(NOTE: The first case of Ebola Virus Disease (EVD) diagnosed in the United States occurred yesterday in Dallas. With this sentinel event, I’ve revisited this article from August to update some of the information. If you are a healthcare worker, PLEASE review the information found at http://www.cdc.gov/vhf/ebola/ . ~ MH 9/30/2014.)
Earlier this week, I had the opportunity to listen-in to a conference call hosted by the Centers for Disease Control (CDC) that presented detailed clinical information for physicians and health care policymakers on the transmission and prevention of the Ebola virus. Because there is a lot of fear and misinformation surrounding the virus and the possibility of it jumping onto other continents, I’d like to share with you what I’ve learned from both the CDC call and the physicians I work with who will have major responsibilities in directing the response if the virus shows up in the US. Of course, please refer to the CDC page on the virus or your local epidemiologist for specifics.
By now we know that Ebola is a fearsome killer. Its five known strains kill up to 90% of the people it infects, dissolving the body’s connective tissue until it becomes like an overfilled, leaky sponge of blood. But understand that much of Ebola’s power lies in the fear it provokes in our minds as a relatively new disease to the human condition, only having been known about since 1976. The current strain burning through West Africa has a 60% mortality rate, which is exceptionally high for any infectious disease, but yet far below the 100% mortality rate of an even nastier virus that’s probably within a mile of you right now, rabies.
Of course, the difference between contracting rabies and Ebola lies in the way they are transmitted, and knowing how any disease is transmitted is the best way to avoid it. Rabies transmits from animals to humans, but we live with this scourge because we’ve been educated to avoid contact with wild animals. Ebola can be transmitted from both animals and humans, and it’s pretty difficult to avoid contact with humans unless you lock yourself in your house until this is all over. (If you do decide to lock yourself in your house to avoid Ebola, may I suggest ordering The Spider and the Wasp to keep you company in your isolation? It’s my new book!)
However, it may come as a surprise that although the virus is highly infectious, it’s not highly transmissible. It’s actually kind of a difficult virus to contract. “You kind of have to earn Ebola,” one physician here told me. You have to be in close enough contact such that a body fluid of an infected person enters your body through a membrane or cut. When they say “body fluid,” they mean any body fluid of the infected person: blood, sweat, urine, feces, vomit, saliva, tears, breast milk, and semen can all carry live virus particles.
Although Ebola can be spread by droplets (such as when an infected person sneezes or coughs on another), but it is not an aerosolized virus like measles or smallpox that has evolved to transmit itself through the air. Measles, for example, can be contracted by simply walking into a room and breathing the air within four hours after an infected person has been there. Smallpox, thankfully, was the target of a coordinated WHO eradication effort in the ’70s and is now believed to be eradicated. (In the first 75 years of the 20th Century alone, an estimated 500 million humans died from the virus.)
This is why we are seeing the virus spread primarily to health care workers and immediate family members taking care of the patients, because it spreads among those who are in what the CDC refers to as “prolonged proximity” to the patient. These are the people who are working around infected fluids, and who then absentmindedly rub their eyes or take off their personal protective equipment incorrectly. As per the CDC call, you basically don’t have to worry about catching the virus unless you’re within three feet of the patient for an extended period of time. Walking by an infected person will not hurt you, nor will sitting next to the person on a subway car, unless he sneezes or coughs or vomits or bleeds on you. Unless the person is exhibiting symptoms, he’s not contagious anyway. Although Ebola is a master at sustaining itself in the human body (it can remain present in a recovered person for over three weeks), that’s about all it can do: The virus dies when the fluid it’s in dries out, and it can be easily killed with a 10% bleach solution. Flamethrowers are not a necessity with Ebola.
There are other issues with this Ebola outbreak, the most pressing being the uncertainty of how, where, and when infected individuals may enter the country. (Again, that happened today, September 30, 2014.) There’s also no cure. Although the ZMapp serum holds promise, the entire stock of ZMapp was used to treat seven patients. At least 5 of those patients recovered, but it is statistically unknown if the recipients were cured by ZMapp; simply being treated at Western hospitals gave several of those 7 patients access to a level of sustained, high-quality medical care that is often not found in Africa. Many of the victims in Africa are succumbing to Ebola in part due to complications caused by dehydration and hypokalemia, which is rare to occur in US hospitals.
There are two other long-term issues when the epidemic is over, first being the issue of the virus leaving Africa and finding an animal reservoir that will give it a sustained (a.k.a., “endemic”) presence in North America. But it’s been 150 years since rats jumped off ships on the West Coast and their fleas carried bubonic plague to the American Southwest, and we have yet to be wiped out from the Black Death despite fleas being everywhere. A second issue is that with each new infection, natural selection means the virus may mutate to become aerosolized like measles and smallpox. But although Ebola is now encountering many more humans than it ever has, the chances of this happening quickly are very slim. Consider the one virus whose shape-shifting powers of mutation puts Ebola and pretty much every other virus known to man to shame – the seasonal flu. The seasonal flu is so adept at mutating into new strains that it is not uncommon for one strain to enter an individual, and a completely different strain to leave the same person a few days later; this is why each year’s flu vaccine is essentially a guess on the behalf of researchers as to which strains they might see. But even with that awesome power, the really deadly flus – the pandemic flus – only occur two to three times a century.
In the end, you really need not worry about the apocalypse occurring with Ebola. Like rabies and plague and nearly every other transmissible disease, Ebola can be stopped by education far more effectively than it can be stopped by medication.
Matt Haarington, MPH, MSHI is an advisor on public policy and health care issues for Social Justice Solutions. He is the author of The Spider and the Wasp, which is the funniest book you’ll ever read about being traumatized.
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