STD Awareness: Is There a Vaccine for Syphilis?

Before antibiotics, syphilis was the most feared sexually transmitted disease (STD) out there. It was easy to get, quack cures were ineffective and often unpleasant, and it could lead to blindness, disfigurement, dementia, and even death. Syphilis rates were highest during World War II, and plummeted when penicillin became widely available later in the 1940s. By 2000, syphilis rates hit an all-time low, and many scientists thought the United States was at the dawn of the complete elimination of syphilis.

What a difference an antibiotic makes. Image: CDC

Unfortunately, it soon became apparent that syphilis wasn’t ready to go out without a fight. Since 2000, syphilis rates have nearly quadrupled, climbing from 2.1 to 7.5 per 100,000 people by 2015 — the highest they have been since 1994. If you look at the above graph, you might think syphilis rates have been pretty stable over the past 20 years — but if you zoom in, the fact that we’re in the midst of an epidemic becomes more clear.

After hitting an all-time low in 2000, syphilis rates have been increasing nearly every year since.

The epidemic is disproportionately affecting men who have sex with men (MSM), with Arizona seeing a higher-than-average syphilis rate in this group. Additionally, syphilis rates are climbing among women, who have seen a 27 percent bump between 2014 and 2015. And, since women can carry both syphilis and pregnancies, a rise in syphilis in this population also means a rise congenital syphilis (the transmission of syphilis from mother to fetus), which causes miscarriages, stillbirths, preterm births, neonatal death, and birth defects. Ocular syphilis — that is, syphilis infections that spread to the eyes and can lead to blindness — is also on the rise.

Men, women, babies — no one is immune to the grasp of syphilis. Continue reading

Why Do Newborns Need the Hepatitis B Vaccine?

The first vaccine a baby receives — within hours or days of birth — protects them from hepatitis B virus (HBV). In a lot of people’s minds, HBV is associated with drug use and sexual activity — which stigmatizes people who have been infected with HBV or are carriers of the virus. Unfortunately, this stigma causes a lot of people to question why babies even need to be vaccinated against it, often pointing to “Big Pharma” conspiracy theories. A lot of other people are put off by the misconception that the HBV vaccine is made with human blood (it’s not).


May is Hepatitis Awareness Month, a time to learn about a childhood vaccine that’s saved millions of lives.


There are perfectly good reasons to vaccinate babies against HBV, mainly that HBV is the leading cause of liver cancer, itself one of the Top 10 types of cancer worldwide. Nine out of 10 infants born to a mother who is an HBV carrier will develop chronic infections and become carriers themselves — and a quarter of them will die prematurely of liver disease. Babies who develop chronic HBV infections are 63 times more likely to develop liver cancer than non-carriers, a connection that is 2 to 3 times stronger than the link between smoking and lung cancer.

When it comes to HBV, age at infection matters. Most people with chronic HBV infections are exposed at birth or in early childhood, when they are most likely to develop chronic, lifelong infections — whereas only 2 to 6 percent of infected adults will develop chronic infections, with only 15 percent of them eventually dying from liver disease. The fact that chronic infection risk is inversely correlated with age at infection means that birth is the time when a child is the most vulnerable to this virus — hence the importance of vaccinating as early as possible. Continue reading

STD Awareness: Gonorrhea’s Latest Dubious Honor

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

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: Sexual Transmission of Zika Virus

Zika

Zika virus. Image: Cynthia Goldsmith, CDC

I first heard of Zika virus in an epidemiology class, when another student made on offhand remark: “Did you know Zika virus can be transmitted sexually?” Ever vigilant for material for the STD Awareness column, I excitedly scribbled the name of the virus in my notes. But upon further investigation, I found that there were only a couple of documented cases of the sexual transmission of this virus that no one had heard of, and decided there was no reason to freak people out about yet another potential STD when rates of more common STDs, like chlamydia and gonorrhea, were on the upswing.

A year later, Zika virus was splashed across headlines on a daily basis, mostly for its newfound association with birth defects, but also in light of revelations that it could be transmitted by sex.


Access to condoms and reliable contraception is more vital than ever.


While Zika virus is usually transmitted by mosquito bites, the discovery that it can be sexually transmitted made it the only known virus that could be spread both sexually and by mosquitoes. It’s also the only known mosquito-borne virus that can cross the placenta to harm a fetus. Like several other viruses, including CMV and rubella, Zika is implicated in serious birth defects. But many health authorities worry that its potential as a sexually transmitted pathogen is dangerously underestimated. As of August 31, there have been 23 confirmed sexually transmitted cases of Zika virus in the United States — but sexual transmission will rise as the virus jumps into local mosquitoes, which will also make it difficult or impossible to tell if a sexually active Zika patient got the virus from sex or directly from a mosquito.

Earlier this year, sexually transmitted Zika virus in Texas made headlines, with many journalists incorrectly proclaiming it the first known case of sexual transmission. In fact, Zika’s sexual transmission was first documented in 2008, before “Zika” was a household name and the married couple who published their experience in a scientific paper thought they could share their STD status in relative obscurity. Despite referring to themselves as “Patient 1” and “Patient 3,” a science reporter quickly figured it out and (with their permission) revealed their identities in a 2011 article — still years before Zika-bearing mosquitoes would hit the Americas and trigger a microcephaly epidemic that propelled the virus to infamy. Continue reading

STD Awareness: What Does “Congenital Syphilis” Mean?

Treponema pallidum, the bacteria that causes syphilis

Treponema pallidum, the bacteria that causes syphilis

Congenital syphilis, for centuries a leading cause of infant mortality, is often thought of as an antique affliction, relegated to history books — but it is on the rise again. Between 2012 and 2014, there was a spike in congenital syphilis rates, which increased by 38 percent and are now the highest they’ve been in the United States since 2001. As of 2014, the last year for which we have data, more babies were born with syphilis than with HIV.

The word “congenital” simply means that the baby was born with syphilis after being infected in the womb. When an expecting mother has syphilis, the bacteria that cause the disease can cross the placenta to infect the fetus — and will do so 70 percent of the time. As many as 40 percent of babies infected with syphilis during pregnancy will be stillborn or will die soon after birth. It can also cause rashes, bone deformities, severe anemia, jaundice, blindness, and deafness. Congenital syphilis is especially tragic because it’s almost completely preventable, especially when expecting mothers have access to adequate prenatal care and antibiotics. Penicillin is 98 percent effective in preventing congenital syphilis when it is administered at the appropriate time and at the correct dosage.


More babies are being born with syphilis — but this trend can be reversed with wider access to prenatal care.


Incidence of congenital syphilis is growing across all regions of the country, but rates are highest in the South, followed by the West. Rates have also been increasing across ethnic groups, but, compared to white mothers, congenital syphilis rates are more than 10 times higher among African-American mothers and more than 3 times higher among Latina mothers, illustrating the need to increase access to prenatal care for all expecting mothers — and to ensure that this prenatal care is adequate.

Anyone receiving prenatal care should be screened for syphilis at their first visit, and some pregnant people — including those at increased risk or in areas where congenital syphilis rates are high — should be screened a second time at the beginning of the third trimester and again at delivery. Continue reading

STD Awareness: June Is National Congenital Cytomegalovirus Awareness Month

CMVPop quiz: Can you name the virus that most commonly infects developing fetuses when they are still in the womb?

Here’s a hint: June is National Congenital Cytomegalovirus Awareness Month.

In case that clue didn’t make it obvious enough, I’ll tell you the answer. The most common infection among developing fetuses is caused by a virus you might not have heard of: cytomegalovirus, or CMV. Around 30,000 children are born with this infection every year, and some of these babies will go on to develop serious problems because of it. National Congenital Cytomegalovirus Awareness Month is a time to learn about how CMV can affect pregnancy.


Cytomegalovirus can damage developing brain cells early in an embryo’s gestation.


This year, it might be of even greater interest, given the parallels that can be drawn between CMV and Zika virus, the emerging pathogen that has been dominating headlines lately. First of all, both CMV and Zika virus can be transmitted sexually, though they are not the first things you think of when the topic of STDs comes up, as they are overshadowed by more famous sexually transmitted viruses like herpes and human papillomavirus. While many of us are infected with CMV as children, we can also be infected as adults, often through sexual transmission — the virus can be found in cervical and vaginal secretions, saliva, and semen. The sexual transmission of Zika virus is not as well understood, but we know it can be found in semen, and there are documented cases of men passing the virus to sex partners through vaginal and anal intercourse. It might even be transmitted from a male to a partner by oral sex.

Second of all, both CMV and Zika virus are associated with birth defects. However, while the connection between CMV and birth defects has been known to us for decades, it was only in April that the Centers for Disease Control and Prevention concluded that Zika virus can cause fetal brain defects (though we’re still waiting for conclusive proof). Microcephaly is probably the most infamous of the birth defects associated with Zika virus, as well as CMV, but it’s not well defined. When you get down to it, though, microcephaly just refers to an abnormally small head, which itself might be indicative of a brain that has failed to develop fully. Continue reading