A virus is creeping across the world, infecting millions from Seattle to Johannesburg, from Tokyo to Mexico City.

Store shelves are barren, the University is closed, 30 percent of the Minnesota workforce is absent, the economy has tanked and medical supplies are inadequate.

Though it hasn’t happened yet, this scenario could become a reality if a pandemic influenza were to hit, according to University health officials.

In recent years, a media storm has raised fears over a particular strain of avian flu, H5N1, which has a 59 percent mortality rate in humans.

Since the initial cases of avian influenza erupted in humans, the global health community has made efforts to curb the effects of a potential pandemic.

Each week, the World Health Organization confirms additional human cases of the highly pathogenic H5N1, which has not yet surfaced in North America. But after initial concern when the strain appeared, the public has paid little attention to the subject.

While some officials say a pandemic is imminent, others are less convinced.

Despite conflicting opinions, governments around the world are following WHO recommendations and preparing for the worst, and University researchers are contributing to the global effort.

A ‘natural’ phenomenon

The possibility of a pandemic avian flu became a reality in 1997, when the H5N1 virus was transmitted to 18 people in Hong Kong. Six of them died.

In three days, veterinary authorities killed nearly 1.5 million birds – all of Hong Kong’s poultry population – in hopes of preventing additional cases.

To date, the WHO has confirmed a total of 256 cases, resulting 152 deaths, mainly in Southeast Asian countries. With a 59 percent mortality rate, Indonesia and Vietnam have seen the highest number of cases. The virus has infected humans and caused death as far as Turkey, Egypt and Iraq.

Although rare, pandemic influenzas are a natural and reoccurring part of the world, said Michael Osterholm, director of the University’s Center for Infectious Disease Research and Policy in the School of Public Health.

“Pandemics are not optional events,” he said. “Another pandemic is going to occur.”

But the United States is not properly allocating funds to fight the avian flu, said Marguerite Pappaioanou, a University professor of epidemiology.

The United States has pledged $3.8 billion to fight avian flu. Only $91.4 million of the funding is for agriculture and animal health, sectors Pappaioanou said “remain underfunded.”

The majority of the money the United States has allocated to fight the avian flu is earmarked for human vaccine development and anti-viral drugs, she said.

“It’s kind of like there is this presumption it will become a pandemic and so we’ll put these billions of dollars into after-the-fact trying to treat people, instead of appropriately beefing up budgets that are going to agriculture so that it stays in birds in the first place and never gets to a pandemic,” Pappaioanou said.

Pandemic return?

Pandemics circled the globe three times during the 20th century: in 1918, 1957 and 1968.

The 1918 flu was the most devastating infectious disease outbreak in recorded history, causing an estimated 40 million deaths worldwide – nearly eight times the population of Minnesota – and 675,000 deaths in the United States.

At the time, the University’s Board of Regents postponed the opening of school until the beginning of October because of the flu.

While pandemics like the one in 1918 blindsided public health officials, the highly pathogenic form of H5N1 is being closely monitored to accelerate detection.

Less lethal forms of avian flu, such as low-pathogenic H5N1, are prevalent, Pappaioanou said. They have been detected recently in Illinois, Ohio, Maryland and Michigan, and previously in Minnesota.

These forms are not considered an immediate threat to humans.

In the last three years, the genetic diversity of the highly pathogenic H5N1 virus has rapidly increased, meaning the virus’s variations could become transmissible from human to human, Osterholm said.

“There’s no end in sight in (H5N1’s) changing genetics,” he said.

But the virus won’t necessarily mutate for the worse.

The same change that would allow person-to-person transmission could also make H5N1 less pathogenic, Pappaioanou said.

In May, genetic changes of the virus in humans were observed up to the time of death by a WHO affiliate researcher in Hong Kong, Osterholm said.

“All it’s going to take is one event in Asia to spark this and we could easily have a pandemic overnight,” he said. “There are twice as many cases this year as last year,” with 74 cases this year.

Osterholm said the small but increasing number of cases is just the tip of the iceberg because “as the cases grow, they reflect the potential for more genetic changes.”

However, this form of avian flu still might never cause a pandemic, said William Hueston, director of the University’s Center for Animal Health and Food Safety in the College of Veterinary Medicine.

“For the people that say it’s just a matter of spreading this disease, that’s simply not the case,” Hueston said. “This is a bird disease that requires very intensive exposure of humans in order for transmission to occur.

“The best strategy is to prepare for the worst, while at the same time hope for the best.”

To help understand how animal-to-human flu transmission occurs, the Centers for Disease Control and Prevention recently awarded the University a $2.6 million grant to study the process during a three-year period.

University preparations

As countries around the world prepare for a possible pandemic, University officials are forming their own strategy. The planning started in May 2005.

“Every college campus is going though this process right now,” said Jill DeBoer, director of the University’s Academic Health Center Office of Emergency Response.

Planning for the pandemic flu is particularly difficult because “the greatest impact is on people,” said Terry Cook, director of the University’s Department of Emergency Management.

If a pandemic were to hit, Cook said, the University would gather essential personnel to determine which actions to take.

Class attendance, research, Housing and Residential Life and students studying abroad are all considered in the plan, Cook said.

The Office of Emergency Response is evaluating the University’s essential services and communications through a task force that met for the first time this fall, DeBoer said.

If a pandemic hits, it will come in waves, she said. The virus will circle the world once in as little as three months, according to the WHO. After a pandemic is declared, DeBoer said, there will be a four- to six-month delay before the vaccines are produced.

Based on research, “there’s some speculation that it could be similar to the 1918 pandemic,” she said.

In the first wave, 25 percent to 30 percent of the population will become infected during a 12-week period, DeBoer said. After about six months, the cycle will repeat.

A recipe for pandemic

Pandemics are always caused by a new form of influenza unknown to the human immune system, according to the WHO. New forms like this seldom occur.

In addition, the new viral form must cause disease in humans and be easily transmissible between them to be considered a pandemic.

H5N1 has met two of the three conditions, according to the WHO. Although the disease has not yet widely spread between people, public health officials have said it could just be a matter of time.

Influenza is “constantly adapting, looking for new ways to find new hosts and modify the cells,” said Jeff Bender, University professor of veterinary public health. “That’s the scary thing about influenza.”

H5N1 is adapted for birds, rather than humans, Bender said.

“There is, in a sense, a species barrier,” he said. “Some of these viruses are really well-adapted to a particular species.”

The H5N1 flu strain has proven significant because of the virus’s ability to cross the species barrier.

Poultry and avian flu

The current concern surrounding avian flu lies in Southeast Asia.

The region’s poultry production systems are vastly different from those in the Americas and much of Europe, said David Halvorson, a University professor of animal sciences who studies avian flu in North America.

Throughout much of Southeast Asia, poultry and other species of birds are close to one another and people, he said, and they sometimes even share living quarters.

The biggest threat for avian flu comes from Indonesia, Pappaioanou said, because the country has not “mounted a serious control effort to stop transmission in their poultry populations.”

The country needs the poultry for food and income, she said. Indonesia might follow the example of China, which is currently vaccinating its entire poultry population.

Avian flu in America

The highly pathogenic H5N1 virus could enter the United States in a variety of ways, including through infected poultry, migratory birds and air travel.

Contaminated poultry or poultry products that are smuggled into the United States could come in contact with free-range or “backyard flocks,” Pappaioanou said.

The industrial poultry production system in North America is designed to keep other bird and animal species from mixing with poultry, Halvorson said.

If avian flu were to enter the United States via migratory birds, he said, they would most likely come from Alaska because of the state’s proximity to Asia.

Pappaioanou said the new University center created with the CDC grant will study how avian flu affects free-range poultry farms and migratory bird populations in Minnesota, Wisconsin and Thailand.

Other public health officials said H5N1 could also enter the United States through human air travel, most likely originating in Southeast Asia.

DeBoer said the good news is that the University is aware of the potential for a pandemic and is working to prevent it.

“The best-kept secret about an influenza pandemic is that most people – perhaps 98 percent – will survive it,” she said. Still, she said, “when this thing hits, there could be widespread panic.”

1918 Spanish flu

The Spanish flu of 1918 hit at the end of World War I. An estimated 8.3 million people died in the war, but from 1918 to 1919 the flu killed an estimated 40 million.

The first wave of the pandemic began in March of 1918 and spread as troops moved between the United States and Europe, according to the WHO. Although contagious, the first wave of the pandemic was not nearly as deadly as the second.

In August 1918, the second wave of the pandemic started simultaneously throughout the world, resulting in 10 times as many deaths, according to the WHO.

Although the current concern comes from a highly pathogenic form of H5N1, all three pandemics in the 20th century started as low-pathogenic strains, Pappaioanou said.

“If chance follows the right path, then low pathogenic viruses can become highly pathogenic,” she said.

The highest mortality rate of those that got the Spanish flu was between 15- and 35-year-olds, and life expectancy dropped by 10 years or more.

Many died from viral or bacterial pneumonia that caused “extensive hemorrhaging of the lungs that could kill the perfectly fit within 48 hours or less,” according to a WHO report.

One physician from the time wrote that patients “died struggling to clear their airways of a blood-tinged froth that sometimes gushed from their nose and mouth,” according to the Stanford University Human Virology Program.

No one knows if H5N1 will be the next pandemic influenza, DeBoer said.

She said researchers see similarities between the 1918 pandemic and H5N1 because they both moved from birds to humans.