(CBS News) So how much of the government is shutting down?
We were surprised when our research department came up with this. It turns out 82 percent of spending is mandatory, including Social Security, Medicare, Medicaid and interest on the debt.
The part subject to the shutdown is only 18 percent. But those agencies get slammed. For example, the Treasury Department loses 89 percent of its workers, the Department of Defense loses 50 percent.
The Centers for Disease Control headquarters in Atlanta felt deserted. Two thirds of the center's 13,000 employees worldwide have been furloughed, and its director, Dr. Thomas Frieden, is worried.
"I usually don't lose sleep despite the many threats we face, but I am losing sleep because we don't know that we will be able to find and stop things that might kill people," he said.
The shutdown means the CDC will not be able to produce the weekly national map that tracks flu outbreaks state by state. Flu season began last month.
"We will be less able to determine when it's come, what kind of flu has come or to respond to outbreaks," Frieden said.
More people are likely to get sick because there has been no warning to let them know what problem they have.
"What we won't know is what's happening with flu," Frieden said. "Where is it spreading? What types of flu are spreading? Should we be using one medication or another?" he asked. "Is it in nursing homes or elsewhere? This really interferes with our ability to protect people."
Frieden worries about other outbreaks the CDC will not be able to track, including hepatitis A, salmonella, and measles.
"If there is an outbreak of something like Legionella pneumonia, we may not detect it, we may not find it, we may not stop it," he said. "If there is a outbreak of food-borne illness that affects people in multiple states, we may not identify it promptly."
Despite the shutdown, hundreds of CDC employees will be able to keep working on long-term projects, including AIDS research and the World Trade Center health study.