The United States is poised to plunge into flu season, with millions of people suffering the coughing, body aches, headaches, sore throats and fatigue wrought by the potentially deadly viruses.

But the federal agency charged with tracking, monitoring and analyzing seasonal flu activity has been laid low by the partial government shutdown that began Oct. 1.

The shutdown has greatly impeded the U.S. Center for Disease Control and Prevention's handling of seasonal flu, says Dr. Barbara Reynolds, who is the CDC's crisis communication specialist.

"About two-thirds of CDC staff have been furloughed," she says. "Our job is to find threats, stop threats, and prevent threats from happening again. We are weakened in our effort to find threats. We will do all that we can to stop them when we are aware of them. We are not doing the prevention work during the shutdown."

The shutdown has also affected how CDC monitors and tracks seasonal flu outbreaks. CDC publishes flu data online through FluView, which is not being updated.

"We are not analyzing data from our sentinel spots across the nation," Reynolds says. "This means three things: One, we will not be offering the weekly flu view that gives health care providers and the public a snapshot of how much flu is circulating in their area. Two, we will not be doing the lab analysis to determine whether or which antivirals (for example, Tamiflu) works against the circulating strains, and three, we will not do the lab analysis to determine whether the flu virus strains circulating are a good 'match' with the flu vaccine formulated for this year - meaning we won't be able to predict how effective the flu shot will be against the flu viruses this year.

"It is more difficult for CDC to make recommendations to health care providers about managing the influenza illness," Reynolds said.

The Pennsylvania Department of Health also tracks outbreaks. DOH monitors flu activity, and posts updates and information on its website at www.flufreepa.com.

Influenza

Seasonal flu tends to emerge between October and March, peaking in January and February. As the United States edges to the start of the flu season, medical providers urge people - especially the very young, the very old, and those with compromised immune systems - to be vaccinated.

Although most people weather a bout with the seasonal flu with no ill effects, the virus can be deadly - there are an estimated 23,000 deaths a year, according to CDC.

An exact figure is not known, because states aren't required to report flu deaths in those over age 18 to the U.S. Centers for Disease Control and Prevention. Seasonal flu isn't likely to be listed on death certificates of those who die from complications. Also, many flu deaths occur more than a week after the initial infection with the virus, after a person has developed a secondary bacterial infection or because the virus aggravated a chronic condition, such as heart failure.