When An Epidemic Becomes a Pandemic

By Medical Discovery News

July 7, 2012

For at least thousands of years, people have suffered flu epidemics and pandemics.  In 412 B.C., Hippocrates described what was likely an influenza epidemic in Ancient Greece. The term influenza comes from 15th century Italy, when people believed stars influenced the illness because it always came in cycles. Soon after, in 1580, the first clear account of a flu pandemic was written. From that point on, records show flu pandemics have been recurring every one to three decades somewhere in the world.

So what is the difference between an epidemic and pandemic? Flu epidemics occur every year because each year the virus comes back just slightly different. In a flu pandemic, a much larger geographic area is affected, sometimes worldwide, when a new strain of the virus infects people for the first time and everyone is susceptible.

The World Health Organization has defined three phases of pandemics. The first, or earliest, is called the Inter-Pandemic period. During this time, no new influenza viruses are detected in humans, but new flu viruses could be circulating in animal populations.

The next level is the Pandemic Alert period. Here, the flu virus is infecting humans but is either incapable or has limited ability for human-to-human transmission. The last is the Pandemic period where there’s widespread and rapid transmission in human populations.

The potential for a flu virus to be capable of causing pandemics lays in its ability to infect many different species including horses, pigs, and birds. As various strains of the flu virus spread from species to species, multiple viruses can infect the same animal, allowing the viruses to exchange genetic information and create a new virus. Once it can infect and efficiently transmit between humans, a pandemic starts.

The annual flu epidemic sickens 20 percent of America’s population and kills 40,000 people, creating a $10 billion loss in productivity and medical costs. Imagine the cost of a pandemic.  The largest recorded was the 1918 Spanish flu pandemic, which killed 675,000 people in America and 20 to 40 million people worldwide.

Today, health officials worry about avian flu (H5N1) and whether, or more likely when, this flu strain will start a new pandemic. The H5N1 virus was first recognized in Hong Kong in 1997.  Since then it has spread extensively throughout Asia and can now be found in the Middle East, Africa, and Europe. The virus is in the Pandemic Alert period with no means yet for extensive human-to-human transmission. As of spring 2012, approximately 600 people have been diagnosed with H5N1 and the mortality rate is an alarming 60 percent.

In order to understand how this virus may attain efficient transmission between people, American and Dutch scientists created a transmissible H5N1 in the lab. The controversial study could help other scientists create a vaccine for when an avian flu pandemic occurs. But others fear this research could provide a “blueprint” for terrorists to create a potential biological weapon.

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The Danger of Dual Use Research

By Medical Discovery News

June 9, 2012

Dual use research is a worldwide concern

While intently working to solve the mysteries of the universe, scientists need to consider whether their work is a security risk. The question is especially relevant in life science research where new developments can improve human health but could also be misused for bioterrorism.

This type of research is called dual use, meaning that while it enhances current knowledge, it could also be misapplied to create a threat to public health, agriculture, or the environment.

In some cases, scientists don’t anticipate the negative impact of their research until it’s pointed out. In 2001, Australian scientists searching for ways to solve a rodent problem created a solution that was so threatening, it raised the dual use issue.

The researchers’ challenge was to control rodent populations that swell in years of a good grain harvest, potentially spreading infectious diseases and damaging crops. They decided to use a non-lethal mouse virus called mousepox, engineered to carry a gene that will produce a mouse egg protein. Once the virus infects a mouse and produces the egg protein, the mouse’s immune system would produce antibodies attacking the virus and all egg proteins, including its own, which would make female mice sterile.

The problem was a mouse’s immune system recognized the virus-encoded egg protein as its own and did not produce a strong immune response. To overcome this, researchers added another protein – interleukin-4 (IL-4). This protein excites the immune system and boosts the level of antibodies. Instead, the IL-4 gene made the normally benign mousepox virus incredibly lethal. Even mice vaccinated against the mousepox virus died from the infection.

When the Australian researchers published their study, other scientists recognized the potential danger of this information being made public. It could serve as a “blueprint” for a devastating biological weapon. They worried that this same approach could be used with a human pathogen, the lethal smallpox virus.

The debate that followed questioned whether the Australian scientists should have published their results. Today, a federal advisory committee, the National Science Advisory Board for Biosecurity, monitors and guides scientists on dual use research. It provides guidelines to help scientists identify studies that could endanger public safety.

But sometimes the parameters are not so clear. The latest controversy involves Dutch and American scientists who created an avian influenza virus (H5N1) with the potential for efficient human-to-human transmission. The natural virus doesn’t have this capability yet. Those who want the study published argue that sharing this knowledge will speed the development of a vaccine once H5N1 begins its pandemic spread. But opponents believe it’s a security threat.

The federal advisory board reviewed the paper and initially found it was dual use. On first review, the board recommended the study be released with the sensitive parts left out. Yet recently it reversed its decision and allowed the full paper to be published. The debate over this issue rages on, and scientists suggest the creation of clearer guidelines based on international consensus.

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