When the World Health Organization declared Nigeria officially Ebola-free in October, most of the fanfare centred on how Africa's most populous country had managed to keep the virus from spreading.
But there was another, less heralded aspect of Nigeria's success story that a Canadian doctor and her colleagues wanted to explore in more depth: How had 12 of Nigeria's 20 Ebola patients beaten the virus?
"The hospitals in Nigeria weren't maybe to the standards of a Western hospital in terms of equipment, but the staff were phenomenal. They managed to get a very high survival rate," said Eilish Cleary, a New Brunswick chief medical officer of health who travelled to Nigeria to provide epidemiological support to the World Health Organization during the outbreak. "Case fatality rate for Ebola can be up to 70 to 90 per cent. In Nigeria, it was 40 per cent."
Dr. Cleary conducted detailed, videotaped interviews with six of the Nigerian patients to learn more about their treatment and recovery. The key to their survival seemed to be guzzling a stunning amount of water with oral rehydration solution [ORS] to fend off the cascade of internal failures typically caused by the virus.
Some of the survivors drank as much as five or six litres of ORS a day, an impressive feat considering Ebola can cause persistent vomiting and leave patients too weak to lift a bottle to their lips.
Only one of the six interviewed patients received intravenous fluids, another intervention that has been shown to increase the odds of survival, but which is not always available at poorly resourced treatment centres in West Africa where patients often arrive too late in the course of the disease for ORS to be effective.
"I was really encouraged to drink," nurse Tochi Anunobi, one of the survivors, told Dr. Cleary in an interview shared with The Globe and Mail. "I was even drinking if I was sleeping. When I wake up to urinate, I will drink."
Although the sample size is small, Nigeria's experience is part of a larger body of treatment evidence that is growing – sadly – because of the sheer volume of cases and starkly varied health-care settings in which patients have been treated during the worst Ebola outbreak in history, which has killed more than 6,200 mostly West Africans, according to the WHO's most recent official figures.
This outbreak marks the first time Ebola has been tackled outside of poor, remote pockets of Africa, and the results have shown the wider world that Ebola need not be a death sentence.
Of at least 22 Ebola patients cared for in the United States and Europe so far, five have died, a death rate of just 23 per cent. (Some of the surviving patients are, however, still in treatment, including an Italian doctor who was airlifted out of Sierra Leone late last month.)
Some of those patients received experimental therapies, and all received intensive care that is not available on a wide scale in Africa.
But the irony, experts say, is that the Western cases appear to reinforce what veterans of past Ebola outbreaks already knew about what works and what does not in helping patients defeat the virus.
The keys are still intervening as soon as possible after symptoms start, keeping patients hydrated, and keeping electrolytes in balance, all basic treatments that could be delivered in West Africa with adequate staff.
"The feedback I get from them [doctors in the West] is their big intervention is the delivery of IV crystalloid and management of the electrolytes," said Armand Sprecher, a hemorhaggic fever specialist with Médecins sans frontières (Doctors Without Borders.) "There's been a little bit of dialysis, a little bit of ventilator therapy … things we're not able to deliver in the field [in West Africa] right now. None of them have said that that makes a big difference."
Rob Fowler, a critical care physician at Sunnybrook Health Sciences Centre in Toronto who has worked for the WHO in West Africa during the outbreak, echoed that.
"For the most part," he said, "most patients are able to be adequately treated with IV fluids and commonly available medications. If we can prevent the complications that can often arise because of the inability to treat supportively, then I think most patients would not get critically ill and the survival rate, I think, would be much higher."
A commentary in The Lancet last week made that point more sharply. "It is often stated that there are no proven therapies for Ebola virus disease but that potential treatments, including blood products, immune therapies, and antiviral drugs, are being evaluated. This view is inaccurate," the authors wrote, before urging that clinical trials be conducted in the field to better determine what regimen of fluid and electrolyte replacement saves the most lives.
The trick for doctors and relief agencies has been figuring out how best to deliver that supportive care in the field, where conditions are far from ideal.
In a paper published in the New England Journal of Medicine last month, Dr. Sprecher and his colleagues described how difficult it was to deliver basic supportive care at Liberia's largest treatment centre, which saw more than 700 moderate to severely sick patients between Aug. 23 and Oct. 4.
Responsible for 30 to 50 patients each, physicians confined to personal protective equipment in stifling temperatures could devote just one to two minutes per patient to "evaluate needs and establish a care plan."
The sick had to be divided into three categories: Patients with organ failure who could not be saved; patients with low blood volume who were not in shock but could no longer care for themselves; and patients with low blood volume who were not in shock and could still care themselves.
The outlook was brightest for the last group, whose members had a good shot at recovery if they took anti-nausea and anti-diarrheal medications and, like the Nigerian patients, drank four to five litres of oral electrolyte solutions per day, ideally beginning the moment fever set in.
Dr. Sprecher said MSF's treatment centres are already achieving a case fatality rate of roughly 50 per cent; Dr. Fowler said the WHO's more recent internal figures show the overall case fatality of 70 per cent released earlier in this outbreak is beginning to come down as well.
"Simple, but rigorous supportive measures have a disproportionate impact on disease if you can apply them early enough," said Simon Mardel, a British relief physician who helped arrange Dr. Cleary's interviews with the Nigerian survivors.
"When we say drink ORS, I don't mean, did they have some ORS that day? What quantity did they get down? If they just drank a cupful, a few cups, I'm sorry, that's not treatment."
The WHO's guidelines on this are unsparing. Ebola patients need to drink four to five litres of ORS a day or, by day five of the illness, it will be too late to drink – they'll require IV support to keep their organs from collapsing.
Drinking so much fluid while stricken with Ebola was extraordinarily difficult, the survivors told Dr. Cleary.
She marvelled at their will to live.
"I was careful to try not to prompt any of the responses and the two things that amazed me [were] the fact that all of them identified for us – they brought it up themselves – the determination to survive," she said. "They recognized that they could survive and they would … the second thing was the rehydration and how it was hard to take it. But they knew they had to take it."