Sneeze heard 'round the world: World Health Organization declares a swine flu pandemic.

RODALE NEWS, EMMAUS, PA—The World Health Organization (WHO) met with flu experts from around the world today and made official what many experts already knew—the novel H1N1 virus, initially referred to as swine flu, is a pandemic.

THE DETAILS: WHO’s six-tiered pandemic system calls for the declaration of a pandemic when a virus that infects animals, or a virus with human and animal genes, fits the following criteria: widespread human-to-human transmission of the virus to at least two countries in one WHO region, and community-level outbreaks in at least one other country in a different WHO region. Since the outbreak appears to have started in the Americas, with Mexico hit the hardest, and is continuing to spread in other countries outside that region, such as Britain, Australia, and Japan, it fits the WHO’s pandemic criteria.

WHAT IT MEANS: Although the word “pandemic” certainly sounds frightening, the WHO definition pertains to how widespread the virus becomes, not how severe it is. (In the future, the organization may institute severity guidelines to help the public gauge the danger of an outbreak.) Although the WHO announced that 74 countries have officially reported more than 28,000 cases of H1N1 infection, including 144 deaths, at this point, H1N1 seems a relatively mild virus. It could mix with the seasonal flu germs now circulating in the Southern Hemisphere, however, and pick up drug-resistant characteristics that could make it more dangerous. Still, Mary Klotman, MD, chief of the division of infectious diseases at Mount Sinai School of Medicine in New York City, says the vaccine now in development (which could be ready by October) should still offer some protection even if that happens.

It’s also important to put the threat into perspective. Although many of these unfortunate deaths are highlighted in media reports, it’s important to note that this virus strain appears to be less lethal than seasonal flu viruses we see each year. The best advice to avoid getting sick with this virus continues to be: Wash your hands frequently, and if you’re sick with flulike symptoms (fever, headache, body aches, sore throat, and sometimes diarrhea and nausea), stay home and call your doctor.