Oropharyngeal gonorrhoea transmitted by tongue kissing

By Nicole MacKee
Tongue kissing may be an important, but long overlooked, transmission route for oropharyngeal gonorrhoea in men who have sex with men (MSM), says a leading Australian sexual health expert.

Professor Basil Donovan, Head of the Sexual Health Program at the Kirby Institute, UNSW Sydney, said the role of kissing in gonorrhoea transmission had been ‘staring us in the face’ for many years. ‘We just really didn’t want to think about it,’ he said.

Professor Donovan was commenting on Australian research, published in the journal, Sexually Transmitted Infections, that found that tongue kissing may be associated with transmission of oropharyngeal gonorrhoea in MSM, irrespective of whether sex also occurs.

In the study, 3677 men (median age, 30 years) who attended a public sexual health centre in Melbourne completed a survey about their male partners over the previous three months. They were categorised into three groups: those who had kissed only, those who had sex only (anal or oral) and those who had engaged in kissing and any kind of sex. Oropharyngeal gonorrhoea was diagnosed in 6.2% of study participants.

The researchers reported that the adjusted odds for having oropharyngeal gonorrhoea were 1.46-fold for men with four or more kissing-only partners and 1.81-fold for men with four or more kissing-and-sex partners, compared with men who had one or no partners in these categories. Participants who reported having only sex, without kissing, did not have an increased risk.

‘The evidence is pretty compelling,’ Professor Donovan told Medicine Today. He noted that researchers had been able to readily culture gonorrhoea from saliva, and mathematical modelling, cited in the current study, had shown that kissing was needed to maintain gonorrhoea transmission.

Professor Donovan said the findings should prompt doctors to make throat swabs routine for anyone who kisses a lot of people, including gay men, sex workers and very sexually active heterosexuals.

The study authors noted that antibacterial mouthwash was being investigated as a preventive measure against oropharyngeal gonorrhoea.

Professor Donovan, who is involved in this research, said his team was looking at a ‘conventional, commercial mouthwash’, and the results would be available later this year. His team is also hoping to secure funding to trial a vaccine for gonorrhoea, which has become increasingly difficult to treat due to the growing prevalence of antibiotic-resistant strains of Neisseria gonorrhoeae.

‘We have to do something to bring [gonorrhoea] back under control,’ he said. ‘It’s starting to look like the 1970s again.’
Sex Transm Infect 2019; doi: 10.1136/sextrans-2018-053896.