Antibiotic resistance is making gonorrhoea much harder and sometimes impossible to treat, the World Health Organisation (WHO) has warned.
There have been three untreatable cases of the sexually transmitted infection globally, however experts warn this could rise.
“The bacteria that cause gonorrhoea are particularly smart,” said Dr Teodora Wi, medical officer at the World Health Organisation (WHO).
“Every time we use a new class of antibiotics to treat the infection, the bacteria evolve to resist them.”
Experts have urged people to use condoms to prevent the spread.
WHO collected data from 77 countries and found a widespread resistance to older and cheaper antibiotics.
Some countries – particularly high-income ones – are finding cases of the infection that are untreatable by all known antibiotics.
“These cases may just be the tip of the iceberg, since systems to diagnose and report untreatable infections are lacking in lower-income countries where gonorrhoea is actually more common,” said Dr Wi.
An estimated 78 million people are infected with gonorrhoea every year.
The STI can infect the genitals, rectum and throat - the latter of which is particularly concerning to health officials.
Dr Wi told the BBC: “When you use antibiotics to treat infections like a normal sore throat, this mixes with the Neisseria species (bacteria which causes gonorrhoea) in your throat and this results in resistance.”
Therefore transmitting gonorrhoea through oral sex could lead to a super strain of the infection.
“In the US, resistance [to an antibiotic] came from men having sex with men because of pharyngeal infection,” added Wu.
Decreasing condom use, increased urbanisation and travel, poor infection detection rates and inadequate or failed treatment have all contributed to the increase in the STI’s spread.
Roughly one in 10 heterosexual men and more than three quarters of women and gay men have no easily recognisable symptoms.
When they do, symptoms in men include: an unusual discharge from the tip of the penis, which may be white, yellow or green; pain or burning when urinating; inflammation of the foreskin and pain or tenderness in the testicles.
In women, symptoms include: unusual vaginal discharge which may be thin or watery and green or yellow in colour; pain or burning when passing urine; pain or tenderness in the lower abdominal area and bleeding between periods, heavier periods or bleeding after sex.
According to WHO, complications of gonorrhoea disproportionally affect women and can cause pelvic inflammatory disease, ectopic pregnancy and infertility, and an increased risk of HIV.
In most countries, ESCs are the only single antibiotic that remain effective for treating gonorrhoea. But resistance to the antibiotic cefixime – and more rarely to the antibiotic ceftriaxone – has now been reported in more than 50 countries.
As a result, WHO issued updated global treatment recommendations in 2016 advising doctors to give two antibiotics: ceftriaxone and azithromycin.
It is now a matter of developing new drugs to help tackle the problem.
There are currently three new drugs in various stages of clinical development: solithromycin, zoliflodacin and gepotidacin. However the WHO said the development of new antibiotics is not very attractive for commercial pharmaceutical companies.
Treatments are taken only for short periods of time (unlike medicines for chronic diseases) and they become less effective as resistance develops, meaning that the supply of new drugs constantly needs to be replenished, they said.
To address the problem, a not-for-profit research and development organisation called the Global Antibiotic Research and Development Partnership (GARDP) has been launched. Its aim is to develop new antibiotic treatments and promote appropriate use, so they remain effective for as long as possible.
Director of GARDP, Dr Manica Balasegaram, said: “To address the pressing need for new treatments for gonorrhoea, we urgently need to seize the opportunities we have with existing drugs and candidates in the pipeline.
“In the short term, we aim to accelerate the development and introduction of at least one of these pipeline drugs, and will evaluate the possible development of combination treatments for public health use.
“Any new treatment developed should be accessible to everyone who needs it, while ensuring it’s used appropriately, so that drug resistance is slowed as much as possible.”
In the meantime, health officials have urged people to engage in safe sex by using condoms consistently and correctly.