--- title: Zika Virus Puerto Rico: Could Spread to Mainland U.S. description: A rare virus spread by mosquitoes linked to severe birth defects could travel to the continental U.S. canonical: https://time.com/4167891/zika-virus-mosquitoes-birth-defects/ author: Justin Worland article:opinion: false article:content_tier: free article:published_time: 2016-01-05T19:20:49.000Z article:modified_time: 2026-02-22T13:47:43.703Z article:section: Health og:title: Virus That Causes Birth Defects Could Spread to Mainland U.S. og:description: The Zika virus has been linked to babies born with abnormally small heads og:url: https://time.com/4167891/zika-virus-mosquitoes-birth-defects/ og:site_name: TIME og:image: https://static.time.com/v3/assets/bltea6093859af6183b/bltde093bcdab65f2d0/6988d9b9bc6cfc69913e2a3c/time-logo.jpg?branch=production og:image:width: 1200 og:image:height: 675 og:image:alt: TIME og:type: article twitter:card: summary_large_image twitter:title: Virus That Causes Birth Defects Could Spread to Mainland U.S. twitter:description: The Zika virus has been linked to babies born with abnormally small heads twitter:image: https://static.time.com/v3/assets/bltea6093859af6183b/bltde093bcdab65f2d0/6988d9b9bc6cfc69913e2a3c/time-logo.jpg?branch=production --- # Virus That Causes Birth Defects Could Spread to Mainland U.S.  by [Justin Worland](https://time.com/author/justin-worland/)  ## Justin Worland Senior Correspondent Jan 5, 2016 7:20 PM UTC  by [Justin Worland](https://time.com/author/justin-worland/)  ## Justin Worland Senior Correspondent Jan 5, 2016 7:20 PM UTC A rare virus spread by mosquitoes linked to severe birth defects in Brazil has spread to Puerto Rico and health officials worry it could travel to the continental U.S. The Zika virus was long thought to be harmless, but recently it has been linked to a neurological disorder called microcephaly, which can stymie brain development in newborn babies. The condition causes babies to be born with abnormally small heads and can lead to early death. More than 2,400 suspected cases of the brain condition have been reported in Brazil since the Zika virus was first reported there early last year, according to government [documents](http://i2.cdn.turner.com/cnn/2015/images/12/22/coes-microcefalias---informe-epidemiol--gico---se-49---15dez2015---10h.pdf) posted online by CNN. The country’s government has asked that families temporarily hold off on pregnancies. The disease has appeared elsewhere in South and Central America and recently spread to the U.S. via Puerto Rico in a case reported last week. Now, officials at the Centers for Disease Control and Prevention (CDC) have [warned](http://wwwnc.cdc.gov/travel/notices/watch/zika-virus-puerto-rico) U.S. travelers to the region, especially pregnant women, to take special caution to avoid mosquito bites. The disease is likely to follow the patterns of other mosquito-borne illnesses and wind up in the Southern Gulf states and Hawaii, according to a CDC official [cited](http://www.nytimes.com/2016/01/05/health/us-becomes-more-vulnerable-to-tropical-diseases-like-zika.html) in the New York _Times_. [Symptoms](http://www.cdc.gov/zika/symptoms/index.html) of Zika, including fever, rash and headaches, are unpleasant, but the virus is not thought to lead to death in healthy adults. There is no medicine or vaccine to treat it. And, while health officials have called on the population to remain vigilant, they ask that people not overreact. “There is no reason for alarm, and the public should continue to take commonsense steps to avoid mosquito bites,” Pedro Pierluisi, Puerto Rico’s non-voting U.S. congressman, said in a [statement](http://pierluisi.house.gov/media-center/press-releases/pierluisi-in-communication-with-the-cdc-about-the-zika-virus). ```json [{"@context":"https://schema.org","@type":"NewsArticle","@id":"https://time.com/4167891/zika-virus-mosquitoes-birth-defects/","mainEntityOfPage":{"@type":"WebPage","@id":"https://time.com/4167891/zika-virus-mosquitoes-birth-defects/"},"headline":"Virus That Causes Birth Defects Could Spread to Mainland U.S.","datePublished":"2016-01-05T19:20:49.000Z","dateModified":"2026-02-22T13:47:43.703Z","description":"The Zika virus has been linked to babies born with abnormally small heads","url":"https://time.com/4167891/zika-virus-mosquitoes-birth-defects/","keywords":["Infectious Disease"],"thumbnailUrl":"","author":[{"@type":"Person","name":"Justin Worland","jobTitle":"Senior Correspondent","url":"https://time.com/author/justin-worland/"}],"articleSection":"Health","image":[],"publisher":{"@type":"Organization","name":"Time","url":"https://time.com/","logo":{"@type":"ImageObject","url":"https://time.com/images/logo.png","width":528,"height":156},"foundingDate":"March 3, 1923","sameAs":["https://www.facebook.com/time","https://www.instagram.com/time/?hl=en","https://twitter.com/time","https://www.pinterest.com/timemagazine"]}},{"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"item":{"@id":"/section/health/","name":"Health"}},{"@type":"ListItem","position":2,"item":{"@id":"/tag/infectious-disease/","name":"Infectious Disease"}},{"@type":"ListItem","position":3,"item":{"@id":"https://time.com/4167891/zika-virus-mosquitoes-birth-defects/","name":"Virus That Causes Birth Defects Could Spread to Mainland U.S."}}]}] ```