THE ACCURACY AND PATIENT PREFERENCE FOR SELF-COLLECTED GROUP-B STREPTOCOCCUS CULTURES

OBJECTIVE: Our purpose was to determine the accuracy of and patient at titudes regarding self-collected group B Streptococcus cultures. STUDY DESIGN: Women seen for prenatal care at 24 to 42 weeks' gestation wer e asked to collect distal vaginal and anal samples for group B Strepto coccus. Subsequently, distal vaginal and anal samples were obtained by the nurse. The patients were then asked their preference toward self- sampling. RESULTS: A total of 251 women participated in the study. The incidence of positive group B Streptococcus cultures was 12.7%, 9.6%, 10.0%, and 7.6% for the patient-collected vaginal and anal and nurse- collected vaginal and anal specimens, respectively. The incidence of g roup B Streptococcus carriage was 17.5% and 13.5% for any positive pat ient- or provider-collected specimens, respectively, and 19.1% for any positive culture. Single patient-collected vaginal and anal and nurse -collected vaginal and anal samples were insensitive for group B Strep tococcus carriage (67%, 50%, 52%, 40%, respectively). The combination of patient-collected samples was more sensitive than nurse-collected s amples (sensitivity 91.7% vs 70.8%, p < 0.05). Repeat sampling of the vagina or anal canal did not offer significant additional benefit to a single culture. Overall, patient-collected samples were 98.4% accurat e in predicting group B Streptococcus carriage versus 94.4% for nurses . A total of 58% of women preferred obtaining their own specimens, whe reas 9.6% found the technique difficult. Ninety percent desired the op tion of self-sampling in the future. CONCLUSIONS: Single vaginal or an al cultures were insensitive in detecting group B Streptococcus carria ge. Combined patient-collected cultures were more sensitive than provi der-collected specimens. On the basis of accuracy and patient preferen ce, women should be given the opportunity of combined vaginal-anal sel f-sampling for group B Streptococcus when indicated.