A study of group B streptococcal carrier state during late pregnancy.

The carriage of Group B Streptococcus was investigated in 500 females in the third trimester of their pregnancy by culturing vaginal and rectal swabs and urine collected from each patient. A high rate of colonization was noted since 152 cases (30.4%) were found to harbor the organism, and 219 specimens (48%) from a total of 456 collected from these 152 cases were positive for Streptococcus agalactiae. Of the 219 positive specimens, 94 (42.9%) were vaginal swabs, 90 (41.1%) were rectal swabs and the remaining 35 (16%) were urine specimens. It is recommended that vaginal and rectal swab culture be used to detect carriers of group B streptococci, since using such a combination in this study revealed 91.4% of all positive cases.