STD Awareness: New STDs on the Block, and STDs Making a Comeback

Lately, a lot of us have had tunnel vision when it comes to infectious diseases. We talk about how long the virus that causes COVID-19 can live on various surfaces, even though other viruses can live on those same surfaces for even longer. We wonder if it can be sexually transmitted, while there are dozens of other bugs out there that are even more easily passed through sexual contact. There are more microbes out there than just the one that causes COVID-19, and we need to be mindful of their risks, too.

Last month, the New England Journal of Medicine published a piece about “old-timey” STDs that are making a comeback (think shigellosis), newer STDs to hit the scene (think Zika virus), and “classic” STDs that are finding new ways to harm us (think antibiotic-resistant gonorrhea). Let’s meet this rogues’ gallery of sexually transmitted bugs.

Shigella bacteria. Image: CDC

Shigellosis is a diarrheal disease caused by Shigella species of bacteria, which can be found in abundance in feces — making it relatively easy to pick up these bugs during sexual encounters involving oral-anal contact (“rimming” or anilingus). While Shigella are mostly transmitted through nonsexual routes, researchers have discovered that sexually transmitted shigellosis is much more likely to be resistant to multiple antibiotics — making them a serious threat.

Reduce your risk by practicing good hand hygiene and keeping a clean kitchen and bathroom; using condoms and dental dams during sex. Continue reading

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

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

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: Mycoplasma genitalium

“I’m not small, I’m just streamlined!” Image of Mycoplasma genitalium adapted from American Society for Microbiology.

In November and December of last year, headlines touting a “new” STD made an ever-so-minor flurry across the Internet. CNN referred to it as “mycoplasma genitalium, or MG” — Mycoplasma genitalium is the name of the teardrop-shaped bacteria that can cause several diseases in the urinary or reproductive tracts, such as urethritis and pelvic inflammatory disease.

M. genitalium is the smallest living organism known to science, having “devolved” from more complex organisms — but that doesn’t mean it can’t pack a punch! While these bacteria have surely been around for millennia, we only discovered them in the 1980s. Since then, we’ve known that M. genitalium fits the profile of a sexually transmitted pathogen — the only reason it made the news last year was that a team of British researchers published further evidence that this bug is indeed sexually transmitted and capable of causing disease.


Genital mycoplasmas can be cured — but a doctor needs to know what she’s looking for in order to prescribe the correct antibiotic!


An infection with M. genitalium could more generally be called a “genital mycoplasma.” The term “genital mycoplasmas” refers to a category of several different species of sexually transmitted bacteria, most notably Mycoplasma genitalium, but also less common species, such as Mycoplasma hominis, Ureaplasma urealyticum, and Ureaplasma parvum. M. genitalium is considered an “emerging pathogen,” because it is only over the past couple of decades that technology has allowed us to study these bacteria, along with other genital mycoplasmas.

Risk factors for infection include multiple sexual partners and not using condoms during sex. It is thought that most people with an M. genitalium infection don’t have immediate symptoms — 94 percent of infected men and 56 percent of infected women won’t notice anything amiss. That doesn’t mean it can’t do damage. Continue reading

STD Awareness: 10 Sexually Transmitted Diseases You Probably Don’t Know About

Giardia lamblia, a microbe that can be transmitted sexually. Image: NIH

Gonorrhea and chlamydia go back to antiquity. Syphilis took hold in Europe during the late 15th century. Herpes wasn’t on most people’s radars until the early 1980s, and human papillomavirus (HPV) was relegated to relative obscurity in the popular imagination until the HPV vaccines made their debuts less than a decade ago.


Have you heard of CMV, chancroid, or donovanosis?


But there are still a handful of sexually transmitted diseases (STDs) that you might not know about. These include incredibly common infections, as well as those caused by pathogens you might have heard of but probably don’t associate with sexual transmission. They also include infections that are very rare here in Arizona but are much more common in other parts of the world. They all deserve a closer look.

10 Trichomoniasis: What is the most common curable STD? You might guess that it’s chlamydia or gonorrhea, but according to the Centers for Disease Control and Prevention, it’s trichomoniasis (also known as trich, pronounced “trick”). This infection is caused by Trichomonas vaginalis, a single-celled parasite that is actually pretty cute as far as microbes go. What’s not so cute is its propensity to attach to your cells and degrade their surfaces, which on a large scale can produce unpleasant symptoms. Continue reading