STD Awareness: The Curious Case of Chancroid

Haemophilus ducreyi arrange themselves in parallel rows, which researchers have called “railroad tracks,” “schools of fish,” and “fingerprints.” Image: Mike Miller, CDC

Earlier this year, I asked a room full of scientists and medical professionals to raise their hands if they’d ever heard of chancroid. Everyone sat there, motionless, confused by the odd syllables I had uttered — shan kroyd. If you’ve never heard of chancroid, you’re not alone.

Chancroid is a sexually transmitted disease (STD) brought to you by Haemophilus ducreyi, a type of bacteria that can pass through microscopic tears in the skin during sexual contact. When one partner is infected, there is a 1 in 3 chance the other will become infected. An infection can cause painful sores and swollen lymph nodes, most often in the genital region. About half of people with chancroid infections will experience “buboes,” or swollen lymph glands that might rupture. Before it could be cured with antibiotics, a persistent infection could cause permanent skin damage.


Humanity can make chancroid the first STD to go extinct.


One reason you probably haven’t heard of chancroid is that, in the developed world at least, it has mostly disappeared. In fact, researchers believe chancroid can be completely wiped off the planet — which would make it the first STD ever to be forced into extinction. How amazing would that be?

Chancroid has been hopping from loin to loin since at least the days of the ancient Greeks, and was common until the 20th century, when rates began to decline. Thanks to antibiotics, U.S. chancroid rates decreased 80-fold between 1947 and 1997, all but vanishing by the late 1950s. It was virtually unheard of until there was another spike in the 1980s, correlating with the crack epidemic. But, since 1987, cases have been steadily declining. Continue reading

STD Awareness: The Surprising Sexual Transmission of Non-STDs

What is a sexually transmitted disease, or STD? If someone catches their partner’s cold during sex, is that cold an STD? According to the Office on Women’s Health, an STD is “an infection passed from one person to another person through sexual contact.” Unless the cold was passed through sexual contact, rather than mouth-to-mouth contact, it would not be considered an STD. Others say that, for an infection to be considered an STD, its sexual transmission must make it significantly more common in the population. So, a disease like the common cold would probably be just as common even if people never had sex.


MRSA, meningitis, and the virus that causes pinkeye can be transmitted sexually.


However, there are some infections, such as hepatitis C or bacterial vaginosis, whose status as official STDs is controversial. While researchers argue with one another over where to draw the line between an STD and a non-STD, let’s take a look at some bacteria and viruses that can be transmitted sexually, even though they’re not officially categorized as “STDs.”

MRSA: Methicillin-Resistant Staphylococcus aureus

MRSA bursting out of a dead blood cell. Image: Frank DeLeo, NIAID

MRSA bursting out of a dead blood cell. Image: Frank DeLeo, NIAID

You’ve probably heard of MRSA, which is pronounced “mersa” and stands for methicillin-resistant Staphylococcus aureus — a strain of bacteria that is resistant to every antibiotic in the penicillin family, as well as others. S. aureus, or “staph” for short, is the same bacteria responsible for TSS, or toxic shock syndrome, which has most infamously been associated with the use of highly absorbent tampons. But mostly, staph is a common cause of skin infections, which could be deadly in the pre-antibiotic era, but these days usually don’t raise too many eyebrows.

Unfortunately, with the emergence of MRSA, which is difficult to treat with the usual drugs, we might once again have to worry about minor skin infections blossoming into life-threatening conditions. Additionally, MRSA has found a way to hop from person to person via sexual contact, and sexually transmitted MRSA has been documented in both heterosexual and MSM (men who have sex with men) populations. Untreated, it can lead to a form of gangrene in which tissue blackens as it dies. Continue reading

STD Awareness: Is Chlamydia Bad?

chlamydiaPerhaps your sexual partner has informed you that they have been diagnosed with chlamydia, and you need to get tested, too. Maybe you’ve been notified by the health department that you might have been exposed to chlamydia. And it’s possible that you barely know what chlamydia even is, let alone how much you should be worried about it.

Chlamydia is one of the most common sexually transmitted diseases (STDs) out there, especially among young people. It can be spread by oral, vaginal, and anal sex, particularly when condoms or dental dams were not used correctly or at all. It is often a “silent” infection, meaning that most people with chlamydia don’t experience symptoms — you can’t assume you don’t have it because you feel fine, and you can’t assume your partner doesn’t have it because they look fine. If you’re sexually active, the best way to protect yourself is to know your partner’s STD status and to practice safer sex.


Chlamydia increases risk for HIV, leads to fertility and pregnancy problems, and might increase cancer risk.


The good news about chlamydia is that it’s easy to cure — but first, you need to know you have it! And that’s why it’s important for sexually active people to receive regular STD screening. Left untreated, chlamydia can increase risk of acquiring HIV, can hurt fertility in both males and females, can be harmful during pregnancy, and might even increase risk for a certain type of cancer. So why let it wreak havoc on your body when you could just get tested and take a quick round of antibiotics?

To find out just how seriously you should take chlamydia, let’s answer a few common questions about it.

Can Chlamydia Increase HIV Risk?

Chlamydia does not cause HIV. Chlamydia is caused by a type of bacteria, while HIV is a virus that causes a fatal disease called AIDS. However, many STDs, including chlamydia, can increase risk for an HIV infection, meaning that someone with an untreated chlamydia infection is more likely to be infected with HIV if exposed to the virus. Continue reading

STD Awareness: Will STDs Go Away on Their Own?

teensCan gonorrhea go away without treatment? Does chlamydia eventually clear up? Can trichomoniasis go away on its own? These are the kinds of questions people pose to Google before Google sends them here — at least that’s what I learned by looking at the blog’s stats. They’re tricky questions to tackle, and for so many reasons.

Some viral STDs stay with you for life, such as herpes and HIV. Others, such as hepatitis B and human papillomavirus (HPV), can be prevented with vaccines but cannot be cured. It’s also possible for the immune system to defeat hepatitis B virus and HPV — but in some cases, these viruses are able to settle in for the long haul, causing chronic infections that can endure for life and even lead to cancer.


Left untreated, syphilis can kill, and gonorrhea can cause infertility.


Non-viral STDs, like chlamydia and gonorrhea, can be cured. However, they usually don’t have symptoms, or symptoms can come and go, making it seem like an infection went away when it actually didn’t. You can’t know your STD status without getting tested, and you can’t self-diagnose an STD based on symptoms and then assume the infection went away when symptoms subside. Getting tested can uncover a problem and clear the way for treatment.

Nonetheless, people want to know if an STD can go away by itself — but there aren’t many studies on the “natural history” of curable STDs like gonorrhea, chlamydia, and trichomoniasis. Studying the natural course of a curable infection would require that scientists put their subjects at risk of the dangers of long-term infection, and no ethics board would approve such an experiment. 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: Can I Use Plastic Wrap as a Dental Dam During Oral Sex?

plastic wrapIf you read this blog — or any sexual health website, really — you’ll probably see dental dams getting a lot of props. A dental dam (not to be confused with a female condom) is a square piece of latex that can cover the vaginal opening or the anus. Anyone wishing to avoid the oral transmission of STDs like herpes, gonorrhea, HPV, syphilis, chlamydia, and intestinal parasites, dental-dam advocates say, should use a latex barrier. Most people, however, have probably never even seen a dental dam, and they are not widely used. Perhaps their unpopularity is related to myths about oral sex being safe sex (it’s not!); perhaps it’s due to dental dams being expensive or difficult to find.


Plastic wrap hasn’t been evaluated by the FDA for STD prevention, and no studies have assessed its effectiveness in reducing disease risk during oral sex.


Some safer-sex aficionados have found ways around that, though. They might cut the tips off of condoms and make incisions along the sides, creating little latex rectangles. An even easier and cheaper option lies in plastic wrap, which many people use as a barrier while performing cunnilingus (oral contact with the female genitalia) or rimming (oral contact with the anus). It is inexpensive, easy to find, odorless, and tasteless, and can be purchased without even a hint of embarrassment (unless perhaps your other purchases include duct tape, cucumbers, and clothes pins). And it can be pulled off the roll in sheets as long as your heart desires!

Planned Parenthood endorses the use of plastic wrap for oral sex when dental dams aren’t available. The Centers for Disease Control and Prevention and AIDS.gov both recommend plastic wrap for use during rimming. Health authorities, such as AIDS.gov and the Idaho Department of Health & Welfare, recommend non-microwavable Saran Wrap, because microwave-safe Saran Wrap has tiny pores to let out steam — which might also let viruses and bacteria through. Continue reading

STD Awareness: Is Bacterial Vaginosis a Sexually Transmitted Disease?

Not to scale: Gardnerella vaginalis under a microscope. Image: K.K. Jefferson/Virginia Commonwealth University

Gardnerella vaginalis under a microscope. Image: K.K. Jefferson/Virginia Commonwealth University

Bacterial vaginosis, or BV, is the most common vaginal infection among people 15 to 44 years of age. It’s caused by an overgrowth of harmful bacteria, such as Gardnerella vaginalis. A healthy vagina hosts thriving populations of Lactobacillus bacteria species, but when these “good” bacteria are crowded out by certain types of “bad” bacteria, the vaginal ecosystem can be shifted, causing BV.

There is a lot of confusion about BV. Is it a sexually transmitted disease (STD)? What are the symptoms? How can you avoid it?

All good questions. Let’s examine them one by one.

Is BV an STD?

The consensus seems to be that BV isn’t officially an STD, but even reliable sources have somewhat contradictory information. Planned Parenthood doesn’t list BV as an STD on their informational webpages. The Centers for Disease Control and Prevention (CDC) does include BV on their STD website, but also says that “BV is not considered an STD.”

On the other hand, the Office on Women’s Health says that “BV can … be caused by vaginal, oral, or anal sex” and that “you can get BV from male or female partners.” And there’s an entire chapter devoted to BV in the premier medical textbook on STDs, and its authors say that, while sexually inexperienced females can get BV, “the weight of evidence supports sexual transmission” of G. vaginalis, the bacteria species most famously implicated in BV infections.

The same webpage on which the CDC declared BV not to be an STD also says that it can be transferred between female sexual partners. Indeed, women who have sex with women have higher rates of BV. Since vaginal fluid could spread BV, partners can change condoms when a sex toy is passed from one to another, and use barriers like dental dams when engaging in cunnilingus (oral contact with the female genitalia) or rimming (oral contact with the anus).

What about heterosexual transmission? Continue reading