Like many of you, I've been following the story about the Ebola outbreak in West Africa and the infected American missionaries who are being transported back to the United States.
I've been deeply dismayed by some of the hysteria online and in the MSM surrounding the return of Dr. Brantly and Ms. Whitebol. A subject other diarists have addressed. Ranging from crazy conspiracy theories (the US government created Ebola to kill us all!) to the more understandable, but largely unfounded, fear of the disease spreading in the United States or Europe.
I think it's time we discussed the facts surrounding Ebola.
1. What is Ebola hemorrhagic fever?
In 1976, Ebola (named after the Ebola River in Zaire) first emerged in Sudan and Zaire. The first outbreak of Ebola (Ebola-Sudan) infected over 284 people, with a mortality rate of 53%. A few months later, the second Ebola virus emerged from Yambuku, Zaire, Ebola-Zaire (EBOZ). EBOZ, with the highest mortality rate of any of the Ebola viruses (88%), infected 318 people. Despite the tremendous effort of experienced and dedicated researchers, Ebola's natural reservoir was never identified. The third strain of Ebola, Ebola Reston (EBOR), was first identified in 1989 when infected monkeys were imported into Reston, Virginia, from Mindanao in the Philippines. Fortunately, the few people who were infected with EBOR (seroconverted) never developed Ebola hemorrhagic fever (EHF). The last known strain of Ebola, Ebola Cote d'Ivoire (EBO-CI) was discovered in 1994 when a female ethologist performing a necropsy on a dead chimpanzee from the Tai Forest, Cote d'Ivoire, accidentally infected herself during the necropsy.
While the exact reservoir of Ebola viruses is still unknown, researchers believe the most likely natural hosts are fruit bats.
In Africa, infection has been documented through the handling of infected chimpanzees, gorillas, fruit bats, monkeys, forest antelope and porcupines found ill or dead or in the rainforest.
2. Unlike the flu, Ebola is not airborne. It is highly infectious, but not highly contagious.
From CNN:
Ebola is extremely infectious but not extremely contagious. It is infectious, because an infinitesimally small amount can cause illness. Laboratory experiments on nonhuman primates suggest that even a single virus may be enough to trigger a fatal infection.
Instead, Ebola could be considered moderately contagious, because the virus is not transmitted through the air. The most contagious diseases, such as measles or influenza, virus particles are airborne.
Humans can be infected by other humans if they come in contact with body fluids from an infected person or contaminated objects from infected persons. Humans can also be exposed to the virus, for example, by butchering infected animals.
From the Guardian:
Flu is a massive danger to every country because it is spread through water droplets in the air, so coughs and sneezes spread the disease. But Ebola is transmitted via physical contact with the bodily fluids of somebody who has fallen sick. It appears that they are not infectious until they have symptoms – and then the danger is from blood (and they haemorrhage so there is a lot of it), saliva, urine and diarrhoea. Their clothes, their bedding, needles and any other surfaces in contact with bodily fluids will also carry the virus, hence the need for full body suits and face masks for nursing staff.
From nature.com:
To become infected [with Ebola] in the first place, a person's mucous membranes, or an area of broken skin, must come into contact with the bodily fluids of an infected person, such as blood, urine, saliva, semen or stools, or materials contaminated with these fluids such as soiled clothing or bed linen.
By contrast, respiratory pathogens such as those that cause the common cold or flu are coughed and sneezed into the air and can be contracted just by breathing or touching contaminated surfaces, such as door knobs. A pandemic flu virus can spread around the world in days or weeks and may be unstoppable whereas Ebola only causes sporadic localized outbreaks that can usually be stamped out.
From our own
Greg Dworkin, explaining the difference between how the measles and the flu are spread vs. Ebola:
So on occasion they can spread it to the person sitting next to them should they cough in your nose, but the [Ebola] virus is not aerosolized, thereby limiting the distance the virus can spread.
You need mucus membrane exposure or broken skin (a simple mask and goggles would protect you.) But the virus isn't contained in microscopic particles and aerosolized.
Viruses that are aerosolized can travel 6-10 feet or more, stay airborne, infect doorknobs etc. and pose more of a hazard. That's what measles does, and is much more contagious.
Prof. Peter Piot, a Belgian scientist who co-discovered Ebola, has expressed no fear of it spreading in the West.
Piot co-discovered the Ebola virus as a 27-year-old researcher in 1976.
He is now director of the prestigious London School of Hygiene and Tropical Medicine and was previously executive director of the United Nations' HIV/AIDS programme UNAIDS.
Even if someone carrying Ebola were to fly to Europe, the United States or another part of Africa, "I don't think that will give rise to a major epidemic," he said on Wednesday.
"Spreading in the population here, I'm not that worried about it," he 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."
3. Why has the disease spread so quickly in West Africa and why is the death rate so high?
Extreme Poverty. This tragedy is unfolding in one of the poorest parts of the world.
The countries at the center of the outbreak — Guinea, Liberia, and Sierra Leone — are among the poorest in the world. All three have GDPs per capita that are less than Haiti's. Heath care spending is also dismally low: between $40 and $100 per person per year. With health infrastructure that weak, it's not so surprising that there have been reports of mistrust and fear of medical workers during the outbreak.
As such, a lot of the job of fighting Ebola in western Africa has fallen to non-governmental organizations such as Doctors Without Borders. That group has been warning for some time that it doesn't have enough support: "With resources already stretched, health authorities and international organizations are struggling to bring the outbreak under control."
Another factor making the current outbreak so deadly: This is the first Ebola outbreak in the region, which has made awareness and education especially difficult.
Many people in West Africa not only lack access to modern medical care, they also distrust modern medicine and the physicians who practice it. Many are reluctant to seek needed care.
From Reuters:
In the African nations currently experiencing the outbreak, patients don’t trust their local healthcare systems – sometimes with good reason. Their clinics and hospitals are understaffed and have inadequate stocks of drugs and other supplies. Healthcare workers suffer from poor morale in difficult working conditions. In such settings, people turn to traditional healers. These healers may not be able to cure their illnesses, but they offer care and empathy that healthcare workers may not.
Affected communities don’t trust the foreign doctors who have come to help treat patients with Ebola, sometimes because they believe they are the very source of the disease. They conflate healthcare workers’ arrival to help treat Ebola with the coming of the illness itself...
Families have been told not to care for sick relatives or to engage in traditional burial practices because of fears of contagion, but lack of trust leads communities to hide the sick from medical attention. When they come to help, Doctors Without Borders and Red Cross workers have been threatened and attacked by locals suspicious of their activities.
From nature.com:
Local health authorities and international organisations such as WHO and Médecins Sans Frontières (also known as Doctors Without Borders) are struggling to control the spread in these areas because of a lack of trust and cooperation among the affected populations. Doctors and health workers have sometimes been blocked from accessing affected places because of opposition from villagers who fear the medics will bring the disease. According to the WHO, not all people who are infected are getting or seeking care, and so are passing the virus on to family and other close contacts.
From the ibtimes:
The history of Sierra Leone and Liberia, which has seen over 224 and 130 fatalities repectively since February, was hindering efforts to tackle the virus.
"These countries are coming out of decades of civil war," he said. "Liberia and Sierra Leone are now trying to reconstruct themselves so there is a total lack of trust in authorities, and that combined with poverty and very poor health services I think is the explanation why we have this extensive outbreak now."
The reuse of needles and local burial practices have exacerbated the problem.
Another major driver of new infections is that families are often continuing to perform traditional burial rites that involve mourners having direct contact with the bodies of the dead – and unfortunately all too often Ebola.
The virus, they discovered, was being spread through the reuse of infected needles on pregnant women, as well as through the funeral preparation process.
"Someone who dies is washed, the body is laid out but you do this with bare hands. Someone who died from Ebola, that person is covered with virus because of vomitus, diarrhea, blood," explains Piot, adding that the same thing was now happening in the most recent outbreak.
As the Guardian points out, many of the factors that contribute to the spread of Ebola in Africa simply aren't present in the West.
In Europe and north America, infection control measures are stringent and would rapidly be put in place. The sick person would be isolated in hospital and every contact would be traced. Those people in turn would be quarantined in case they developed symptoms. It happened with Mers, where a man from Qatar died in a London hospital. Experts from the Health Protection Agency, now part of Public Health England, followed up over 60 people who had come into contact with him and traced more than 100 others who had had contact with his family. None had picked up the virus – but the reassuring part is the efficiency of the tracing process in the UK. Sadly, in west Africa, that sort of effort is presently nearly impossible.
4. Is there a cure or vaccine? No, not yet.
There are no licensed drugs or vaccines for Ebola, although candidates are in development. New treatments would help reduce the high mortality rate of the disease – which has ranged in past outbreaks from 25% to 89%, with an average of around 62%. Jeremy Farrar, head of the UK Wellcome Trust in London, has argued for the use of experimental, unapproved drugs in the current outbreak. But other scientists have said that with distrust of health workers already hampering efforts to bring the outbreak under control, such measures could be counterproductive by creating suspicion and so further undermining trust.
The government plans to fast-track development of a vaccine shown to protect macaque monkeys, aiming to test it in humans as early as next month.
If the vaccine proves effective, it may be given to health care workers and others at high risk for infection sometime in 2015, said Dr. Anthony S. Fauci, the head of the National Institute of Allergy and Infectious Diseases.
But the development effort depends on several contingencies: fast regulatory approval of the trial, the first of its type in healthy humans; results proving the vaccine is safe and provokes an immune response; and, perhaps most crucial, the interest and investment dollars of the pharmaceutical industry.
5. Is the death rate always this high? No, it varies widely (from 25% to 90%), and is likely affected by the availability of proper medical care.
From the Guardian:
Reports that 90% of people die have not helped and are not accurate. With intravenous fluids, patients with strong immune systems can fight off the virus, and the death rate has been closer to 50% in some places.
From the LA Times:
On Friday, Dr. Anthony Fauci, head of the National Institute of Allergy and Infectious Diseases, said that the species of the current Ebola virus outbreak was very closely related to the so-called Zaire strain -- the most virulent of the five known strains...
Fauci said proper medical care could reduce the rate of death.
"You could have a strain that’s real virulent, like the Zaire strain and in conditions in which individuals don’t go to a healthcare center, don’t get intravenous replacement of fluids, don’t get anti-inflammatories to bring their fever down, don’t get supportive care, and don’t get antibiotics for secondary bacterial infections, those persons may have a mortality rate of 90%," Fauci said.
However, people with the same disease and access to good medical care stand greater odds of survival.
"The mortality could be down as low as 45, 50, 55 percent," Fauci said. "So the mortality is influenced not only by whether you are inherently dealing with a virulent strain -- which in this case you are -- but also the accessibility to medical care, particularly fluid replacement."
6. According to the CDC, Ebola is not a food-borne illness.
Can I get Ebola from contaminated food or water?
No. Ebola is not a food-borne illness. It is not a water-borne illness.
The only food I can think of that might pose a danger is bush meat, and it is extremely unlikely that Americans would be consuming this. The normal food supply is safe.
We don’t know why West Africa is currently suffering from the largest outbreak of Ebola, but humans were almost certainly first infected through contact with “bush meat”.
The virus, which causes internal and external bleeding and is often fatal, is spread through close contact with the sweat, blood and organs of infected animals.
Wild animals killed in the forest are an African delicacy known as bush meat, and many of these illegally-hunted creatures, including chimpanzees, gorillas, fruit bats, monkeys, forest antelope and porcupines, carry Ebola. Every year, 7,500 tonnes of bush meat is imported into Britain, according to wildlife charity the Born Free Foundation...
So no matter how curious you are, don’t accept any offerings of monkey meat. Chicken may be boring, but at least there’s no risk of Ebola.
7. When similar viruses (Lassa and Marburg) have been treated in the United States using the methods employed at Emory, there haven't been any secondary infections.
Second, you might not know that we’ve already experienced patients coming into the US with deadly hemorrhagic fever infections. We’ve had more than one case of imported Lassa fever, another African hemorrhagic fever virus with a fairly high fatality rate in humans (though not rising to the level of Ebola outbreaks). One occurred in Pennsylvania; another in New York just this past April; a previous one in New Jersey a decade ago. All told, there have been at least 7 cases of Lassa fever imported into the United States–and those are just the ones we know about, who were sick enough to be hospitalized, and whose symptoms and travel history alerted doctors to take samples and contact the CDC. It’s not surprising this would show up occasionally in the US, as Lassa causes up to 300,000 infections per year in Africa.
How many secondary cases occurred from those importations? None. Like Ebola, Lassa is spread human to human via contact with blood and other body fluids. It’s not readily transmissible or easily airborne, so the risk to others in US hospitals (or on public transportation or other similar places) is quite low.
If Ebola does come to the United States, it wouldn’t be our first tango with it. There was an outbreak of it in monkeys in Reston, Virginia, in 1990. (If you read “Virus Hunter” by Dr. C.J. Peters, you can read his first-hand account of what happened.) It was successfully contained, and there were no human cases. If you want to look at human cases in the United States, look no further than Denver in 2009. Someone traveled to Africa and brought back Marburg Disease, something not much different than Ebola.
Some graphs demonstrating the spread of Ebola.
source
source
I hope this diary answers a few of the questions readers might have about Ebola. Hopefully, the scientists of DKos will contribute more information in the comments.
Update: An excellent suggestion from mem from somerville:
For those of you with interest (1+ / 0-)
in doing something constructive should this kind of event actually occur in the US (although Ebola is not the likely scenario)--you can volunteer with your local MRC or Medical Reserve Corps.
https://www.medicalreservecorps.gov/
I am part of the Region 4B group: http://www.region4b.org/....
Although they certainly treasure MDs and nurses with training, you do not have to have to have those credentials to help. You can help with registrations, medicine distribution, shelters, and other types of non-medical tasks.
Luckily since I've been a member we haven't been called out--even during the Marathon bombing the regular services had things under control. But we have frequent training events on preparedness and such.
What will happen the next time the mob comes?--Neil deGrasse Tyson
by mem from somerville on Sun Aug 03, 2014 at 08:46:22 AM PDT
