It started with a kiss: are we passing on gonorrhea in our saliva?

By Emen8, updated 2 years ago in Health / Sexual health

man in pink and blue hoodie blowing bubblegum

Ah, saliva. From helping to prevent tooth cavities to providing instant, free lubrication to anything you can spit on. While this can be extremely handy, could it be causing more harm than good?

Research from the Melbourne Sexual Health Centre, is bringing to light something not so great about saliva — and that’s to do with transmitting gonorrhea (see our Knowledge Hub for facts on gono).

We have a lot of questions, so we spoke to Dr Vincent Cornelisse, a Specialist in Sexual Health Medicine based in Sydney and previously at Melbourne Sexual Health Centre.

If gonorrhea can be transmitted in saliva, why didn’t we know about it sooner?

“Actually, there were earlier reports, but we didn’t have the testing technology to confirm them at the time,” says Cornelisse. “Back in the 1970s and 1980s there were a couple of case reports of gonorrhea transmission by kissing. But the idea’s received no further attention since then, and gonorrhea was generally considered to be transmitted through genital contact.”

And the difference now?

“The idea re-surfaced because of recent improvements in testing technologies, which made it clear that most gonorrhea infections were located in people’s throats,” he says. “And we now know that from there, transmission via saliva can happen quite easily.”

So, it’s possible to transmit gonorrhea by kissing? Any kissing?

The news isn’t great. “We now have convincing evidence that gonorrhea is transmitted by kissing,” says Cornelisse. “We’re not talking a peck on the cheek, of course, but something a bit more passionate that involves some transfer of saliva. This is new information, and some public health statements have not yet caught up with this.”

“We now have convincing evidence that gonorrhea is transmitted by kissing,”

Want to know how to up your lip-smacking game for that perfect kiss? See how in Am I a bad kisser?

What about sharing food and drinks? There’s some saliva involved there for sure.

“We haven’t studied whether sharing drinks or food can transmit gonorrhea,” Cornelisse says, “but I suspect that these activities don’t involve enough saliva to facilitate gonorrhea transmission.”

Wait. If we’re talking about using saliva as lube, is there a chance you could transmit gonorrhea to yourself?

There is a word for this: ‘autoinoculation’. And yes, that means it’s a real thing that could happen if you had gonorrhea of the throat and gave your own genitals a spit-shine (for whatever reason).

“Gonorrhea is a surface infection rather than a blood-borne infection,” says Cornelisse. “This means that yes, there is a possibility that you could pass gonorrhea from your throat/saliva to other parts of your own anatomy, such as your own urethra or anus. However, this hasn’t been studied.”

Are other STIs likely to be transmitted by kissing as well, or is it just gonorrhea?

Along with gonorrhea there are a number of STIs which we know can be transmitted via oral sex, including chlamydia and syphilis. Does this mean they can also be transmitted by kissing?

“Along with gonorrhea there are a number of STIs which we know can be transmitted via oral sex, including chlamydia and syphilis.”

“There is no convincing evidence that other STIs are also transmitted by kissing, but this is currently being investigated for syphilis,” says Cornelisse. “Over the last couple of years we have also seen an outbreak of meningococcal disease among men who have sex with men, which we know is transmitted by kissing.”

Why is this information particularly important for men who have sex with men (MSM)?

It’s partly about the numbers. “This information is important for anyone with multiple sexual partners,” explains Cornelisse, “but it is particularly important for gay, bisexual and other men who have sex with men, because this population has much higher rates of gonorrhea than the rest of the population.”

The fact that a lot of us use saliva as lube for anal sex (by spitting and/or rimming) is also a factor. The original 2016 study found that “almost half of rectal gonorrhea cases may be eliminated if MSM stopped using [their] partner’s saliva for anal sex.”

And finally, throat infections may have a key role to play in the future of gonorrhea prevention. “One of the big worries about gonorrhea is that we are increasingly seeing antibiotic-resistant strains,” Cornelisse says. “The biology is a bit complex, but it is thought that most of these resistant strains are the result of throat infections, which is another reason why it’s so important that we find more effective ways to prevent throat gonorrhea.”

So what can we do to help prevent the spread of gonorrhea, given this new information?

Condoms and lube are still one of the best ways to help stop the spread of gonorrhea and other STIs when you’re having anal sex. It’s also a good idea to avoid using saliva as lube.

“almost half of rectal gonorrhea cases may be eliminated if MSM stopped using [their] partner’s saliva for anal sex.”

But what about kissing?

“The transmission of gonorrhea by saliva has important implications for ‘sexual safety’, as it implies that gonorrhea is transmitted by kissing and oral sex, and most people don’t use condoms for these activities,” Cornelisse confirms. “Because of this, we are now looking at new gonorrhea prevention strategies that don’t rely on condoms.”

There may be some hope in the form of new research about mouthwash. “MSHC is currently running a large trial to investigate whether using antiseptic mouthwash can prevent throat gonorrhea. If this proves to be effective, then it would provide a way by which people can protect their sexual partners from gonorrhea of the throat, penis or anus.”

Don’t worry – follow Emen8 on Facebook and we’ll keep you updated. “In the meantime, a good prevention strategy is frequent screening for gonorrhea, particularly with a throat swab, which will help to protect your sexual partners,” says Cornelisse.

Sexually active guys are recommended to test for STIs at least once every three months, or more if you’re experiencing symptoms or have been notified about a potential exposure from a sexual partner. Of course, it’s worth remembering that gonorrhea throat infections often don’t have symptoms, so it’s still worth getting tested frequently even if you don’t think you need to.

You can find STI and HIV testing services nearby and across Australia using our interactive map.

For more information about STIs, HIV, testing and other sexual health topics, check out our Knowledge Hub.