Posted on 05/29/2003 1:33:48 AM PDT by chance33_98
Thursday, May 29, 2003
West Nile Virus could be “bigger than sars” in 2003
BOSTON — West Nile Virus, which sickened 4,156 people and resulted in 284 deaths in North America last year, could end up in 2003 having a considerably bigger human and non-human impact than that seen to date with SARS, according to two Harvard experts. The pair indicated that the Plains, western states and Alaska may be particularly susceptible to 2002-like West Nile Virus conditions, which already are at alarming levels in Central and Latin America.
Dr. Paul Epstein, associate director of the Harvard Medical School Center for Health and the Global Environment, and Douglas Causey, Ph.D., senior biologist at the Harvard University Museum of Comparative Zoology, warned that climate-change contributors such as excessive burning of fossil fuels and deforestation will have to change in order to bring under control the recent surge in 30 major infectious diseases, including West Nile Virus.
Dr. Epstein said: “The attention focused in recent weeks on SARS is extraordinary and, it can be argued, excessive. This is an illness that — no matter how deadly — has sickened only a few thousand around the globe and killed a few hundred.
This stands in sharp contrast to West Nile Virus, which resulted in 4,156 human illnesses and 284 deaths in North America alone last year.”
He added: “It is entirely reasonable to expect that the North American impact of West Nile virus will be as significant in 2003 as it was in 2002 ... As cold and cruel as the winter has been in the U.S. and, in particular, the Northeast, we are concerned that present and persistent drought projected in the Plains states, the West and Alaska could set the stage for amplification and spread of West Nile, as it did in 2002. That doesn’t mean that we won’t have a bad West Nile Virus season in the East and South in the U.S. Where West Nile Virus already is established among wildlife, heavy rains may increase the ‘bridge vectors’ that carry the virus to humans and horses. But we are particularly concerned about seeing what is essentially a ‘replay’ of the circumstances in certain parts of the country that led to so many illnesses and deaths in 2003.”
The experts cautioned against evaluating the danger posed by West Nile Virus and other emerging infectious diseases in strictly human terms.
Dr. Causey said: “The problem with looking at the disease picture from a strictly human standpoint is that we and animals are all in this together. Infectious diseases like West Nile that can jump species can have devastating effects in animals and in humans. Of great concern is the fact that West Nile Virus has spread to 230 species of animals, including 138 species of birds! We are particularly concerned about what we are seeing with birds. Last year, avian deaths increased five-fold over 2001 … West Nile Virus has spread to the Caribbean in 2003, and it now is a leading suspect in the disturbing 10-fold drop in several bird species in Costa Rica over the past year. Many of these are migratory songbirds, the loss of which will be noted across the United States.”
Causey added: “The domination of urban landscapes by ‘generalist’ birds, such as crows, starlings and Canada Geese, may contribute to the spread of West Nile, along with the numerous mosquito breeding sites, such as old tires and stagnant waterways. The disease-related problem faced by birds does not begin and end with birds. Declines in raptors – condors, owls, hawks, eagles, kestrels and marlins – could have dramatic consequences for human health. These birds of prey are our guardians as they prey upon wayward rodents and keep their numbers in check. When rodent populations explode – when floods follow droughts, forests are clear-cut, or diseases attack predators – their legions can become prolific transporters of pests and pathogens.”
THE GLOBAL WARMING ISSUE
Epstein and Causey called for a number of steps, including better disease surveillance and response and stepped-up coordination among disease, climate and other experts. They also pointed out that an effective fight against West Nile Virus and other emerging infectious diseases will require the undertaking of efforts to curb global warming.
Dr. Epstein asked: “Measures to nourish Earth’s natural systems are essential, for biological diversity serves as a buffer against disease emergence and spread. For prevention, we need to change directions on our treatment of the environment. Thus, we must first slow down. That means cutting far fewer trees and burning much less of the coal, oil and natural gas that release globe-warming gases. Global warming is a huge problem, but the good news is that – through a large investment in renewable energy and greater efficiency, ecological restoration and infrastructure retrofits, and coherent transport systems – we can make the energy transition the engine of growth for the 21st Century, and provide the best insurance policy for developing a cleaner, healthier and more equitable future.”
Dr. Causey noted: “We clear land extensively and penetrate fragmented forests at our peril. Now, global warming is enabling microbes to migrate pole-ward and up mountains, and the accompanying extreme floods and droughts create conditions conducive to “clusters” of outbreaks. Pathogens that hitch rides with animal vectors – like mosquitoes, ticks and rodents (little ones that respond rapidly to environmental change and thrive on adversity) – form the majority of diseases newly emerging in humans … Prevention will mean nourishing the biological diversity that protects humans and animals against runaway pathogen spread – cutting far fewer trees, restoring lost wetlands, diversifying farming, and burning much less coal, oil and natural gas that release globe-warming gases.”
WEST NILE VIRUS BACKGROUND
In 2002 West Nile Virus made a furious dash across the nation during what was a hot, dry summer. Spreading to 44 states, the District of Columbia, and five Canadian provinces, neurological cases of the virus numbered over 4,000 and 284 people died. It also was learned that West Nile Virus could be transmitted via blood transfusions, organ transplants, pregnancy and probably breast milk. West Nile Virus and SARS are just the latest in about 30 infectious diseases that have been on the rise in recent years.
In the past three decades, previously unknown diseases have surfaced at a pace without precedence in the annals of medicine. The cast of new diseases includes: HIV/AIDS, Lyme disease, Legionella, Ebola, Nipah, hantavirus pulmonary syndrome, toxic E. coli, a new strain of cholera, and a host of antibiotic-resistant organisms. Old diseases, like malaria, cholera, TB, rabies and dengue fever are resurging, while others, like West Nile Virus, have relocated.
CONTACT: Christine Kraly, (703) 276-3258 or ckraly@hastingsgroup.com.
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