Wednesday, December 23, 2009

H1N1: The Worst is Over

More than 6 million doses of H1N1 swine flu vaccines were made available in the United States in early October 2009. By mid-October, another 40 million doses, with reportedly production continuing at a rate of 10 million to 20 million doses a week to reach a total of over 250 million doses by the year’s end for the US alone.

Each year, in the United States, on average 36,000 people die from flu-related complications and more than 200,000 people are hospitalized from flu-related causes.

Yet, according to the World Health Organization (WHO), since the swine flu first started infecting people, there have been more than 300,000 laboratory confirmed cases and just 3,917 deaths -- worldwide.

There are many signs that the worst is behind us for the pandemic:

1. During the week of December 6-12, 2009, only 11 states were still reporting widespread influenza activity, and flu hospitalizations decreased in all age groups.

2. The Centers for Disease Control and Prevention (CDC) web site stated: "Most people who have been sick from H1N1 have recovered without needing medical treatment. About 70 percent of people who have been hospitalized with this 2009 H1N1 virus have had one or more medical conditions previously recognized as placing people at 'high risk' of serious seasonal flu-related complications. This includes pregnancy, diabetes, heart disease, asthma and kidney disease."

This is because the swine flu symptoms are just like the regular flu, causing fever, cough, sore throat, runny or stuffy nose, body aches, headache, chills and fatigue, and in some cases vomiting and diarrhea.

3. Harvard researcher Marc Lipsitch, DPhil, and colleagues from the U.K. Medical Research Council and the CDC are now saying that the H1N1 swine flu pandemic will end up no more severe than the average flu season.

Initially, before H1N1 emerged, planners were preparing for a pandemic with a case/fatality ratio of 0.1%, or one death in every 1,000 symptomatic infections. Now, Lipsitch and colleagues say the case/fatality ratio for swine flu is no higher than 0.048%, and may be even seven to nine times lower depending on calculation methods.

However, one difference between H1N1 and seasonal flu is how it could be deadly. Lipstitch and colleagues pointed out that deaths attributed to seasonal flu include heart attacks, strokes and other conditions triggered by the flu. Deaths attributed to H1N1, however, are due to flu or bacterial complications of the flu.

New research that will be published in the Archives of Pathology and Laboratory Medicine found that H1N1 typically kills by damaging the upper airways, lower airways or deep lung. The damage was similar to autopsy findings of victims during the 1918 and 1957 flu pandemics.

A separate study by Canadian and Spanish scientists also found a molecule called Interleukin 17 (IL-17) in H1N1 patients may determine the severity of the illness. The researchers found high levels of IL-17 in the blood of severe swine flu patients and low levels in those with mild H1N1. While IL-17 is normally produced by the body to help fight infection, if it becomes out of control it can contribute to inflammation and diseases like H1N1.

More information:
» H1N1 Vaccination Concerns

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