Public Release: 

Many in families with pregnant women don't know key facts about Zika

Four in 10 among general public mistakenly believe Zika virus infection in women likely to harm future pregnancies

Harvard T.H. Chan School of Public Health

Boston, MA - Many people in U.S. households where someone is pregnant or considering getting pregnant in the next 12 months are not aware of key facts about Zika virus, according to a new poll by Harvard T.H. Chan School of Public Health researchers. The nationally representative poll of 1,275 adults, including 105 who live in households where someone is pregnant or considering getting pregnant in the next 12 months, was conducted March 2-8, 2016 in cooperation with the National Public Health Information Coalition (NPHIC), an organization serving state and local public health communications officers.

Among people in households where someone is pregnant or considering getting pregnant, the researchers found:

  • Approximately one in four (23%) are not aware of the association between Zika virus and the birth defect microcephaly.
  • One in five (20%) believe, incorrectly, that there is a vaccine to protect against Zika virus.
  • Approximately four in 10 (42%) do not realize Zika virus can be sexually transmitted.
  • A quarter (25%) think individuals infected with Zika virus are "very likely" to show symptoms.

Such results suggest this key segment of the population does not have the latest Zika virus information presented by public health officials.

"We have a key window before the mosquito season gears up in communities within the United States mainland to correct misperceptions about Zika virus so that pregnant women and their partners may take appropriate measures to protect their families," says Gillian SteelFisher, director of the poll and research scientist in the Department of Health Policy and Management at Harvard Chan School.

The general public also has misperceptions about Zika virus, the researchers found.

  • Four in 10 mistakenly believe Zika virus infection in women likely to harm future pregnancies

    Within the public as a whole, approximately four in 10 (39%) believe that if a woman who is not pregnant gets infected with Zika virus, it is likely ("very" and "somewhat") to harm future pregnancies. This contrasts with the latest scientific evidence reported by the Centers for Disease Control and Prevention (CDC), which suggests "Zika virus infection in a woman who is not pregnant would not pose a risk for birth defects in future pregnancies after the virus has cleared from her blood," which takes about a week.

  • Sizable minority mistakenly believe Zika virus is transmitted by coughing and sneezing

    While most of the public (87%) understand that Zika virus is transmitted by mosquitoes, many have other facts about transmission wrong. About one in five (22%) are not aware that Zika virus can be transmitted from mother to baby during pregnancy and more than a quarter (29%) are unaware it can be transmitted through blood transfusions. Four in 10 (40%) are unaware that it can be transmitted sexually. About a third (31%) believe, incorrectly, that Zika virus is transmitted through coughing and sneezing.

    SteelFisher adds, "These misperceptions about Zika virus transmission could lead people to take unnecessary or inappropriate precautions, as we have seen in other kinds of outbreaks."

  • Limited public knowledge about symptoms of Zika virus disease

    Few people understand that a person who is infected with Zika virus most likely will not show symptoms. Nearly three-quarters (71%) say a person infected with Zika virus is likely ("very" or "somewhat") to show symptoms. Approximately two-thirds (68%) say fever is common if someone does show symptoms, but other symptoms are much less frequently identified (headache 49%; joint pain 41%; rash 34%; conjunctivitis or red eyes 18%). Further, approximately a third (35%) believe incorrectly that coughing and sneezing are symptoms of Zika virus disease.

  • Many unware of link between Zika virus and Guillain-Barré

    Nearly three-quarters of the public (71%) are unaware of a link between Zika virus and Guillain-Barré syndrome, which can cause paralysis.

  • Most support mosquitos spraying if there are cases of Zika virus where they live

    Most people say they would approve of mosquito spraying if there were cases of Zika virus in their city or town. More than four out of five (81%) would approve of ground spraying, and approximately two-thirds (66%) would approve of spraying from the air.

  • Majority routinely take personal precautions against mosquitoes during the summer

    Two-thirds of the public (67%) say they routinely take personal precautions during the summer to avoid getting mosquito bites. In total, more than half say they wear mosquito repellant (56%) or remove standing water (55%). Just under half replace or repair window screens (46%) or avoid activities and areas that would bring them into contact with mosquitos (43%). Fewer (39%) say they wear long sleeves and only a small fraction (16%) use mosquito netting.

  • Public is paying attention to Zika virus, but most are not concerned about getting infected

Approximately three-quarters of the public (78%) are following the news about the current outbreak of Zika virus, including about half (52%) who say they are following the news "very" or "somewhat" closely. Only a quarter of the public (25%) say they are concerned ("very" or "somewhat") that they or someone in their immediate family may get infected with Zika virus in the next 12 months.


For more information about Zika virus, see:

(Note: for charts showing some of the findings, contact Marge Dwyer.)

This poll is part of an ongoing series of surveys focused on the public's response to public health emergencies by the Harvard Opinion Research Program (HORP) at Harvard T.H. Chan School of Public Health. The research team includes Gillian K. SteelFisher, research scientist and deputy director of HORP; Robert J. Blendon, professor of health policy and political analysis and executive director of HORP; and Hannah Caporello, research assistant.

Interviews were conducted via telephone (including both landline and cell phone) for Harvard Chan School by SSRS of Media (PA). The team at SSRS includes Eran Ben-Porath, vice president of public opinion polling; Linda Lomelino, associate research director; and Rebecca Sevem, project director. Interviews were conducted March 2-8, 2016 among a nationally representative sample of 1,275 respondents age 18 and older, including 105 who live in households where someone is pregnant now or considering getting pregnant in the next 12 months. The sample was designed to oversample women between the ages of 18 and 44, and also included 177 Hispanics and 161 African Americans. Interviews were conducted in English and Spanish. The margin of sampling error is +/-3.23 percentage points for total respondents and +11.6 percentage points for those in households where someone is pregnant or considering getting pregnant in the next twelve months at the 95% confidence level.

Possible sources of non-sampling error include non-response bias, as well as question wording and ordering effects. Non-response in telephone surveys produces some known biases in survey-derived estimates because participation tends to vary for different subgroups of the population. To address known biases, including sample design as well as variations in probability of selection within and across households, sample data are weighted by household size and composition, and respondents' access to cell phones and landlines and by demographics (sex, age, race/ethnicity, population density, educational attainment, marital status, cell phone use, and census region) to reflect the true population. Other techniques, including random-digit dialing, replicate subsamples, and systematic respondent selection within households, are used to ensure that the sample is representative.

Funding: This poll is funded under a cooperative agreement with the Centers for Disease Control and Prevention (CDC) through the National Public Health Information Coalition (NPHIC). The award enables HORP to provide technical assistance to local, state, and national government health officials in order to support two critical goals: (1) to better understand the general public's response to public health emergencies, including biological threats and natural disasters; and (2) to improve related public health communications.

Harvard T.H. Chan School of Public Health brings together dedicated experts from many disciplines to educate new generations of global health leaders and produce powerful ideas that improve the lives and health of people everywhere. As a community of leading scientists, educators, and students, we work together to take innovative ideas from the laboratory to people's lives--not only making scientific breakthroughs, but also working to change individual behaviors, public policies, and health care practices. Each year, more than 400 faculty members at Harvard Chan School teach 1,000-plus full-time students from around the world and train thousands more through online and executive education courses. Founded in 1913 as the Harvard-MIT School of Health Officers, the School is recognized as America's oldest professional training program in public health.

SSRS is a full-service survey and market research firm managed by a core of dedicated professionals with advanced degrees in the social sciences. SSRS designs and implements solutions to complex strategic, tactical, public opinion, and policy issues in the U.S. and in more than 40 countries worldwide. SSRS partners with clients interested in conducting high-quality research. SSRS is renowned for its sophisticated sample designs and its experience with all modes of data collection, including those involving multimodal formats. SSRS provides the complete set of analytical, administrative and management capabilities needed for successful project execution. For more information on SSRS, visit or to contact SSRS researchers directly, contact Eran Ben-Porath; 484-840-4333 or Melissa Herrmann; 484-840-4404.

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