Health Journal Entry

Swine Flu Emergency Declared in U.S. (May 4, 2009)

The United States declared a swine flu emergency after a big surge in the number of cases this week. By the weekend, 160 cases were confirmed in 19 states, with New York, Texas, and California hit the hardest. About half of the infected people had visited or had close contact with someone recently in Mexico where the outbreak began. Although most flu cases in the country have been relatively mild, the virus killed a Mexican toddler getting treatment in Texas.

Worldwide, nearly 800 cases of swine flu have been confirmed in 17 countries. The total includes over 500 cases in Mexico, where 19 people have died. These numbers are much lower than those reported earlier in the week, which Mexican officials now say were inflated. The World Health Organization (WHO) raised its health alert to phase 5, the second highest level, after the number of cases rose sharply. Phase 5 means the virus has potential to become a global pandemic if it keeps spreading.

Swine flu is a respiratory disease caused by a type A flu virus. The version of the virus causing the outbreak appears to be a new strain that most people have no immunity to. It contains an unusual mix of genes from pig, bird, and human flu viruses. The pig virus genes are a combination of European and North American strains.

Normally, people in regular contact with pigs are the ones most likely to get sick. That's not the case in the current outbreak. Health experts are alarmed at the ease with which the virus is spreading from person to person contact. It spreads from coughing, sneezing, or touching a contaminated object. According to WHO, there is no risk of infection from eating pork if it's fully-cooked. The virus is usually infectious, but not deadly, to pigs. A puzzling fact about the current outbreak is the virus wasn't even detected in pigs until infected pigs were found on a farm in Canada this weekend. Curiously, these pigs appear to have caught it from infected people, not the other way around.

The symptoms of swine flu, like other types of flu, include fever, cough, sore throat, body and headaches, and chills. But in some cases, it can cause more serious symptoms. The Centers for Disease Control and Prevention (CDC) advises people to wash their hands frequently and keep away from anyone who's sick to help avoid catching it.

To learn more about the outbreak, do this Planet Diary classroom activity Swine Flu: The Start of an Epidemic.