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Merged So Ebola's back......

Capsid said:
It's a pity they didn't cite the references they "believe" provide the evidence. An aerosol challenge study in an animal model is required to be definitive about this.
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You didn't look far enough. These sources are all from the citations in the article:

All patients with positive serum RT-PCR results also had positive results for their oral fluid specimens.

We report transmission of Ebola virus (Zaire strain) to two of three control rhesus monkeys (Macaca mulatta) that did not have direct contact with experimentally inoculated monkeys held in the same room.

Potential for aerosolization of Clostridium difficile after flushing toilets

Replication, Pathogenicity, Shedding, and Transmission of Zaire ebolavirus in Pigs
Results. Following mucosal exposure, pigs replicated ZEBOV to high titers (reaching 107 median tissue culture infective doses/mL), mainly in the respiratory tract, and developed severe lung pathology. Shedding from the oronasal mucosa was detected for up to 14 days after infection, and transmission was confirmed in all naive pigs cohabiting with inoculated animals.
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Transmission of Ebola virus from pigs to non-human primates
Here we show ZEBOV transmission from pigs to cynomolgus macaques without direct contact. Interestingly, transmission between macaques in similar housing conditions was never observed. Piglets inoculated oro-nasally with ZEBOV were transferred to the room housing macaques in an open inaccessible cage system. All macaques became infected. Infectious virus was detected in oro-nasal swabs of piglets, and in blood, swabs, and tissues of macaques. This is the first report of experimental interspecies virus transmission, with the macaques also used as a human surrogate.
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Aerosol exposure to Zaire ebolavirus in three nonhuman primate species: differences in disease course and clinical pathology
This study appears to involve direct inoculation, but demonstrates the ability of the virus to replicate when inhaled.


For anyone who doesn't understand the significance of this (because I believe Capsid does) this is not about airborne spread, it is about the potential for droplet spread. Pertussis and most influenza is droplet spread. You need to be in the vicinity of the patient to get infected and it's not likely the virus would stay suspended in the air in an infectious dose after the infected person leaves the area.

Surface contaminants however, do remain potentially infectious but transmission is low.
SURVIVAL OUTSIDE HOST: Filoviruses have been reported capable to survive for weeks in blood and can also survive on contaminated surfaces, particularly at low temperatures (4°C) Footnote 52 Footnote 61. One study could not recover any Ebolavirus from experimentally contaminated surfaces (plastic, metal or glass) at room temperature Footnote 61. In another study, Ebolavirus dried onto glass, polymeric silicone rubber, or painted aluminum alloy is able to survive in the dark for several hours under ambient conditions (between 20 and 250C and 30–40% relative humidity) (amount of virus reduced to 37% after 15.4 hours), but is less stable than some other viral hemorrhagic fevers (Lassa) Footnote 53. When dried in tissue culture media onto glass and stored at 4 °C, Zaire ebolavirus survived for over 50 days Footnote 61. This information is based on experimental findings only and not based on observations in nature. This information is intended to be used to support local risk assessments in a laboratory setting.

A study on transmission of ebolavirus from fomites in an isolation ward concludes that the risk of transmission is low when recommended infection control guidelines for viral hemorrhagic fevers are followed Footnote 64. Infection control protocols included decontamination of floors with 0.5% bleach daily and decontamination of visibly contaminated surfaces with 0.05% bleach as necessary.
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We are not likely to see an airborne outbreak. Viruses rarely mutate to different routes of transmission with the exception of when they jump species. But a virulent virus that infects naso-oral fluids (be it saliva or bleeding into the nose/mouth) has the potential to become an explosive epidemic which we've already seen.
 
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Well, I did have a scan of the papers but obviously not closely enough. Ref 27 by Reed et al in the CIDRAP article that Skeptic Ginger cited is a definitive aerosol challenge study using nebulisers. In the real world setting it would be useful to know how far the virus could be transmitted when it is air borne.
 
Death toll of 2,885 now confirmed.
The three-day lockdown in Sierra Leone found more than 200 additional Ebola cases, infected and dead.
The World Health Organization has stated that the Ebola outbreak is "pretty much contained" in Senegal and Nigeria.
 
Skeptic Ginger said:
Christians.

Much as a lot of bad goes with the little good, this is one mind bogglingly good thing Evangelicals are doing.
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luchog said:
And somewhat ironic, since those same Evangelicals are at least partially responsible for the anti-science/medicine memes that have contributed heavily to the spread of so many otherwise controllable diseases in Africa.
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Ninja'd, not for the first time.



Skeptic Ginger said:
Number of cases are seriously undercounted and cases are doubling every three weeks.

Some ignorant people will surely blame the vaccine for deaths if one is developed and used. People in the incubation period might get the vaccine and soon after die from the disease.


The implications are staggering.
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I agree, SG. :(
 
Capsid said:
Well, I did have a scan of the papers but obviously not closely enough. Ref 27 by Reed et al in the CIDRAP article that Skeptic Ginger cited is a definitive aerosol challenge study using nebulisers. In the real world setting it would be useful to know how far the virus could be transmitted when it is air borne.
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Droplet spread rarely travels across more than a meter from the source in an infectious dose.

Another bad thing about droplet spread however, is that it also contaminates the surrounding surfaces.

What's happening in droplet spread is the virus is maintained in body fluids. Individual particles that travel further through the air don't have enough fluid to keep the virus viable. Airborne organisms don't need that body fluid vehicle.
 
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Foreign Policy has an article on how colonial lines are drawn for ebola aid (Liberia from the U.S., Sierra Leone from Great Britain, and Guinea from France). The divided response from the United States, Great Britain, and France only complicate the possibility of containing the outbreak.
 
A Swiss nurse who was bitten by an Ebola patient while working in Sierra Leone has been flown to Switzerland as a precaution.

CDC predictions suggests there actually 21,000 current cases currently with predictions for half-a-million cases by February unless measures are taken.
 
Sierra Leone has deployed it's army to seals off it's borders with Liberia and Guinea in an attempt to halt the further spread of Ebola

The NY Times is carrying the CDC's worst case scenario, 1.4 million cases (and ~600,000 dead) during this epidemic.
 
BenBurch said:
1.4 million.

To put this in perspective the total population of Sierra Leone is around 6 million.

:(
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Well even the report's authors have admitted that that is a worst-case scenario, with quite a bit of hyperbole I suspect.
However I fully agree with the original NEJM editorial, by Piot and others, that described the epidemic "an avoidable crisis".


The WHO has described the situation in Guinea as having stabilised.
Sierra Leone has imposed quarantines on the districts of Port Loko, Bombali and Moyamba (sealing in about 1.25 million people in total) along with 12 (of 149) of the country's chiefdoms, in an effort to fight the Ebola epidemic.
 
catsmate1 said:
Well even the report's authors have admitted that that is a worst-case scenario, with quite a bit of hyperbole I suspect.
However I fully agree with the original NEJM editorial, by Piot and others, that described the epidemic "an avoidable crisis".


The WHO has described the situation in Guinea as having stabilised.
Sierra Leone has imposed quarantines on the districts of Port Loko, Bombali and Moyamba (sealing in about 1.25 million people in total) along with 12 (of 149) of the country's chiefdoms, in an effort to fight the Ebola epidemic.
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There is SO much criminal activity in the region that I really don't think they can seal those regions off completely. Smugglers aren't going to ask permission and are already avoiding the police.
 
BenBurch said:
There is SO much criminal activity in the region that I really don't think they can seal those regions off completely. Smugglers aren't going to ask permission and are already avoiding the police.
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I suspect troops are going to start shooting quarantine violators.
 
Capsid said:
Well, I did have a scan of the papers but obviously not closely enough. Ref 27 by Reed et al in the CIDRAP article that Skeptic Ginger cited is a definitive aerosol challenge study using nebulisers. In the real world setting it would be useful to know how far the virus could be transmitted when it is air borne.
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The CDC guidelines address the possible aerosol transmission route. However there has been some discussion, and correspondence, in The Lancet over whether current standard infection control measures are sufficient, e.g. here and here.
 
catsmate1 said:
The CDC guidelines address the possible aerosol transmission route. However there has been some discussion, and correspondence, in The Lancet over whether current standard infection control measures are sufficient, e.g. here and here.
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Your first link suggests droplet spread precautions for patients that are not vomiting:
goggles and masks might not even be necessary to speak with conscious patients, as long as a distance of 1—2 metres is maintained (the maximum distance that infectious droplets might reach).
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In the second link the author of the letter appears to not know the difference between contact precautions and droplet precautions.
From the CDC on ebola precautions:
Standard, contact, and droplet precautions are recommended
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None of this is inconsistent with the source I cited. The animals that were infected without direct contact were still in close proximity to each other.

Aerosol challenges simply demonstrated inhalation as a portal of entry. Portal of entry differs from route of transmission.

I think some of the problem here comes from a lack of understanding the use of respirators for droplet precautions. An N95 respirator looks like a face mask.
 
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Skeptic Ginger said:
Your first link suggests droplet spread precautions for patients that are not vomiting:

In the second link the author of the letter appears to not know the difference between contact precautions and droplet precautions.
From the CDC on ebola precautions:

None of this is inconsistent with the source I cited. The animals that were infected without direct contact were still in close proximity to each other.

Aerosol challenges simply demonstrated inhalation as a portal of entry. Portal of entry differs from route of transmission.

I think some of the problem here comes from a lack of understanding the use of respirators for droplet precautions. An N95 respirator looks like a face mask.
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Absolutely. There seems to be a certain amount of confusion about the aerosol risk.
 
A U.S. professor wrote an article for a major Liberian newspaper claiming that the U.S. Defense Department manufactured Ebola, and that organizations trying to fight the disease like World Health Organization and Doctors Without Borders are a part of the conspiracy.

Source here.
 
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