STD Awareness: When Syphilis Goes North

Posted on January 13, 2020 by Anna C.

The bacteria that cause syphilis are shaped like corkscrews. Image: David Cox, CDC

Last month, a “weird” medical case made headlines. An Australian man with unexplained headaches and eye pain got a diagnosis for his mysterious symptoms when his doctors discovered he had syphilis — and the infection had spread to his head. Syphilis had caused both optic nerves to become swollen, triggering pain that worsened whenever he moved his eyes.

It might seem strange that a disease most people associate with below-the-belt symptoms can wreak havoc above the neck, but syphilis is a wanderer that can travel all over the body, sowing chaos wherever it goes.

Syphilis can quickly enter the nervous system and travel to the head, where it can cause blindness, psychiatric problems, and other trouble.

Ocular Syphilis

The bacteria that cause syphilis can be passed from one person to another through contact with a sore, which can appear on or around the mouth, genitals, or anus. Any type of sexual contact, including oral sex, can transmit these bacteria. Sores are painless, contain a highly infectious liquid, and can appear between three weeks to three months after infection. These sores aren’t always visible, which means you can’t tell if someone has syphilis just by looking at them.

Although the bacteria typically land in the mouth, genitals, or anus, they can also be sexually transmitted directly into the eye, causing redness and vision problems. After infection, syphilis sores can appear on the eyelids, tear ducts, and soft tissues around the eyes. Bacteria can also travel to the eye by entering the nervous system and blazing a trail to the optic nerve — no direct contact between the eye and a sore necessary. Continue reading →

STD Awareness: Is Bacterial Vaginosis a Sexually Transmitted Disease?

Posted on November 2, 2015 by Anna C.

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 →

STD Awareness: Antibiotic-Resistant Syphilis

Posted on November 20, 2012 by Anna C.

Treponema pallidum under a microscope. Image: Dr. Edwin P. Ewing, Jr., CDC

The image to your right, with lively yellow splotches against a pale green background, is not a long-lost Jackson Pollack piece, and the dark squiggly lines aren’t strands of paint haphazardly splattered onto a canvas. In fact, those squiggly lines are magnified images of the spiral-shaped bacteria species Treponema pallidum. You might not have heard of T. pallidum, but you’ve probably heard of syphilis, the sexually transmitted disease (STD) that these bacteria cause. While syphilis isn’t as common as other STDs, like chlamydia and HPV, it’s still out there, and occasionally communities experience outbreaks. It’s always best for sexually active people to be screened for STDs and practice safer sex.

The evolution of syphilis strains that are resistant to certain antibiotics underscores the need to use antibiotics properly.

Syphilis can inflict serious long-term damage — in fact, before the introduction of antibiotics, syphilis was the worst STD out there! Known as the Great Pox when it descended upon Europe 500 years ago, it could cause large and painful boils. Eventually, natural selection led to T. pallidum’s evolution into a form with milder symptoms, which benefited the bacteria by enabling its less boil-ridden (and presumably more attractive) human hosts to spread it farther and wider. Nevertheless, the symptoms of syphilis, if present, still include infectious sores, and when the disease goes untreated, it can cause severe, possibly fatal, damage to the nervous system.

Back in the day, there were myriad inadequate “treatments” for syphilis, ranging from straight-up quackery to the use of partially effective but toxic chemicals such as mercury. But a century ago, in 1912, a new arsenic-based chemical called Neosalvarsan was hailed as a “magic bullet.” Unfortunately, this treatment took weeks or even more than a year to administer — and had dangerous side effects. Quack treatments continued to flourish, and it wasn’t until the widespread adoption of penicillin in the 1940s that an effective cure with few side effects was available.

But natural selection endures; in fact, by flooding T. pallidum’s habitat with certain antibiotics, we’ve created an environment that favors the organism’s evolution against us. While not as immediately threatening as antibiotic-resistant gonorrhea, syphilis has been quietly evolving resistance to some of the antibiotics we use to treat it. This underscores the importance of using antibiotics correctly and emphasizing safer-sex practices, such as using latex condoms during vaginal or anal intercourse and during oral contact with a penis. Continue reading →

STD Awareness: Syphilis

Posted on September 6, 2011 by Anna C.

Treponema pallidum, the causative agent of syphilis, is seen in this electron micrograph adhering to a surface with the tapered end of its structure. Image: Public Health Image Library, CDC

When syphilis first descended upon Europe, it was seen as a new plague, and anxiety and blame coalesced around this mysterious scourge. Was it a punishment from God? Was it introduced by a hated Other? Was it caused by the stars’ alignment or the presence of “bad air”? The panic it provoked foreshadowed the hysteria that surrounded the emergence of HIV in the 1980s, as syphilitics were discriminated against, feared, or thought to have received punishment for their “unbridled lust.”

We now know that syphilis is not caused by supernatural forces, foreigners, or “bad air,” but rather by a species of spiral-shaped bacteria called Treponema pallidum, which can cause infections in the vagina, anus, urethra, or penis, as well as the lips and mouth. It is mostly spread by sexual contact — vaginal or anal intercourse, as well as oral sex — in which one person comes into contact with a syphilis sore. These sores can be hidden on the cervix or in the vagina, urethra, rectum, or mouth, making it not immediately apparent that one is infected with syphilis. Syphilis can also spread to a fetus during pregnancy. Sexually active people can reduce their risk of contracting syphilis by using latex barrier methods such as condoms or dental dams. Continue reading →