The U.S. health officials on Monday said that, the local transmission of Zika virus in Florida may have occurred as early as June 15 of last year and likely infected people who lived not only in the Miami-Dade County, but also in the two nearby counties.
The warning given by health officials mean that some men who donated semen to sperm banks in the area may not have been aware that they were at the risk of infection, and they may have donated sperm infected with the Zika virus, officials from the U.S. Centers for Disease Control and Prevention and also the Food and Drug Administration told to the reporters in a telephone briefing.
The information is concerning because Zika has been shown to cause birth defects in the babies of women who become infected while they were pregnant.
Previously, the CDC had warned of the risk of Zika in the Miami-Dade County, beginning on July 29th. But the new warning dials that the risk back to June 15, and adds in both the Broward and Palm Beach Counties, a home to the major tourist destinations of Fort Lauderdale and Palm Beach.
Zika's arrival in the Florida last summer followed the rapid spread of the mosquito-borne virus through Latin America and the Caribbean. The World Health Organization in the last year declared Zika a global health emergency because of its link in Brazil with the thousands cases of birth defect microcephaly, which is marked by the small head size and underdeveloped brains that can result in severe developmental problems.
U.S. officials said that because of frequent travel between the three Florida counties, some women may have been infected with Zika and not been aware of it, either through contracting the infection directly from a mosquito bite while visiting the Miami-Dade or through sex with an infected partner who had the infection.
And because Zika has been shown to last up to three months in the semen, it may mean some men living in the affected counties may have donated sperm without reporting they were at risk of Zika.
CDC Zika expert Dr. Denise Jamieson said that the risk applies particularly to women who became pregnant or are planning to become pregnant through the use of donor semen. She urged these women to consult their healthcare provider to discuss the sperm donation source and whether Zika virus testing is indicated.
The new warning came to light through the investigations of several cases of Zika reported by the Florida Health Department in the last year which suggested residents of Palm Beach or Broward counties may have become infected while traveling back and forth from the Miami-Dade.
According to the CDC, a total of 215 people are believed to have contracted Zika virus in Florida in the last year through the bite of a local mosquito. But since then only one in five people infected with Zika become ill, experts believe that the actual number was higher.