Organisation - March 9, 2017

Healthy humans and animals

Text:
Albert Sikkema

‘Global One Health’ is the theme of Wageningen University & Research’s 99th Foundation Day celebrations on Thursday 9 March. The keynote speaker is the British professor of epidemiology Sir Roy Anderson. He came up with the model for the spread of infectious diseases that is now used by experts worldwide.

text Albert Sikkema  photo Hollandse Hoogte

The increased movement of people, animals and goods around the world has also helped the spread of infectious diseases. The Ebola virus, which probably originated with bats, caused a major epidemic in West Africa; the Zika virus, which is transmitted by mosquitoes, is spreading like wildfire throughout Latin America; and migrating birds from Asia are bringing bird flu to Europe. The dividing line between human and animal health is becoming blurred, leading to the birth of a new research topic: Global One Health.

Roy Anderson, the keynote speaker at Wageningen University’s 99th Foundation Day event on 9 March, is considered to be one of the world’s leading authorities on this subject. In 1992, the British epidemiologist published Infectious Diseases of Humans, the ‘bible’ for researchers and policy-makers who seek to combat dangerous infectious diseases. Experts around the world still use the book’s mathematical formulas for predicting the spread and quantifying infectious diseases. ‘A breakthrough in epidemiological thinking,’ says Willem Takken, professor of Medical Entomology in Wageningen.

Mad Cow Disease

Anderson used his formulas to predict the spread of HIV. His model also turned out to be good at predicting how many other infectious diseases would develop. Takken: ‘You always have a critical parameter, the weakest link in an infectious disease. You need to tackle that for the epidemic to die out.’

When Mad Cow Disease (BSE) broke out in Britain in the 1980s, leading to Creutzfeldt-Jacob disease in humans, Anderson advised the UK government to introduce a ban on the sale of beef on the bone and the processing of bone meal in animal feed. He argued that this would soon cause the fatal brain disease in humans to disappear. That optimistic assessment was controversial at the time but Anderson was proved right.

In trouble

Roy Anderson had the same status in Britain as the Rotterdam virologist Ab Osterhaus had for a long time in the Netherlands – the most important scientific advisor on infectious diseases. But like Osterhaus, this got him into trouble in 2009. At that point, a new kind of flu was spreading — influenza A(H1N1), better known as swine flu. The World Health Organization (WHO) said there was a threat of a pandemic. Anderson advised the British government to order millions of vaccines. One year later, the threat had passed and the vaccines had not been needed.

Anderson was roundly condemned, like Osterhaus in the Netherlands. Anderson was suspect because he was also an advisor to the pharmaceutical company GlaxoSmithKline (GSK), which paid him an annual fee of 116,000 pounds. He was depicted as a ‘false prophet’ who had exaggerated the danger of a pandemic in order to help GSK win a mega-contract. However, these accusations were rebuffed by the WHO and the British government. Takken thinks it is all very well to criticize him after the event. ‘Imagine if he had advised against a vaccine and the pandemic had taken effect with thousands of fatalities. Fortunately we can afford the costs of such a vaccine.’

Neglected diseases

What is more, in the past decade Anderson has been focusing on neglected tropical diseases that companies like GSK barely look at. Takken: ‘A lot of attention is paid to the major infectious diseases such as malaria, HIV and tuberculosis. But there are also about 15 tropical infectious diseases that claim large numbers of victims in a particular area but that we don’t know much about. Take Leishmania, a parasite that is spread by sand flies, and sleeping sickness, river blindness, dengue fever and (until recently) Ebola. These are diseases that the pharmaceutical industry does not develop medicines or vaccines for because the people who suffer from them cannot afford the medication. And it is precisely those diseases that Anderson is working on.’

The main priority for Anderson and Takken is that if an epidemic develops, the international community should rapidly be in a position to figure out the disease and develop a vaccine. Takken: ‘Take Ebola. It took six months before the world acknowledged the seriousness of the epidemic. After that, measures were soon in place and now there is even a vaccine that is being tested in Africa. But you have to realize that Sierra Leone lost one third of its doctors to Ebola – one third. Rapid intervention saves lives.’

Flu

Even so, it is not Ebola that concerns scientists most, or Zika. The greatest threat to human health is the flu. Not the run-of-the-mill flu we get every winter but the Asian influenza of type H5N1. A virus with a mortality rate of between 50 and 60 percent that has taken hold in bat and bird populations in Southeast Asia and that sooner or later will be brought to Europe. Anderson pointed to the danger posed by this virus back in 2005. He advocates setting up an international organization with the mandate to take swift action to combat a flu epidemic or pandemic by developing a vaccine with the pharmaceutical industry.

But Takken stresses that Global One Health is broader than fighting diseases that are harmful to humans. For example, the Usutu virus that is gaining ground in Europe is claiming many victims among blackbirds. ‘That virus is threatening our ecosystem.’ Last year, armyworm caterpillars from North America ended up in Africa, where they caused enormous damage to maize harvests, thus affecting food security. ‘Global One Health is also about hunger and obesity, food safety, deforestation and the climate, intensive livestock farming and fine particles, in other words all the processes that threaten health in our society.’


Roy Anderson

18-ACH roy-anderson.jpg

Sir Roy Anderson is professor of Infectious Disease Epidemiology at Imperial College London, the university where he did his degree and obtained his doctorate. Before that he was professor of Zoology at Oxford and scientific advisor to the UK Ministry of Defence. Anderson chairs the science advisory board of WHO's Neglected Tropical Diseases programme and he is director of the London Centre for Neglected Tropical Disease Research. He is also on the scientific advisory board of the Netherlands Centre for One Health (NCOH), a collaborative venture between WUR, Utrecht University and four university medical centres. Anderson received a knighthood in 2006.


In this video, Roy Anderson explains what we should do if there is an outbreak of an infectious disease.


Re:act