The outbreak of a new form of swine flu has prompted the United States and the World Health Organization to declare a public health emergency. President Obama today called the emergency a "precautionary tool," since so far the outbreak has had only limited impact in the United States. But public health officials are scrambling to determine the extent of the outbreak.
So far, 20 cases have been confirmed in the United States, in California, Kansas, New York City, Ohio, and Texas. All have been relatively mild. More than 20 people have been killed by confirmed cases of the virus in Mexico, however, and dozens more have died of respiratory infections that might have been swine flu but haven't been confirmed as such. The U.S. cases started in late March and early April in Southern California and Texas, according to the Centers for Disease Control and Prevention. Other confirmed cases have been identified in Canada and Spain.
This outbreak could peter out, like a 1976 swine flu outbreak did. Or the virus could spread easily from one person to the next, sparking a pandemic in which millions of people are infected. Richard Besser, the acting CDC director, says it's too early to say if we'll see more severe disease here in the United States. "Viruses are unpredictable and variable over time," he said yesterday. "What we say and what we learn will change."
Here's the rundown on what we know so far, as well as the options for avoiding swine flu and for treating it if you get it.
How is swine flu different than seasonal influenza and bird flu?
This is a new flu bug that includes genetic segments from human, swine, and avian flu viruses. It is an influenza A H1N1 strain, named for two proteins in the bug's protein coat. H1N1 viruses often circulate without causing major outbreaks. But since this flu virus is new, people might not have immunity to it. That's why the global public health system is on alert. No one knows where this outbreak might lead.
What symptoms would tell me I have swine flu?
Swine flu symptoms are similar to the symptoms of regular seasonal flu, according to the CDC. Those include:
- Lack of appetite
Some people with swine flu have also reported runny nose, sore throat, nausea, vomiting, and diarrhea.
How can I tell if someone sitting next to me has swine flu?
You can't. If someone is showing the symptoms described above, it couldn't hurt to keep your distance. Jeff Duchin, chief of the communicable disease section at Public Health Seattle, says it's best to say 6 feet away from someone who has the flu because the virus spreads in droplets when people talk, cough, or sneeze. Of course, your neighbor might just have a stuffy nose caused by a mild cold or seasonal allergies.
Should I be wearing a face mask, like they're wearing in Mexico?
Not unless you're taking care of a person who's sick with swine flu or are sick yourself. Wearing masks is a popular reaction to respiratory outbreaks in parts of the world, but it's not a step that the U.S. government has recommended for the current outbreak. The CDC has an online guide to using masks and respirators to prevent flu transmission.
Is there a vaccine available for this new swine flu?
No. Developing and producing a vaccine matched to this flu virus will take several months. Anne Schuchat, director of the CDC's National Center for Immunization and Respiratory Diseases, said yesterday that a swine flu vaccine could be added to the seasonal flu vaccine now being produced for next fall, either as a replacement for one of the three strains in that vaccine or as an addition that makes it a four-strain vaccine.