MRSA Infection Rates Soaring In Nursing Homes Says Study

Connie K. Ho for — Your Universe Online

A new study by researchers from the University of California, Irvine (UCI) has found a high prevalence of various strains of community-assisted methicillin-resistant Staphylococcus aureus (CA-MRSA) in nursing homes, highlighting the importance of developing more targeted interventions to help stop the spread of the dangerous bacterial infections.

MRSA is a strain of the S. aureus bacteria that became resistant to the normal antibiotics used to treat the staph infections. Many of these MRSA infections can be found in hospitals or other health care settings, and cases of infection are often related to invasive medical procedures such as the insertion of intravenous tubing or surgeries. Community-associated MRSA infections (CA-MRSA) is a newer strain of MRSA that can infect even healthy people who have not been hospitalized or had recent medical procedure procedures.

“MRSA infections acquired outside of hospital settings — known as community-acquired MRSA or CA-MRSA — are on the rise and can be just as severe as hospital-acquired MRSA,” said Amir R. Sapkota, assistant professor of epidemiology and biostatistics at the Maryland Institute for Applied Environmental Health.

“However, we still do not fully understand the potential environmental sources of MRSA or how people in the community come in contact with this microorganism,” he continued. Though unaffiliated with the UCI study, Sapotka conducted a groundbreaking study of MRSA contamination in wastewater treatment plants last year.

Since nursing home patients are often admitted directly to hospitals, the researchers believe the increase of CA-MRSA in nursing home facilities will also lead to an increase of CA-MRSA cases in hospitals.

In the study, the scientists evaluated the frequency of CA-MRSA carriage in nursing home residents in Orange County from October 2008 to May 2011. They sampled strains by swabbing noses of 100 residents in each nursing home during a single visit, and then took another 100 additional swabs from newly admitted residents.

Out of the MRSA-positive swabs, a total of 25 percents tested positive for CA-MRSA. Additionally, CA-MRSA was discovered in 20 out of the 22 nursing homes examined in the study.

“Community-type strains first arose among healthy community members without exposure to the healthcare system and have steadily infiltrated many hospitals,” explained the study´s lead researcher Courtney Reynolds-Murphy, a researcher with the Division of Infectious Diseases at the UCI School of Medicine.

“We believe these at-risk facilities could benefit from further infection control interventions, such as enhanced environmental cleaning or skin decolonization.”

The researchers also found CA-MRSA was more prevalent in nursing homes that had a higher percentage of residents under 65 years of age. Researchers suspect the cause for this is that younger nursing home residents tend to be more mobile and have higher levels of interaction with others, thus increasing the risk of exposure to CA-MRSA.

The researchers say it is important to develop infection control strategies specific for nursing home settings, as they represent a different environment with different types of patient interactions than hospitals. In order to better determine the interventions necessary to limit the transmission of CA-MRSA among residents, the researchers believe further research is needed.

The current research study by the UCI team was published in the March edition of the journal Infection Control and Hospital Epidemiology, a publication affiliated with the Society for Healthcare Epidemiology of America.