Martin Ince forecasts benefits for Africa

Infectious diseases are humanity’s oldest and most durable enemy. Some have been on the scene for hundreds of years.

Influenza killed millions during the 20th century and is still emerging in new varieties, as the arrival of Avian Influenza shows. Other infections, such as HIV, have appeared recently as human diseases after existing for many years in other species.

Yet other infectious diseases threaten not human life but human livelihoods. By attacking crops and animals, they can cause famine and poverty. Phythophthora infestans, the virus responsible for the Irish Potato Famine in the 1850s, still causes millions of pounds’ worth of damage to potato crops around the world each year. There are estimates that infectious disease destroys 10-15 per cent of world crop production.

Foresight findgings

A new analysis of the problem shows that we could make a better job of managing risks from new and existing infectious diseases with future detection, identification, and monitoring (DIM) systems – provided these are linked to effective control measures. The study has been carried out by the Office of Science and Innovation’s (OSI) Foresight directorate.

That is good news for us all, particularly in Africa, a focus of the project, where infectious diseases continue to be a major barrier to achieving the Millennium Development Goals. (1)

Effects of technology

Foresight’s international Detection and Identification of Infectious Diseases (DIID) project drew on the knowledge of over 400 scientists and experts, from over 30 countries. They agreed that although advancing technology has much to offer, it could also exacerbate the problem of infectious disease. For example, people can now cross the world in 24 hours, less than the incubation period of many diseases. So they can arrive in a new country with an infection whose symptoms have not yet appeared.

Modern travel and tourism have been especially important in the spread of HIV/Aids.  In addition, the growth in international trade and travel allows disease-bearing organisms, ranging from infected plants to malarial mosquitoes, to travel in bigger numbers than before.

Some infectious diseases of humans, such as smallpox, have been conquered by vaccination and other means. Among the animal diseases, the impact of rinderpest, once a scourge of cattle in east Africa, has been much reduced although it is yet to be eradicated because of the large reservoir of the infection in wild animals.

The control of future infectious diseases will be affected by economic and social change such as the urbanisation of the developing world. Our increased ability to model complex systems means that it is getting more feasible to anticipate the effects of such change.

The project also found that new technology has much to offer in the struggle against infectious disease.

Detection, identification, monitoring

We can now describe the genome of a new infection in a few days. Equipment under development may make it possible to detect an outbreak of infection more rapidly than before. The 2001 outbreak of Foot and Mouth Disease in UK cattle cost £2.3 billion, so there are financial as well as human reasons to speed such innovation.

Such developments might make it simpler to identify infection at key points such as in hospitals, ports and airports. However, they might be even more valuable in the developing world. Africa has the biggest load of infectious disease and the least well-developed systems for coping with it.

Detection systems that were designed to cope with African conditions, for example by not requiring power or refrigeration, could allow diseases to be controlled but could also have commercial benefits. Their use might reassure trade partners that they were buying products which did not pose a threat of infection.

Another key technology is satellite-based monitoring of weather, plant health and other conditions on the ground. This could allow vulnerable areas for plant and animal infection to be spotted more quickly so that vaccination programmes and other measures can get going more rapidly. All experience shows that speedier response is key to cutting the impact of an outbreak of infection.

The lesson of the project is that on a 10 – 25 year view, the potential benefits of DIM systems will only be accrued if the new systems are linked to effective control measures, and we become more joined up across plants, animals and humans, at national and international levels.

Reference
1  See www.un.org/millenniumgoals

Martin Ince was science writer for the DIID project