14 March 2008
Emerging Infectious Diseases Focus of International Meeting
Civilian, military scientists work to bolster global disease surveillance
Washington -- Infectious diseases are among the world’s leading causes of death, and scientists from every nation perform research, share information, build laboratory capacity in poorer nations and create global surveillance networks to help prevent and control their spread.
When the incidence of such a disease in people increases over 20 years or threatens to increase, it is called an “emerging” disease, and a growing number have made watch lists and headlines in nearly every country -- highly pathogenic H5N1 avian influenza, severe acute respiratory syndrome (SARS), Ebola virus, food- and waterborne illnesses, and a range of anti-microbial-resistant bacterial diseases like multidrug-resistant and extensively drug-resistant tuberculosis (TB).
Public health professionals from across the globe will meet in Atlanta March 16-19, at the sixth International Conference on Emerging Infectious Diseases, to discuss these and other emerging pathogens and current work on surveillance, epidemiology, research, bioterrorism and more.
“I view [the meeting] as an opportunity,” Dr. Joel Gaydos, coordinator for Military Health System Emerging Disease Programs in the Department of Defense Global Emerging Infections Surveillance and Response System (GEIS), told America.gov, “for all the groups involved in surveillance and response to emerging and infectious diseases to get together, [determine] the priorities and assess how well we’re doing and where the gaps are.”
PATHOGENS NEW AND OLD
Emerging diseases can be new infections that arise from changes in existing organisms or known infections that spread to new geographic areas or populations. They can be previously unrecognized infections that appear when, for example, tropical forests are cleared to make way for new roads, displacing disease-carrying animals and insects. And old infections can re-emerge because of anti-microbial resistance or breakdowns in public health measures.
Most emerging infectious diseases (60.3 percent) are zoonoses, or animal diseases that can be transmitted to people, according to the authors of “Global Trends in Emerging Infectious Diseases,” a paper published in February in the journal Nature.
They analyzed a database of 335 emerging infectious disease events from 1940 to 2004 and found that most zoonoses (71.8 percent) arise from wildlife, are increasing significantly over time, and “are more concentrated in lower-latitude developing countries.” According to the authors, the findings “provide a basis for identifying regions where new emerging infectious diseases are most likely to originate (emerging disease ‘hotspots’).”
“Once you know the trends in emerging diseases, you can do something to prevent them,” said study co-author Dr. Peter Daszak, executive director of the Consortium for Conservation Medicine, based at the Wildlife Trust in New York. “I know there’s been a lot of effort for avian influenza surveillance, but who’s going out there to look for the next one? That’s my message -- that we can put a little bit of our resources into seeking out the next pathogen and doing something about it,” he told America.gov.
The authors also found that drug-resistant microbes made up about 20 percent of the database and that there is a significant increase in those over time as a proportion of emerging diseases.
“We don’t just need to be worried about SARS and Ebola,” Daszak said. “We should also worry about extremely drug-resistant TB.”
According to the study, disease surveillance is concentrated not in developing countries, where emerging diseases are most likely to arise, but in developed countries that can afford laboratories and other means to conduct it effectively.
All disease surveillance is important, said Gaydos, who was not involved in the work. The study shows “where emerging diseases have occurred or might occur,” he added, “but we really don’t know where they’re going to occur.”
DISEASE DEFENSE
Two of the most effective global disease surveillance networks are the U.S. Defense Department’s GEIS and the World Health Organization’s (WHO’s) Global Outbreak Alert and Response Network (GOARN), a technical collaboration of institutions and networks established in 2000 that pool resources to identify, confirm and respond to outbreaks of international importance.
GEIS, established by presidential directive in 1996, is a network of overseas laboratories that work with each country’s health ministry -- and sometimes militaries -- on disease research and surveillance and on a range of efforts with international partners, including WHO.
The labs are the U.S. Naval Medical Research Unit Number 3 in Cairo, Egypt (established 1946); the U.S. Naval Medical Research Unit Number 2 in Jakarta, Indonesia (1940s); the U.S. Army Medical Research Unit in Nairobi, Kenya (1969); the U.S. Naval Medical Research Center in Lima, Peru (1983); and the U.S. Army Armed Forces Research Institute of Medical Sciences in Bangkok, Thailand (1959).
“It’s impressive when you look at the scope of the work that some of our partners are doing,” Dr. Jean-Paul Chretien, a U.S. Navy lieutenant commander and coordinator of the GEIS Overseas Research Laboratories, told America.gov.
The lab in Cairo, for example, “is working in so many countries and is important regionally for influenza,” he added. “But even with all the work that GEIS and CDC [Centers for Disease Control and Prevention] and USAID [U.S. Agency for International Development] and many other governments, international organizations and nongovernmental organizations are doing, a lot more could be done in the way of surveillance in these areas.”
In the developing nations of Peru and Thailand, GEIS works with the militaries to strengthen disease surveillance programs run by the ministries of health.
Chretien said that military-to-military and military-to-civilian partnerships, with the support of national and international civilian health organizations, could help bolster global infectious disease surveillance, particularly in remote and post-disaster areas where military forces are present.
More information about emerging infectious diseases is available at the National Institute of Allergy and Infectious Diseases Web site.
See also the Web sites for the DoD Global Emerging Infections Surveillance and Response System, Consortium for Conservation Medicine and GOARN.
