An analysis of locally acquired Zika cases conducted by the CDC and the Florida Department of Health suggests more people may have been exposed to the virus than previously thought, which means semen donations could have been made by men in the Miami area who were unwittingly infected.
The CDC is warning women and couples trying to conceive about the newly identified infection risk.
Here are five things to know.
1. The newly identified risk is backdated fromto June 15, 2016, through the present. The new guidance was issued after an assessment of the local travel patterns of area residents. The CDC found evidence that some people may have traveled to Miami Beach when it was active for the mosquito-borne transmission of Zika and forgotten about it, according to NBC News.
2. This new evidence means residents of nearby Broward and Palm Beach counties could have been infected during the period of active transmission and not known about it because many people with Zika infections never display symptoms.
3. Zika can remain in the semen for months, meaning men who may have contracted Zika and not experienced symptoms could have donated contaminated semen without knowing it. The issue is further complicated by the fact that there is no way to test the donated semen supply for Zika.
"Blood donations throughout the United States are tested for Zika with laboratory testing, resulting in the removal of Zika virus positive collections in multiple states and Puerto Rico. Testing for tissue donors, including semen donors, is not currently available," said the CDC in a media statement. "CDC encourages women and their partners, in consultation with their healthcare providers, to consider this potential risk when trying to conceive. Additionally, healthcare providers should counsel their pregnant patients who might have been exposed to semen from men potentially infected with Zika virus about this risk."
4. Women who used semen from sperm banks across Miami-Dade, Broward and Palm Beach counties since June 15 should consult with their physician.
5. The CDC has yet to identify a case of Zika transmission through donated semen or a blood transfusion, according to USA Today.
In 2016, Florida recorded 1,093 travel-associated Zika cases, 279 locally acquired cases and 21 cases that were undetermined. Among all cases in the state, 278 pregnant women displayed laboratory evidence of Zika. Contracting Zika during pregnancy isn known to increase the risk of birth defects in newborns. Zika is most, most notably linked with microcephaly, which causes infants to be born with abnormally small heads.
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