A 2011 study in the New England Journal of Medicine underscored the problem, observing that while hospitals have reduced the frequency of many infections over the last decade, they could do better if staff complied with recommendations. Those include always washing their hands and using maximal barrier procedures when tubes are being inserted, such as covering patients from head to toe with a sterile drape and wearing sterile caps, masks, gowns, and gloves.

"The percentage of time that healthcare providers do all of the things they are supposed to do when caring for a patient with a contagious disease can be pretty low," said one of the authors, Dr. Don Goldmann, chief medical and science officer at the Institute for Healthcare Improvement, a nonprofit in Cambridge, Massachusetts. "There’s a lot of room for improvement."

Goldmann said that hospitals tend to become more focused on following procedures when facing novel, highly publicized outbreaks such as Ebola. "When [an infection risk has] been around for a long time, it kind of becomes part of the background," he said.

Since 2012 the federal government has been analyzing and publishing the CDC rates for specific hospitals on Medicare’s Hospital Compare website. Starting this fall, Medicare is considering infection rates when deciding how much to pay hospitals.

The CDC reports six categories of infections: those from flexible tubes inserted into veins to deliver medicines or nutrients; infections from catheters that drain bladders; two antibiotic-resistant germs, Clostridium difficile (C. diff) and Methicillin-resistant Staphylococcus aureus (MRSA); and two surgical-site infections after hysterectomies and colon operations.

States with more than a quarter of hospitals having at least one high infection rate in the CDC data were Arizona, California, Colorado, Connecticut, Florida, Massachusetts, Montana, Nevada, New Jersey, New York, Rhode Island, South Carolina, and Utah, according to analysis of the most current CDC records.

Three highly regarded institutions—New York-Presbyterian Hospital in Manhattan, Geisinger Medical Center in Danville, Pennsylvania, and the University of Michigan Health System in Ann Arbor—were among seven hospitals the CDC rated as having worse than average rates for four of the six infections, KHN found.

The CDC data, based on reports hospitals submit, are considered the most reliable assessments that exist. Still, many hospitals the CDC judged as having worse than average rates disputed those verdicts. They said that they look bad because they are more vigilant in identifying and reporting infections, or because they handle very sick patients who are more prone to catching a bug.

For instance, Dr. Darrell Campbell Jr., chief medical officer at the University of Michigan Health System, said hysterectomies are performed on cancer patients at four times the rate of at other Michigan hospitals that compare information with each other. Because cancer surgeries take longer than regular hysterectomies, often involving removal of pelvic lymph nodes, the chances of infection are greater, he said.