It may be possible to pass gonorrhea through kissing, challenging the widely accepted notion that the sexually transmitted disease is spread almost exclusively through sexual contact, a new study says.

Researchers in Australia found that kissing with tongue may be a way to transmit oropharyngeal gonorrhea, or oral gonorrhea, particularly among gay and bisexual men.

Although the idea has not been well-studied, one expert says the findings, published Thursday in the journal Sexually Transmitted Infections, could be important for understanding gonorrhea as it continues to spread and become more resistant to treatment.

Anthony Lutz, a nurse practitioner in the department of urology at Columbia University Medical Center, said that although he has not personally seen such cases, the suggestion that it could be transmitted mouth to mouth has been percolating within the medical community.

"It's a worthwhile topic to continue investigating, for sure," so medical practitioners can better screen and treat patients for the disease, he said.

Gonorrhea is a sexually transmitted infection caused by the bacterium Neisseria gonorrhoeae. It can be transmitted among people who have vaginal, anal or oral sex with someone who has it, and it can infect the genitals, rectum and throat, according to the Centers for Disease Control and Prevention.

But gonorrhea - even oral gonorrhea - is not considered to be a kissing disease; rather, public health authorities say oral gonorrhea is contracted through oral sex.

The researchers studied questionnaires from more than 3,000 gay and bisexual men at a sexual health center in Melbourne, 6 percent of whom tested positive for oral gonorrhea, about their recent sexual history.

The men noted that they had had an average of four kissing-only partners, five kissing-with-sex partners and one sex-only partner over the past three months.

The researchers found that those with a higher number of kissing-only and kissing-with-sex partners were at a greater risk of testing positive for oral gonorrhea, the study said.

"We found that the more people an individual kissed also placed them at an increased risk of having throat gonorrhoea, irrespective of whether sex occurred with the kissing.

"This data challenges the accepted traditional transmission routes of gonorrhea held for the past 100 years, where a partner's penis was thought to be the source of throat infection," Eric Chow, the lead author of the study, wrote in an email to The Washington Post.

He added: "We found after we controlled statistically for the number of men kissed, that 'the number of men someone had sex with but did not kiss was not associated with throat gonorrhoea."

Gonorrhea has become a major concern as the number of reported cases of gonorrhea and some other sexually transmitted diseases have been rising across the country and public health authorities have expressed concern about an increasing resistance to treatment.

According to the CDC, gonorrhea diagnoses climbed 67 percent from 2013 to 2017 in the United States, reaching more than 555,000 cases.

Some strains of gonorrhea have become resistant to most of the antibiotics that have been prescribed for them, according to the CDC.

"We expect gonorrhea will eventually wear down our last highly effective antibiotic, and additional treatment options are urgently needed," Gail Bolan, director of the CDC's Division of STD Prevention, said last year.

"We can't let our defenses down - we must continue reinforcing efforts to rapidly detect and prevent resistance as long as possible."

Lutz, who has studied STDs among men who have sex with other men, said studies on mouth-to-mouth transmission of oral gonorrhea would be challenging because it is difficult to find people who have kissing-only partners - as well as oral gonorrhea - and who would be willing to discuss it.

It would also be difficult to prevent transmission, he said.

Lutz said assuming the new findings from Australia are true, the idea could initially incite fear. But because kissing is so common, it could also help destigmatize the disease and encourage people to talk about it.

In any case, he said, research is vital to help both practitioners and their patients completely understand the disease.

Chow, the lead author of the study, said he hopes the new findings will provide better understanding about gonorrhea.

"Through our research, we have shown that gonorrhea can be passed on through kissing. This will help people understand how the infection was introduced - particularly if they have not have been sexually active," he wrote in the email.

"We know it's unlikely that people will stop kissing, and our team is already doing a clinical trial examining whether daily use of mouthwash could prevent gonorrhoea. If it works, it could be a simple and cheap intervention for everyone."

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This article was originally published by The Washington Post.