On the heels of a new study from the Centers for Disease Control and Prevention showing that Zika has increased the rate of birth defects in the United States, Florida health officials on Thursday reported three more cases of the virus that were locally acquired in Miami-Dade — two infections dating to October 2016 and the first one of 2017.
The two Zika cases from 2016 required confirmatory testing from the Centers for Disease Control and Prevention, the health department said in a press release announcing the cases. The third case involved a person who had no symptoms but donated blood in January, leading to the discovery of a past infection.
The blood donor had “multiple exposures in Miami-Dade,” the health department said, and likely contracted Zika in 2016. However, since the sample was collected this year, the health department classified it as the first local case of 2017.
There are no areas in Florida with ongoing Zika spread by mosquitoes, the health department reported.
So far in 2017, Florida has confirmed 13 cases of Zika, including four pregnant women, though all involved people who acquired the virus while traveling outside the country. In 2016, Florida’s health department reported a total of 1,325 Zika cases.
Also Thursday, the CDC released a study providing more evidence that Zika causes microcephaly, a birth defect where the baby’s head is smaller than expected, and other neurological disorders in babies born to women infected with the virus during pregnancy.
The study said, based on limited data from three states, that the U.S. saw a 20-fold increase in certain types of birth defects in 2016, the first year Zika was confirmed in the United States, compared with prior years.
The types of birth defects included microcephaly, brain malformations, eye defects, and other central nervous system problems.