ATLANTA — Inside a complex of special government labs, scientists in full-body protective suits work with some of the world’s deadliest pathogens: Ebola, smallpox and certain strains of bird flu.

Many of the organisms have no treatment or vaccine, so the labs housed in this facility on the sprawling campus of the Centers for Disease Control and Prevention are equipped with extensive safety features. There is special air pressurization to prevent any accidental release, and hoses attached to the bulky protective outfits pump in breathing air for the scientists wearing them.

But the facility, which dates to 2005, needs to be replaced, CDC officials said in interviews this week. Some components that support air-handling systems and ensure the integrity of pressurized door seals are no longer manufactured. Other new technologies can’t be integrated into existing facilities.

The administration is asking Congress for $350 million to build a new high-containment lab complex on the CDC campus. It is among dozens of requests on the administration’s wish list that was sent to Capitol Hill in mid-February. Lawmakers must decide in the coming weeks how to allocate billions in nondefense spending as part of the budget deal to fund the government for the remainder of the fiscal year.

CDC officials flagged the need for a new facility during the Obama administration with officials at the Health and Human Services Department and the White House, but this is the first official request to Congress by any administration.

“What the engineers are telling us is that all of the equipment that is running this thing, the brain to it, all of these things are aging,” said Stuart Nichol, chief of CDC’s viral special pathogens branch, which studies highly infectious viruses. Many of those cause lethal hemorrhagic fevers. Since early January, an outbreak of Lassa fever in Nigeria has killed at least 73 people, according to that country's Center for Disease Control.

Construction of new labs would take four years, and Nichol warned that “in the relatively near future, things will start to break down, and you start to have less of a safety margin for operation.”

The proposed facility is competing for funds with about 80 other administration priorities, including a border wall with Mexico, a new FBI headquarters and full renovation of the National Air and Space Museum. An appropriations committee aide, who spoke on the condition of anonymity because the budget process is ongoing, said Thursday that it’s too soon to know what requests will receive serious consideration. “Everything is open for negotiation,” the aide said, adding that “public health is definitely a priority.”

Former CDC director Tom Frieden called the labs “an essential line of defense against the deadliest health threats.” He noted that 15 years is a long time in the life span of such crucial high-containment units.

“Although the age of the labs has not contributed to any lapse in health security,” he said, “CDC needs the upgrades to avoid future problems and to keep pace with improving technology and evolving threats.”

Scientists work with about 35 viruses at the facility. Research there was key to identifying the African fruit bat as the primary host and source for Marburg virus, a hemorrhagic fever that kills up to 8 out of 10 people.

The facility is also one of only two labs in the world working with live smallpox virus. Although smallpox has been eradicated, it remains one of the highest-priority pathogens because of its potential as a biological weapon. The CDC research, in collaboration with other parts of the U.S. government and the private sector, helped produce a potential new smallpox vaccine, a new antiviral drug and a test to diagnose smallpox cases quickly, said Inger Damon, director of the agency's Division of High-Consequence Pathogens.

Critical research about influenza also takes place in the labs. When China began seeing human infections from a lethal strain of bird flu in 2013, officials reached out to CDC researchers to assess the likelihood that the virus could emerge as a pandemic, and if so, “how bad it would be,” said Daniel Jernigan, who heads the influenza division.

That risk assessment involved animal studies and required “specialized equipment that basically sucks in the air and determines what size particles and how infectious they are,” he said. Of all emerging influenza viruses, that strain of H7N9 has the greatest potential to cause a pandemic if it evolves to spread easily from human to human. It also poses the greatest risk to cause serious disease.

The CDC’s high-containment facility has four quadrants, each focusing on different viruses, with the main work centered in a biosafety level 4 lab — the maximum safety level — surrounded by a suite of biosafety level 3 labs.

In 2014, the labs came under scrutiny because of incidents involving the mishandling of dangerous pathogens, including Ebola, anthrax and bird flu. Those problems involved human error and breakdowns in protocol, and prompted an overhaul in lab safety and creation of an associate director for lab safety. They did not result in any known infections or illnesses.

During an agencywide meeting Friday, CDC Acting Director Anne Schuchat said the new facility would address issues that have arisen over the years as well as the aging of several automated systems.

Last year, the CDC briefly suspended work at the high-containment facility because of concerns about air quality in the hoses that are part of the required full-body protective suits. The original hoses had been installed in 2005. Work resumed after testing by an outside laboratory determined that the breathing air being supplied met federal standards for such labs.

Over the years, there have also been news reports about shower and other equipment malfunctions. In 2009, a software error in a lab operating system caused a shower to fail to release chemicals in a decontamination chamber, according to USA Today. Officials said that and other failures posed no risk and that building engineers were able to operate the chemical shower manually.

Read more: