Well before the recent superbug outbreaks at UCLA and Cedars-Sinai hospitals, federal health officials had labeled deadly CRE bacteria an urgent threat.
Yet there are still no national reporting requirements for the antibiotic-resistant superbug, and only 20 states have imposed any rules. California is not among them.
When L.A. County officials examined the problem in 2011, they found 675 cases of CRE among patients at hospitals, nursing homes and long-term acute-care facilities over a one-year period.
Those cover a broader set of CRE infections, beyond just those from tainted hospital scopes that are grabbing attention now. The number of patients affected is probably far greater, experts say, and increasingly worrisome.
The incidents at UCLA and Cedars are "just the tip of the iceberg," said Dr. Benjamin Schwartz, deputy chief of the acute communicable disease control program at the L.A. County Department of Public Health. "It's really a problem that is much more widespread."
Now outbreaks across the nation have prompted calls for mandatory reporting to stem the spread of CRE and to make the public more aware of the risks.
"It's important to know what's out there, because these are serious infections," said Peter Mendel, a researcher and expert on infection reporting at Rand Corp., a Santa Monica think tank. "You shouldn't wait until there's an outbreak."
Rep. Ted Lieu (D-Los Angeles) said he plans to introduce legislation soon requiring hospitals to report CRE cases to the Centers for Disease Control and Prevention.
"I don't see how we can combat superbugs if the CDC doesn't even know the full scope of the problem," Lieu said. "We should have uniform national reporting for all hospitals."
The stakes are high. With few treatment options, CRE can be fatal in up to half of infected patients.
On Wednesday, Cedars-Sinai Medical Center disclosed that four patients were infected with CRE from a contaminated scope. Seven people were sickened by CRE at UCLA's Ronald Reagan Medical Center.
A spokeswoman for the CDC said reporting requirements are generally set at the state level so "ultimately the decision should be based on what makes sense for prevention in a particular state."
In 2013, the CDC labeled CRE an urgent threat, and director Tom Frieden has called it a "nightmare bacteria."
But at the federal level, two other deadly germs have received far more attention. Officials already require reporting of MRSA, or methicillin-resistant Staphylococcus aureus, and Clostridium difficile, a bacterium that can cause deadly bouts of diarrhea.
There are other approaches to take beyond mandatory reporting, infection-control experts say. In Illinois, for instance, the state runs a registry of CRE-infected patients so hospitals and other medical providers can know whether a highly contagious patient requires isolation and other precautions to be taken.
Health officials can periodically survey hospital lab data for CRE, and hospitals can conduct routine monitoring of high-risk areas such as intensive-care units.
There are many ways patients can be exposed to CRE. It's often spread by contaminated medical equipment and on the hands of healthcare workers.
Health officials say the CRE fight is at a crucial moment. It's largely confined to healthcare settings for now, but there are concerns about the bacteria spreading in the wider community without stronger preventive measures.
With that in mind, L.A. health officials are gearing up for a new round of CRE surveillance backed by $1.5 million in federal grant money.
The most recent county study dates to 2011, and it discovered a CRE outbreak of 24 cases at a 177-bed long-term-care facility over a two-month period. Those details were published in a 2013 medical journal article.
Schwartz said the county doesn't name facilities that report cases or release information on patients. There weren't details available on the outcome for patients overall.
Thirteen of those patients in the outbreak were sent to other hospitals for further treatment of their infections, according to the county. If not for its surveillance, officials acknowledged, the outbreak would probably have gone unreported.
Those 24 CRE cases were part of the 675 overall for a one-year period ending in May 2011.
"We had a lot more of it than we thought," said Dr. Dawn Terashita, a medical epidemiologist with the county.
Two-thirds of the 102 acute-care hospitals analyzed had at least one case. The infection rate was significantly higher inside the eight long-term-care facilities reviewed.
Schwartz said those long-term-care patients often bounce in and out of the hospital, carrying the bacteria with them.
In the aggregate, infected patients tended to be older and more female.
L.A. County is one of eight public health agencies across the country, including ones in New York and Oregon, taking part in the CDC program on CRE surveillance.
For that new program, county officials said they are considering whether to require medical facilities to submit CRE cases versus take voluntary reports. Schwartz said 27 hospitals have already agreed to share data.
"We want to understand how this resistant bacteria is transmitted between different parts of the healthcare system," he said. "It may give us some good clues on what we can do to prevent transmission."
Times staff writer Soumya Karlamangla contributed to this report.