*Updated on 11/01/2016 at 5:00 PM EST
An investigation into four non–travel-related Zika cases led both Centers for Disease Control and Prevention (CDC) and Florida Department of Health (DOH) officials to confirm what many had feared: active Zika transmission in Florida. Since the first case was identified on July 19, 2016, there have been more than 70 cases of locally acquired Zika in Miami-Dade, Palm Beach, Broward, and Pinellas counties in Florida. As a result of active Zika transmission, the US Food and Drug Administration (FDA) has urged blood establishments in the infected areas to stop blood collection efforts. More recently, the FDA approved the release of the genetically modified Aedes Aegypti mosquito, OX513A, in Key Haven, Florida, in an effort to reduce Zika-carrying mosquito prevalence.
In a teleconference, Tom Frieden, MD, MPH, director of the CDC, confirmed that “Zika is here.” The four Florida cases are the first locally acquired cases of Zika in the United States. The CDC is working closely with the DOH to investigate the geographical origins of each case presenting with non–travel-related Zika in Florida. The investigation will use epidemiological analysis to report the origin of infection.
Zika is confirmed to cause microcephaly and other neurological complications in developing fetuses. However, the CDC is not advising women residing in Florida to postpone pregnancy; the CDC calls it a “highly personal decision.” Nonetheless, the CDC recommends that all pregnant women, including those who do not present with Zika-like symptoms, be tested for the Zika virus, “even if the odds [of infection] are low.” Because Ae. aegypti mosquitoes, which transmit Zika, only travel around 150 meters in a lifetime, active Zika transmission in these areas is a “focal problem that needs to be addressed locally.” Based on past transmission of mosquito-borne viruses in Florida, Dr. Frieden notes that local Zika transmission within the state is “not unexpected.” According to the CDC, active Zika transmission has been ongoing in Florida since early July. However, efforts to confirm local Zika transmission require extensive investigation through testing of the Zika vector, Ae. aegypti, which is difficult. Dr. Frieden described the process as “looking for a needle in a haystack.” Thus far, there have been approximately 3,132 travel-related cases of Zika in the United States, and now 92 locally acquired cases of Zika-infected individuals in Florida. The Florida DOH reports that a total of 90 of the total number of Zika-infected individuals in the state are pregnant women.