Scientists Say Ebola’s Transmission Route Unlikely to Have Changed

[morningfog]

News that two Dallas nurses were infected with Ebola despite wearing protective gear has sparked fears that the virus may be changing in a way that scientists don’t yet understand—by becoming airborne, for example.

While there’s no doubt that the Ebola virus is constantly altering its genetic makeup, those changes don’t seem to add up to anything significant so far. That makes scientists confident that Ebola hasn’t suddenly acquired the ability to be transmitted via air and that it is unlikely to do so.

“Ebola is more-or-less the same as it was in 1976,” when it was discovered, said Ian Jones, professor of virology at the University of Reading in the U.K. “Most viruses, once they’ve established a way of life, stick with it.”

No human virus is known to have changed its mode of transmission. Viruses like yellow fever that are transmitted by mosquitoes, or HIV that is transmitted by body fluids, continue to be passed on in the same way.

Ebola’s transmission route hasn’t changed either. It is usually the result of close and direct physical contact with a patient’s infected body fluids, especially blood, feces and vomit. While the virus can also be transmitted indirectly—via contaminated surfaces and objects—that risk is low and it can be lowered further by disinfection procedures. Ebola can survive on dry surfaces, such as doorknobs, for several hours but is easily killed.

Viruses that store their genetic information in DNA, such as small pox, typically don’t undergo a large number of mutations. By comparison, RNA-based viruses such as Ebola and HIV are less stable. HIV’s high mutation rate is one reason why it’s so hard to develop a vaccine for it.

So it wasn’t a big surprise when a study published in the journal Science in August found the 2014 Ebola virus had undergone more than 300 genetic changes compared with the virus that caused earlier outbreaks in the region.

What did those changes amount to? Is Ebola changing in a way that allows its host to live a few weeks longer, so that it could potentially infect even more people? Is it acquiring properties that could make it airborne?

The answer to those questions is no. “There’s no evidence that a particular mutation is being selected,” said Dr. Jones. “We don’t see anything happening that’s changing the direction of the virus in one direction or another.”

http://online.wsj.com/articles/scientists-say-ebolas-transmission-route-unlikely-to-have-changed-1413475957

[uppityperson]

1. 2 word. Proper Gear. eom

[jwirr]

2. Are they basing this on more than the results of the Texas hospital exposure? If this were so

wouldn't the other hospitals be having the same troubles?

[yellowcanine]

3. The reason the other hospitals didn't have the same problem is because they did a better job

following the protocols - which are based on bodily fluid transmission.

[Avalux]

4. They're basing it on the type of virus, and what we know about its behavior thus far.

If Ebola had mutated to a form more easily transmitted, we would absolutely know it. In the hot spots where Doctors without Borders have treated thousands, there have been cases of healthcare workers becoming infected, but not many. None of that has changed; people who haven't had direct contact with a person with Ebola are not becoming infected.

What occurred at Texas Presbyterian is nothing more than noncompliance with infection control protocols. They messed up big time.

[kestrel91316]

5. They base it on epidemiological EVIDENCE.

There would be tons of cases who had no known contact with Ebola victims if it were transmitted by aerosol since it would be floating clear across rooms and entering airways and going very deep.

It still only spreads by droplets (which can fly into orifices and land on mucous membranes) and contact.

[AverageJoe90]

6. Good point, TBH. nt