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: Sexually Transmitted Diseases and Pregnancy

Every month since January 2011, we’ve been sharing installments of our STD Awareness series, and each month, we’ve encouraged you to protect yourself from sexually transmitted diseases (STDs) by using dental dams and condoms. But what if you’re trying to get pregnant? In that case, you’re probably not using condoms! However, it is very important that partners know their STD status — being screened and treated for STDs prior to pregnancy is a good idea for your health, and can protect your future baby.


If you and a partner are trying to get pregnant, you might consider being screened for STDs together.


When present during pregnancy, certain STDs can have negative health effects for you or your future baby (including preterm labor, stillbirth, low birth weight, pneumonia, certain infections, blindness, and liver disease), especially if they are not cured or treated in time. Receiving prenatal care can help prevent these problems, so it is important to be screened and treated for STDs prior to or early in your pregnancy.

During pregnancy, the immune system undergoes changes, which are probably necessary to ensure that the body doesn’t reject the fetus — normally, the immune system recognizes non-self cells as potential pathogens and attacks. These immune system changes might make a pregnant person more susceptible to disease. Latent viral infections, like genital warts or herpes, might come out of dormancy. Additionally, anatomical changes lead to a larger exposed area of the cervix, which is potentially more vulnerable to initial infections. Continue reading