CDC Updates Guidance for Travel and Testing of Pregnant Women and Women of Reproductive Age for Zika Virus Infection Related to the Ongoing Investigation of Local Mosquito-borne Zika Virus Transmission in Miami-Dade County, Florida

Distributed via the CDC Health Alert Network
September 20, 2016, 11:45 ET (11:45 AM ET)
CDCHAN-00396

Summary

CDC previously issued travel, testing, and other guidance related to local mosquito-borne Zika virus transmission (active Zika virus transmission) that the Florida Department of Health (FL DOH) identified in two areas of Miami-Dade County: (1) a one-square-mile area in Wynwood, and (2) a 1.5-square-mile area in Miami Beach. CDC has updated the guidance for people who live in or traveled to these areas.

FL DOH continues to investigate active Zika virus transmission in South Florida. Investigation has shown an expanded area of active transmission in Miami Beach, now measuring 4.5 square miles, which includes the original 1.5-square-mile area.

The FL DOH has determined that active Zika virus transmission is no longer ongoing in the one-square-mile area of Wynwood after three mosquito incubation periods have passed without any new cases of local transmission. As of September 19, 2016, CDC has modified recommendations for the Wynwood area. CDC no longer recommends that pregnant women avoid travel to the Wynwood area. However, pregnant women and partners of pregnant women who are concerned about potential Zika virus exposure may consider postponing nonessential travel to all parts of Miami-Dade County, including areas without identified active transmission. For all of Miami-Dade County, CDC advises strict adherence to precautions to prevent mosquito bites.

Because the incubation period for Zika virus infection is up to two weeks and many people infected with Zika virus won’t have symptoms or will only have mild symptoms, it is likely that there are additional people infected in the population. In addition, because the diagnosis and investigation of cases may take several weeks, coupled with additional cases of local mosquito-borne Zika virus infection and increase in travel-related cases in Miami-Dade County, it is possible that other neighborhoods besides Miami Beach in Miami-Dade County have active Zika virus transmission that is not yet apparent.

For the newly expanded area of active transmission in Miami Beach, CDC advises that the recommendations outlined below be followed. As outlined in prior guidance, based on the earliest time of symptom onset and a maximal two week incubation period for Zika virus infection, these recommendations apply to pregnant women, women of reproductive age, and their partners who live in or traveled to the designated 4.5-square-mile area of Miami Beach after July 14, 2016.

This is an ongoing investigation, and FL DOH and CDC are working together to rapidly learn more about the extent of active Zika virus transmission in Miami-Dade County. CDC will update these recommendations as more information becomes available.

Recommendations

Miami Beach

1. Pregnant women should avoid travel to the identified 4.5-square-mile area of Miami Beach (http//www.cdc.gov/zika/intheus/florida-update.html) located in Miami-Dade County, because active Zika virus transmission has been confirmed in this area.

2. Pregnant women and their partners living in or traveling to the designated Miami Beach area should be aware of active Zika virus transmission and should strictly follow steps to prevent mosquito bites (https://www.cdc.gov/zika/prevention/prevent-mosquito-bites.html). Healthcare providers caring for pregnant women and their partners should visit CDC’s Zika website (https://www.cdc.gov/zika/) frequently for the most up-to-date recommendations.

3. Women and men who live in or traveled to the designated area of Miami Beach any time after July 14, 2016, should be aware of active Zika virus transmission, and those who have a pregnant sex partner should consistently and correctly use condoms to prevent infection during sex or should not have sex during the pregnancy.

4. Pregnant women with ongoing risk of possible Zika virus exposure include those who live in or frequently travel to the designated area of Miami Beach. Pregnant women with limited risk of Zika virus exposure include those who traveled to the designated area of Miami Beach or had sex without using condoms to prevent infection with a partner who lives in or traveled to the designated area of Miami Beach.

5. Pregnant women with ongoing or limited risk of exposure to Zika virus and signs or symptoms consistent with Zika virus disease should be tested for Zika virus infection based on time of evaluation relative to symptom onset in accordance with CDC guidance (https://www.cdc.gov/mmwr/volumes/65/wr/mm6529e1.htm?s_cid=mm6529e1_e).

6. Pregnant women with ongoing risk of possible Zika virus exposure who do not report symptoms of Zika virus disease should be tested in the first and second trimesters of pregnancy in accordance with CDC guidance (https://www.cdc.gov/mmwr/volumes/65/wr/mm6529e1.htm?s_cid=mm6529e1_e).

7. Pregnant women with limited risk of possible Zika virus exposure who do not report symptoms should consult with their healthcare providers to obtain testing for Zika virus infection based on the elapsed interval since their last possible exposure in accordance with CDC guidance (https://www.cdc.gov/mmwr/volumes/65/wr/mm6529e1.htm?s_cid=mm6529e1_e).

Wynwood

8. Women and men who live in or traveled to Wynwood should be aware that this location was considered an area of active Zika virus transmission from June 15 to September 18, 2016. Pregnant women who lived in or traveled to Wynwood during this time or had sex without using condoms to prevent infection with a partner who lived in or traveled to Wynwood during this time should talk to their healthcare provider about getting tested for Zika virus. People who lived in or traveled to this area during this time and have a pregnant sex partner should consistently and correctly use condoms to prevent infection during sex, or should not have sex during the pregnancy.

Additional Recommendations

9. Pregnant women and partners of pregnant women who are concerned about potential Zika virus exposure may also consider postponing nonessential travel to all parts of Miami-Dade County.

10. All pregnant women in the United States should be evaluated for possible Zika virus exposure and signs or symptoms consistent with Zika virus disease at each prenatal care visit. Each prenatal evaluation should include an assessment of signs and symptoms of Zika virus disease (acute onset of fever, rash, arthralgia, conjunctivitis), travel history, and exposure during sex to determine whether Zika virus testing is indicated. Healthcare provider should discuss the limitations of laboratory tests used to diagnose Zika virus infection with pregnant women and their partners.

11. CDC currently recommends that women with Zika virus disease should wait at least eight weeks after symptom onset to attempt conception, and men with Zika virus disease should wait at least six months after symptom onset to attempt conception with their partner.

12. Women and men with possible Zika virus exposure who do not report signs or symptoms consistent with Zika virus disease should wait at least eight weeks after last possible exposure to attempt conception.

13. Women and men with ongoing risk of possible Zika virus exposure who do not have signs or symptoms consistent with Zika virus disease and are considering pregnancy should consult their healthcare provider. Because of the ongoing risk of possible Zika virus exposure in the identified area in Miami-Dade County, healthcare providers should discuss the risks of Zika, emphasize ways to prevent Zika virus infection, and provide information about safe and effective contraceptive methods. As part of their pregnancy planning and counseling with their healthcare providers, some women and their partners living in the designated Miami Beach area might consider postponing pregnancy because of the possibility of exposure to Zika virus during pregnancy or the periconceptional period.

Background

Zika virus is spread to people primarily through the bite of an infected Aedes species mosquito (Ae. aegypti and Ae. albopictus). Zika virus can also be sexually transmitted. Zika virus infection during pregnancy is a cause microcephaly and severe fetal brain defects and has been associated with other adverse pregnancy outcomes. Most people infected with Zika virus will not have symptoms; infants with microcephaly and other birth defects have been born to women with Zika virus infection who did not report symptoms.

CDC’s testing recommendations for pregnant women are the same for those with ongoing and those with limited risk for possible Zika virus exposure who report clinical illness consistent with Zika virus disease (symptomatic pregnant women). Symptomatic pregnant women who are evaluated less than two weeks after symptom onset should receive serum and urine Zika virus rRT-PCR testing. Symptomatic pregnant women who are evaluated 2 to 12 weeks after symptom onset should first receive a Zika virus immunoglobulin (IgM) antibody test; if the IgM antibody test result is positive or equivocal (unclear), serum and urine rRT-PCR testing should be performed.

Testing recommendations for pregnant women with possible Zika virus exposure who do not report clinical illness consistent with Zika virus disease (asymptomatic pregnant women) differ based on the circumstances of possible exposure. For asymptomatic pregnant women with ongoing risk for possible exposure who are evaluated less than two weeks after last possible exposure, rRT-PCR testing should be performed. If the rRT-PCR result is negative, a Zika virus IgM antibody test should be performed 2 to 12 weeks after the exposure. Asymptomatic pregnant women with limited risk for possible exposure who are first evaluated 2 to 12 weeks after their last possible exposure should first receive a Zika virus IgM antibody test; if the IgM antibody test result is positive or equivocal (unclear), serum and urine rRT-PCR should be performed. Asymptomatic pregnant women with ongoing risk for possible exposure to Zika virus should receive Zika virus IgM antibody testing as part of routine obstetric care during the first and second trimesters; immediate rRT-PCR testing should be performed when IgM antibody test results are positive or equivocal (unclear).

Further information on the interpretation of laboratory test results and clinical management of pregnant women with laboratory evidence of possible Zika virus infection are available below.

For More Information

• Interim Guidance for Health Care Providers Caring for Pregnant Women:
  MMWR: https://www.cdc.gov/mmwr/volumes/65/wr/mm6529e1.htm?s_cid=mm6529e1_w
  Summary: https://www.cdc.gov/zika/hc-providers/pregnant-woman.html
• Fact Sheet with Testing Algorithms: https://www.cdc.gov/zika/pdfs/testing_algorithm.pdf
• Interim Guidance for Prevention of Sexual Transmission of Zika Virus:
  https://www.cdc.gov/mmwr/volumes/65/wr/mm6529e2.htm?s_cid=mm6529e2_w
• Updated information on active transmission of Zika virus from the Florida Department of Health:
  http://www.flgov.com/2016/08/01/gov-scott-florida-calls-on-cdc-to-activate-emergency-response-team-following-confirmed-mosquito-borne-transmissions/