The case of a British man being infected with a particularly strong case of gonorrhea has caused new worries about the sexually transmitted disease.

The ongoing escalation in the long battle against gonorrhea has taken a worrying turn.

Since the 1940s, when penicillin was first used to combat the infection, gonorrhea has gradually become resistant to every drug that’s been thrown at it.

Now, a man in Britain has caught a strain that’s resistant to some of the last antibiotics the medical community has left to fight the illness.

The case highlights the challenges of combating the sexually transmitted disease and, experts say, it comes as efforts to develop the next gonorrhea-fighting drugs have largely stalled.

The man reportedly picked up the superbug from a sexual partner in Southeast Asia earlier this year.

A combination of the antibiotics azithromycin and ceftriaxone — the cocktail recommended by the World Health Organization and other agencies — has failed to cure it.

That’s a first in Britain, although Dr. Manica Balasegaram, director of the World Health Organization’s Global Antibiotic Research & Development Partnership, said there’s been reports of similar drug resistant gonorrhea in the recent past in France, Japan, and Spain.

This could mark a frustrating trend in a disease that’s already common and on the rise.

“Countries with good surveillance are reporting an increase in cases,” Balasegaram told Healthline.

He added that gonorrhea is the second most commonly reported infection in the United States and that cases rose by 13 percent between 2014 and 2015.

That spread of so-called “super gonorrhea” is causing scientists to rethink tactics.

Dr. Heidi Bauer, head of the California Department of Public Health’s STD Control Branch, said the man in Britain was given a gram of the antibiotic cephalosporin, four times the amount recommended in the United States.

And it failed to work.

It’s an extreme case, but the problem is familiar.

“One of the unique characteristics of the organism that causes gonorrhea is that it has the ability to develop resistance fairly quickly,” Bauer told Healthline.

She said there hasn’t been “overt treatment failure” in the United States, although a cluster of cases in Hawaii in 2016 had high levels of drug resistance.

Still, there’s “some inevitability” to gonorrhea developing high levels of drug resistance, Bauer said, which has led in some cases to relying on antibiotics that are more broadly potent rather than targeted at certain bacteria.

That arms race likely isn’t a viable long-term strategy, though.

“It’s hard to be optimistic that the answer will be more antibiotics,” she cautioned.

A 2013 report from the Centers for Disease Control and Prevention (CDC) named gonorrhea as the third most urgent antibiotic-resistant threat in the United States — despite the fact that the disease isn’t deadly.

The White House later developed the Combat Antibiotic-Resistant Bacteria strategy, and Congress allocated funds to research and develop new drugs.

But Bauer said there are few clinical trials exploring new medications.

She called the pipeline for new gonorrhea treatments “severely depleted, with only three new chemical entities in various stages of clinical development.”

One of those is being developed by her Global Antibiotic Research and Development Partnership in collaboration with a small company, which she says is the “only drug in clinical development specifically targeting gonorrhea.”

She said they hope to make the product available in the next three to four years.

More useful, for now, would be interrupting the transmission of gonorrhea through program’s “sentinel sites” in cities around the country that collect specimens each month from gonorrhea patients to monitor the bacterium’s evolution toward ever more powerful strains.

There’s also the CDC’s Strengthening the United States Response to Resistant Gonorrhea (SURRG) initiative, which started in 2016 to further enhance spying on the bacterium.

A big part of interrupting that spread might be increased awareness.

Bauer noted that April is STD Awareness Month.

Despite how common gonorrhea is and despite the recent increase in federal funding, the threat is still all too often underestimated, she said.