As you may know by now, I am a serial debunker of alarm and it usually serves me in good stead. On the threat posed by diseases, I’ve been resolutely sceptical of exaggerated scares about bird flu and I once won a bet that mad cow disease would never claim more than 100 human lives a year when some “experts” were forecasting tens of thousands (it peaked at 28 in 2000). I’ve drawn attention to the steadily falling mortality from malaria and Aids.
Well, this time, about ebola, I am worried. Not for Britain, Europe or America or any other developed country and not for the human race as a whole.
This is not about us in rich countries, and there remains little doubt that this country can achieve the necessary isolation and hygiene to control any cases that get here by air before they infect more than a handful of other people — at the very worst. No, it is the situation in Liberia, Sierra Leone and Guinea that is scary. There it could get much worse before it gets better.
This is the first time ebola has got going in cities. It is the first time it is happening in areas with “fluid population movements over porous borders” in the words of Margaret Chan, the World Health Organisation’s director-general, speaking last Friday. It is the first time it has spread by air travel. It is the first time it has reached the sort of critical mass that makes tracing its victims’ contacts difficult.
One of ebola’s most dangerous features is that kills so many health workers. Because it requires direct contact with the bodily fluids of patients, and because patients are violently ill, nurses and doctors are especially at risk. The current epidemic has already claimed the lives of 60 healthcare workers, including those of two prominent doctors, Samuel Brisbane in Liberia and Sheik Umar Khan in Sierra Leone. The courage of medics in these circumstances, working in stifling protective gear, is humbling.
Inevitably, some health workers are fleeing the affected areas and inevitably many families of victims are coming to see the isolation wards as places of death to which they do not want their loved ones taken. It does not help that doctors and hospitals are now so associated with the disease that machete-wielding villagers in Guinea have been refusing to allow doctors to enter some areas, on the suspicion that they were bringing the disease.
So no wonder Dr Chan says the outbreak “is moving faster than our efforts to control it. If the situation continues to deteriorate, the consequences can be catastrophic in terms of lost lives but also severe socio-economic disruption.” There is little doubt that the ebola epidemic will have huge indirect effects, through interrupting treatment and prevention for other serious diseases, as well as through the dislocation of the economy of west Africa.
Consider just one case, that of the woman who probably first brought the virus to Liberia in March when she returned from Guinea feeling unwell. She was cared for by her sister till she died. The sister felt ill and took a communal taxi to Liberia’s capital Monrovia on the way see her husband, which resulted in the deaths of five other passengers in the taxi. She rode pillion on a motorbike some of the way and the driver has not been traced. That sort of thing is happening all the time.
I still maintain that ebola is very unlikely to cause a global pandemic. As a disease of human beings it is too quick, too virulent, too easy to contain — for its own good. With reasonable precautions like hygiene and isolation, strictly enforced, it fizzles out fast. This is true, not just of ebola, but of all the haemorrhagic fevers, like the lassa, hanta and marburg viruses.
These have caught the imagination of scriptwriters because the deaths they cause are so gory and the prognosis of those infected so dire. However, they have never managed to create a pandemic — unless the theory is right that the plague recorded by Thucydides in 430BC, which supposedly came down the Nile from Africa, was ebola. Lassa (from rodents) and marburg (from bats) flare up from time to time in Africa, and hanta (also rodents) killed 121 soldiers during the Korean war.
The first and (until this time) worst recorded outbreak of ebola, in Yambuku in Congo in 1976, was exacerbated by well-meaning nuns running a remote clinic. They re-used needles to give quinine injections to people with malarial symptoms and the early symptoms of ebola are like malaria. Three quarters of those who died caught the virus this way; four of the nuns also died. Today, the chances of health workers making the problem worse are remote.
The more febrile kind of science writer is given to suggesting that ebola is a sort of revenge from the ravished rainforest for the destruction we have wrought on it. That is nonsense. Blood samples from pygmies suggest that ebola outbreaks have been happening sporadically for a very long time and killing apes as well as people. If anything, it is intact forests, full of fruit for bats to feed on, that represent the greatest reservoir. Bats carry and reproduce the ebola virus very effectively, but are much less affected by it and they are almost certainly its natural host.
We do need to treat bats with caution. They have already given us rabies, marburg virus and a morbillivirus in Australia that is lethal to horses. Ebola is their deadliest gift. Given that a quarter of all mammal species are bats, that they often share our living spaces and they live like us in dense colonies, the chances are they have more viruses to pass on. In the 1990s, a woman in an animal sanctuary in Australia died from a bat-borne lyssavirus. (I would forbid zoos and animal sanctuaries from handling bats in tropical regions.)
Liberia and Sierra Leone are two of only six countries in the world whose average per capita income is lower today than it was 50 years ago, and that is why they are so vulnerable to this epidemic. The key lesson is not to slow or reverse development in rural Africa. Quite the opposite. The sooner we can engage more of the citizens of Liberia, Guinea and Sierra Leone in the global economy, so they can get jobs in urban areas, afford decent healthcare and begin to eat fast food rather than bushmeat, the better.
Matt Ridley, a member of the British House of Lords, an acclaimed author who blogs at www.rationaloptimist.com. This article was first published in the Times.