Nearly 5 percent of patients in U.S. hospitals may have acquired a particular antibiotic resistant staph infection, according to a nationwide survey conducted by the Association for Professionals in Infection Control and Epidemiology (APIC).

Researchers surveyed a total of 1,200 hospitals and other health care facilities from all 50 states, and found 8,000 patients infected or colonized with methicillin-resistant Staphylococcus aureus (MRSA) — or 46 out of every 1,000. This suggests that up to 1.2 million hospital patients across the country may be infected every year.

Colonized patients are those who were found to be carrying the bacteria in or on their bodies, but who had not showed any symptoms of disease.

“This rate is between eight and 11 times greater than previous MRSA estimates,” APIC wrote.

The majority of the infections had originated within the medical facility; 67 percent arose in patients being treated for general medical conditions (such as diabetes or pulmonary or cardiovascular problems) and not in intensive care patients.

APIC recommended simple measures, such as hand washing, to prevent the spread of MRSA within medical institutions. A number of studies have shown that many health care workers are not appropriately vigilant about washing their hands consistently.

“Hand hygiene is the most important means of preventing the spread of infection,” said APIC President Denise Murphy.

MRSA is resistant to all forms of penicillin, which has earned it the moniker of “superbug.” Due to its drug resistance, it is twice as fatal as other staph infections.

In 1974, the Centers for Disease Control and Prevention estimated that 2 percent of the staph infections occurring in medical facilities were cases of MRSA; in 2004, the estimate had risen almost to 63 percent.

Worldwide, approximately 2.7 percent of S. aureus carriers are estimated to be infected or colonized with MRSA.