Wednesday, May 6, 2009

Mexico City’s 5-Day Shutdown Defeats Flu

Mexico is slowly getting back to normal after a shutdown that appears to have succeeded in halting the momentum of the flu there. The number of new cases in Mexico dropped sharply during the shutdown, to the point where the United States is now the center of the new flu outbreak.

The shutdown was done at a tremendous economic cost, yet it may have been worthwhile. Telling people to stay home for five days, a move that even included canceling yesterday’s Cinco de Mayo celebrations, prevented thousands of people from catching the flu, and could have bought enough time to prevent the flu from becoming a large-scale outbreak within the city. As the infection continues to spread across the United States and Europe, it is a fair guess that it would have continued to spread across Mexico City if the shutdown had not been ordered. If so, it appears that the benefits of the shutdown were greater than its costs.

The World Health Organization (WHO) confirms cases in at least 21 countries, with quite a few cases contracted outside of North America. If it finds a pattern of people catching the new factory farm-based form of H1N1 flu in public places on multiple continents, it will declare a pandemic. Last week I wrote about why I think it is harder to have a flu-like disease spread globally now, but I believe it is important to note that the factory farm flu has spread faster than other recent new flu outbreaks, so it is likely to spread much farther among humans than bird flu did, for example.

An encouraging note is that the flu has killed far fewer people in the last week, as people know to watch for it and to take it seriously if symptoms appear. But WHO cautions that flu mutates easily and could turn into a more harmful form in the coming weeks, so it encourages people to remain vigilant. As I have mentioned, the key to limiting the spread of flu seems to be washing hand-contact surfaces such as doorknobs and handrails in busy public places, and washing hands after passing through such places.