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What if Ebola isn’t Africa’s biggest health threat?

Malcolm Potts, professor of population and family planning | October 22, 2014

Over a long professional life in global health, I have learnt a bitter lesson: it seems almost impossible for decision-makers to recognize and respond to slowly unfolding threats that take two or three decades to unfold and can involve millions of people. Sadly, big organizations with big money have a poor record of confronting big problems, however compelling the evidence.

In the early 1980s, I headed a moderately big international organization in North Carolina, now called FHI360. A lot of people thought me crazy, but I became obsessed with a new disease called AIDS. It was sexually transmitted, killed nearly everyone who was infected, and I had a sneaking suspicion not everyone was monogamous. To me, it seemed obvious that AIDS had the potential to kill a lot of people.

I thought I was pretty clever when my organization received the first U.S. government money to slow AIDS in Africa. Perhaps I was quicker than others to see the problem, but in retrospect the budget we received (about $20 million a year in today’s money) was totally inadequate. In fact, our annual budget was equivalent to one day’s expenditure on AIDS by the international community in 2011. It was too little, too late — 30 years later, 30 million people have died of AIDS and 30 million carry the virus.

If only

The current Ebola epidemic began in West Africa in December last year. To date, 4,500 people are known to have died, although the actual number may be nearer 12,000. What is certain is that the number of deaths is doubling every month.

diagram of Ebola transmission scycle

(CDC image)

The AIDS virus is never eliminated and it has proved impossible to develop a vaccine. People who recover from Ebola become completely free of the virus and it should be possible to develop a vaccine. Twenty years ago, medical scientists and public-health professionals understood Ebola’s transmission routes and could predict the logistical problems that would arise if an infected person arrived in an urban slum.  It was plain a vaccine would be needed sometime.  If in 1994, USAID, the Gates Foundation, UKaid, and other big donors had assembled a group of Ebola experts together and funded their research, we could probably have a vaccine by now. Instead, donors continued to focus on yesterday’s diseases while ignoring tomorrow’s big problems.

Both AIDS and Ebola originated in the African bush-meat trade. AIDS comes from chimpanzees. Ebola is thought to come from eating fruit bats. Both diseases are spread by bodily fluids. It is likely that both diseases have very occasionally jumped from the host animal to humans when someone butchering a chimp or a fruit bat cut themselves.

If a century ago a man caught AIDS from a chimpanzee, he probably gave it his wife and both died some years later. End of story. Sometime in the 20th century, perhaps a man butchering a chimpanzee cut himself, but now he had a bicycle, and a logging company had cut a road in the forest. He not only infected his wife but he visited a brothel on his bicycle. Different story.

Enter Ebola

Ebola was first identified in 1976 in the Congo. Early outbreaks were in small villages. A few people died a horrible death. Others fled, setting up an almost automatic quarantine system. The epidemic was self-limiting. Today’s epidemic is in crowded urban slums. Again, different story.

microscope image of Ebola virus

Scanning electron microscope image of Ebola virus (PLOS via Wikimedia Commons)

Ebola kills in a matter of days and more than 70% of those infected die. It kills anyone of any age and an infected person can infect two or more people before they die or become free of the virus. Even the corpse of a person dead from Ebola can infect others.

By contrast, AIDS is difficult to transmit and kills slowly. In most situations an AIDS-infected individual infects fewer than one other person before they die. In fact, if AIDS killed quickly the disease would never have spread – anyone infected would have died before they passed the infection to the next person.

While neither AIDS nor Ebola can be coughed or sneezed around the place, both are “airborne’” diseases in the sense that modern air travel allows infected people to crisscross the globe in a day. Several early cases of AIDS were traced to a gay Canadian air steward who flew from Africa to North America. All the cases of Ebola outside of Africa have been in air travelers and the medical professionals who cared for them.

For many years, when AIDS was the focus of my life, I worried that a self-sustaining heterosexual epidemic of the type found in some parts of Africa (such as Botswana) might spread to India. While a terrible disease in India, at least  AIDS remains largely confined to groups with high-risk behaviors, such as gay men, IV drug users and sex workers, who are infected by their clients.

Ebola is different, and a major fear I have is that an infected air traveler could spread the disease to a slum in cities such as Mumbai or Manila, where it could take off in the way it has spread in Monrovia, the capital of Liberia.

Some estimates are that Ebola deaths could reach a million by next January. As the international community failed to see the need for a vaccine, and as containing the disease in overcrowded slums is proving difficult, the worst-case scenario for Ebola is that, like AIDS, it could kill tens of millions of people, mostly in the developing world and more rapidly than occurred with AIDS. Hopefully, the disease will be contained before many millions die.

Tomorrow’s health threat

map of Sahel

Africa’s Sahel region (via Wikimedia Commons)

There is, however, another threat to literally hundreds of millions of people in Africa, where the evidence of an unprecedented humanitarian disaster is more certain than the possible trajectory of Ebola. The Sahel is a semi-arid zone running from the Atlantic to the Red Sea, much of it bordering the Sahara Desert.

In 1950, the Sahel was home to 30 million people. Today there are 125 million and in 2050, unless voluntary family planning is made available and there are substantial investments in girls’ education, there could be 321 million people  with the population still growing  exponentially.

Already 10 million people in the Sahel are short of food; by mid-century, global warming will wither the crops and kill the livestock. In fact, the UN Convention to Combat Desertification estimates that there could be 60 million ecological refugees as soon as 2020.

Is it really too late for big organizations with big money to stop investing in yesterday’s problems and learn to confront tomorrow’s big problems, even if they will take several decades to unfold?