaccine development to help the elderly and younger adults with chronic underlying conditions.
The Group B Strep International has more about Group B streptococcus .