swine flu

New Swine Flu Study Raises Alarming Historical Parallels

July 15, 2009 07:00 AM
by Jill Marcellus
After months of uncertainty over swine flu’s nature, a new study reveals that it’s a virulent class apart from seasonal flu and potentially more akin to the 1918 Spanish influenza.

Study Emphasizes H1N1 Severity

Researchers from the University of Wisconsin have determined that swine flu, technically known as the H1N1 virus, is “more severe than ordinary winter flu” and “different from seasonal influenza,” the Associated Press reports.

The researchers studied the internal effects of swine flu on a host of animals, including ferrets, mice and monkeys. Although seasonal flu mainly affects the nose and throat, swine flu fiercely attacked the lungs and the whole respiratory system, even causing lesions. Monkeys with H1N1 showed levels of virus that were at least double that of monkeys infected with seasonal flu.

One of swine flu’s particularly troubling aspects, reminiscent of 1918, has been its young, otherwise healthy victims. Only 1 percent of swine flu cases occurred in people over 65, according to a study reported by The Economist, but seasonal flu kills thousands of elderly people in the U.S. each year.

Now, researchers report that survivors of the 1918 pandemic are apparently immune to H1N1. According to the journal Nature, “on the basis of DNA sequence alone, the two viruses are not strikingly similar. But it is still possible that the immune response elicited by one virus can offer protection against the other.”

Unfortunately, exposure to the viruses of the 1920s and 1950s wasn’t “enough to elicit these antibodies,” Nature reported.

Yoshishiro Kawaoka, the lead author of the study, insists that swine flu hasn’t reached the severity of the 1918 pandemic. Experts who spoke to Nature, however, worry that the virus could intensify over time.

Background: The pandemic panic

Caused by type A influenza, the H1N1 virus is a respiratory disease of pigs that rarely occurs in humans, but is currently spreading through human-to-human contact. In June, the World Health Organization raised the H1N1 virus alert level to a pandemic, but cautioned that the announcement reflects the flu’s global reach, not its deadliness. On June 26, Dr. Anne Schuchat of the Centers for Disease Control and Prevention announced that the CDC estimates there have been at least 1 million cases of swine flu in the United States; reported cases at that time were less than 30,000.

Misinformation about swine flu has spread as widely as the virus itself, partly due to the many mysteries still surrounding the outbreak. The WHO attributes some of the confusion to the term “swine flu,” which it has stopped using in order to protect pigs. In the mistaken belief that swine flu could spread through pigs or pig products, Egyptians slaughtered thousands of pigs, while China, Russia and Ukraine, among others, banned pork from Mexico, where the outbreak is believed to have originated. Afghanistan, meanwhile, has finally released its only pig from quarantine, Reuters reports.

Historical Context: 1918 pandemic or 1976 scare?

The shadow of 1918 looms behind President Obama’s warnings of a potentially “significant outbreak” this fall, despite declining media and public concern. As late as spring 1918, a Spanish wire service declared the epidemic “of a mild nature,” according to PBS. Come autumn, that “mild” flu became a global pandemic, ultimately killing an estimated 20 to 50 million people.

Not much was known about the epidemic at the time, and there was little doctors could do. Mysteries still remain, but researchers partly attribute the deadliness of the 1918 influenza to its origins, spreading first from birds to pigs, and then to humans, The New York Times reported in 1997.

The virus of 1976, however, provides a less threatening counterpoint. One person died in that first major outbreak of swine flu among 500 soldiers at Fort Dix, N.J., but an epidemic never developed. Many remember the event as more of a public relations disaster, rather than a health disaster: The government instituted a federal vaccination program that was stopped after it caused serious complications in hundreds of people. 

Reference: Swine flu resources

The U.S. Health and Human Services Department has set up a Web site,, where people can find general information, as well as the latest swine flu developments. For more background, see findingDulcinea’s “5 Sites for Understanding the Swine Flu (H1N1 Influenza A) Pandemic.”

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