Higher MRSA Risk Linked to Family Members Post-Hospital Discharge

A study published in Infection Control & Hospital Epidemiology, the journal of the Society for Healthcare Epidemiology of America, suggests that hospitals may contribute to MRSA Risk. Family members of patients who have recently been discharged from the hospital may be more susceptible to acquiring an antibiotic-resistant infection, often known as a superbug, even if the patient was not diagnosed with the same infection.

The risk to family members living with hospitalized patients increased when those individuals were found to have the superbug, Methicillin-resistant Staphylococcus aureus infection (MRSA). Even in the absence of an MRSA diagnosis, family members are at greater risk the longer their relative stays in the hospital.

“Patients can become colonized with MRSA during their hospital stay and transmit MRSA to their household members. This suggests hospitals contribute to the spread of MRSA into the community through discharged patients who are asymptomatic carriers.”- Aaron Miller, PhD, lead researcher on the study and research assistant professor of internal medicine-infectious diseases, University of Iowa

Even in the absence of illness symptoms, Miller advises hospitals to improve infection control procedures, such as testing for MRSA colonization, particularly at discharge. In order to more precisely detect and prevent transmission, he added that MRSA colonization and infections could be monitored among hospital patients and their household contacts.

“This important study illustrates the risk of spread of resistant pathogens related to healthcare and highlights the essential importance of core infection practices,” said SHEA President Thomas Talbot, M.D., chief hospital epidemiologist at Vanderbilt University Medical center. Talbot was not involved with the research. “Hand hygiene, environmental cleaning, and standard interventions to reduce Staphylococcal colonization are crucial to preventing the spread of resistant bacteria in healthcare settings,”

Because MRSA infections are difficult to treat and do not react to standard antibiotics, they are referred to as superbugs. MRSA typically affects individuals who have visited a hospital or another healthcare facility, like a nursing home. However, MRSA can also spread outside of hospitals, typically through skin-to-skin contact. The majority of MRSA patients do not exhibit any symptoms, but if the bacteria penetrates the skin, it can lead to excruciating swelling. If it spreads to other body organs like the blood or lungs, it can be fatal.

Researchers studied how MRSA spread after a household member was hospitalized using a massive database of insurance claims that contained 158 million registrants with two or more family members on the same plan.

Examining 424,512 MRSA cases among 343,524 insured individuals, the research discovered 4,724 cases of MRSA that might have been passed to a family member by a relative who had recently visited the hospital and received an MRSA diagnosis. Additionally, 8,064 possible MRSA transmissions were discovered following the hospitalization of a family member who was not infected with the bacteria.

“It is important not over-emphasize the hospital stay risk,” Miller said. “While we identified a significant risk factor for transmission in the household and community the absolute risk remains relatively low.”

Compared to registrants who did not have a family member hospitalized or exposed to MRSA within the preceding 30 days, those who were exposed to a recently hospitalized family member carrying the virus had a greater risk of contracting an MRSA infection by over 71 times, or 7000%.

A family member’s hospital stay without MRSA raised the likelihood of a relative contracting MRSA in the month after release by 44%.

The probability that someone in their household will contract MRSA increased with the length of time the family member was in the hospital. Relatives of patients who spent one to three days in the hospital the month prior had a 34% higher risk of contracting MRSA than those whose household had no recent hospitalizations. Relatives were 49% more likely to contract MRSA infection if a family member was hospitalized for four to ten days, and the likelihood of infection increased by 70% to 80% if the hospital stay exceeded ten days.

Additional variables linked to MRSA infections in household members included the quantity of other ailments, the use of antibiotics in the past, and the presence of small children.

For more information: Hospitalizations among family members increase the risk of MRSA infection in a household,  Infection Control & Hospital Epidemiology, https://doi.org/10.1017/ice.2024.106