Asymptomatic Neisseria meningitidis oropharyngeal carriage was observed at 25.2% among MSM at a Brussels sexual health clinic, with serogroup B (50%) most frequently identified and non-vaccination against Nm being the only factor significantly associated with colonization.
The prevalence of asymptomatic Neisseria meningitidis oropharyngeal carriage among MSM was 25.2%.
Serogroup B was the most commonly identified encapsulated Neisseria meningitidis strain among colonized MSM.
Non-vaccination against Neisseria meningitidis in the past 5 years was the only characteristic significantly associated with Nm colonization in multivariable analysis.
Colonized individuals had a median age of 36.5 years and reported varied sexual and social behaviors.
This research suggests that a notable proportion—about 1 in 4—of men who have sex with men (MSM) attending a sexual health clinic in Brussels carried Neisseria meningitidis (the bacteria that can cause meningitis) in their throats without showing any symptoms. This is higher than carriage rates typically reported in the general adult population. The most common type found was serogroup B, which accounts for a significant portion of meningococcal disease in Europe. The study found that being unvaccinated against meningococcal disease in the past five years was the only factor that was statistically linked to carrying the bacteria. Interestingly, many colonized individuals reported kissing partners but no sexual partners during the study period, which is consistent with existing knowledge that meningococcal bacteria spread primarily through close contact such as kissing rather than sexual contact specifically. These findings matter because asymptomatic carriers can unknowingly transmit the bacteria to others, and MSM as a group may face elevated exposure risk in social and sexual networks. This research suggests that vaccination coverage against meningococcal disease in MSM populations may be an important public health consideration, and that further studies are needed to better understand transmission dynamics and carriage in this group.
Doubinsky A, Miendje Deyi V, Mattheus W, Delforge M, Libois A, Dauby N, et al.. (2025). Prevalence of Neisseria meningitidis carriage among men who have sex with men at a sexual health clinic in Brussels, Belgium: a cross-sectional study.. European journal of clinical microbiology & infectious diseases : official publication of the European Society of Clinical Microbiology. https://doi.org/10.1007/s10096-024-05031-2