The Ebola virus is a hemorrhagic fever that kills about 70 percent of its victims. Ebola typically strikes like the worst and most humiliating flu you could imagine. People get the sweats, along with body aches and pains. Then they start vomiting and having uncontrollable diarrhea. They experience dehydration. These symptoms can appear anywhere between two and 21 days after exposure to the virus. Sometimes, patients go into shock. Rarely, they bleed.
In fatal cases, death comes fairly quickly — within a few days or a couple of weeks of getting sick. Survivors return to a normal life after a months-long recovery that can include periods of hair loss, sensory changes, weakness, fatigue, headaches, eye and liver inflammation.
There are five strains of Ebola, four of which have caused the disease in humans: Zaire, Sudan, Taï Forest, and Bundibugyo. The fifth, Reston, was discovered in Virginia and has infected monkeys only. Though scientists haven’t been able to confirm this, the animal host of Ebola is widely believed to be the fruit bat, and the virus only seldomly makes the leap into humans.
The current outbreak involves the Zaire strain, which was discovered in 1976 — the year Ebola was first identified in what was then Zaire (now the Democratic Republic of the Congo). That same year, the virus was also discovered in South Sudan.
The Ebola virus is extremely rare. Among the leading causes of death in Africa, it only accounts for a tiny fraction. People are much more likely to die from AIDS, respiratory infections, or diarrhea, as you can see.
Since 1976, there have only been about 20 known Ebola outbreaks. Until last year, the total impact of these outbreaks included 2,357 cases and 1,548 deaths, according to the Centers for Disease Control and Prevention. They all occurred in isolated or remote areas of Africa, and Ebola never had a chance to go very far.
To get Ebola, you need to have direct contact with the bodily fluids — such as vomit, urine, or blood — of someone who is already sick and symptomatic to get the disease.
But what, exactly, does that mean? Here’s a more concrete guide on how the virus can move from one person to another.
How you can get Ebola
1) You can get the virus if you have “direct contact” with a range of bodily fluids from a sick person, including blood, saliva, breast milk, stool, sweat, semen, tears, vomit, and urine. “Direct contact” means these fluids need to get into your broken skin (such as a wound) or touch your mucous membranes (mouth, nose, eyes, vagina). As well, the sick person has to be far enough along in the illness — with enough virus in the bloodstream — to successfully transmit the disease.
2) So you can get Ebola by kissing or sharing food with someone who is infectious.
3) Mothers with Ebola can give the disease to their babies. Ebola spreads through breastfeeding — even after recovery from the disease. As one study put it, “It seems prudent to advise breastfeeding mothers who survive (Ebola) to avoid breastfeeding for at least some weeks after recovery and to provide them with alternative means of feeding their infants.”
THE EBOLA VIRUS HAS BEEN ABLE TO LIVE IN SEMEN FOR UP TO 82 DAYS4) You can get Ebola through sex with an Ebola victim. The virus has been able to live in semen up to 82 days after a patient became symptomatic, which means sexual transmission — even with someone who has survived the disease for months — is possible.
5) You can get the virus by eating wild animals infected with Ebola or coming into contact with their bodily fluids. The fruit bat is believed to be the animal reservoir for Ebola, and when it’s prepared for a meal or eaten raw, people get sick.
So you can get the virus through exposure to bat secretions. However, if you cook a bat infected with Ebola and then eat it, you won’t get sick because the virus dies during cooking.
6) You can get Ebola through contact with a contaminated surface. Though Ebola is easily killed with disinfectants like bleach, if it isn’t caught, it can live outside the body on, say, a doorknob or counter top, for several hours. In body fluids, like blood, the virus can survive for several days. So you’d need to touch an infected surface, and then put your hands in your mouth and eyes to get Ebola.
This is why the funerals of Ebola victims are problematic. Someone who has died from the virus will have a very high viral load. Since the virus can live in bodily fluids on their body, if you participate in the ritual washing of an Ebola victim and then touch your hands to your face, you could get the virus.
7) You could also get the virus by working in a biosafety-level-4 lab that studies Ebola, touching lab specimens, and then putting your contaminated hands in your mouth, eyes or a cut.
8) You can get Ebola by being pricked with a needle or syringe that has been contaminated with the virus. This has been a source of transmission for health workers, but unless you’re an Ebola health worker or sharing needles with Ebola victims, this isn’t likely.
How you can’t get Ebola
1) You can’t get Ebola from someone who is not already sick. The virus only turns up in people’s bodily fluids after a person starts to feel ill, and only then can they spread it to another person.
2) You can’t get Ebola from just sitting next to an asymptomatic, or even mildly symptomatic person on, say, a plane or subway. As one of the Ebola discoverers, Peter Piot, said, “I wouldn’t be worried to sit next to someone with Ebola virus on the Tube as long as they don’t vomit on you or something. This is an infection that requires very close contact.”
YOU CAN’T GET EBOLA FROM MOSQUITOES3) You can’t get Ebola from mosquitoes. The CDC says, “Only mammals (for example, humans, bats, monkeys and apes) have shown the ability to spread and become infected with Ebola virus.”
4) You usually can’t get Ebola through coughing or sneezing. The virus isn’t airborne, thankfully, and experts expect that it will never become airborne. But, the Centers for Disease Control and Prevention said, “If a symptomatic patient with Ebola coughs or sneezes on someone, and saliva or mucus come into contact with that person’s eyes, nose or mouth, these fluids may transmit the disease.” This happens rarely and usually only affects health workers or those caring for the sick.
The bottom line: Ebola is difficult to catch
Ebola isn’t very easy to transmit. The scenarios under which it spreads are very specific. And Ebola doesn’t spread quickly, either. A mathematical epidemiologist who studies Ebola wrote in the Washington Post, “The good news is that Ebola has a lower reproductive rate than measles in the pre-vaccination days or the Spanish flu.” He found that each Ebola case produces between 1.3 and 1.8 secondary cases. That means an Ebola victim usually only infects about one other person. Compare that with measles, which creates 17 secondary cases. NPR had an excellent graphic to that effect:
If you do the math, that means a single case in the US could lead to one or two others. (That’s what happened in Dallas: one patient infected two nurses when he was very sick.) Because we have robust public health measures here, it probably won’t go further than that. Compare that to West Africa, which is now dealing with upwards of 20,000 cases in a completely broken health system. That’s where experts say the worry about Ebola should be placed.
Ebola killed more than 7,000… Our thoughts and prayers are with all the families and those affected.
Read more on this deadly virus visit Vox’ main website by clicking here.