Mike Adams and NY Post promote more hysteria over Ebola

I’ve been asked several times about this NY Post article on the CDC’s “admission” that a sneeze could spread Ebola. The Post (which, I should note, is the least credible newspaper in New York City, for those not familiar with the paper) suggests that the CDC has changed their tune regarding the spread of Ebola.

Except, they haven’t, and this is a ridiculous, trumped-up non-story, passed along not only by the Post but by others of the typical suspects like conspiracy theorist extraordinaire Mike Adams, aka “The Health Ranger” of Natural News.

Here’s what the NY Post claims:

“Droplet spread happens when germs traveling inside droplets that are coughed or sneezed from a sick person enter the eyes, nose or mouth of another person,” the poster states.

Nass slammed the contradiction.

“The CDC said it doesn’t spread at all by air, then Friday they came out with this poster,” she said. “They admit that these particles or droplets may land on objects such as doorknobs and that Ebola can be transmitted that way.”

Of course, no poster is linked in their article, so I feel like I’m playing a game of telephone, trying to figure out just what has been added.

The NY Post article is basically messing up the definition of “airborne,” as I and others have discussed ad nauseum. The kind of contact the NY Post describes above isn’t “airborne,” as measles or chickenpox are, where one can come into a space that had been occupied by an infected person, breathe in the suspended virus, and get ill. With Ebola, you have to have *direct contact* with a person’s secretions. So their entire story (not surprisingly, due to their tabloid-y nature) is based on either a purposeful or accidental incorrect definition of just what it means to be “airborne.”

Adams takes it one step further, suggesting that CDC not only misinformed, but revised history; that a poster was  “scrubbed” from CDC’s site because it supported “airborne” transmission.

From what I can tell, Adams claims this poster (which he saved) was removed from the CDC site, and replaced by this file. Adams claims that the latter is “entirely empty,” so he may have tried the link before it went live? I have no idea. In any case, the two documents are almost identical in content. Both note that droplet spread can happen, when “germs traveling inside droplets that are coughed or sneezed from a sick person enter the eyes, nose, or mouth of another person” in the first poster, and “droplets that are coughed or sneezed from a sick person splash the eyes, nose, or mouth of another person” in the second poster.

Wow, that’s a sinister difference there.

You can see that both documents still show a picture of doorknobs as possible fomites for transmission (possible in theory, but they’d have to be heavily contaminated by a person late in the disease). It appears that CDC just did a minor redesign of the poster, with the first having an emphasis just on Ebola and the second version trying to be more of an explainer on “air vs. droplet spread,” with Ebola as the example. The content is almost exactly the same: the first portion defines “airborne” spread; the second “droplet” spread; the third focuses on how one protects oneself from getting sick; and the final one clarifies that Ebola is not spread by air, but it could be by droplets. There are minor wording changes as I noted above, but that’s it.

This is nothing new. There’s never been a conspiracy to suggest that droplet transmission can’t happen–but the CDC and others have tried to emphasize that droplet transmission is still direct contact. That’s what people like Adams don’t want to accept. They assume because those droplets travel via air, it’s “airborne,” taking a layman term instead of one accepted and used by the scientific community. Now, given, I understand this can be a source of confusion as scientific terms frequently are. Virologist Ian Mackay has even solicited ideas for other terms to describe such transmission, and make it more clear to the general public what the difference is. But either way, the usage has been clear from the beginning and I guarantee Adams understands the difference. He just doesn’t care.

And now I just spent a half hour of my life to uncover that vast governmental conspiracy-that-wasn’t. Not that it will stop Adams or the NY Post from misinforming and driving fear of the virus and distrust of the government, because *that’s what they do.* Adams is making a pretty penny, I’m sure, off of his absurd Pandemic Prevention kits (only $99 or $199! Bargain!). Perhaps I should get into a different and more lucrative business, because if you believe shtick from Adams or the Post over the CDC or, hey, a trained epidemiologist like myself, I just may have a shiny bridge to sell you.

Are we *sure* Ebola isn’t airborne?

Since yesterday’s post, several people have asked me on various social media outlets about the airborne nature of Ebola. Didn’t I know about this paper (“Transmission of Ebola virus from pigs to non-human primates“), which clearly showed that Ebola could go airborne?

Indeed I do–I wrote about that paper two years ago, and it in no way changes my assertion that Ebola doesn’t spread between people in an airborne manner.

Let me back up. The paper in question was an experimental study done in the wake of the 2008 finding of the Reston Ebola virus in pigs and a previous study looking at the Zaire virus in pigs. In the air transmission study, they inoculated pigs with Ebola and examined transmission to macaques (who were not in direct contact with the infected pigs). They did find aerosolized Ebola in air samples, and some of the macaques did come down with symptoms of Ebola. So, it looked like pigs could spread Ebola through the air, which is something that had already been suggested by the epidemiology of the 2008 pig Ebola outbreak. It’s always nice when experimental data matches up with that observed during a real-life occurrence of the virus.

*However*, the kicker was not that Ebola is transmitted by air in human outbreaks, but rather that there may be something unique about pig physiology that allows them to generate more infectious aerosols as a general rule–so though aerosols aren’t a transmission route between primates (including humans, as well as non-human primates used experimentally), pigs may be a bigger threat as far as aerosols. Thus, this may be important for transmission of swine influenza and other viruses as well as Ebola.

So unless you’re sitting next to an Ebola-infected pig, seriously, airborne transmission of Ebola viruses isn’t a big concern. (Perhaps this corollary should be added to this handy diagram examining your risk of Ebola).

 

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Student guest post: New Study Finds that the Flu has Multiple Ways of Spreading

Student guest post by Sean McCaul

Sean pic 1

Image Source:  http://www.cejournal.net/?p=1934

The next time somebody in your office or household has the flu, you might want to consider keeping your distance.  A new study published this month in Nature Communications suggests that about half of the transmission of influenza A results from inhalation of microscopic infectious droplets created by the coughing and sneezing of people infected with the flu.  The flu virus hitches a ride in these droplets, and may infect nearby susceptible people who breathe them in.1

The influenza A virus generally causes fever, coughing, body aches, runny nose, sore throat, headache, and fatigue.  Vomiting and diarrhea may occur, but are more common in children.3 Fever and most other clinical signs usually resolve within 5 to 7 days, but coughing may last two weeks or more.2 Children under 2 years old and the elderly are at greatest risk for complications such as pneumonia, and over 90% of influenza deaths are in people over age 65.2

Seasonal outbreaks of influenza are common in the United States, and typically occur during winter months.  During and average outbreak, 5% to 20% of the people in a community may become ill with the flu, and up to half of the people in environments like schools and nursing homes may get sick.2

In adults with healthy immune systems, the flu virus is shed in highest numbers during the first 3 to 5 days of illness, making spread of the flu most likely during this time.  Children may shed the virus for up to 10 days, and people with weakened immune systems may shed the virus even longer.2 In a typical outbreak, a person sick with the flu passes the illness on to an average of 1 to 2 other people.1,2

Previously, influenza A viruses were thought to be transmitted primarily by direct contact and by larger (but still very tiny) droplets generated by coughing, sneezing, and talking.1,2,3  These droplets are capable of travelling 1 to 2 meters, where they may come to rest in the eyes, nose, or mouth of a susceptible person and cause them to become sick with the flu.  These droplets may also fall upon nearby surfaces and objects, where the flu virus can survive for hours.  A person touching these surfaces or objects may get the flu virus on their hands, and then transfer the virus to their eyes, nose or mouth and become ill.1,2

The recent study, published on June 4, 2013, used a mathematical model of influenza virus transmission to evaluate the data from two previously published studies of the effectiveness of hand hygiene and facemasks for the reduction of transmission of influenza A viruses.   It suggests that the flu virus may survive in very tiny droplets created by coughing and sneezing that can remain suspended in the air as an aerosol long enough to be inhaled by nearby susceptible people.   The study shows that aerosols are an important route of transmission of the virus, and may account for as much as 50% of the spread of the flu.1

Sean pic 2

Image Source:  http://www.livescience.com/32307-why-do-bright-lights-make-me-sneeze.html

How you get the flu may determine, in part, how ill you get.  Influenza researchers have long suspected that inhalation of aerosols containing the flu virus can lead to more severe illness than exposure to the flu virus by direct contact or by the settling of larger droplets in the eyes, mouth or nose of susceptible people.  This is thought to be because larger droplets are trapped by the defense mechanisms of the upper respiratory tract, such as the large surface area of the nasal turbinates and the mucus lining the nose, pharynx, and trachea.  Smaller droplets, meanwhile, are capable of being inhaled deep into the lungs, resulting in infection in the lower respiratory tract which can cause more severe disease.  The current study found that there was an increased risk for fever plus cough in people suspected to have contracted the flu by inhalation of infective aerosols, which is consistent with current ideas regarding the importance of the route of infection.1

Understanding the routes of transmission of influenza is also important for designing control measures to reduce the spread of this disease.    Interventions such as increased hand hygiene and facemasks help to limit transmission of influenza by larger droplets produced by coughing and sneezing, but may offer little protection from inhaled aerosols.1 Additional methods for controlling the spread of influenza through aerosols, such as improved ventilation of enclosed spaces, ultraviolet lights (which are capable of killing the flu virus), and minimizing exposure to those infected with the flu could reduce the risk of becoming sick.1

So, what can you do avoid getting the flu?  The most effective way is to get vaccinated before flu season.  In the United States, flu season can start as early as October, though the peak months for flu are January and February, and sometimes even later.3 Because the flu strains circulating through the population change from year to year, you should be vaccinated each year.  The vaccine is developed to prevent illness caused by the flu strains likely to cause outbreaks during the flu season, but may not prevent illness from novel or unanticipated strains causing outbreaks.  Some people, such as babies less than 6 months old and those with allergies to eggs should not receive the flu vaccine.3  So the CDC recommends that you take additional preventive measures, such as good hand hygiene, avoid close contact with people who are sick with the flu, avoid touching your eyes, nose, and mouth, and practice good health habits such as remaining well hydrated, eating a healthy diet, exercising, and getting plenty of rest.5

If you do get the flu, what can you do to avoid infecting your family, friends, and colleagues?  First, avoid close contact with others.  Stay home from school or work if at all possible, and don’t run errands while you are sick.  In this way, you can avoid exposing others to your illness.  Second, cover your nose and mouth when you cough or sneeze.  Experts recommend that you cough and sneeze into a cloth or into your elbow, so that you don’t contaminate your hands, which are commonly implicated in the spread of the flu.  This simple practice can reduce the amount of infectious material you spread into your environment.  Practice good hand hygiene, particularly before touching doorknobs and other items that may leave the virus where others are likely to become exposed.5

References

  1. Cowling, B.J., Dennis, K.M., Fang, V.J., Suntarattiwong, P., Olsen, S.J., Levy, J., Uyeki, T.M., Leung, G.M., Malik Peiris, J.S., Chotpitayasunondh, T., Nishiura, H., & Simmerman, J.M. (2013).  Aerosol Transmission is an Important Mode of Influenza A Virus Spread.  Nature Communications, DOI: 10.1038/ncomms2922  LINK
  2. Bridges, C.B., Fry, A., Fukuda, Shindo, N., & Stohr, K. (2010).  Influenza (Seasonal).  In Heymann, D.L. (Ed.).  Control of Communicable Diseases Manual.  American Public Health Association, Unbound™ Mobile Platform
  3. Centers for Disease Control (February 13, 2013), Key Facts About Influenza (Flu) and Flu Vaccine, accessed at http://www.cdc.gov/flu/keyfacts.htm , June 8, 2013
  4. Centers for Disease Control (May 6, 2013), What You Should Know for the 2013-2014 Flu Season, accessed at http://www.cdc.gov/flu/about/season/flu-season-2013-2014.htm, June 8, 2013
  5. Centers for Disease Control (January 11, 2013) Preventing the Flu: Good Health Habits Can Help Stop Germs, accessed at http://www.cdc.gov/flu/protect/habits.htm, June 8, 2013
  6. Flu Virus Image:  Tom Yulsman (May 26, 2009), U.S. and Other Countries Fail to Adequately Monitor Pigs for Flu, accessed at http://www.cejournal.net/?p=1934, June 8, 2013
  7. Sneeze Image:  Ben Mauk, photo credit Andrew Davidhazy/RIT (November 28, 2012), Why Do Bright Lights Make Me Sneeze?, accessed at http://www.livescience.com/32307-why-do-bright-lights-make-me-sneeze.html, June 8, 2013

Pig-to-monkey Ebola: is there something in the air?

Ebola has long been known to be a zoonotic virus–one which jumps between species. Though it took several decades to find evidence of Ebola virus in bats, these animals had previously been associated with human index cases of Ebola disease have worked in bat-infested warehouses or traveled to caves where bats roost. Non-human primates have also become infected with the virus, sometimes transmitting the virus to humans when killed primates are butchered for food. Ebola has also been suggested to infect dogs and other wild animals. However, livestock are a newer angle to Ebola virus ecology.

Ebola was first found in pigs in 2008 in the Philippines. This was the Reston virus, named after its discovery in imported Filipino monkeys in a facility in Reston, Virginia, in 1989. Though this virus spread among the captive monkeys, no humans came down with symptoms. However, follow-up studies showed that some humans did develop an immune response to the Reston virus–suggesting they had been infected, even if they didn’t realize it. At the time, there was suggestion that perhaps Reston might be spread via aerosol, as the virus appeared to spread amongst monkeys in two different rooms who did not come into physical contact with one another. However, this was not proven at the time and alternative explanations were possible.

When Reston resurfaced in swine and swine farmers in 2008, a similar phenomenon was observed. Though it was not known how the pigs initially became infected with the virus, they did appear to be able to spread it to humans working amongst them, even if those farmers didn’t have contact with blood or other secretions (the most efficient way to transmit Ebola viruses). Suggestive of possible transmission from pigs to people via air, but far from conclusive. Since then, two experimental studies have examined airborne transmission of Ebola via pigs.

The first study examined transmission of the Zaire strain of Ebola–the nastiest one, which can kill up to 90% of those infected–within laboratory pigs. Pigs were inoculated with the Zaire virus and housed with uninfected pigs, who were later tested and found to have acquired the virus. Interestingly, when the pigs got sick with Ebola Zaire, the symptoms were mainly respiratory and the virus replicated in the lungs. This was quite unlike what Zaire does in humans and our other primate cousins, where it’s a systemic disease and we can find virus in the blood. This suggests that pigs could be infected with even nasty types of Ebola, and we wouldn’t realize it.

Last week, Ed Yong reported on a new paper examining transmission of Zaire virus from experimentally-infected pigs to co-housed macaques. Like the previous paper, they observed that Ebola in pigs was a respiratory disease, and that it could spread to other animals (in this case, non-human primates). The macaques they tested developed the symptoms of Ebola that were expected–a systemic disease, with virus isolated from the blood. In this study, they also added in an air sampling component, and were able to detect evidence of virus (via PCR) in the air. However, the authors do note that this could have been aerosolized in other manners than directly from the exhaling pigs (such as during the floor-cleaning process). Finally, even if it does become aerosolized and spread in this manner, as noted in Ed’s article, Ebola is not “suddenly an airborne virus, like influenza.” Certainly more efficient transmission takes place via close contact with infected secretions during hospital procedures and funeral rites.

Interestingly, the authors note that other experimental studies that have looked specifically at airborne, primate-to-primate transmission of Ebola have come up negative, and that swine are known to generate “infectious short range large aerosol droplets more efficiently then other species.” Is there something specific about pig physiology that may make them better respiratory virus shedders? We know that pigs can be intermediate hosts for other viral pathogens as well, such as Nipah virus and of course influenza.  Are pigs playing any role in Ebola ecology, either in Asia or Africa? Might Ebola have more airborne potential than we previously thought? According to Ed, the authors of the second study are currently working on field studies in Africa to examine the pig question outside of the laboratory. The timing may be good for them, as Uganda is currently experiencing another Ebola outbreak;–the country’s third Filovirus outbreak in five months.

Reference

Weingartl, H., Embury-Hyatt, C., Nfon, C., Leung, A., Smith, G., & Kobinger, G. (2012). Transmission of Ebola virus from pigs to non-human primates Scientific Reports, 2 DOI: 10.1038/srep00811