Zika Virus and important information for Pregnant Women
Zika virus is a mosquito-borne flavivirus, in the same family as yellow fever, dengue and West Nile viruses. As of January 15, 2016, local transmission had been identified in at least 14 countries or territories in the Americas, including Puerto Rico and further spread to other countries in the region is likely.
Local transmission of Zika virus has not been documented in the continental United States. However, Zika virus infections have been reported in travelers returning to the United States. With the recent outbreaks in the Americas, the number of Zika virus disease cases among travelers visiting or returning to the United States likely will increase. An estimated 80% of persons infected with Zika virus are asymptomatic. In symptomatic infection, the incubation period is 3-12 days. Symptomatic disease is generally mild and characterized by at least two of the following:
• acute onset of fever,
• maculopapular rash,
• arthralgia, and/or
• nonpurulent conjunctivitis.
Symptoms usually last from several days to 1 week but severe disease requiring hospitalization is uncommon.
ZIKA VIRUS AND PREGNANT WOMEN
Pregnant women can be infected with Zika virus in any trimester. The incidence of Zika virus infection in pregnant women is not currently known, and data on pregnant women infected with Zika virus are limited. No evidence exists to suggest that pregnant women are more susceptible to Zika virus infection or experience more severe disease during pregnancy. Maternal-fetal transmission of Zika virus has been documented throughout pregnancy. Studies are under way to investigate the association of Zika virus infection and microcephaly and fetal losses, including the role of other contributory factors (e.g., prior or concurrent infection with other organisms, nutrition, and environment).
Planning Travel to an Area with Zika Virus Transmission
Because there is neither a vaccine nor prophylactic medications available to prevent Zika virus infection, the Centers for Disease Control and Prevention (CDC) and the Massachusetts Department of Public Health (MDPH) recommend that all pregnant women consider postponing travel to areas where Zika virus transmission is ongoing. If a pregnant woman travels to an area with Zika virus transmission, she should be advised to strictly follow steps to avoid mosquito bites. Mosquitoes that spread Zika virus bite both indoors and outdoors, mostly during the daytime; therefore, it is important to ensure protection from mosquitoes throughout the entire day. Mosquito prevention strategies, recommended for all travelers to an area with transmission, include:
• wearing long-sleeved shirts and long pants;
• using U.S. Environmental Protection Agency (EPA)–registered insect repellents;
• using permethrin-treated clothing and gear; and
• staying and sleeping in screened-in or air-conditioned rooms.
When used as directed on the product label, insect repellents containing DEET, picaridin, and IR3535 are safe for pregnant women.
History of Travel to an Area with Zika Virus Transmission
Laboratory tests for Zika virus infection diagnosis are of limited availability. Consultation about laboratory testing is available through the MDPH in the following circumstances:
1. Pregnant women, with a history of travel to an area with Zika virus transmission, who present during or within 2 weeks of travel with a clinical illness consistent with Zika virus disease (two or more of the following signs/symptoms: acute onset of fever, maculopapular rash, arthralgia, or conjunctivitis) can be tested for evidence of Zika virus RNA and anti-Zika antibody. a. If the test results are either positive or inconclusive, fetal ultrasound(s) should be performed to detect microcephaly or intracranial calcifications.
b. If the test result is negative, then the patient should be monitored with serial ultrasounds as indicated by clinical judgement and level of concern.
2. Pregnant women, with a history of travel to an area with Zika virus transmission, but without evidence of clinical illness, are not currently being recommended for testing.
REQUESTING LABORATORY TESTING
At this time, all testing will be performed at the CDC. Testing capacity is very limited and CDC is accepting samples from symptomatic pregnant women with recent travel to countries with identified transmission.
To discuss testing, please contact the MDPH, Epidemiology and Immunization Program at 617-983-6800, available 24/7. If the testing requested meets current CDC capacity and priority, testing can be approved. Availability of testing may increase in the future, and criteria for approval will change.