How does Ebola spread and can it be stopped?
As a deadly Ebola outbreak continues in West Africa, health officials are working to calm fears about how the virus spreads, while encouraging those with symptoms to get medical care. Typically, outbreaks of the disease have been in other parts of the continent, not in West Africa.
How is Ebola spread?
By direct contact with an Ebola patient’s blood or other bodily fluids like urine, saliva, and sweat. The highest concentration of virus is thought to be in blood, vomit and diarrhea.
The most vulnerable people are health care workers and family members or others who care for the sick.
Because of the deadly nature of the disease, health workers should wear protective gear, especially when handling things like contaminated syringes. Such equipment is not commonly available in Africa, and the disease isn’t always quickly recognized. Symptoms are similar to other diseases like malaria and cholera.
Someone can also get infected by handling soiled clothing or bed sheets without protection, and then touching their nose, mouth or eyes. People can also catch the disease by eating infected bushmeat, as Ebola can sicken animals including bats, chimpanzees and antelopes. Scientist think fruit bats might be the source of the virus, but aren’t certain.
Can Ebola spread in the air, like flu?
There is no evidence Ebola can be spread in the air by sneezing or coughing. “If there was a role for airborne transmission, we’d be seeing a lot more cases and deaths by now,” said Ben Neuman, a virologist at Britain’s University of Reading.
Ebola is in some ways similar to the AIDS virus because it is spread through bodily fluids, according to Stephen Morse, of Columbia University’s Mailman School of Public Health. Unlike those infected with HIV, those with the Ebola virus are considered infectious only when they show symptoms, which include fever, vomiting and diarrhea.
Can the spread of Ebola be stopped?
Yes, by isolating anyone with symptoms while testing is done, taking precautions while providing them medical care and tracking down anyone they were in close contact with when they got sick. Those who have had direct contact with an Ebola patient are advised to take their temperature twice a day for three weeks, the incubation period for the disease.
If they show symptoms, they should then be isolated and tested.
Ebola first appeared nearly 40 years ago. In past Ebola outbreaks, many cases have been linked to people burying their loved ones, involving ritual cleansing of the body and kissing the body.
The World Health Organization recommends that only trained personnel handle the bodies of Ebola victims.
“We know how to stop Ebola,” said Gregory Hartl, a WHO spokesman. “We have stopped all previous outbreaks in the past using old-fashioned methods.
“From what we’ve seen, there isn’t any reason to think we can’t stop the outbreak in West Africa using what we have done in the past.”
— MARIA CHENG, Associated Press
WASHINGTON — The use of an experimental drug to treat two Americans diagnosed with Ebola is raising ethical questions about who gets first access to unproven new therapies for the deadly disease. But some health experts fear debate over extremely limited doses will distract from tried-and-true measures to curb the growing outbreak — things like more rapidly identifying and isolating the sick.
The World Health Organization is convening a meeting of medical ethicists next week to examine what it calls “the responsible thing to do” about whatever supplies eventually may become available of a medicine that’s never been tested in people.
At least one country involved in the outbreak is interested in the drug. Nigeria’s health minister, Onyenbuchi Chukwu, said at a news conference that he had asked the U.S. Centers for Disease Control and Prevention about access. CDC Director Tom Frieden “conveyed there are virtually no doses available” but that basic supportive care can work, a CDC spokesman said Wednesday.
President Barack Obama said Ebola is controllable and the U.S. and its allies are working to help overwhelmed public health systems in West Africa take the needed steps.
Asked about the experimental drug, Obama said all the information isn’t in: “We’ve got to let the science guide us.”
There is no proven treatment or vaccine for Ebola, which so far has infected more than 1,700 people and killed more than 930 in West Africa in what has become the worst outbreak of this viral hemorrhagic fever.
“How many times have we found magic therapies that ended up … doing more harm than good?” cautioned University of Minnesota professor Michael Osterholm, who advises the U.S. government on infectious disease threats.
“Vaccine and drug treatment right now is not going to be the main way you bring this to a stop,” he added.
Scientists stress that there’s no way to tell if the experimental drug ZMapp really made a difference for two American aid workers infected while working in Liberia.
“We don’t even know if it works,” stressed Dr. Anthony Fauci of the National Institutes of Health, which helped fund research that led to the drug’s development.
The drug is a cocktail of three antibodies engineered to recognize Ebola and bind to infected cells so that the immune system can kill them. People’s immune systems make antibodies to fight off various diseases, and attempts to cull those antibodies — from the blood of people who survive an illness, or from animals — date back to the 19th century and early diphtheria treatment. Using modern techniques to fight Ebola, scientists culled antibodies from laboratory mice, Fauci said, and ZMapp’s maker now grows the antibodies in tobacco plants and then purifies them.
Fauci said the manufacturer has told the government that it would take two to three months to produce even “a modest amount.” So the NIH is exploring ways to ramp up production.
“Everybody’s trying to speed things up,” said Fauci, director of NIH’s National Institute of Allergy and Infectious Diseases.
To help improve diagnosis in affected countries, the Food and Drug Administration on Wednesday authorized emergency use of an experimental blood test to detect Ebola. Early symptoms — fever, vomiting and diarrhea — can be confused with other illnesses. The test was developed by the Defense Department, and is only for use in DOD-designated laboratories.
This week, the WHO is convening an emergency committee to determine if the outbreak warrants being declared a “public health emergency of international concern,” meaning it poses significant risk to other countries and requires more of an international response.
The WHO said that particularly in Liberia, health officials face community resistance from residents who fear going to the hospital and secretly care for ill loved ones at home, thus exposing themselves. Ebola is transmitted only through direct contact with the blood and other bodily fluids of someone who is sick.
But health care workers have to recognize the virus, too. Authorities in Nigeria have acknowledged that they didn’t immediately suspect Ebola in the first known patient to travel to that country.
“The bottom line with Ebola is we know how to stop it: traditional public health,” said CDC’s Frieden said Wednesday: Finding and isolating patients, finding and educating who’s been in contact with them and strict hospital infection control.
“Do those things with meticulous care and Ebola goes away,” he said.
Minnesota’s Osterholm fears those tried-and-true methods could be overshadowed by misunderstanding about any availability of the experimental drug.
“If the Americans had this serum all the time, why didn’t they send it to us Africans to help save lives?” said Winston Ojukutu Macauley, a social commentator in Sierra Leone.
But taking an experimental drug requires making sure the patients fully understand there’s no proof it will help — and it might even harm, said Osterholm, noting that 40 percent of Ebola patients are surviving. And would it be appropriate for the U.S. to offer a drug to people in developing countries that hasn’t been tested on its own citizens?
That’s among the things the WHO meeting could address. Even if enough doses were available for wider experimental use, “we need to find a way to do this in a fair manner so that we can live with ourselves when someone asks why this person got it and why not that person?” said Dr. Heinz Feldmann, NIAID’s virology chief.