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Wednesday 18 March 2015

5 WAYS YOU STILL CAN'T GET EBOLA


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5 Ways You Still Can't Get Ebola
By Meisa Salaita,
How Stuff Works, 9 February 2015.

Just the idea of a virus like Ebola gives people the heebie-jeebies. The thought of something so powerful that it can infect and kill its victims within weeks is enough to make you want to hide out and not have contact with anyone.

In reality, that's a bit extreme. Sure, the virus is scary and certainly a threat to be taken seriously as it arises, but the more we can understand about this fast-acting killer, the better prepared we will be in our fight against it.


Like other viruses, Ebola hangs out in the environment somewhere waiting to infect a host cell that may be passing through. But unlike some other viruses, Ebola is only transmitted through human-to-human direct contact via bodily fluids, and only if the person with the virus is showing symptoms. As long you stay clear of known outbreak areas and don't come in contact with infected people, you should be fine.

Just in case you are still feeling a little wary, let's explore five ways you still can't get Ebola.

5. Ebola Doesn't Linger in the Air

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Coughing and sneezing, both prime ways to pass on germs, aren't the main routes of transmission for Ebola.
Credit: James Gathany/Wikimedia Commons.

Unlike other viruses such as SARS and influenza, Ebola cannot pass through the air; it's only transmitted through direct contact of bodily fluids. Airborne illnesses are passed through inhalation of tiny virus-laden particles floating in the air. What makes all the difference in determining how airborne a virus may be is the size of the droplet through which transmission occurs. Fine mist aerosols (like those that occur when you cough or sneeze) linger in the air and can travel through it fairly easily.

Thankfully, unlike the flu, Ebola does not cause symptoms of coughing or sneezing. Technically, Ebola victims can send large droplets of contaminated bodily fluids into the air if, for example, they vomit onto the floor and some droplets splatter upward. But large droplets can't travel far, nor do they persist in the air for very long, making this transmission method a near impossibility.

In 2012, scientists discovered that Ebola was transmitted from pigs to monkeys without direct contact, but so far, this study isn't really of concern to us. Pigs generate large infectious droplets better than any other animal, and these may have easily been passed to the monkeys during cage cleaning. Plus, people aren't pigs or monkeys. All studies done with humans have shown no support for transmission to occur without direct contact [source: Poon].

4. Ebola Doesn't Pass Through Drinking Water or Food

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A man washes his hands in chlorinated water as UNICEF health workers walk through the streets, speaking
about Ebola prevention on Aug. 18, 2014 in New Kru Town, Liberia.

Chances are, you aren't going to get Ebola from anything you drink or eat. The only liquids Ebola persists in are bodily fluids - blood, diarrhoea and vomit mostly (1 millilitre can carry a million infectious particles!) [source: Poon]. Unlike bacteria, viruses are not very resistant outside the body, so coming across Ebola in your drinking water is not going to happen. Water does a terrible job at protecting the Ebola virus, and it gets deactivated in a matter of minutes [source: Poon]. What if your water isn't contaminated with the virus alone, but with Ebola-infected cells? Even with the protection that the cell would offer the virus, the change in salt concentration between water and bodily fluids is enough to cause the cell to burst, killing the virus in the process.

You also are highly unlikely to end up eating your way to an Ebola infection. There's really only one category of food that might make you sick - bushmeat, wild animals captured in developing regions of the world like Africa. Ebola infections have been associated with people handling and eating these animals when the animals are infected with Ebola [source: National Centre for Emerging and Zoonotic Infectious Diseases]. Without lab tests, there's no real way to confirm if an animal is infected with Ebola, so it's best to stay away from eating and handling dead animals from Africa.

As we said, Ebola only lives in bodily fluids of infected people. While saliva doesn't carry the virus as strongly as blood, vomit and diarrhoea, Ebola has been detected in the saliva of patients in severely advanced stages of the disease. So technically if you share food or drink with someone very sick with Ebola, the disease may be transmitted to you through his or her leftover saliva.

3. That Bug Bite Won't Cause Ebola

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Mosquitoes are excellent at spreading all sorts of pathogens, but Ebola isn't one of them. Credit:
James Gathany/Wikimedia Commons.

It's probably safe to assume that everyone finds mosquitoes annoying. In certain parts of the world, they move beyond the annoying category into the dangerous category as they spread diseases like malaria and dengue fever. While these diseases are nothing to sneeze at, at least we can take comfort in knowing that mosquitoes do not spread Ebola. Neither do fleas or ticks. In fact, only mammals have been shown to be infected with and able to spread Ebola.

While we don't know with total certainty, scientists hypothesize that fruit bats in Africa are the most likely carriers of the disease. How the virus gets from the bats to humans and other mammals is still a mystery, however. Bats have been associated with known index cases (the first human infected in an outbreak) of Ebola in past outbreaks of the disease, but the exact connection to humans is still unclear.

If mammals can be infected with the virus, does that mean you need to worry about your cat or dog getting infected, or even infecting you? Nope. Even in areas of outbreak where Ebola has affected a large number of people, there have been no reports of dogs or cats getting sick from the disease [source: CDC].

2. You Can't Get Ebola From Someone Who Isn't Sick With Symptoms

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A man has his temperature taken using an infrared digital laser thermometer at the Nnamdi Azikiwe
International Airport in Abuja, Nigeria, on Aug. 11, 2014. Fever is one of the early symptoms of Ebola.

If there's anything "nice" about Ebola, it's that the virus only transmittable from person to person when the infected person is showing symptoms. That makes it much easier to contain, and helps give us all a clue of who we need to stay away from. So even if someone on your airplane starts to show Ebola symptoms the day after your flight, there's no way that you could have gotten sick from them. In fact, even if they had symptoms on your flight, just being in proximity to them is not enough to get you Ebola. You've got to swap bodily fluids in some way - blood, vomit, diarrhoea, semen (sweat, saliva and tears can also contain the virus, but at low levels compared to these other fluids [source: Poon]).

How about from people who have had Ebola - can you get sick from them? If they succumbed to the disease and you have direct contact with their bodily fluids even after they've died, yes. If they survived the disease, you are safe. That said, men who have been cured can still carry the virus in their semen for up to seven weeks post-recovery [source: World Science Festival].

1. Ebola Can Be Cleaned From Surfaces

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Two German doctors stand in a disinfection chamber after cleaning their protective suits at the quarantine
station for patients with infectious diseases at the Charite hospital in Berlin on Aug. 11, 2014.

Ebola is scary. And it's a frightening to think about touching something that was previously contaminated with the virus. After all, a drop of Ebola-laden blood can remain contagious outside the body with the virus surviving for days or even weeks, depending on the environment [source: Poon]. Cooler temperatures and humidity will keep it active for longer.

But if there's 100 percent certainty that a surface has been decontaminated with hospital grade disinfectants like bleach, then you can't get the virus by coming in contact with that surface. And if the surface has never even seen the likes of Ebola, then there's definitely no danger. So there's no need to fear goods from Africa that are shipped abroad.

As with all infectious diseases, it's important to think about good hygiene practices. Ebola and more common diseases like the flu can all be kept at bay by simply taking good care to wash your hands.

Author's Note: I first wrote about Ebola for How Stuff Works near the start of the 2014 outbreak in West Africa, and then again months later for this piece. During that time, I went from digging in the library for journal articles about the virus to simply typing an "e" in Google and getting a million hits about Ebola. Also during that time, we went from books and journal articles saying that treatments for Ebola were ineffective and not worth the pursuit for pharmaceutical companies to experimental testing of drugs and fast-tracking of clinical trials. Astounding what the threat of something like Ebola in your backyard can do to make people snap into action and sad that the many lives lost to the disease before this outbreak weren't enough to make much headway in treatment options.

Related Articles:

Article Sources:
1. Centres for Disease Control and Prevention. "Questions and Answers about Ebola and Pets." Oct. 13, 2014. (Oct. 30, 2014)
2. National Centre for Emerging and Zoonotic Infectious Diseases, Division of Global Migration and Quarantine. "Facts About Bushmeat and Ebola." September 2014. (Oct. 30, 2014)
3. Poon, Linda. "How Do You Catch Ebola: By Air, Sweat or Water?" NPR. Sept. 12, 2014. (Oct. 22, 2014)
4. World Science Festival. "Everything You Need to Know About Ebola." Oct. 21, 2014. (Oct. 30, 2014)
5. Zimmer, Carl. "As Ebola Spreads, So Have Several Fallacies." The New York Times. Oct. 23, 2014. (Oct. 29, 2014)

Top image: A registered nurse demonstrates putting on personal protective equipment (PPE) during an Ebola educational session for health care workers in New York on Oct. 21, 2014. Credit: © MIKE SEGAR/Reuters/Corbis.

[Source: How Stuff Works. Edited.]

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