The U.S. Centers for Disease Control and Prevention (CDC) has confirmed that an Arkansan has tested positive for the mosquito-borne Zika Virus.
According to the CDC, the individual recently traveled out of the country and had a mild case of the virus. Zika virus is a relatively new disease for the Western Hemisphere. It first appeared in Brazil in May of 2015. It has since spread to 20 countries in Central and South America and the Caribbean.
While no locally transmitted Zika cases have been reported in the continental United States, there have been cases reported in returning travelers, including the first case in Arkansas.
“This particular individual is already over the symptoms and is way past the time that it would be infectious,” said Dr. Susan Weinstein, veterinarian with the Arkansas Department of Health.
Here’s what scientists say they do and do not know about the Zika virus:
How it spreads. It’s mostly mosquitoes. “I think it’s important to step back and emphasize that Zika is a mosquito-borne virus, and the overwhelming majority of cases are spread by mosquitoes,” CDC director Dr. Thomas Frieden told reporters last week.
Sometimes semen. There are two documented cases of Zika virus in a man’s semen, and one documented and one suspected case of a man infecting someone else that way. A recent case in Dallas, where officials say a traveler to Venezuela infected his sex partner.
Blood. Any virus can spread in blood, and Zika is no exception.
“It goes away from the blood within about a week,” Frieden said. That’s why, he said, “the American Association of Blood Banks issued the guidance to defer blood donations for all individuals who had traveled to an area with Zika transmission for 28 days. That was a margin of safety for blood transfusion.”
How it probably doesn’t spread. Saliva. Frieden is very careful not to say it’s impossible that Zika could spread through saliva or kissing, but Dr. Anthony Fauci, head of the National institute of Allergy and Infectious Diseases, says it is unlikely.
Urine. That’s another unknown but again, scientists say it’s unlikely. Zika is spread by mosquitoes and virologists say it would be unlikely to also be transmissible through urine.
Air. Some viruses do spread through the air. Measles is the most notorious, and flu can spread on tiny droplets that remain suspected in the air. But these viruses are very different from Zika, a flavivirus in the same family as dengue virus, which is well-studied and which does not spread in the air.
While anyone can contract the virus, doctors warn that pregnant women are most vulnerable to the effects. “We’ve had a lot of pregnant patients that are concerned about this,” said Dr. Curtis Lowery, Maternal Fetal Medicine Specialist and Chairman of the OBGYN Department at UAMS. Dr. Lowery said while the pregnant woman may show mild symptoms, the unborn child is most at risk.