Local Transmission of Zika in Miami; CDC Issues First US Travel Advisory

During a telebriefing on August 1, 2016, the CDC announced that the CDC issued a travel advisory and testing recommendations for people who traveled to or live in Wynwood, a neighborhood north of downtown Miami, on or after June 15, 2016, the earliest known date that an individual with Zika became infected. According to the Florida Department of Health (FDH), the14 people confirmed to be infected with the Zika virus likely contracted it through a mosquito bite sustained in the Wynwood neighborhood. The FDH believes local transmissions are still only occurring in the same square mile area of Miami.


According to Dr. Denise Jamieson, Co-Lead of the Pregnancy and Birth Defects Team on the CDC Zika Virus Response Team, the CDC advised pregnant women not to travel to Wynwood and recommends “that women who are considering pregnancy not get pregnant for up to eight weeks after returning from that area.” The CDC also recommended that pregnant women who traveled to this area on or after June 15th talk with their health care provider to be tested for Zika and that pregnant women without symptoms of Zika who live in or frequently travel to this area be tested for Zika in the first and second trimesters of pregnancy. Male and female sexual partners of pregnant women who live in or have traveled to this area should consistently and correctly use condoms or other barriers against infection during sex for the duration of the pregnancy. Everyone coming back from locations where Zika is spreading should use mosquito repellent for three weeks to protect their family in case a mosquito bites them and then gets infected.


The CDC recommends all pregnant women throughout the U.S. be assessed for possible Zika virus exposure during each prenatal care visit and tested according to CDC guidance. Men with symptoms of Zika should wait at least six months before trying for a pregnancy. All pregnant women in the potential range of the mosquito Aedes aegypti, which covers 25 U.S. states, should use mosquito repellent.


The FDH has conducted testing for the Zika virus for more than 2,300 people statewide. Since the FDH began its investigation into possible local transmissions of Zika on July 7th, more than 200 individuals in Miami-Dade and Broward counties have been tested for the virus who live or work within 150 meters (the Aedes aegypti mosquito does not travel more than 150 meters in its lifetime) of the individuals that have already been confirmed with likely mosquito-borne transmissions. The FDH has been testing individuals in three locations in Miami-Dade and Broward Counties for possible local transmissions through mosquito bites. Based on the FDH’s investigations, two locations have been ruled out for possible local transmissions of the Zika virus. The FDH believes local transmissions are still only occurring in the same square mile area of Miami. According to CDC Director Tom Frieden, M.D., M.P.H., “Florida is following the recommendation of going to about five times that distance [150 meters] to have a buffer zone in a one-mile radius around the very specific area where the virus has been spreading.”


The FDH has 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. According to CDC Director Tom Frieden, M.D., M.P.H., “In Miami, aggressive mosquito control measures don't seem to be working as well as we would have liked. This may happen for at least one of three reasons. First, it's possible that the mosquitoes there are resistant to the insecticides that have been used. Second, it's possible that there are what we call cryptic breeding places or small amounts of standing water where mosquitoes continue to hatch. And third, it's possible simply that this is a very difficult mosquito to control, particularly in a complex urban environment like the one north of downtown Miami. In any case, the vector control expert CDC sent as part of the CDC Emergency Response Team will work with Florida authorities to begin resistance testing so we can determine whether mosquitoes in this area are susceptible to the insecticides being used. That testing, however, is complex and takes at least a week and sometimes three weeks or more. So the mosquito control experts in Florida who have extensive experience with mosquito control as well as our own mosquito control experts are meeting intensively to outline additional measures that may be taken to reduce mosquito populations.”


See the CDC Telebriefing Transcript


Also see the Florida Governor’s Announcement


Also see the CDC’s maps showing the geographic distribution of Aedes aegypti in the United States


See also Medical Law Perspectives, May 2016 Report: Vectors of Risk: Zika, West Nile, and Similar Tick and Mosquito Disease Litigation


See also Medical Law Perspectives, January 2015 Report: Mothers, Infants, and Obstetrical Injuries: Labor and Delivery Liability


See also Medical Law Perspectives, April 2014 Report: Danger and Controversy: Lyme Disease Liability Risks



See also Medical Law Perspectives, March 2014 Report: Blood Draws, Testing, Transfusions: Venipuncture Injury, Inaccurate Results, Tainted Blood - The Liability Risks