The U.S. Centers for Disease Control and Prevention is investigating 14 new reported cases of Zika infections in the United States that may have been transmitted by sexual activity. Several of these cases involve a pregnant woman. The possibility of sexual transmission means that controlling the virus in the United States may be even more difficult than previously thought.
The surprisingly high number of sexually transmitted infections also means that this type of spread may not be a rare event. The CDC is asking healthcare providers to be on alert for Zika and for possible sexual transmission of it. Zika virus can be carried in semen, but there have been no reports that it can be spread from a woman to her male sexual partner, the CDC said.
As yet, only two of these cases have been confirmed, in women whose only risk factor was their sexual contact with a man who was ill and who had recently traveled to an area where Zika is present. In an additional four cases, evidence suggests Zika, but it has not been confirmed, the CDC said. Eight other cases are still under investigation. In all the cases, the male partner reported symptoms within two weeks of the female partner becoming ill.
Testing male partners for the virus is underway, according to the CDC.
In all, the United States has had an estimated 90 cases of Zika, including the 14 cases that may have been sexually transmitted. The primary way that Zika is spread is through mosquito bites and areas of the United States have already increased their mosquito eradication programs.
Zika causes a relatively mild illness, with a fever and rash that is seen in about 80% of those infected. It is believed to cause a serious birth defect called microcephaly in babies when pregnant women become infected.
There is no cure for Zika nor is there a vaccine against it.
The CDC recommends that even people without symptoms of the Zika virus should be tested after they return from affected areas. There have been outbreaks of Zika in 29 countries in the Western Hemisphere. It has also been reported in the South Pacific.