Swine Flu's Pandemic Path
The novel strain of swine influenza H1N1 that first appeared last month in Mexico City is rapidly sweeping the globe, raising concerns of an imminent pandemic. According to the most recent figures, the virus is suspected in 152 deaths and 1,995 possible cases in Mexico, though most of these await confirmation from lab tests.
Swine flu is believed to have caused infection in 23 countries so far, spanning distances from Canada to New Zealand. The number of possible US cases stands at over 212 across 15 states, with 50 cases confirmed. No deaths have been reported outside of Mexico as yet.
The World Health Organization authorities raised the level of the pandemic alert on Monday from phase three to four, indicating "sustained human-to-human transmission" is taking place. This is a decisive move, one that has been a subject of much controversy for years regarding avian flu, as the WHO has been very reluctant to advance the alert level for fears of causing undue concern. Comparatively, the H5N1 bird flu virus -- which has worried officials for years -- has never proven to easily spread between humans, keeping its potential for pandemic at bay.
It is too early to tell whether swine flu will prove more virulent in locations outside Mexico, or how widespread the infections will be. Health officials around the world are anxiously monitoring the situation, but many have noted that containment measures would be futile at this stage. In a White House press briefing held Sunday, CDC head Dr. Richard Bresser said that more severe cases should be expected in the US as things develop.
Infectious disease expert Dr. Michael Osterholm has warned for years of the potential for an influenza pandemic to disrupt the global "just-in-time" delivery system of vital goods and services. Swine flu also poses an unexpected new threat to the struggling US economy, still weighed down by a recession.
It was an avian strain of the H1N1 flu virus that caused the 1918 Spanish flu pandemic, which is believed to have killed some 675,000 in the United States and 50 to 100 million worldwide.
For a detailed examination of pandemic influenza and preparedness information, please see my Reality Sandwich article on avian flu from May 2008.
Images by johnmuk and Playadura*, courtesy of Creative Commons license.