Women with bacterial vaginosis (BV) were more than three times as likely to test positive for at least one nonviral sexually transmitted infection (STI) compared to those without the condition. The finding comes from a study that analyzed lab results from over 1.5 million women.
The research, published in O&G Open, reviewed deidentified data from women aged 15 and older who received molecular testing for BV, vulvovaginal candidiasis (VVC), chlamydia, gonorrhea, or trichomoniasis between 2022 and 2024. A subset of more than 37,000 women were also screened for Mycoplasma genitalium.
BV and STI rates in the study population
Nearly 39% of participants tested positive for BV, while 28.5% had VVC. About 10.8% had both conditions at the same time.
Among those with BV, 12% had at least one concurrent STI, compared to 3.8% of women without BV. The gap was statistically significant, with BV-positive women also more likely to have multiple infections—1.1% carried two to four STIs, versus 0.2% in the BV-negative group.
Related: User Account Blocked by Social Media Platform
After adjusting for age, region, and VVC status, BV was associated with much higher odds of all four nonviral STIs studied. The strongest link appeared with gonorrhea, where women with BV faced nearly four times the risk. Chlamydia risk was almost three times higher, while trichomoniasis and Mycoplasma genitalium risks were 3.6 and 1.9 times greater.
VVC status alone was not associated with increased risk of STI coinfection.
Implications for clinical practice
The study’s size makes the results notable. Data from a single national lab may not represent every population, but the pattern remains clear: BV may indicate a greater chance of other infections.
Centers for Disease Control and Prevention guidelines recommend that women with BV be tested for STIs, which can present with overlapping symptoms that complicate diagnosis. Modern molecular diagnostics allow for full assessment of vaginal infections from a single specimen.
Related: User Account Blocked by Moderators
“This large study shows the value of full molecular testing when clinically indicated, enabling clinicians to detect coinfections from a single specimen, optimize patient management, and strengthen evidence-based care,” said study co-author Elizabeth M. Marlowe, MS, PhD, Executive Director, Infectious Disease, Quest Diagnostics, in a statement.
Limitations and next steps
The study’s main drawback is its reliance on data from one lab. Without patient details like sexual history, socioeconomic factors, or antibiotic use, it’s unclear whether BV directly raises STI risk or if other influences are involved.
In a recent interview with Contemporary OB/GYN, co-author Damian Alagia further discussed STI rates in women, including follow-up gaps in pregnant persons. Click here to watch.
The results align with existing guidelines but reinforce their importance. For clinicians, the takeaway is that testing for other infections in patients with BV is worthwhile.
