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.

The microbiology of zombies, part IV: hidden infections

(As previously, spoilers abound)

So on this week’s Walking Dead soap opera, we find that Daryl/Michonne’s group is still out and about searching for medical supplies. Back at the prison, the food situation is dire (apparently all the food stores were in the cell block where the infection broke out), so Rick and Carol head out to look for both medicines and food from the local ‘burbs. During their outing, discussion ensues of Carol’s attempt to stop the prison’s apparent influenza outbreak by killing two people who, at that point, were the only ones showing symptoms of disease. Rick decides he can’t trust her, and ends up banishing her from the group.

Carol said multiple times that she was trying to do the right thing, to protect the rest of the group from those who were sick and was only trying to end the outbreak. However, here’s where some knowledge of infectious disease would have helped her. Every disease has an incubation period: the time when the microbe is multiplying in your body, but you’re not showing any physical disease symptoms yet. This can be short–as little as perhaps a few hours for something like Salmonella food poisoning. It can be extremely extended, as I mentioned with rabies virus in my previous post, where the incubation period can be months to years. With influenza, the typical incubation period is 2 days, but it can be as short as 1 or as long as 4-5. The kicker is that a person who’s incubating flu can still spread it even before they show symptoms of the illness. So just because Karen and David were the only ones actively coughing and looking miserable, Carol was mistaken in her assumption that they were the only ones infected, and that she could stop the outbreak by snuffing them.

This is the difference between two similar concepts, quarantine and isolation. People who have been *exposed* to an infectious agent, but are not yet showing any signs of illness, can be quarantined to keep them away from others due to their *potential* to spread a disease. Those who are already showing signs and symptoms are placed into *isolation* to keep them from spreading it–they’re a known quantity. The prison group has used primarily isolation to keep the infection from spreading: they’re putting the ill in the Death Row cell blocks as an isolation area, and those who are well can roam around as they choose. (Maggie, for instance, hasn’t been sent to quarantine even though she clearly was exposed to the illness by being in such close contact with Glenn).

However, one thing that the group hasn’t yet determined (probably because no one has recovered as of yet) is how long they’re going to keep anyone who gets better in the isolation area. Though adults usually stop releasing influenza virus even before their symptoms are completely gone, kids can shed the virus for a long time: up to two weeks after their symptoms started according to one study (and others have found similar results). So while right now they have the healthy young children segregated from everyone else for their own protection, in theory, if Lizzie (the flu-infected child currently in held in isolation) gets well and is released back to the healthy kid’s room, she could simply re-start the outbreak there, among the most susceptible. 

This is why disease eradication is so difficult, and why it’s been accomplished for so few pathogens to date: many pathogens can spread on the sly, even when people don’t know they’re sick. For influenza, even if it’s knocked down in this group (and of course, it soon will be one way or another–at some point, the susceptible hosts in the prison will be exhausted, either by infection & recovery or by death), there is always another reservoir of disease out there. It may be other humans. Darryl/Michonne’s group finally made it to the veterinary school mentioned two episodes ago, and the zombies they ended up fighting there had clinical signs that looked an awful lot like the survivors had seen at the prison: blood that had come from the eyes and nose. Had flu been circulating there as well? It’s a vet school, pigs could certainly be housed (there were a number of animal cages, and could easily be an outdoor space for livestock somewhere). So pigs could be serving as a reservoir. Flu can also come from a number of other animals–most notably, birds, who don’t even have to appear sick to transmit the infection to people.

Infections can be sneaky and unseen, as this group should well know.

See also:

Part I: the microbiology of zombies

Part II: ineffective treatments and how not to survive the apocalypse

Part III: “We’re all infected”

Pigs with Ebola Zaire: a whole new can o’ worms

Ebola has long been associated with wildlife. From the early days, bats were viewed as a potential reservoir (though it wasn’t confirmed that they actually harbored the virus until 2005). Contact with wild animals–particularly primates which were butchered for food–was also long thought to be a risk factor, and now we know that primates can become ill with Ebola and pass the virus to humans.

What hadn’t been examined until 2008 were pigs. I mean, it’s not exactly the animal you associate with central Africa, where many of the Ebola cases have been concentrated. However, pigs are much more plentiful in the Philippines, where another Ebola subtype–Ebola Reston–is thought to lurk. The Reston strain actually was first documented in the United States, where twice it was associated with outbreaks in primates originating from the Philippines. When the facility in the Philippines was closed down in 1997, Reston disappeared for 11 years–until it surfaced in pigs in 2008.

The ecology of Ebola Reston in the Philippines isn’t known–unlike African Ebola strains (and their cousin, Marburg), no bats have been caught in that country and tested positive for the virus, though they probably serve as a reservoir of the virus in the Philippines just as they do in Africa. So it was a huge surprise when pigs from that country tested positive for Ebola Reston–and so did 6 of their human caretakers, suggesting cross-species transmission. (I should note here that the Reston strain has yet to be linked to any symptomatic infections in humans–the pig farmers who tested positive probably had no idea they’d been infected and did not show any clinical signs of illness). Pigs hadn’t previously been linked to any Ebola infection, so this brought in a whole other wrinkle when it came to Ebola transmission–the possibility of being exposed to Ebola via contaminated food, and the potential for pig populations to harbor the filovirus (and transmit it to their caretakers, as we have seen with outbreaks of Nipah and Hendra viruses).

A new study delves further into Ebola in pigs. Instead of using the Reston strain, they use the much-more-deadly Zaire strain. This is the one that movies are made about; the one which can cause outbreaks so nasty that they kill up to 90% of those who are infected. Why use Zaire instead of the Reston strain–the one which has actually infected pigs in nature? Well, the researchers wanted to find an animal that’s easier to work with than primates (there are all kinds of very strict regulations when it comes to working with non-human primates), so if pigs could work as a good model for human Ebola disease, that would make studying the virus just a bit easier. (In any case, for any live Ebola work, it still needs to be done in a biosafety level 4 environment, meaning complete spacesuits and the whole works).

The authors did 2 studies. In the first, they inoculated 6 pigs with Ebola Zaire, via a combination of intranasal, intraocular, and oral routes of infection. (Interestingly, no injection, which can be a key way Ebola is spread). They had an additional 2 pigs that they inoculated the same way with a saline solution, and housed them separately from the Ebola-inoculated animals. The goal of this experiment was to look at the pathogenesis of a virulent Ebola strains in the pig model. The infected animals all developed fevers and respiratory disease, with some internal hemorrhaging and evidence of airway replication by Ebola. Infectious virus was found at low levels in nasal washes and oral and rectal swabs; one animal also had a low level of virus in the blood. Higher levels of virus were found in various organs, including the heart and bladder, while the highest levels were found in lung tissue.

In the second experiment, they inoculated 3 new pigs in the same fashion, but then added in 4 additional (uninoculated) animals to stay with them, and kept 2 additional control animals in a separate area so that they could investigate pig-to-pig transmission of the virus. They did find viral RNA from the mucosa of all contact animals, and infectious virus was detected from 2 of 4, demonstrating that the virus can be passed among pigs. Not stated in the article was if the authors thought this was due to direct contact with respiratory secretions among the pigs, or via airborne transmission (a much more concerning route of transmission, as in humans, Ebola Zaire doesn’t seem to transmit well via air–typically it’s spread via close direct contact and bodily fluids).

Notably, pigs didn’t seem to develop severe systemic disease from Ebola, as primates do–the main symptoms exhibited were respiratory, which the pathology supports (finding little virus in the blood, but a lot in the lungs). This suggests that even for Ebola Zaire, infection in a pig could be mistaken for other respiratory diseases, such as influenza or PRRS virus (porcine respiratory and reproductive syndrome virus, which the initial pigs in the Phillipenes were co-infected with). So, Ebola may be circulating even more than we realize in the pig population, disguised by its commonplace symptoms.

A commentary published in tandem with the research article ponders the issue of foodborne Ebola, suggesting that this is a remote possibility and noting that butchering infected animals in the wild in Africa has certainly spread the virus. However, solely eating meat as a means of infection hasn’t been reported, and cooking likely destroys any risk (similar to influenza viruses). Like influenza virus, Ebola doesn’t seem to survive long in most environments, but it’s also noted that differences in African food storage (with little refrigeration) versus more typical cold storage may affect that as a risk factor, possibly prolonging the life of the virus when held in the cold. I think foodborne transmission is unlikely, but it can’t be completely ruled out right now.

Because of the respiratory symptoms, does this mean Ebola could enter the population via meat from animals that farmers don’t consider very ill, or put butchers at a heightened risk of infection during slaughter? This to me is more concerning than simple foodborne transmission. With Reston, at least no human symptoms have been observed, but if pigs (and potentially other animals?) can present with Ebola Zaire as a rather generic respiratory infection…well, that could spell trouble in a lot of different ways. It means that telling individuals to simply avoid sick-looking primates (and bats) is going to be even more woefully inadequate than it already is. Plus, it raises the remote-but-not-completely-outside-the-realm-of-possibility of someone intentionally spreading the virus via animals that are infected in this manner.

Science fiction? Maybe. Probably. Hopefully. But this research opens the door on many new lines of investigation and once again, raises even more questions.

Kobinger GP, Leung A, Neufeld J, Richardson JS, Falzarano D, Smith G, Tierney K, Patel A, & Weingartl HM (2011). Replication, Pathogenicity, Shedding, and Transmission of Zaire ebolavirus in Pigs. The Journal of infectious diseases PMID: 21571728

Dengue in Florida

At his new digs, PalMD discusses recent news revealing the presence of dengue virus in the Florida Keys–the first appearance in the state in almost 75 years. Dengue is a mosquito-borne virus that can cause serious disease, including a hemorrhagic manifestation, and the current outbreak is pitting public health professionals against the tourism industry in the Keys. It’s also brought to public attention the closing of CDC’s vector-borne disease branch due to funding difficulties. The intersection of these–viral emergence, politics, and economic interests–has the potential to cause a huge mess on the gulf coast, where they’ve obviously already had enough recent heartbreak.