One of the scientists who discovered Ebola said it is impossible to be too careful when dealing with Ebola disease.
"This should be a lesson for everybody that you can't overreact. You can't overprotect," Peter Piot said after tests confirmed a 40-year-old nurse at a Madrid hospital had become the first person to contract Ebola outside Africa.
"Dealing with patients with Ebola ... is very risky business, and the slightest mistake can be fatal," said the Belgian scientist who co-discovered the Ebola virus in 1976.
"It's better to be accused of overreacting than to not take all the measures," he told reporters in Geneva.
Piot was in the Swiss city to head a World Health Organization-hosted expert review of the science behind the global response to the ongoing outbreak -- by far the deadliest on record.
Following the teleconference with 15 experts from around the world, he said he was "not surprised" that a nurse had been infected in a European hospital despite the best efforts to avoid transmission.
The infected nurse cared for two elderly Spanish missionaries who died from the virus after being flown home from west Africa, sparking questions about how safety procedures were applied.
News of her infection also sparked renewed questions about Madrid's decision to repatriate infected missionaries from Africa. Critics said Spanish hospitals were not equipped to deal with Ebola.
Piot, a professor at the London School of Health and Tropical Medicine, agreed it was risky to "import someone with Ebola" to a place with no experience of the virus or without using the protective equipment.
He noted that even two doctors with the Doctors Without Borders (MSF) charity had been infected, despite "draconian discipline."
"A dangerous moment is when you undress. When you come out of the isolation unit, you take off your protective gear and you're full of sweat, and you may take off your glasses and do like this," he explained, rubbing his eye.
"And that would be the end."
To ensure the safety of people working with Ebola patients, Piot stressed the need for very strict discipline, with basically "police" watching over them as they undress, making sure they make no missteps.
"That discipline is necessary. That's illustrated by the nurse in Madrid," he said.
But while Ebola poses a threat to health care workers around the world, Piot said there was "no risk that I see for outbreaks" in developed countries like the one that has killed 3,439 people in west Africa, according to the latest WHO toll.
He warned that the few cases surfacing in Europe and the United States should not remove the focus from the most affected countries, Guinea, Liberia and Sierra Leone.
"The only way to prevent the popping up of Ebola patients and maybe even outbreaks (elsewhere in the world) is to bring the epidemic under control in west Africa," he said.