Screening for abnormal vaginal microflora by self-assessed vaginal pH does not enable detection of sexually transmitted infections in Ugandan women

Abstract

Objective: Is self-assessed vaginal pH measurement to detect abnormal vaginal bacterial microflora (AVF) an adequate prescreening method for detection of genital sexually transmitted infections (STIs)?

Materials and methods: A total of 360 Ugandan women tested themselves with a gloved finger and a pH color strip. PCR for bacterial vaginosis (BV)-associated bacteria was tested by PCR for Mycoplasma hominis, Ureaplasma urealyticum, and/or Atopobium vaginae, while the STIs were diagnosed by positive PCR for Chlamydia trachomatis, Neisseria gonorrhoeae, Mycoplasma genitalium, and/or Trichomonas vaginalis.

Results: A strong correlation was found between self-assessed pH values and BV-associated bacteria (P<0.0001), but not with STIs, not as single infections, nor in general.

Conclusion: Self-measured vaginal pH correlated well with markers of high-risk microflora types such as BV or aerobic vaginitis, but not with STIs. Hence, in a screening program addressing AVF in low-resource countries, extra specific tests are required to exclude STIs.

Keywords: Abnormal vaginal flora; Aerobic vaginitis; Bacterial vaginosis; C. trachomatis; Lactobacillary grades; M. genitalium; N. gonorrhoeae; PCR; Screening; T. vaginalis.