Experts worry Ebola could mutate to spread by air

[AnnaLisa]

Re: Experts worry Ebola could mutate to spread by air

Norovirus in an RNA virus, (albeit not the same family as Ebola.) It's not airborne, but it spreads very rapidly. It appears to have a lot longer life on fomites than Ebola and perhaps it aerosolizes more effectively. It spreads like wildfire and isn't airborne.

[Nika]

Re: Experts worry Ebola could mutate to spread by air

The infectiousness of norovirus is hard to overestimate. It's disease course is vicious (1st hand experience) but mostly over quickly then gone - tho we don't seem to mount a very effective nor enduring immune response to it. Because it causes very impressive explosive projectile vomiting often coupled with uncontrollable and forceful diarrhea the virus is easily aerosolized. I don't know that it's quite the same physio-dynamic with ebola.

[AnnaLisa]

Re: Experts worry Ebola could mutate to spread by air

Interestingly 20% of the population is immune to Norovirus, due to status as FUT2 non-secretors. (No blood antigens present in saliva and mucous membrane secretions). I am one of the lucky ones. That said, it has a downside, making me more susceptible to other infections and influenza. I assume this genetic immunity has been studied in terms of Ebola.

[Graupel]

Re: Experts worry Ebola could mutate to spread by air

Noro is so nasty as it is absurdly infective- a single vireon is probably sufficient.

My worry for EBV is not mutation to be airborne (that seems like a big evolutionary leap) but simply a shift in when viral shedding begins. Currently, viral shedding doesn't appear to happen before acute febrile illness, but if that were to change....

Can any virologists comment?

[foxp3]

Re: Experts worry Ebola could mutate to spread by air

To become a true airborne pathogen would the virus not have to change tissue tropism and be able to infect the upper airways, i.e. the respiratory epithelium. I thought it was confined to entering immune cells such was monocytes and macrophages, and endothelium cells. It is well known monocytes and dendritic cells in the airways are very unique from other locations. They are at different differential stages and express many different surface molecules than those present in other mucosal and systemic surfaces.

Being an RNA virus makes it inherently unstable and let's hope it becomes less virulent with the passages through humans. Confections with parasites, HIV, and other chronic infections that can result in immunosuppression, may also effect the ongoing evolution of this virus.

As for changes in Ebola shedding times, it is naive to think everyone will shed at a defined time. As I previously highlighted in in another post, in immunocompromised hosts the cytokines response required to raise the temperature etc is often delayed, by which point the viral load is probably very high and already being shed.

Immune responses are often over generalised and although much is controlled by your genetic make up, various outside factors, environmental exposures, past and present infections influence your future responses. The immune system can be split into two components innate and adaptive, the adaptive response is the more variable piece, where past and present exposures leave lasting footprints that may shape the pathway your body takes in response to infections in the future. I think what I am saying is that an individuals immune system is a self educating entity, it never stands still. Of course therefore different individuals will have different shedding times, it is just about what proportion will shed before symptoms and if this number is significant.

Really good points on this topic which have made good reading.

fp

Ps the dreaded Noro. In UK hospitals it seems at times impossible to get it through to staff that alcohol based gels do nothing to penetrate the virus. So great against influenza, but these gels don't penetrate noro viral membranes. Also the rise in use of pH neutral soaps which don't disrupt a whole range of bacterial and viral outer membranes. You need a good alkaline soap to break many infectious agents open. Also require hot water to make many enzymes in soap work. Simple steps often missed

[Pathfinder]

Re: Experts worry Ebola could mutate to spread by air

Ebola Could Spread Like Flu: Top Researcher

Friday, 19 Sep 2014 02:04 PM
By Charlotte Libov

...
?I don?t want to be an alarmist, but the possibility of Ebola becoming an airborne virus clearly has to be taken into account,? said David Sanders, associate professor of biological sciences at Purdue University.

"Ebola does share some of the characteristics of airborne viruses like influenza and we should not disregard the possibility of it evolving into something that could be transmitted in this way,? added Sanders, whose work on Ebola led to his participation in the U.S. Defense Threat Reduction Agency's Biological Weapons Proliferation Prevention Program.
...
Testifying before a Congressional subcommittee this week, Dr. Anthony Fauci, a top White House infectious disease advisor, said it was very unlikely Ebola would mutate in a way that would make it transmittable through the air like flu.
...
But Sanders disagrees. ?I want the facts to be clear. It?s important that we not get the idea that this can?t happen,? he said, adding, ?When people say that it is impossible for this virus to mutate, this is simply not true.?

According to Sanders, a key factor in the successful mutation of a virus centers on how it enters and exits the body. Sanders led a research team that established the Zaire form of the Ebola virus, which is the one involved in the West Africa epidemic, could enter the mucus-lined cells that line the human airway in much the same way the flu virus does.
...
To pose a major threat in the U.S., the Ebola virus would have to mutate so that it could survive outside the body for a significant length of time like influenza can, Sanders said.

?This is not how the Ebola virus is currently known to spread, but there is evidence that it has some of the necessary components for respiratory transmission,? he said.
...
?When people have looked at the current outbreak, the virus really hasn?t changed much,? Sanders said. ?However, this research was done when there were 1,500 cases and now it?s up to 4,000 and if it gets to be 100,000 cases, there is more and more of a chance for mutations to occur.?
...
He pointed to another strain of the Ebola virus that has already mutated to become transmittable through the air. In fact, it has already hit the U.S., although it turned out to be non-lethal to humans. The disease was dubbed Ebola-Reston because its initial outbreak occurred in Reston, Va., in 1989.
...

http://www.newsmaxhealth.com/Health-News/ebola-mutation-contagious-spread/2014/09/19/id/595742

[Emily]

Re: Experts worry Ebola could mutate to spread by air

Maybe nothing is impossible, but he must think it is highly unlikely:

http://www.newsmax.com/US/ebola-dise.../19/id/595818/

Purdue Professor: Ebola 'Unlikely to Spread Here' in US
Saturday, 20 Sep 2014 09:18 PM
By Bill Hoffmann

The Ebola virus is unlikely to cause a deadly epidemic in the United States, according to David Sanders, an associate professor of biological science at Purdue University.

"The panic is, in fact, worse than the disease. It is unlikely to spread here and even if it did, Western containment should be sufficient to prevent it from spreading rapidly," Sanders said Friday on "The Steve Malzberg Show" on Newsmax TV...