Texas health officials reported the first case of sexual transmission of the Zika virus in the USA on Tuesday.
The patient contracted the virus from a sexual partner who was ill with Zika. The sexual partner became infected while traveling to Venezuela, which has a Zika outbreak, the Dallas County Health and Human Services said.
Although scientists have known for some time that Zika can be transmitted through sex, the vast majority of cases are spread through the bite of infected mosquitoes, much like malaria or West Nile virus.
“Now that we know Zika virus can be transmitted through sex, this increases our awareness campaign in
educating the public about protecting themselves and others,” said Zachary Thompson, director of the Dallas County health department. “Next to abstinence, condoms are the best prevention method against any sexually transmitted infections.”
Although Zika infections are usually mild and deaths are rare, health authorities are concerned because of a link between the disease and a sharp increase in birth defects in Brazil. The World Health Organization declared Monday that the Zika outbreak is a “public health emergency of international concern.”
Four out of five people with Zika have no symptoms. Those who do become ill typically have mild symptoms: fever, rash, headache, joint pain and pink eye, according to the WHO.
Although more than 30 Americans have been diagnosed with Zika, these have largely been travel-related cases, which pose a relatively low risk for spreading. The continental USA is not considered to have a Zika outbreak because the virus has not become entrenched in the mosquitoes that cause the illness.
Zika is spreading among mosquitoes and residents of Puerto Rico and the U.S. Virgin Islands, as well as American Samoa.