Intersecting infections: the enhancing effect of Neisseria gonorrhoeae pathogenesis on HIV-1

Despite the relatively low transmission rates of HIV-1, the virus accounted for 1.5 million new infections in 2020, with widespread infection and devastating sequelae. Various mechanisms have been described, which exacerbate HIV-1 progression, including concurrent infection with other sexually transmitted infections (STIs). Epidemiological evidence has suggested the strongest association between Neisseria gonorrhoeae and HIV-1 compared to other STIs and the presence of untreated N. gonorrhoeae before infection with HIV-1 has been shown to enhance viral infection. Molecular investigation has corroborated this by showing that presence of N. gonorrhoeae enables transmission of HIV-1 across the epithelial membrane, enhances replication of HIV-1, increases viral shedding, and heightens immune dysregulation. Gonorrhoea infections are rapidly increasing worldwide providing a potential platform for increased HIV-1 incidence. Furthermore, whilst treatment of N. gonorrhoeae in parallel infection alleviates HIV-1 progression and transmission, this is becoming a less viable option as the threat of multidrug resistance within N. gonorrhoeae proliferates. These findings highlight the requirement for greater surveillance of concurrent infections to tackle the HIV-1 epidemic and warrant monitoring of the resistance crisis in N. gonorrhoeae to prevent worsening outcomes of HIV-1 patients.