April 28, 2009

Number of Confirmed Swine Flu Cases Rise

This update is as of Tuesday afternoon.

Developments continue along the expected course of a new influenza virus spreading fairly easily from person-to-person.

"Many hundreds" of schoolchildren are sick with suspected cases of swine flu, according to New York City's Health Commissioner Thomas Frieden. Mayor Bloomberg reports that two people are hospitalized with suspected swine flu in Brooklyn and the Bronx, separate from any exposure to the outbreak which occurred at St. Francis Prep in Queens.

The number of confirmed cases in the U.S has climbed from 40 to 68, including "at least five hospitalizations."

Two California deaths are being investigated for possible swine flu links.

The virus has spread to Asia and the Middle East, with the first cases of confirmed swine flu in Israel and New Zealand, though in both cases the affected individuals had recently returned from travel to Mexico. Costa Rica has confirmed its first swine flu case.

The World Health Organization yesterday officially changed our pandemic status from Pandemic Stage 3 to Stage 4, but not to Stage 5. Their explanation is that first they would need to see sustained transmission in remote communities before a WHO Stage 5 would be justified. This would require not just that people who have been to Mexico and returned home develop illness, but that sustained outbreaks, for example, in New York are confirmed.

This may only be a matter of time.

Think of it this way: If each person who has the flu infects 2.0 other people on average before the illness resolves, there will be exponential growth in the number of cases, and the pandemic is upon us. However, if each person infects just 0.9 people on average before their infection resolves, the outbreak will linger a little while but then peter out completely. On such mathematics the fate of our interaction with the flu virus rests.

* * * * * *

Russia and China have banned the importation of pork from certain parts of the United States, allegedly due to "risks" from the swine flu outbreak.

This makes no scientific sense whatsoever. The virus is a respiratory virus being spread from person-to-person. It genetically originated in a flu virus native to swine, but it has grown past that stage of its genetic history. Consumption of pork products has nothing to do with the spread of this virus. The Russian and Chinese moves take advantage of international rules that permit restrictions on trade, but only if they are instituted for safety reasons. They are simply protecting their domestic pork industries from competition.