The most dangerous animal on the planet

Maggie Fox reports for NBC News,

Fourteen more people may have caught the Zika virus in the U.S. without traveling to affected zones, federal health officials said Tuesday — strong evidence that the virus is sexually transmitted fairly often.

Some of those suspected of having been infected sexually have been pregnant women, the Centers for Disease Control and Prevention says.

...Evidence is growing that Zika can cause serious birth defects, especially microcephaly, which results from a damaged brain that stops developing in the womb. There are also suspicions that Zika is causing a paralyzing condition called Guillan-Barre syndrome.

...Zika's spreading fast across the Americas and the Caribbean and the World Health Organization has declared it a public health emergency of international concern. The virus itself is relatively harmless to most people, but what's worrying is the potential that it causes severe birth defects.

The CDC's already advised travelers to be aware of the risk, recommending that men who have traveled to Zika-affected zones should use a condom if they want to be absolutely sure they don't infect sex partners.

...Zika's clearly a mosquito-borne virus, spread as female Aedes mosquitos sip blood from one person after another, often in the same room. Other viruses are spread this way, too: yellow fever, dengue, West Nile and chikungunya. And the malaria parasite is also spread by mosquitoes.

"It's not likely that sexual transmission is anywhere close to the frequency of mosquito-borne transmission. The mosquito is the most dangerous animal on the planet," said Dr. William Schaffner of Vanderbilt University, past president of the National Foundation for Infectious Diseases.

...But with Zika, right now the only way the virus is getting to unaffected countries like the U.S. is in the bodies of travelers. So the cases of sexual transmission stand out. CDC says 30 million to 40 million Americans fly to Latin America and the Caribbean every year and even more go by land.

Zika is actively spreading in more than two dozen Latin American and Caribbean countries.

Read more here.