Invasive disease due to group B streptococcal infection in adults: Resultsfrom a Canadian, population-based, active laboratory surveillance study - 1996

In 1996, a population-based surveillance program for invasive adult group B streptococcal (GBS) diseases in Canada was undertaken, to define the epide miologic and microbiologic characteristics of the disease. Nine public heal th units across Canada, representing 9.6% of the population, participated i n the program. In total, 106 culture-positive cases of invasive adult GBS d isease were reported, which represented an incidence rate 4.6 per 100,000 a dults (41/100,000 for pregnant and 4.1/100,000 for nonpregnant adults). Six ty-two (58.5%) of the 106 cases occurred in females, and, of these, 15 (14. 2%) were associated with pregnancy. Serotype V was the most common, account ing for 31% of the 90 GBS isolates typed (26.7% of nonpregnant and 4.4% of pregnant cases). This was followed by serotypes III (19%), Ia (1.7%), Ib (1 0%), II (9%), and VII (1%). Thirteen percent were nontypeable. All isolates were susceptible to penicillin, ampicillin, and vancomycin. Resistance to erythromycin and clindamycin was 6.7% and 4.4%, respectively.