Steady flu transmissions cause CDC to see 'something different'

Jun 19, 2009 by &#9632 - Ongoing transmission of the H1N1 flu virus throughout the United States causes CDC to claim 'something different' is happening.
The H1N1 flu virus that originated in Mexico and spread throughout the North American continent has caused the Centers for Disease Control to announce that "something different" may be happening to extend the North American flu season through late spring and into the summer.

One of many factors that CDC officials cited in a Reuters report included an unusually cool late spring - particularly in U.S. Northeast where infections continue to spread, especially in densely populated areas in New York and Massachusetts.

The World Health Organization has officially designated the H1N1 virus a global pandemic, but the southern hemisphere is now in late autumn - where flu seasons typically begin. It is unusual for North America to see continual flu outbreaks in mid-June.

"The fact that we are seeing ongoing transmission now indicates that we are seeing something different," the CDC's Dr. Daniel Jernigan told a news briefing, according to Reuters.

Another factor may be the lack of immunity the new H1N1 strain represents - particularly among younger populations. High population densities and younger, more socially active demographics mixed with unusually low temperatures are all contributing elements to the flu's ongoing infection rate.

"The areas of the country that are most affected, some of them have very high population densities, like Boston and New York. So that may be a contributor as well. Plus the temperature in that part of the country is cooler, and we know that influenza appears to like the cooler times of the year for making transmission for effective," said Jernigan.

It is anticipated that the H1N1 strain will continue to be transmitted throughout the summer in the United States and will increase transmissions once the temperatures decrease again in the fall.

Perhaps the most troubling finding in the CDC's current understanding of the H1N1 transmission behavior is that healthcare workers appear to be getting infected and coming back to work sick. The CDC found that many healthcare workers did nothing to protect themselves from the virus, and an alarming amount of healthcare-personnel to healthcare-personnel transmissions have occurred.

Like all viruses, the H1N1 flu is an opportunistic animal - however, it is a new species entering an open ecology. This - more than anything else - presents the most numerous unknowns.
Michael Krebs