Infectious diseases specialist Kristin Englund, MD, has not seen a patient with antibiotic-resistant gonorrhea -- yet.
“But, unfortunately, we anticipate that it’s coming, and that’s pretty scary,” says Englund, of the Cleveland Clinic. “We have no other antibiotics to use against gonorrhea.”
The CDC says that gonorrhea is among three diseases called “urgent threats” for their potential to become more widespread. This means that many of the antibiotics once used to treat it no longer work. Currently, the CDC recommends only one cure: a combination of two powerful antibiotics.
The threat prompted the World Health Organization last year to release new guidelines for treating the three STDs. The organization says drug resistance “has increased rapidly in recent years and has reduced treatment options.”
Eventually, health officials fear, current antibiotics will no longer be effective against gonorrhea. There have been cases that do not respond to antibiotics usually used to treat them. In the U.S., there’s evidence that the current recommended treatment may be weakening. In September, a cluster of seven cases in Hawaii showed resistance to the last line of treatment. This was an alarming first.
What is antibiotic resistance, and how does it develop?
Antibiotics have been widely used to fight infections, including sexually transmitted diseases like gonorrhea, for more than 75 years. However, the bacteria that cause STDs have fought back. Over time, they have adapted so that a growing number of antibiotics can no longer treat them.
Each year, according to the CDC, at least 2 million people in the U.S. pick up these difficult-to-treat infections, which include a growing number of gonorrhea cases, that are resistant to antibiotics.
They develop resistance in two ways, says Jeffrey Klausner, MD, a professor of medicine and public health and a specialist in sexually transmitted diseases at UCLA’s David Geffen School of Medicine.
“The organism changes its surface so that the antibiotic no longer recognizes it, or it starts to produce new enzymes that break down the antibiotic,” Klausner says. Gonorrhea, he says, has long been known as a bacteria that learns to evade antibiotics.
Which STDs are causing the most concern?
Gonorrhea is far and away the most pressing concern. Currently, there’s only one CDC-recommended treatment for it: a combination of two powerful antibiotics, azithromycin and ceftriaxone.
Syphilis and chlamydia have also begun to show resistance to antibiotics in some parts of the world, though Klausner says there are several treatment options for both.
STDs, which don’t always have symptoms, can cause serious complications if left untreated:
- Gonorrhea can lead to pelvic inflammatory disease (PID), which causes inflammation of the ovaries, the fallopian tubes, and the uterus, which can ultimately lead to infertility. In men, it can cause infection of the testes and sterility. In rare cases, gonorrhea can spread to your blood or joints, which can be life-threatening. Untreated gonorrhea may increase your risk of HIV.
- Chlamydia can also cause PID in women, which may result in permanent damage. Though men seldom have long-term complications from untreated chlamydia, it can lead to sterility in rare cases.
- Syphilis, in its early stages, can cause chancre sores, rashes, fever, swollen lymph glands, and other symptoms. If left untreated for years, it can eventually damage the brain, heart, liver, and other organs, causing paralysis, numbness, blindness, dementia, and death.
Can these STDs still be treated?
Gonorrhea treatment requires both azithromycin, a pill, and an injection of ceftriaxone. The CDC refers to this regimen as the “last available effective gonorrhea treatment option.”
“The two have to be given together,” says Englund. “We used to be able to give one or the other, but now we’re seeing resistance to both of those.”
Between 2013 and 2014, gonorrhea cases that showed resistance to azithromycin, an oral antibiotic, increased by 300%, although they’re still rare, according the CDC. In September, the agency announced the discovery of a cluster of gonorrhea cases in Hawaii that showed -- for the first time -- a decreased susceptibility to ceftriaxone.
So far, no cases in the U.S. have proved untreatable. But “If resistance continues to increase and spread, our current treatment regimen will eventually fail,” Jonathan Mermin, MD, director of the National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention at the CDC, told those gathered at an STD prevention conference in September.
Syphilis can be treated with penicillin, but Klausner says there have been shortages of the antibiotic in the United States and around the world. It can also be treated with azithromycin, though it has shown some resistance to this antibiotic, he says.
Chlamydia still responds to several antibiotics, including erythromycin, amoxicillin, and azithromycin. Nevertheless, public health officials must be vigilant, says Englund.
“Any time you see resistance rising [in one STD], you need to look at the others for potential rise and make sure it doesn’t start to develop there as well,” she says.
How common are these STDs in general? How common are the antibiotic-resistant cases?
The CDC estimates there are 820,000 cases of gonorrhea in the United States each year. Klausner says that less than 1% fail to respond to the currently recommended treatment. However, he says, resistance to older, less expensive antibiotics is much higher.
Chlamydia is the most common STD in the United States, with nearly 3 million cases occurring annually. So far, no treatment-resistant cases have been reported.
There were close to 75,000 new cases of syphilis in the U.S. in 2015, according to CDC statistics. Most cases of syphilis happen in men who have sex with men.
The numbers for these three STDs, which are the most common, are at a record high, according to the CDC.
“We’re absolutely seeing an increase in overall rates of STDs, particularly in younger patients,” says Englund. “Half of cases are diagnosed in patients aged 15 to 24.”
What can be done to address the problem?
Klausner says a three-way approach is needed:
- Control the spread of new infections through prevention, screening, and treatment. However, there is much less funding for such efforts. The CDC says that more than half of state and local STD programs have seen budget cuts in years. “The money taken out of budgets absolutely correlates with the increases in cases of STDs that we’re seeing,” Englund says.
- Develop new antibiotics. There’s good news here: A new antibiotic now being tested has shown promising results in recent trials. When and if it will be effective and enter the market is unknown.
- Develop tests to identify the best treatments. Klausner’s lab has developed a test, now in use at UCLA Health System, that can tell physicians which antibiotic a particular case of gonorrhea will respond to. This has allowed them to successfully treat many cases of gonorrhea with older, less expensive antibiotics.