The journal of maternal-fetal & neonatal medicine : the official journal of the European Association of Perinatal Medicine, the Federation of Asia and Oceania Perinatal Societies, the International Society of Perinatal Obstetricians 2016 6 22() 1-18
There are limited data regarding Xpert performance to detect GBS in HIV-infected pregnant women. We evaluated the accuracy of a rapid real-time polymerase chain reaction test in a cohort of HIV-infected women.
At 35-37 weeks of pregnancy, a pair of combined rectovaginal swabs were collected for two GBS assays in a cohort of sequentially included HIV-infected women in Rio de Janeiro: 1) culture; and 2) real-time polymerase chain reaction assay [GeneXpert GBS (Cepheid, Sunnyvale, CA, US)]. Using culture as the reference, sensitivity, specificity, positive and negative likelihood ratios were estimated.
From June 2012 to February 2015, 337 pregnant women met inclusion criteria. One woman was later excluded, due to failure to obtain a result in the index test; 336 were included in the analyses. The GBS colonization rate was 19.04%. Sensitivity and specificity of the GeneXpert GBS assay were 85.94% (95% CI, 75.38-92.42) and 94.85% (95% CI, 91.55-96.91), respectively. Positive and negative predictive values were 79.71% (95% CI, 68.78-87.51) and 96.63% (95% CI, 93.72-98.22), respectively.
GeneXpert GBS is an acceptable test for identification of GBS colonization in HIV-infected pregnant women and represents a reasonable option to detect GBS colonization in settings where culture is not feasible.