Deep kissing may be important and neglected route for passing on throat gonorrhea

Deep (tongue) kissing may be an important and neglected route for passing on throat (oropharyngeal) gonorrhoea among gay and bisexual men, suggests Australian research, published online in the journal Sexually Transmitted Infections.

Strains of gonorrhoea that are resistant to antibiotics are becoming more common in many countries, sparking concerns that the infection will become increasingly difficult to treat.

But public health campaigns to curb the spread of the infection among gay and bisexual men have focused on promoting condom use, in the belief that most gonorrhoea is passed on during sex, say the researchers.

To assess whether throat (oropharyngeal) gonorrhoea might be passed on through tongue kissing either by itself or as part of sex, the researchers gathered information from new and returning gay and bisexual patients at a major public sexual health service in Melbourne, Australia in 2016-17.

The 11,442 men were invited to fill in a brief survey on their sexual practices with male partners over the past three months. Practices were categorised as kissing with no sex; sex with no kissing; and kissing with sex.

Some 3677 completed surveys from 3091 men were included in the final analysis.

The proportion of those with throat gonorrhoea was just over 6 per cent; the figures for anorectal and urethral gonorrhoea were just under 6 per cent and nearly 3 per cent, respectively.

Nearly all the men (95%) had had kissing with sex partners; 70 per cent had had kissing only partners; and just over 38 per cent had had sex only partners.

Around one in four of the men (981; just under 27%) had had all three categories of sex in the preceding three months. Just 52 (1.4%) had had kissing only partners during this time.

But the proportion of these men testing positive for throat gonorrhoea was higher than it was for those who had had sex without kissing.

In all, the men had had an average of 4 kissing only partners, 1 sex only partner, and 5 kissing with sex partners.

A higher number of kissing only or kissing with sex partners was associated with a greater likelihood of testing positive for throat gonorrhoea.

After accounting for potentially influential factors, the odds of testing positive for throat gonorrhoea were 46 per cent higher among men who had had four or more kissing only partners, and 81 per cent higher among those with four or more kissing with sex partners, compared with men who had only one or no partners in these categories.

This is an observational study, and as such, can't establish cause. It also concerned men at only one sexual health centre so the findings may not be applicable elsewhere. And it excluded other sexual practices which could have influenced infection risk.

But the importance of throat to throat transmission of gonorrhoea has been underestimated and neglected, suggest the researchers, who write: "Our results suggest kissing with or without sex may be a risk factor for oropharyngeal gonorrhoea."

Their study provides the first empiric evidence that this might be an important route of transmission, they say, and if confirmed by other studies, "would open up preventive options such as antibacterial mouthwash that do not rely on condoms."