What you should keep in mind before reporting on Zika virus

Published on
January 27, 2016

Take a viral epidemic with a possible link to birth defects and add sex. It’s the recipe for panic and intrigue and lots of media attention. Now that a case of sexually-transmitted Zika has been announced in Dallas, expect to see lots of reports about the quickly-spreading virus. Here are a few things to keep in mind when reporting on Zika.

The Zika virus can be transmitted sexually, but there’s only one such report in the medical literature. As of February 2, there could be a second. Texas officials announced that a Dallas resident who traveled to Venezuela returned home and transmitted the virus to their partner through sex. We’re waiting for more information about how this was confirmed by the Centers for Disease Control and Prevention who until now have mentioned very little about sexual transmission of Zika. While the infection can be spread through sex and blood transfusions, experts say those modes of transmission are very rare compared to the number of people infected by mosquitoes. The one case of sexually-transmitted Zika that has been reported in the literature involves a mosquito researcher from Colorado who became infected with the Zika virus during a field trip to Senegal. He returned home and had sex with his wife the next day. He developed symptoms about a week later and his wife - who hadn't left the U.S. since 2007 - also fell sick with the virus. The man wrote about  his experience in a medical journal and along with other scientists said the virus was likely spread to his wife during sex but that transmission through other bodily fluids such as saliva couldn’t be ruled out.

A traveler in Houston wasn’t the first case in the U.S. Some news outlets, including the news section of the British Medical Journal, reported that a person in Houston was the first American traveler to be diagnosed with Zika virus. After I read it in one outlet, this nugget of misinformation popped up all over the place. But the first case of Zika acquired in the U.S. was the Colorado case mentioned earlier. To find this case report, I searched PubMed using the search terms “Zika virus USA.” There’s also a report of a man in Tahiti who was infected with Zika during an outbreak on the island in 2013. It’s not reported that he transmitted the virus to anyone through sex but the virus was found in his semen providing more evidence that the virus could be transmitted sexually.

The link between Zika virus and birth defects isn’t proven, it’s suspected. Since the outbreak in Brazil began last May, health officials say an estimated 4,000 babies have been born with a birth defect called microcephaly, in which the brain and skull are smaller than normal. Depending on who you ask, that’s a 10-20 fold increase (the Pan American Health Organization says it’s a 20-fold increase in Brazil’s microcephaly rate while the Centers for Disease Control and Prevention say it’s a 10-fold increase). Either way, until scientific studies prove the virus causes the birth defect, the link between the two is suspected. Microcephaly can be caused by a bunch of infections including syphilis and herpes as well as toxins such as alcohol and cigarette smoke. Some children are born with microcephaly because of genetic abnormalities such as Downs syndrome. Epidemiologists will have to rule out those other causes when investigating any increase in microcephaly in Brazil.

Zika's also been linked to another neurologic disease, this time in adults. In parts of northern Brazil, doctors are reporting unusually high numbers of Guillain-Barre syndrome, a condition where the immune system attacks the nervous system and causes muscle weakness and paralysis. The connection between Zika virus and Guillain-Barre syndrome is also suspected, not proven.

The data on the number of infections and birth defects is sketchy. You’ve probably seen reports that between half a million and 1.5 million infections have occurred in Brazil and that 4,000 babies have been born with microcephaly. But the true number of infections is anyone’s guess. That’s because of poor disease surveillance systems and also because the virus is mostly a mild nuisance causing symptoms that many people will dismiss without going to see a doctor. An estimated 80 percent of people who become infected with Zika won’t experience any symptoms at all. The data on the number of babies born with microcephaly is also sketchy. There’s a debate raging in the scientific community where some are arguing that we might be seeing more cases of microcephaly because healthcare workers are being more vigilant. Experts investigated 732 cases of microcephaly in Brazil and found about half of those cases did not have microcephaly. So far, 270 babies have been confirmed to have the birth defect (that’s still an increase from the 156 cases reported in Brazil each year from 2010 to 2014). Six of those babies are known to have been infected with the Zika virus. That leaves hundreds of cases that haven’t been confirmed or linked to the infection.

Zika virus probably won’t cause big outbreaks in the U.S. While that’s true, some Americans are at higher risk of infection and some communities are more likely to see outbreaks than others. My reporting as a National Health Journalism Fellow was on tropical diseases in the U.S. We found that these infections, which include mosquito-borne viruses such as West Nile virus and chikungunya, affect Americans of all backgrounds but people living in poverty are more likely to be infected, to go longer without getting a diagnosis, and are more likely to die from the infection. Because there isn’t any medicine that can treat or prevent Zika virus, the only way to avoid infection is to avoid mosquitoes. That sounds straightforward enough but insect repellent, secure housing and a clean neighborhood aren’t privileges enjoyed by everyone. Think about the low-income communities in your town where families have to prioritize groceries over repellent and where garbage piles up, making it easier for mosquitoes to breed. In the 2012 West Nile virus outbreak that sickened 1,868 and killed 89 in North Texas, poor neighborhoods were more likely to be infested with mosquitoes and people living in poverty were more likely to die from the infection.

Dig deeper into the health advice. Health officials in at least four countries are advising women to delay getting pregnant until the outbreak is over. But how realistic is that advice? About half of all pregnancies in Latin America are unplanned and women face significant hurdles to accessing reproductive health care. In El Salvador, where officials are suggesting women delay pregnancy until 2018, abortion is illegal. There are ethical and moral components to this outbreak and it’s important to explore the health information doled out by experts. Don’t just tag it onto the end of your reporting. Question its feasibility, especially for vulnerable groups and people living in poverty.

I hope this helps your reporting on Zika virus. If you have any questions, feel free to email me at syasmin@dallasnews.com.

Dr. Seema Yasmin is a staff writer at The Dallas Morning News and professor of public health at the University of Texas at Dallas. She was formerly an epidemiologist at the Centers for Disease Control and Prevention and a 2015 National Health Journalism Fellow.

[Photo by gagneet parmar via Flickr.]