The sexually transmitted disease gonorrhea is becoming resistant to the only two antibiotics left to treat it — and it’s spreading in China, according to new research.
Gonorrhea is currently treated using a cocktail of two drugs, azithromycin and ceftriaxone, but the antibiotics are losing their efficacy. In China, almost 19 percent of gonorrhea cases are resistant to azithromycin and almost 11 percent to ceftriaxone, according to a study published today in Plos Medicine. This latest number is what’s most concerning, says Vanessa Allen, chief of medical microbiology at Public Health Ontario, who was not involved in the research.
“Ceftriaxone is the last drug that we have for the treatment of gonorrhea,” Allen tells The Verge. “We don’t have any replacement drugs after ceftriaxone right now.”
Gonorrhea is one of the most common sexually transmitted diseases worldwide, with an estimated 78 million cases every year. If untreated, gonorrhea can cause permanent health problems, like infertility and long-term abdominal pain in women. Pregnant women who are infected can pass on gonorrhea to the baby during birth, causing serious health effects like eye infections. If the STD spreads to the blood or joints, it can be fatal.
In this latest study, researchers analyzed over 3,000 gonorrhea samples taken from patients across China between 2013 and 2016. The percentage of Neisseria gonorrhoeae samples that were resistant to both azithromycin and ceftriaxone increased to 3.3 percent in 2016 from 1.9 percent in 2013. This percentage increase may not seem high, but it’s worrisome: it means resistance is going up. And if the only two drugs that can treat gonorrhea don’t work, there’s trouble.
“It’s almost like the bug is running faster than our ability to develop safe and effective drugs,” Allen says. “What is the next chapter if no new drugs are developed? And it’s really not clear.”
Two existing antibiotics can be used as alternatives, Allen says. One is called gentamicin, but it’s not ideal because it can cause problems in the kidneys and hearing. The other one is meropenem, but it’s in the same class of drugs as ceftriaxone, and if the bug is resistant to ceftriaxone, it’ll likely become resistant to meropenem as well. So the most important line of defense, before a new antibiotic is developed, is trying to avoid contracting the disease in the first place — by using condoms, for instance. (Gonorrhea can also spread through oral sex.)
Untreatable gonorrhea is not just a problem in China. In the US, there were almost 469,000 cases of gonorrhea in 2016. And drug resistance is going up here, just like in the rest of the world.