Zika Threat Worse Than Researchers Originally Thought

February 2, 2017

Several Zika virus studies have been underway, and recent results indicate Zika is more dangerous than researchers thought.

Six percent of U.S. women infected with Zika had babies with one or more birth defects with that percentage nearly doubling for women infected in the first trimester. Other disconcerting results show that Zika can continue to replicate in mothers’ placentas and fetuses’ brains as well as continue to replicate in babies’ brains after they are born.

In November, the World Health Organization (WHO) “declared an end to its global health emergency over the spread of the Zika virus” — but this was more for technical, definitional reasons than to suggest the virus is under control.

According to The New York Times article, “An agency advisory committee said it ended the emergency … because Zika is now shown to be a dangerous mosquito-­boe disease, like malaria or yellow fever, and should now be viewed as an ongoing threat met as other diseases are.”

Here’s an update on the current scenario:




  • Zika virus can be passed to a fetus when the mother is bitten and cause microcephaly (small brain) and other severe fetal brain defects. Babies exposed to the Zika virus in utero are about 50 times more likely to be bo with microcephaly than babies who haven’t been exposed.
  • According to the CDC, “A pregnant woman already infected with Zika virus can pass the virus to her fetus during the pregnancy or around the time of birth; To date, there are no reports of infants getting Zika through breastfeeding.”
  • Babies bo without defects may still incur issues because the disease can continue to replicate in babies’ brains after birth, according to Reuters.
  • According to the CDC, In “several countries that have experienced Zika outbreaks,” there have also been reported increases in Guillain-Barre Syndrome (GBS). The CDC research indicates a strong association between GBS and Zika, but only for a small percentage of those infected with Zika. GBS is a nervous system sickness “in which a person’s own immune system damages the nerve cells, causing muscle weakness, and sometimes, paralysis.”

Symptoms and diagnosis

  • According to the WHO Zika virus fact sheet, the time from exposure to symptoms is a few days. There is no vaccine to prevent Zika, although research is ongoing.
  • Symptoms include “mild fever, skin rash, conjunctivitis, muscle and joint pain, malaise, or headache. These symptoms normally last for 2-7 days.”
  • Blood or urine tests can confirm Zika infection.


  • There is no antibiotic, associated treatment, or medication to treat Zika.
  • According to the WHO fact sheet, people infected with Zika typically experience mild symptoms and should administer the same self-care as with other viruses. “… get plenty of rest, drink enough fluids, and treat pain and fever with common medicines. If symptoms worsen, they should seek medical care and advice.”
  • People who contract Zika are not likely to suffer a reoccurrence, according to the CDC Transmission and Risks page.

Information for pregnant women and their partners

  • The CDC is still recommending that pregnant women not travel to affected areas. The CDC map mentioned above shows that every state in the U.S. has a reported case — with the exception of Alaska — but the recommended travel restriction is for Florida, specifically Miami-Dade County, and Brownsville, Texas.
  • Those living in these areas can prevent mosquito bites by using insect repellent. Use Environmental Protection Agency (EPA)-registered insect repellents with one of the active ingredients in the infographic below. According to the CDC, “When used as directed, EPA-registered insect repellents are proven safe and effective, even for pregnant and breastfeeding women.”
  • Pregnant women should require condom use to prevent infection during pregnancy if they live in or travel to the Florida areas identified as well as other known locations (mostly Caribbean and Latin American — see map resource) or have sex with someone who has traveled to these areas.
  • Pregnant women at risk for Zika exposure should be tested in the first and second trimester of pregnancy.
  • Women with Zika should wait at least eight weeks after symptoms begin before trying to get pregnant; men with Zika should wait at least six months after symptoms begin.
  • Women who have traveled to these areas and been exposed to Zika should wait at least eight weeks before trying to get pregnant; men should wait at least six months.
  • Studies are underway to determine how long Zika stays in semen and vaginal fluids of those who have been diagnosed with Zika and how long and the likelihood for it to be passed to sex partners. It is known that Zika does stay longer in semen than in other body fluids such as vaginal, urine and blood. To date, the longest documented Zika virus detection in semen is 188 days.


Additional resources

CDC printable resources

CDC Map for all countries and territories with active Zika virus transmission

CDC Zika information

Public Library of Science: “How Relevant Is Sexual Transmission of Zika Virus?”

ABC News: “Miami Now Free of Locally Transmitted Zika Virus, CDC Says”

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