Sunday, October 12, 2014

The nightmare Ebola scenario that keeps scientists up at night -- could it happen? Are assurances credible?


via VERNE STRICKLAND / USA DOT COM 
 
 
 
 
 
The nightmare Ebola scenario that keeps scientists up at night. Could it really happen?

Updated by on October 12, 2014, 8:51 a.m. ET

A burial team from the Liberian Red Cross prays before collecting the body of an Ebola victim near Monrovia, Liberia. John Moore/Getty Images

Ebola fear and conspiracy theories are spreading faster than the disease. But even scientists — who have thought very deeply about Ebola and pandemics — are beginning to worry.

What they fear, however, is slightly different from the zombies and airborne Ebola that keeps many of us up at night. I asked them about what it would take for Ebola to spread further in America and around the world. Here's their worst-case scenario:

1) The Ebola outbreak in West Africa keeps growing

 Ebola outbreak in Sierra Leone. (Photo courtesy of Anadolu Agency)
In order for Ebola to move around the world, the outbreak needs to continue to grow in West Africa. Cases there need to keep on their exponential ascent. The more people infected with Ebola at the source, the more likely they are to infect other people, and the more likely those people are to travel and spread the disease. It's the mathematics of Ebola, and it's scary.
ebolmath
The exponential growth curve of this Ebola crisis.  (Courtesy of the journal EuroSurveillance)
For the situation to deteriorate in West Africa, efforts to address it need to fail. The unprecedented international response — led by the US — needs to be implemented too slowly, and needs to continue to lag the growth in cases.

And this is possible, at least for the foreseeable future, since the epidemic has already had such a long lead time before the international community intervened. "We have had more Ebola cases in the last two months than the entire history of the infection combined. It's still in the growth phase," says Ashish Jha, director of the Harvard Global Health Institute. "The longer it continues in West Africa, the bigger a chance it's going to get much more global."

2) The virus finds new hosts in urban areas with weak health systems

eboaldinia 
  Eighty-eight Indians return from Liberia, an Ebola hot zone. (Photo courtesy of Hindustan Times)

Traditionally, Ebola was a rare disease, relegated to remote and rural areas in Africa. It affected a couple thousand people since it was discovered in 1976. This year, there are more than 8,000 cases, and the virus has popped up in well-populated areas, which has helped it to find new hosts and move further.

For the Ebola caseload to continue to balloon, people with Ebola need to continue to turn up in densified areas, particularly with under-resourced and weak health systems.

Peter Piot, who helped to discover and name the virus, told the Guardian newspaper that he was concerned in particular about the link between West Africa and India:
...an outbreak in Europe or North America would quickly be brought under control. I am more worried about the many people from India who work in trade or industry in West Africa. It would only take one of them to become infected, travel to India to visit relatives during the virus's incubation period, and then, once he becomes sick, go to a public hospital there. Doctors and nurses in India, too, often don't wear protective gloves. They would immediately become infected and spread the virus.

West Africa also has strong links with China, where the health system can be similarly patchy.

Epidemiologists have been preparing for this kind of nightmare for decades. "People have been talking about this for probably 20 years," said Stephen Morse, director of infectious disease epidemiology at the Columbia University Medical Center. Yet, even though there is more travel, and more people are living in cities, our global health responses still don't reflect this reality, says Morse. "I have been discouraged by the lackadaisical, the tepid, and late response by the global community."

3) Rich countries with strong health systems continue to fumble and botch their Ebola cases

eboalspain 
  Spanish officials outside the Madrid hospital where people are in quarantine following the infection of a nurse with Ebola. (Photo by Curto de la Torre/AFP)
Since the beginning of this outbreak, one of the truisms about Ebola hitting America, or another developed country, has been that it would be detected and stamped out so fast, it wouldn't have a chance to gain a foothold. "It is not a potential of Ebola spreading widely in the US," Centers for Disease Control and Prevention director Tom Frieden told reporters in July. "We have strong systems to find people if there is anyone with Ebola in the US."

Yet, the first Ebola patient in the US — a recently deceased Liberian national who had arrived from Monrovia days before seeking care in a Dallas hospital — was misdiagnosed on his first visit. He was sent back into the community with antibiotics to fight what was believed to be a common viral infection, even though he told hospital staff about his travel history. He also made it through airport screening in Monrovia, days after caring for a woman who died from Ebola. Now, one of the health workers who cared for him has tested positive for the virus.

There was similar fumbling with Europe's first Ebola case. A Spanish nurse contracted the disease after caring for a repatriated priest from Sierra Leone who later died. While harboring the virus, she sat in on a civil service exam with 20,000 others and visited clinics to get help with her early symptoms. But her temperature was thought to be too low to sound the Ebola alarm bells.

"I have become a little less optimistic""A few weeks ago, if you had asked me 'is Ebola a danger to the US?' I would say the conventional wisdom is 'no,'" says Morse. "I still think that is largely true but I have become a little less optimistic."

These errors are all very human and all too easy to make. Despite the Ebola public-health protocols sent out to doctors, hospitals, and airports, the airport screenings, the warnings to health professionals who have been exposed to quarantine themselves, the warnings to travelers to stay home if they have come into contact with an Ebola patient, Ebola managed to slip through the cracks of the best health systems in the world. These everyday mistakes need to continue to happen for the virus to move further.

4) Rising panic causes us to make irrational — and harmful — choices that exacerbate the epidemic

ebola
A man is arrested by police officers after a dead body was found in the center of the city of Monrovia. (Pascal Guyott/AFP)
Following the announcement of increased airport screening efforts for travelers from West Africa, New Yorker writer John Cassidy lamented the political hot potato that Ebola has become:
The measures that the Obama Administration announced on Wednesday mimicked what some Republicans, including Rick Perry, the governor of Texas, had been advocating. At a press conference on Monday, where he unveiled a new task force to combat infectious diseases, Perry called on Washington to introduce "enhanced screening procedures" and create "fully staffed quarantine stations." At this stage, the only big difference between Perry and the White House is that he wants screening to be extended to "all points of entry" to the United States; the new C.D.C. policy is limited to airports in Atlanta, Chicago, New Jersey, New York, and Washington, D.C.
It doesn't matter that Ebola is currently a small threat in America, and that the real focus should be stopping the outbreak in West Africa. If this political theater devolves into, say, a travel ban in West Africa that further isolates the region, the nightmare epidemic will inch closer to reality: the economies of the affected countries will continue to crumble, getting aid to the region will be difficult or impossible, and Ebola will rage on over there, which again, means it's a threat everywhere.

5) The virus mutates to become more virulent

Every scientist worth his weight in citations has said that the chances of Ebola mutating to become airborne are slim. This is because it would require the virus to change how it is transmitted. This would be like HIV or herpes suddenly becoming airborne. It's something viruses don't do, though of course, nothing is impossible when it comes to biology.

What is more probable, however, is that the Ebola virus now circulating is more virulent than previous strains. Peter Jahrling, a chief scientist at the National Institute of Allergy and Infectious Diseases, has a field team in Monrovia, running tests on samples of Ebola from the sick in this epidemic.
This kind of mutation might help explain why Ebola seems to have spread so effectively this year.
"They are telling me that the viral loads are coming up very quickly and really high, higher than they are used to seeing," he says. The more concentrated the virus in people's bodily fluids, the more infectious and easily spread.

Though Jahrling and his team need to continue to study this hypothesis, he says this kind of mutation might help explain why Ebola seems to have spread so effectively this year compared to previous outbreaks. And this is saying a lot from someone who has studied Ebola and other dangerous pathogens for more than 25 years.

The good news

Ebola hasn't yet been detected in a developing country outside of West Africa. And even the botched responses in Spain and the US haven't given way to more cases. Nigeria and Senegal were also able to stop their outbreaks. What's more, the international community has underway one of the largest-ever public-health responses to address Ebola. There's potentially promising pharmaceutical solutions on the way, too. The dire scenario playing out in West Africa has spurred unprecedented Ebola treatment and vaccine development by governments and industry.

Viruses have no political boundaries.Hopefully, this worst-case scenario will never come to pass. But, as Harvard's Ashish Jha put it, "Ebola reminds us we do live in one world, and that something that happens in Africa can have a direct effect on our lives, our health, our kids' health."

Writing in JAMA, he argued that we need to strengthen weak health systems in the long term, not only because health is global but because Ebola has shown us that viruses have no political boundaries and even the most rare and obscure pathogens can turn up anywhere.
Card 1 of 18 Launch cards

What is the Ebola virus?

Most people's views of Ebola are probably informed by Hollywood — they think of it as a deadly and contagious virus that swirls around the world, striking everyone in its path and causing them to hemorrhage from their eyeballs, ears and mouth until there is no more blood to spill.
outbreak
Remember this 1995 film?
In reality, Ebola is something quite different. About half of the people who contract Ebola die. The others 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.
As for the blood: While Ebola can cause people to hemorrhage, about half of Ebola sufferers ever experience that Biblical bleeding that's become synonymous with the virus.
More often than not, Ebola 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. These symptoms can appear anywhere between two and 21 days after exposure to the virus. Sometimes, they go into shock. Sometimes, they bleed. Again, about half of those infected with the virus die, and this usually happens fairly quickly — within a few days or a couple of weeks of getting sick.

There are five strains of Ebola, four of which have caused the disease in humans: Zaire, Sudan, Taï Forest, and Bundibugyo. The fifth, Reston, has infected nonhuman primates 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 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.

ebola
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.

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.

And that's what makes the 2014 outbreak so remarkable: the virus has spread to five countries in Africa plus America, and has already infected more than 8,000 people. It has killed more than 4,000 people. That is more than triple the sum total of all previous outbreaks combined.