Story highlights CDC says don't donate sperm or use donated sperm because of Zika

Test to screen semen for Zika virus is still experimental and not yet available

The last local case of Zika was reported on December 21, 2016

(CNN) Sperm donated in three Florida counties since June 15 may be infected with the Zika virus, the United States Centers for Disease Control and Prevention cautioned Monday.

"When semen is donated it can be stored frozen for periods of time. It does not necessarily inactivate Zika, so it could be stored in tissue banks, used subsequently and people should be made aware," said Dr. Peter Marks, director of the Center for Biologics Evaluation and Research at the US Food and Drug Administration. He went on to say having this information can help individuals make informed decisions and they "might want to use these donations from other sources."

Sources other than the 12 sperm banks in Miami-Dade, Palm Beach and Broward counties of Florida, that is.

The agency had previously designated only Miami-Dade County as an area to take precautions after the first local transmission of the virus in the continental United States was confirmed in the Wynwood neighborhood of Miami in July. The area was declared Zika free in December

However, the CDC is now warning anyone in Palm Beach and Broward counties to also consider themselves at an increased risk for the virus. This applies to anyone who has traveled to or between these three counties since June 15, 2016, a change from previous guidance that designated June 29 as the start of the increased risk period.

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