Health, Education, Labor and Pensions Committee Chairman Tom Harkin (D-Iowa) joined colleagues to highlight the shutdown's effect on public health agencies, which Harkin described as "closed for all practical purposes."
"I'm not trying to frighten people unduly, but I do want to alarm people," Harkin said, citing a deadly outbreak of flu in China from earlier this year.
"Do we have to have a virulent flu outbreak where people get sick and die? Is that what has to happen before we come to our senses?" he asked.
The CDC is "significantly" less able to respond to outbreaks, process lab samples and maintain an emergency operations center during the government shutdown, according to a contingency plan from the Department of Health and Human Services (HHS).
Another crucial health agency, the Food and Drug Administration, is continuing "select vital activities" but is "unable to support the majority of its food safety, nutrition and cosmetics" oversight, the plan stated.
Harkin cautioned that this restriction on regulators' work could lead to an increase in food borne illnesses since the FDA won't be conducting routine inspections.
The comments came on the fourth day of the shutdown, as Congress remains at a stalemate over how to fund the government. Republicans had originally insisted on concessions from ObamaCare in order to keep the lights on.
The House GOP is preparing to approve several more piecemeal bills, including measures to fund the Federal Emergency Management Agency and a nutrition program for women, infants and children.
Democrats have rejected this strategy, saying the need is too great for Republicans to pick and choose which parts of the government deserve to reopen.
The two perspectives came into conflict earlier in the week as the House approved a bill to fund the National Institutes of Health (NIH), which is turning away new patients during the shutdown.
Democrats said Friday that the NIH must reopen soon — along with the rest of the government.
"This the greatest country in the world," said Sen. Debbie Stabenow (D-Mich.) at the presser. "The American people deserve better than a piecemeal approach on which health risk will be protected against."