In this photo from the Pacific Commercial Advertiser, Bert Hushaw and Duke Kahanamoku prepare for a return to Hawai'i from the U.S. Mainland during the Spanish flu epidemic of the early 20th century."They are wearing 'flu' masks because on the Coast, they have to or be branded as 'slackers'," the original caption reads. Courtesy photo

History teaches us to be
vigilant about flu threat

By Liza Simon / Ka Wai Ola Loa

Even as Hawai'i joined 43 other states in having confirmed cases of H1N1 swine flu with mostly mild symptoms, disease experts are urging the public not to assume the danger of a deadly epidemic has passed. Flu history in Hawai'i and the Pacific Island territories offers several cautionary tales, dating back to the 1918 Spanish flu global epidemic that took an estimated 50 million lives or one-fifth of the world's population. The 1918 outbreak hit Hawai'i in three distinct peaks between 1919 and 1920. Exact mortality figures are not known but the death toll appears to have been highest for working age adults and Native Hawaiians.

"What everyone who understands this disease is concerned about is that novel viruses sometimes gain in virulence as they pass from one individual to the next, so the each successive wave becomes more serious," said Hawai'i state epidemiologist Dr. Sarah Park. "Our job in public health is to keep that micro-organism in one place, similar to a fireman trying to keep flames contained," said Park, acknowledging that the fire analogy has limited application. "You are never completely sure if (a flu strain) is gone or just percolating under the radar."

Park adds that predictions of mass death from the swine flu disease that emerged this year in Mexico are highly speculative given improved surveillance and diagnostic technology. She also said scientists have gained an important understanding of the behavior of viruses, which hadn't been discovered in 1918. Nevertheless, Park says studies of the 1918 situation have yielded this very important lesson: Timely response to a serious flu disease can stop infection, while inaction can be fatal.

The lesson is reflected in 1918 editions of the Pacific Commercial Advertiser (a precursor of the Honolulu Advertiser). Initially, the local newspaper's articles linked the disease to World War I soldiers in Europe and minimized any imminent threat to the Hawaiian Islands. Within a year, as flu mortality rates climbed in many east coast cities. There were 800 flu deaths in a single month in Philadelphia right after that city's mayor ignored federal orders to cancel mass gatherings. Still, Hawai'i's newspaper quoted a Honolulu health official reassuring local residents that dangerous germs would "wither in the warm tropical climate." Hawai'i authorities quickly switched gears in late 1918, after the Spanish flu epidemic arrived in Hawai'i via two infected sailors who took shore leave from a ship docked in Honolulu harbor. Health officials then issued warnings and developed quarantine procedures in an effort that critics then likened to "closing the barn doors after the horses had galloped off."

A 2007 study of 43 cities by researchers at the Centers for Disease Control showed the cities that reacted with swiftness to the Spanish flu epidemic had the lowest number of deaths. Measures undertaken included closing schools and banning public gatherings.

In addition to government action, the health department's Dr. Park said containment of a serious flu epidemic also hinges on individual responsibility. "Keeping yourself healthy in general is something you can and should do. We all need to have as much reserve possible to draw on to fight any infection. If you are not healthy to begin with, then you are at a big disadvantage once there is an outbreak with severity." Park also echoes longstanding advice of the department in urging families to prepare their keiki and kūpuna to stay home in the event that a serious outbreak of swine flu prompts school closings or a ban on public gatherings.

Like seasonal flu, swine flu is a respiratory disease that enters through mucous membranes and is transmitted easily by touching surfaces where flu germs can survive for up to two days. The national Centers for Disease Control, which provides guidance to state health departments nationwide, says people can do their part in preventing swine flu infection by regularly washing their hands and staying home when sick.

"We've come to understand that the flu virus is bent on surviving, so it is continually twisting and turning and changing into new forms that our bodies can't recognize and therefore can't attack with antibodies," said Dr. Alan Tice, a Honolulu expert in infectious disease. Seasonal flu has a genetic makeup that shifts slightly from season to season. Swine flu, by contrast, mixes in genes from several species and mutates with a quantum leap. Our bodies fail to recognize the novel germ and can't defend against it. Furthermore, the new virus must be in circulation for a while, before scientists can isolate it and use its inert form as the basis for a vaccine, said Tice.

But the rapidity with which researchers can make and distribute mass doses of vaccine has become a matter of months—not years, thanks to improved technology, Tice said.

Another new factor in the global spread of disease is that most populations have some degree of exposure to common viruses and, therefore, have developed natural defenses against such diseases. "Hawaiians lived in isolation for so long and once had immunologically naīve systems that were devastated when Europeans arrived and introduced diseases, but this has changed," said Tice. However, in the face of a novel virus like swine flu, Tice said all populations may be equally susceptible.

Research shows that most indigenous islander populations were ravaged by the 1918 epidemic. It's estimated that Fiji lost 15 percent of its population in less than one year after the Spanish flu first hit its shores. Western Sāmoa lost 20 percent of its people to the disease when the Territorial Government of New Zealand allowed into port a ship with infected individuals. American Sāmoa was a notable exception. After U.S. Naval authorities and local chiefs imposed a rigid quarantine, forbidding departures and arrivals, the main island of Tutuila emerged as one of the few places in the world to be untouched by the Spanish flu. "A virus can be stopped by awareness and infection control," said Tice, citing success in containing the 2003 SARS outbreak, which prompted quick and effective response in the affected nations of Canada, Singapore and China.

Tice said it's not known yet why the swine flu was lethal in Mexico, while the same strain turned out to be relatively meek in Hawai'i cases and elsewhere in the U.S. continent. "There could be as yet unidentified virulence factors unrelated to the typing, or some environmental factors in Mexico, such as another virus already present that is magnifying the swine flu effects in Mexico, but will this pattern remain the same? We just don't know. This is why no one can afford to be complacent."

For the latest information and advice on swine flu, visit www.cdc.gov/flu and www.hawaii.gov/health.