A third case of the mosquito-borne Zika virus has been found in Tennessee, state health officials said Thursday, but they say there is currently no serious threat to the general public from the virus.
In a phone conference Thursday from Nashville, State Department of Health Commissioner Dr. John Dreyzehner said all three people infected with the disease appear to have contracted it while vacationing in a country where the virus is widespread. He said there are no indications that mosquitoes in the state are carrying the virus.
The latest case was discovered in Rutherford County. The two earlier cases were in East Tennessee and in Shelby County, according to health officials.
About 80 percent of the time, people infected with the virus are not even aware of it, according to state epidemiologist Dr. Tim Jones. The other 20 percent would notice a mild rash, he said.
"For the great majority of people, the Zika virus is not a threat," Jones said.
The primary risk is for pregnant women, who are at risk for microcephaly, said Deputy Commissioner for Population Health Dr. Michael Warren. A number of women in Brazil, where the virus is widespread, have given birth to children with smaller-than-normal skulls and brains, which can cause developmental problems, seizures and difficulties with vision and hearing, Warren said.
He said women who are pregnant should avoid travel to countries where the virus is common, including the Caribbean and Central and South America. If a pregnant woman has to visit those countries, "wear mosquito repellent and avoid areas where mosquitoes might be present," Warren said.
Pregnant women should also stay in lodgings that have screens and air-conditioning, he said.
About one out of every 100 pregnant women who become infected with the Zika virus will end up with microcephaly, Warren said.
Between 45 and 50 cases of microcephaly are seen in Tennessee each year, unrelated to the Zika virus, he said.
The virus can also be transmitted through sex, but only from men to their partners, Warren said. He advised women who are pregnant to avoid having sex with anyone who is infected with the virus or is showing symptoms of it.
The state now has the ability to do its own testing for the virus, instead of sending blood samples elsewhere. "We now have the capacity to test people at the state lab, which will allow us to react faster," Jones said. Previously, blood samples in suspected cases were sent to the federal Centers for Disease Control and Prevention in Atlanta to be analyzed.
Taking steps to avoid and kill mosquitoes locally helps prevent the spread of the virus, health officials said. The infection spreads when someone who has the virus is bitten by a mosquito which then bites someone else, transmitting the disease. But there have been no reports of that happening with any of the three Zika cases in Tennessee.
The mosquito is only active in the daytime and typically travels no more than 250 yards from where it was infected, so wearing long-sleeved clothes, using insect repellent and staying away from areas where mosquitoes are visible will all prevent infection.
Similarly, getting rid of areas where mosquitoes breed will reduce the overall mosquito population. "Do a survey of your yard and eliminate all standing water - things like bottle caps or bird baths," state epidemiologist Jones said.