By Richard Knox
The United States has entered a new phase in its response to Ebola. Call it “officially sanctioned panic.”
Governors from both parties — N.J. Gov. Chris Christie and N.Y. Gov. Andrew Cuomo — declared over the weekend that even symptom-free health care volunteers coming home from Ebola duty in West Africa will be considered infected (and infectious) until they prove otherwise — by not falling ill for three weeks after their return.
But experts say mandatory quarantine of health workers and travel bans are unnecessary and could cripple the global fight against Ebola.
"The only way to buy an insurance policy is to defeat the disease in West Africa."Prof. Alessandro Vespignani
Against this backdrop, I had a long conversation this past weekend with Prof. Alessandro Vespignani. He’s a Northeastern University expert on how humans behave in the face of disease threats. The main takeaways: The key to defeating the outbreak is to get health care workers to West Africa and back, so to the extent a travel ban or quarantines impede that flow, they will be dangerously counter-productive. And travel is so hard to control fully that bans do little to stem the spread of disease anyway.
Vespignani is spending a lot of time these days consulting with the U.S. Department of Health and Human Services, the Centers for Disease Control and Prevention and the World Health Organization on how the Ebola situation could evolve over the coming months.
He’s thinking some ominous thoughts, which he says reflect the views of U.S. and international health officials that he talks to. But the scenarios they worry about are very different from those that preoccupy many politicians and voters. Politicians worry more about the small, containable immediate threat to Americans of occasional imported cases than the longer-term and potentially catastrophic Ebola scenario that could affect the whole world — in other words, an Ebola pandemic.
Here’s an edited version of our conversation:
RK: Your group published a paper the other day in the journal Eurosurveillance that would seem counter-intuitive to many Americans. You say that imposing a ban on travelers from Ebola-affected countries won’t do much to prevent importation of the virus to the United States. Why is that?
Vespignani: People think if you have a travel ban everybody from those countries will be kept out. It’s not like that.
It’s important to know that we don’t have direct flights from West Africa. So a travel ban has to be coordinated internationally. There are a lot of people with two passports (whose country of origin can’t be easily tracked). People would try to circumvent the travel ban, and they wouldn’t be trackable — that’s one of the most dangerous things.
You can stop 95 percent of travelers from a country, but it’s very difficult to do 100 percent. And even a 90 or 95 percent travel ban is going to delay the arrival of Ebola (in the U.S.) by only about two months. It’s only buying time.
Already there is almost an 80 percent reduction in travel to the U.S. from that region, so we have already bought some time — about four to five weeks.
So what’s the practical effect of that delay? How much would a travel ban reduce Americans’ risk?
AV: The problem for the United States is not in the next couple of months. We will see at most one or two cases [per month] in that period. The problem is down the road.
The number of cases we will see here increases the more cases there are in West Africa and other countries. By December or January, we can get to hundreds of thousands of cases in Africa. You can have outbreaks in Mali [where a case has just been reported, in a little girl who came by bus from Guinea], in Ivory Coast, and in Nigeria. Nigeria was able to contain one outbreak, but you cannot be confident they will be able to do that over and over again.
If the outbreak continues to grow exponentially, we will see more imports of Ebola in the United States. Instead of two or three cases per month, we will likely have three or four, then five to 10. These are all things we should be prepared for and should not panic over.
On the other hand, the fact is, as long as we have the outbreak in West Africa, nobody can be safe. So the only way to buy an insurance policy is to defeat the disease in West Africa. That’s what we have to do.
What is your worst fear?
If we don’t stop the West African outbreak, we can start to see Ebola cases in South Africa, Kenya — countries with much more [global] trade and travel. People can travel by bus or cross borders in many different ways. With hundreds of thousands of cases, there will be spillover to other countries. It’s a domino effect. The whole world could see cases.
We could see cases of Ebola going to countries in Asia — China or India — where one-third or more of the human population live. In some [Asian] cities, they have health care systems as good as we have [so could control Ebola]. But in other places, they do not. So you never know what could happen there.
In our global world, to seal off a country is a huge task. If the epidemic continues to grow and affects other countries, the task becomes more difficult still. You might eventually have to do a travel ban for more and more countries — for China, for India.
This brings us back to the question of the moment: What should the United States be doing?
To win the battle, we have to have health care workers, doctors, NGOs and the military go there [to Ebola-affected areas]. And they have to be able to come back. You could really make it so complicated for them that they are not going to go there. If you talk to the World Health Organization, they will tell you, “Look, travel bans are just going to make efforts to contain the disease in West Africa more complicated.”
Do you worry about the effect of putting returning health care workers in quarantine?
I do worry about it. These people are heroes. They are going to fight a battle in which they are risking their lives. They are not just helping African people. They are defending us. We need to stop the outbreak there to be sure we won’t have Ebola in our country. The more we hamper their effort, the more it could backfire on us. We have to be very careful about that, and also very rational.
Further reading: The New England Journal of Medicine: Ebola and Quarantine