Tag Archives: drug resistance

STD Awareness: Trichomoniasis, the Pear-Shaped, Blood-Sucking, Silent Scourge

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What’s shaped like a pear, hangs with a posse of bacteria, and is a silent scourge upon millions of urogenital tracts? I hope you guessed Trichomonas vaginalis, the single-celled parasite that causes trichomoniasis, or trich (pronounced “trick”). Trich is the most common curable sexually transmitted disease out there — currently afflicting around 3.7 million Americans and 156 million Earthlings.

These single-celled creatures pack a punch, but the body fights back.

When trich causes symptoms, sufferers might experience vaginal discharge (which sometimes has a bad odor), penile burning or discharge, spotting, and itching or swelling in the genital area. But around 70 percent of infections have no symptoms at all, making it a mostly “silent” disease. Based on the totality of the evidence, the Centers for Disease Control and Prevention (CDC) doesn’t currently recommend routine screening for trich in people without symptoms.

But it’s the subject of some debate. Since both symptoms and screenings are rare, and the disease isn’t reportable, some health experts worry that trich could be doing a lot of damage right under our noses. An infection during pregnancy could increase risk for preterm labor or low birth weight. It can increase risk for both acquiring and transmitting HIV from or to a partner. Women with trich are more likely to acquire an HIV infection when sexually exposed to the virus — in fact, one study estimated that 6.2 percent of all HIV infections among U.S. women could be attributed to trich. It’s also easier to catch HIV from a man with trich than from a man without trich. Continue reading →

STD Awareness: The Long Road to a Chlamydia Vaccine

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Earlier this year, television personality John Oliver was the butt of an elaborate prank orchestrated by actor Russell Crowe. It started with an auctioned jock strap, and ended with Crowe funding the John Oliver Koala Chlamydia Ward at the Australia Zoo. If you want the full story, check out the video below (beware explicit language).

Despite Oliver playing it for laughs, koala chlamydia is very real and very serious. At least half of wild koalas are infected with a chlamydia type that’s related to the human version. As in humans, koalas can transmit these bacteria through sexual contact. And, similar to the havoc it wreaks in our species, in koalas chlamydia can cause blindness, urinary tract infections, and female infertility — and can be passed from mother to infant. Along with other factors, chlamydia is said to be responsible for plummeting koala populations in many parts of Australia. Continue reading →

STD Awareness: Is Mouthwash a Match for Gonorrhea’s Superpowers?

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Since the 1930s, we’ve enjoyed around eight decades of easily cured gonorrhea — at least in places with easy access to antibiotics — but experts fear those days are numbered. In the past year or so, cases of untreatable gonorrhea have occasionally made headlines.

Thanks to the powers of evolution, some bacteria have acquired the multiple genes necessary to withstand the onslaught of the pills and shots administered by doctors. Gonococci, the bacteria that cause gonorrhea, are starting to win this “arms race” with humans, whose antibiotic arsenals are losing effectiveness. And with gonorrhea on the rise, gonococci may be evolving at an ever-quickening clip.

In 1879, Listerine claimed to cure gonorrhea. Today, scientists are finally testing that claim. We await the results.

Oral Gonorrhea: The Silent Scourge

Many experts believe oral gonorrhea is a key driver of antibiotic resistance. These infections usually don’t cause symptoms, and without symptoms people usually don’t seek treatment. Without treatment, gonococci can hang out in a throat for up to three months.

After transmission by oral sex — and possibly even by kissing  — gonococci can set up camp in the throat, which is an ideal environment for acquiring antibiotic resistance. They might not be causing symptoms, but they’re not sitting there twiddling their thumbs, either. If there’s one thing gonococci love to do, it’s collecting genes like some of us collect trading cards, and the throat is a gathering place for closely related bacteria species that hand out antibiotic-resistance genes for their expanding collections.

Gonococci can easily scavenge DNA from their surroundings — say, from a dead bacterium — and patch long segments of these genes into their own DNA, creating genetic hybrids between themselves and other organisms. Last month, scientists from Indiana University caught this phenomenon on video for the first time.

Continue reading →

STD Awareness: UK Announces “Worst-Ever” Case of Gonorrhea

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In late March, the BBC reported a story that was widely repeated in headlines across the world: “Man has ‘world’s worst’ super-gonorrhoea.”

The article told the story of a British man whose symptoms started in early 2018, about a month after he had picked up the bug during a visit to Southeast Asia. Once back home, his doctors were unable to cure it with the standard combination of azithromycin and ceftriaxone — “the first time the infection cannot be cured with first choice antibiotics,” the author wrote.

In most of the world, we don’t have a good picture of antibiotic resistance in gonorrhea.

Actually, a similar case of multidrug-resistant gonorrhea had been documented in the United Kingdom in late 2014, as noted in the New England Journal of Medicine. It was the first verified case to fail to be cured by the azithromycin/ceftriaxone combo — the infection didn’t go away until after the patient was given a double dose of both antibiotics, but by then it had been 112 days and the infection could have cleared on its own. By July 2017, the World Health Organization (WHO) had noted that there had been multiple documented cases of gonorrhea that were “untreatable by all known antibiotics.”

What was different about the man in the BBC story was that his case of ceftriaxone-resistant gonorrhea had a higher level of azithromycin resistance than those that came before. While it may not have truly been the first case of multidrug-resistant gonorrhea that couldn’t be treated with the standard dual therapy of azithromycin and ceftriaxone, it was the “most serious.” Continue reading →

STD Awareness: “Sounding the Alarm” Over Another Antibiotic-Resistant STD

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In 2012, the New England Journal of Medicine ominously stated, “It’s time to sound the alarm.” What followed was a description of the evolution of gonorrhea to all antibiotics we have used to treat it, including the last ones we had left. They closed the article with a warning: “The threat of untreatable gonorrhea is emerging rapidly.”

This summer, just five years after that alarm bell was sounded, the New England Journal of Medicine’s prediction came true. Reports of untreatable gonorrhea surfaced, shared in a World Health Organization press release: “Data from 77 countries show that antibiotic resistance is making gonorrhoea — a common sexually-transmitted infection — much harder, and sometimes impossible, to treat.”

An STD most people haven’t even heard of is rapidly evolving antibiotic resistance.

So maybe we should listen when a medical journal talks about the need to “sound the alarm.”

Sexually Transmitted Diseases, the medical journal of the American Sexually Transmitted Diseases Association, did just that in an editorial called “Mycoplasma genitalium on the Loose: Time to Sound the Alarm,” which accompanied two studies detailing antibiotic resistance in a little-known STD called mycoplasma genitalium, or MG for short.

“Let me get this straight,” you might be saying. “First you’re telling me there’s an STD called MG, which most people haven’t even heard of, and now you’re telling me I already need to worry about antibiotic resistance?” Continue reading →

STD Awareness: Is Gonorrhea Becoming “Impossible” to Treat?

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Image: National Institute of Allergy and Infectious Disease

Health authorities have been worried about it for a long time now, and we’ve been following it on our blog since 2012. The boogeyman? Antibiotic-resistant gonorrhea, a strain of the sexually transmitted bacteria that is becoming more and more difficult to treat. Higher doses of the drug will be needed to cure stubborn cases of gonorrhea — until the doses can no longer be increased. Then, untreatable gonorrhea could be a reality.

“Little now stands between us and untreatable gonorrhea.”

The World Health Organization (WHO), in a press release last month, finally used the word “impossible” when describing treatment of antibiotic-resistant gonorrhea, referring to documented cases of gonorrhea that were “untreatable by all known antibiotics.” Worse, these cases are thought to be the proverbial “tip of the iceberg,” as there aren’t good data on antibiotic-resistant gonorrhea in many developing countries, where gonorrhea is more prevalent and epidemics could be spreading under the radar. Adding to this problem is the fact that gonorrhea rates are climbing worldwide, which is thought to be due to a number of factors, including the decline in condom use, the frequent absence of symptoms, inadequate treatment, and increasing urbanization and travel.

What will happen if gonorrhea can’t be cured? Your infection could clear up on its own, after a lengthy battle with your immune system, but we don’t know a lot about how long this could take (weeks? months? never?). Unfortunately, despite your immune system’s best efforts, gonorrhea doesn’t go out without a fight. Gonorrhea can lead to pelvic inflammatory disease, which can cause tissue damage to the reproductive organs resulting in infertility, ectopic pregnancy, and chronic pain. It can also cause scarring that blocks sperm’s movement out of the testes, resulting in epididymitis, which is associated with infertility, chronic scrotal pain, and testicular shrinkage. Furthermore, gonorrhea increases risk for HIV transmission and can be passed to a baby during childbirth. The CDC estimates that, in the United States alone, untreatable gonorrhea could cause 75,000 cases of pelvic inflammatory disease, 15,000 cases of epididymitis, and 222 extra HIV infections over a 10-year period. Worldwide, where gonorrhea and HIV disproportionately affect developing countries, these problems could get even more out of control. Continue reading →

STD Awareness: Gonorrhea’s Latest Dubious Honor

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Wanted: Scientists who can develop novel antibiotics

A few years ago, the Centers for Disease Control and Prevention (CDC) put out a “greatest hits” list of antibiotic-resistant pathogens. More recently, in late February, the World Health Organization (WHO) followed suit with a dirty-dozen list of 12 “superbugs,” which was composed mostly of potentially fatal microbes that are becoming increasingly impervious to the drugs that once easily killed them. These are the bacteria WHO believes represent the greatest microbial threat to human health, and the list was compiled in the hopes of providing direction — and motivation — to pharmaceutical researchers who are desperately needed to develop new antibiotics.

Investing in antibiotic development now will save lives later.

A quick primer on antibiotic resistance: Antibiotics kill living organisms called bacteria, but like all living organisms, bacteria can evolve. Just as giraffes evolve longer and longer necks that allow them to eat more and more leaves, so too do bacteria evolve resistance to antibiotics. For example, a resistant bacterium can evolve the ability to spit out the drug before it has a chance to kill it, or it can evolve structural changes to its cell wall that make it impossible for the drug to attach to it.

One superbug, classified as an “urgent threat” by the CDC and a “high priority” by WHO, stands out from the pack. Unlike the other bacteria in these lists, an untreated infection with this bug isn’t thought to be deadly — but it still wreaks enough havoc to merit special attention from such esteemed bodies as the CDC and WHO. That bug is Neisseria gonorrhoeae, and you have one guess what disease it causes. (If you said gonorrhea, you guessed right.) Continue reading →