Chattanooga health officials say they need more blood donors because the Zika virus is forcing authorities in certain parts of the U.S. to halt blood donations in those areas.
Florida officials announced Friday they are halting blood donations in Miami-Dade and Broward counties because the Zika virus apparently has spread into the local mosquito population. Four people – one woman and three men – have been identified as carrying the virus, apparently the first cases transmitted by mosquitoes in the continental United States.
Before Friday, some 1,650 people in the U.S. had been diagnosed with the virus, but they apparently were infected when they traveled to countries where it is widespread, including much of the Caribbean and Central and South America.
Health officials have been predicting the virus would appear in the U.S. Zika is spread when a certain type of mosquito bites an infected person and then transfers the virus to another person with another bite. As the number of people in the U.S carrying the virus rose, the odds increased that one of them would be bitten by a mosquito and infect the local mosquito population.
The virus can also spread through sexual activity.