Photo courtesy of
Muhammad Mahdi Karim
Officials have announced what is likely the first known occurrence of local mosquito-borne Zika virus transmission in the continental US.*
Fourteen cases of Zika virus in 2 Florida counties are believed to have been caused by bites of local Aedes aegypti mosquitoes.
The Florida Department of Health (DOH) believes that active transmission of the Zika virus is only occurring in a small area in Miami-Dade County.
The US Centers for Disease Control and Prevention (CDC) has recommended that women who are pregnant or thinking of becoming pregnant avoid unnecessary travel to the impacted area. The agency has also issued a guidance for people living in or traveling to the area.
“All the evidence we have seen indicates that this is mosquito-borne transmission that occurred several weeks ago in several blocks in Miami,” said Tom Frieden, MD, director of the CDC.
The exact location is within the boundaries of the following area: NW 5th Avenue to the west, US 1 to the east, NW/NE 38th Street to the north and NW/NE 20th Street to the south. This is about one square mile.
Protecting the blood supply
The US Food and Drug Administration (FDA) has requested that all blood centers in Miami-Dade and Broward counties stop collecting blood immediately.
Blood centers in these counties can resume blood collection once they begin testing each unit of blood with an available investigational donor screening test for Zika virus RNA or once they implement the use of an approved or investigational pathogen inactivation technology.
The FDA also recommended that blood centers in nearby counties implement the same precautions as soon as possible to help maintain the safety of the blood supply. The agency has encouraged screening of the blood supply in regions of the US at risk of local mosquito-borne Zika transmission.
The FDA said it is working with companies that are making blood screening tests available under an Investigational New Drug (IND) application to ensure these companies are ready to expand testing as needed. Blood collection centers may choose to participate in testing under an IND even in the absence of local mosquito-borne transmission of Zika virus.
Florida/CDC response
Florida state officials have implemented mosquito control measures and a community-wide search for additional Zika cases. Thus far, Florida’s DOH has conducted testing for the Zika virus in more than 2300 people statewide.
The DOH has activated the Joint Information Center within the State Emergency Operations Center to ensure the area impacted by local transmission of the Zika virus has coordinated access to information and resources.
The DOH has also begun the process of contracting with commercial pest control companies to enhance and expand mosquito mitigation and abatement, including increased spraying, in the impacted area.
Earlier this year, Florida’s governor, Rick Scott, directed the State Surgeon General to activate a Zika Virus Information Hotline for Florida residents and visitors. The number for this hotline is 1-855-622-6735.
The CDC said it is coordinating with Florida officials leading the ongoing investigation into local transmission of the Zika virus. At the state’s request, the CDC sent a medical epidemiologist to provide additional assistance.
Governor Scott has also asked the CDC to activate a CDC Emergency Response Team to assist the DOH and other partners in their investigation, sample collection, and mosquito control efforts.
To date, the CDC has provided Florida with more than $8 million in Zika-specific funding and about $27 million in emergency preparedness funding that can be used for Zika response efforts.
“We have been working with state and local governments to prepare for the likelihood of local mosquito-borne Zika virus transmission in the continental United States and Hawaii,” said Lyle Petersen, MD, incident manager for CDC’s Zika virus response.
“We anticipate that there may be additional cases of ‘homegrown’ Zika in the coming weeks. Our top priority is to protect pregnant women from the potentially devastating harm caused by Zika.”
For more information about the Zika virus, visit http://www.cdc.gov/zika/.
*This story was updated on August 1.