Flu outbreak crisis predicted
■ The warnings continue, and experts urge focus and planning.
By Amy Snow Landa — Posted Aug. 8, 2005
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As if the usual worries of medical practice aren't enough, add the frightening prospect of pandemic influenza that could kill tens of millions of people worldwide within months.
That's the scenario that public health officials, epidemiologists and infectious disease experts say will become reality.
"The United States remains unprepared for pandemic influenza that could kill millions of Americans over a short period of time with little warning," said Andrew T. Pavia, MD, professor and chief of pediatric infectious diseases at the University of Utah Health Sciences Center and Primary Children's Hospital.
Dr. Pavia, chair of the Infectious Diseases Society of America's task force on pandemic influenza, warned a House health subcommittee in May such a pandemic "is imminent" and its likely impact "cannot be overemphasized."
Similar strong warnings have been issued by the World Health Organization and the Centers for Disease Control and Prevention as well as by a chorus of scientists and other experts.
"It's going to happen," said Michael Osterholm, PhD, MPH, an epidemiologist and director of the Center for Infectious Disease Research and Policy at the University of Minnesota. "It might not be tonight, it might be several years from now. But the bottom line is that every day we wait is going to be one more day of missing preparedness, and we're going to regret that."
The concern now is focused on the avian flu strain H5N1, which is circulating in Asia and has killed tens of millions of chickens and other birds. This strain is also highly lethal to humans. To date, 50% of infected patients have died.
By comparison, the Spanish flu pandemic of 1918-19 had a far lower mortality rate of 2.5% to 5%. Estimates on the death toll then range as high as 50 million to 100 million.
Evidence suggests the impact of a pandemic caused by H5N1 would be similar, said Dr. Osterholm. Extrapolating from the 1918-19 data to the current population, 1.7 million Americans could die from H5N1, he said. Worldwide, the death toll could reach 180 million to 360 million.
So far, there have been relatively few human cases of H5N1. From December 2003 to June 28, the cumulative confirmed infections reported to the World Health Organization total 108, with 54 deaths. All of these cases occurred in Vietnam, Thailand, Cambodia and Indonesia.
The fear is that eventually the avian flu strain will mix with human influenza viruses and produce a new viral strain capable of sustained human-to-human transmission. Humans would have little, if any, protection in the event of an outbreak.
Manufacturing an effective vaccine will take several months using current egg-based technology. In the meantime, physicians will have to rely on antiviral agents for treatment and prevention.
Unfortunately, the U.S. stockpile of antivirals remains woefully inadequate, according to most infectious disease experts. The IDSA estimates the United States needs enough doses to treat 50% of the population but currently has enough for only about 2%.
Thus, many people in the medical and scientific communities have called for the United States to boost its antiviral stockpiles and accelerate vaccine production.
"All stops should be pulled out to develop these antiviral drugs and vaccines as quickly as possible," said American Medical Association President J. Edward Hill, MD. In June, Dr. Hill attended the Pacific Health Summit in Seattle, where about 300 leaders in medicine, biotechnology and health policy from Pacific Rim countries addressed a series of health concerns, including avian flu and pandemic threats.
Meanwhile, the National Institutes of Health announced in March it had begun human trials to investigate the safety of a new vaccine that uses an H5N1 "seed strain" developed through a technique known as reverse genetics.
If a pandemic flu outbreak were to occur, physicians will be called on to respond as they would in any other local or national emergency.
"A lot of what they need to know for public health emergencies is very applicable to pandemic flu," said Jeffrey Duchin, MD, chief of Seattle and King County's communicable-disease section. "The key things are related to communication and information sharing. Physicians need ways to get current, accurate information on a need-to-know basis."
But it is possible -- some say likely -- that doctors won't have the tools they need to treat patients effectively.
"A primary care physician is going to have very little in the way of resources," said Jack Lewin, MD, executive vice president and CEO of the California Medical Assn. He was among those at the summit.
Not only will a vaccine be late in coming and antivirals in short supply, but there will also be critical shortages of other supplies such as masks and ventilators.
"There will be a lot of primary care physicians who will be asked to be on the front lines of pandemic flu, and without vaccine, without any antiviral drugs and without a mask," said Dr. Osterholm.
Staffing is also a major concern, said Gary Kaplan, MD, chair and CEO of Virginia Mason Medical Center in Seattle, who also attended the summit. "One of the issues in our community, even without an epidemic, is the nursing shortage and staffing of beds."
Given the many issues yet to be fully addressed, it is critical that physicians become involved now in national, state and local discussions about preparedness efforts, according to Dr. Osterholm. "They need to become activists, they need to organize, and they need committees that are at the national level attempting to be part of an urgently needed dialogue on what we should do."
Physicians in the United States are vital to global preparedness efforts, according to Lee Jong-Wook, MD, MPH, director-general of the World Health Organization.
Dr. Lee, speaking at the Pacific Health Summit, said the WHO and its member nations "are counting on the American medical community a lot" for scientific, technical and human resources to contain the spread of pandemic flu and treat infected patients. His remarks to the group focused entirely on the threat of pandemic flu.
Summit organizer Michael P. Birt, PhD, said infectious disease epidemics are a major concern from both a health and an economic standpoint.
The SARS epidemic "made people realize how quickly these pandemics can go from just a minor incident to a major interruption of global travel and trade, at a cost of hundreds of billions of dollars," said Dr. Birt, who is director of the Center for Health and Aging at the National Bureau of Asian Research in Seattle.
"As a result, vigilance and concern have risen dramatically," Dr. Birt said
A halt in global trade would have major implications for health care delivery in the United States, including shortages of new medical devices and drugs for cancer and cardiovascular disease, according to Dr. Osterholm.
For all of these reasons, "we don't have time to waste."