Three Atlanta teaching hospitals were among the lowest scoring for preventing certain infection rates among patients, according to new ratings from Consumer Reports .

The consumer advocacy publication analyzed the prevention rates of central-line infections in the intensive care units at teaching hospitals in the U.S. from Jan. 1, 2011 through Dec. 31, 2015.

Atlanta Medical Center, Emory University Hospital Midtown and Grady Memorial Hospital ranked among the 31 lowest scoring hospitals in the country.

Of the three local hospitals, Grady has shown the most improvement over the five-year period moving from more than two times worse than the national average to between the historic average to 50 percent above average.

Emory has sustained a level between the historic average to 50 percent above average from 2012 to 2015.

Atlanta Medical Center saw a decline in 2015 to a level up to two times worse than the historic average.

About 650,000 people developed infections after being admitted to U.S. Hospitals in 2011 and 75,000 died based on the most recent data from the Centers for Disease Control and Prevention.

Central line infections account for about five percent of all hospital acquired infections. In 2015, more than 27,000 people acquired these deadly, preventable infections which are costly to treat.

Central line infections are infections that can be traced back to the intravenous tubes used to supply medication, fluids and nutrients to patients. When handled improperly, the lines can carry germs which are then directly pumped into the patient's bloodstream giving deadly strains of antibiotic resistant bacteria a path to spread to the heart and other internal organs.

Many hospitals have reduced their central line infection rates by using versions of a checklist developed in 2001 by Peter Pronovost, M.D., now senior vice president for patient safety and quality at Johns Hopkins Medicine in Baltimore. But progress is slower than it should be, said experts, especially at teaching hospitals which should represent the best in healthcare.

For the full story and for tips on preventing infections while in the hospital, see the January issue of Consumer Reports .