Gonorrhea in women: a link between vaginal microbiota and symptoms?
Cervicitis in some women, but no symptoms in others. Why does gonorrhea manifest itself in so many different ways? The abundance of lactobacilli in the cervico-vaginal microbiota may be the cause.
About this article
Each year, nearly 90 million cases of gonorrhea are reported worldwide. In women, infection of the lower genital tract by Neisseria gonorrhoeae has highly variable consequences, from no symptoms at all to cervicitis. Although the factors behind this variability are not known, the cervico-vaginal microbiota may be involved. In fact, a team has recently shown that the cervico-vaginal microbiota predicts the clinical presentation of gonorrhea in women.
90 million Each year, nearly 90 million cases of gonorrhea are reported worldwide.
A pilot study of 19 infected women
These are the results of a pilot study in the US on 19 patients infected with N. gonorrhoeae, 10 of whom were symptomatic and 9 asymptomatic. Most of these patients were African American, a population whose microbiota is more frequently low in lactobacilli than that of Caucasian women. Neisseria spp. accounted for only 0.24% of the bacteria present in all 19 patients, whether symptomatic or asymptomatic. Half of the patients in each group also had co-infections with Chlamydia trachomatis and/or Trichomonas vaginalis.
19 cases per 1,000 The incidence of gonorrhea in women.
23 cases per 1,000 In men, the rate is 23 cases per 1,000.
Symptoms linked to the microbiota
The cervico-vaginal microbiota of the asymptomatic patients with no co-infection more frequently contained microbial communities dominated by lactobacilli (92.2% of bacteria on average) than that of the symptomatic patients with no co-infection (21.6%). This dominance mainly involved L. iners.
In contrast, the symptomatic women had microbial communities characterized by more diverse and heterogenous bacterial taxa. They were composed of a mixture of anaerobic bacteria associated with bacterial vaginosis (BV): Prevotella, Sneathia, Mycoplasma hominis and Bacterial Vaginosis-Associated Bacterium-1 (BVAB1) / Candidatus Lachnocurva vaginae.
Protective effect of flora dominated by Lactobacillus?
However, these results are merely those of a pilot study based on a small sample. They do not allow us to say whether vaginal microbiota composition is associated with the risk of N. gonorrhoeae infection or with protection against it. They simply highlight a relationship between vaginal communities and clinical presentation in women diagnosed with N. gonorrhoeae infection. This is a crucial first step, but further studies are needed to evaluate the potentially protective effect against N. gonorrhoeae infection of a Lactobacillus-dominated vaginal microbiota.