This week in Zika: Assessing risk, mosquito range, a transmission first and more

zika watch 4/15

The big Zika news this week was the announcement from the U.S. Centers for Disease Control and Prevention that yes, the virus can indeed cause microcephaly and other birth defects. 

This confirmation came as no surprise (scientists have been building a case against Zika for months), but it could be just the push Congress needs to authorize emergency funding for Zika research and response.

In February, the White House asked for $1.9 billion. But Congress dawdled, and the request floundered.

In the meantime, officials said, they’d siphon funds from Ebola’s budget — more than $500 million. But the solution is a Band-Aid at best. It’s not nearly enough money for a full-fledged fight against Zika, said White House budget director Shaun Donovan.

That fight continued this week, as researchers raced to add to the understanding of the virus. Among this week’s Zika news:

  • Pregnant women at risk for infection rarely have the disease if they don’t have symptoms. Just 0.3 percent of 2,425 asymptomatic U.S. pregnant women tested were infected with the virus, the CDC reports April 15. The risk jumped to almost 3 percent among pregnant women who had at least one symptom. (All the women had traveled to or moved from active Zika areas.)
  • The CDC estimates that a Zika-spreading mosquito, Aedes aegypti, dwells in more states than scientists once thought: about 30, instead of 12, the CDC’s Anne Schuchat said in a news briefing April 11. That’s a big change from a 2015 CDC map of A. aegypti’s estimated range. The mosquito may now roam the entire southern United States, as well as much of the East Coast.
  • Mosquitoes are now spreading Zika in Belize and Saint Lucia, bringing the current tally of countries reporting “local” transmission up to 62, according to the World Health Organization’s April 14 update.
  • Zika can pass between men via sexual intercourse. The CDC reported the first such case of male-to-male transmission April 14: A Texas man caught the virus from a sexual partner who had recently traveled to Venezuela and returned home infected.
  • In addition to microcephaly, other birth defects and probably Guillain-Barré syndrome (a neurological disorder), Zika may be to blame for another disease as well: acute disseminated encephalomyelitis. ADEM, an autoimmune disorder like multiple sclerosis, targets the brain’s insulating sheaths of myelin. Scientists documented ADEM in two Zika-infected patients in Brazil and will present the study at the American Academy of Neurology meeting that starts April 15. 

MOSQUITO RISING A mosquito species that can carry Zika virus may range throughout much of the United States (right). A previous map had shown a much less widespread distribution of the Aedes aegypti mosquito (left).CDC

Meghan Rosen is a staff writer who reports on the life sciences for Science News. She earned a Ph.D. in biochemistry and molecular biology with an emphasis in biotechnology from the University of California, Davis, and later graduated from the science communication program at UC Santa Cruz.

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