GENEVA – A swine flu outbreak that appears to have caused fatalities in humans in Mexico and nonfatal cases in the United States prompted the World Health Organization this weekend to urge countries around the world to be alert for suspicious cases of influenza.
WHO chief Margaret Chan says the global body is taking the outbreak very seriously, though comparisons with the 1918 epidemic are premature.
Here are some facts: Q. What is swine flu?
A. Swine flu is a highly contagious acute respiratory disease normally found in pigs. It spreads through tiny particles in the air or by direct contact. According to WHO, it tends to infect large numbers of a given pig population, killing 1 to 4 percent of those affected. Not every animal infected displays symptoms.
Q. Where do outbreaks occur?
A. Swine flu is considered endemic in the United States, and outbreaks in pigs have also been reported elsewhere in North America, South America, Europe, Africa, and parts of eastern Asia.
Q. How do humans contract the virus?
A. People usually become infected through contact with pigs, though some cases of limited human-to-human transmission have been reported.
Q. Is it safe to eat pork products?
A. WHO says properly handled and prepared pork products are safe to eat. The swine flu virus dies when cooked at temperatures of 160 degrees or higher.
Q. How high is the risk of a pandemic?
A. Since the swine flu outbreaks in Mexico and U.S. were identified, the risk of a pandemic has increased. Health officials worry the swine flu might develop into a form easily spread among humans. To do this, it could combine with a human flu virus or mutate on its own into a transmissible form. Experts worry that the more the virus circulates, the more likely a pandemic strain will emerge. But there is no way to predict when a pandemic strain will develop.
Q. Does a vaccine exist?
A. Pigs in North America are routinely vaccinated for swine flu, but no vaccine exists for humans. In any case, the flu virus evolves quickly, meaning that vaccines are soon obsolete. Health officials say there is no suggestion that the vaccine prepared for seasonal flu will protect against swine flu.
While people who are given the seasonal flu vaccine will probably not be protected against swine flu, it may prevent them from getting the seasonal flu. If they are then infected with swine flu, that reduces the possibility of the two flus mixing in that person to create a potential pandemic strain.
Q. What other treatment is there?
A. The swine flu virus detected in Mexico and the United States appears to respond to treatment with oseltamivir (Tamiflu) and zanamivir (Relenza).