| Home > Events > Biosafety and Biorisks Conference, 2005 > speakers > henderson Keynote: International Cooperation to Confront New and Old Diseases
Presenter: D. A. Henderson, M.D., M.P.H. slide thumbnails slide show Dr. Henderson reviewed the history of the successes and challenges in confronting infectious diseases and global public health in the last 50 years, with particular attention given to the watershed events in the emergence of new infections and the threat of bioterrorism. After the eradication of smallpox in the mid-1980s and the cessation of smallpox vaccination, people wondered what should be eradicated next, and there was a great deal of optimism about the future. Dramatic changes post-1950 -- the development of vaccines and antibiotics and improvements in nutrition, housing, and sanitation -- did lead to the decline or elimination of many diseases such as smallpox, diphtheria, whooping cough, tetanus, polio, and measles, but a cloud soon appeared on the horizon. In June 1981 the first case of AIDS was diagnosed, and HIV as the etiologic agent was identified in April 1984. While it was predicted that science would triumph quickly by producing a vaccine within two years, 24 years later, there is a global pandemic in progress, HIV/AIDS is now the fourth leading cause of death worldwide, and there is no vaccine or curative drug available. At the 1989 Conference on Emerging Infections, many wondered if there would be any other surprises like HIV? Since then, SARS, monkey pox, Transmissible Spongiform Encephalitis, a deliberate release of anthrax from an unknown source, and now H5N1 influenza, have emerged, and this is only a partial inventory of the more than 30 new infectious agents that have emerged in the past 25 years. Natural mutation of microbes (i.e., SARS), emergence of microbes from remote areas (monkey pox), laboratory produced microbes (plague, anthrax), and the deliberate release of infectious agents (anthrax) are among the sources of new challenges. These threats can arise in any country and threaten nations across the world. Why are these infections emerging now? Among the causes cited for the emergence of infections at this time are the growth in urban populations and international travel; the growth of hospitals in endemic areas; creating sites for disease distribution; blood borne infection and antibiotic resistance; and the internationalization of the food supply, industrialized feed lots, and processing with variable amounts of control and regulation. Most people did not think the threat of intentional release of bioagents was significant until 1995, because they believed that organisms were too difficult to grow, technologically difficult to disseminate, or that moral barriers would prevent their use. All of these assumptions have been proven wrong. Advances in biotechnology including the ability to manipulate organisms, an increase in the number of laboratories and trained microbiologists, internet access to information, advances in the science of aerosolization, and the growth of independent terrorist groups have changed the situation today. Watershed developments in our assessment of the risk of bioterrorism were the 1995 Aum Shinrikyo release of sarin gas, anthrax, and botulinum in Japan; the 1995 revelations about the Iraqi bioweapons program; and the 1980 Soviet bioweapons program. The Shinrikyo release of anthrax on 8 other occasions probably failed only because they had and released a non-lethal strain. Ken Alibek testified that smallpox was included in the Soviet biological weapons program. The threat of biological weapons is clearly there. What is the agenda for the future? Dr. Henderson's conclusion was that we need a greatly strengthened network of international cooperation and communication for epidemiology and laboratory diagnosis, research and development of vaccines and antimicrobials, and a far more generously supported WHO effort to orchestrate the many national initiatives. - Summary by Richard Waldhorn, M.D. return to top next summary |
