Newly released research posits that individuals recently discharged from hospitalization could unwittingly act as a significant conduit for the transmission of methicillin-resistant Staphylococcus aureus (MRSA) within households. The study, made public in the journal Infection Control & Hospital Epidemiology, reveals that those in close contact with a family member newly diagnosed with MRSA are a staggering 71 times more likely to contract a MRSA infection.
Intriguingly, the research also identifies a heightened risk of MRSA infection among those who have recently been exposed to patients discharged without a MRSA diagnosis. This indicates these patients might have been unknowingly colonized with MRSA during their hospital stay. ‘MRSA can colonize patients during hospitalization and, once discharged, these patients can spread the bacteria to household members,’ Aaron Miller, PhD, the lead study author and an assistant professor of internal medicine-infectious diseases at the University of Iowa, explained in a press release. ‘This indicates that hospitals contribute to MRSA’s community spread via discharged patients who are asymptomatic carriers.’
In the United States, MRSA has been a prevalent cause of healthcare-associated infections, especially among patients who’ve undergone surgery or have indwelling devices. These Staphylococcus aureus infections can range from affecting the skin to severe invasive infections. There are community-associated strains of MRSA that can affect otherwise healthy individuals and can rapidly spread in crowded settings and households through direct contact.
To gauge the impact of recent MRSA diagnosis and hospitalization on the rate of MRSA transmission within households, Miller and his team analyzed patient data from a commercial insurance database spanning 2001 through 2021. From over 157 million enrollees included in the study, the team identified 424,512 MRSA cases among 343,524 individuals. Among them, 4,724 cases (1.1%) involved potential transmissions linked to a family member’s recent MRSA diagnosis, while 8,064 (1.9%) cases hinted at possible transmission following the recent hospitalization of another family member.
Notably, the analysis also found the risk of MRSA escalating among household members with the length of the recently discharged family member’s hospitalization. Other factors contributing to infections included the number of comorbidities, prior antibiotic usage, and the presence of young children.
While urging caution in interpretation – as the overall number of MRSA cases was relatively low – this research nonetheless serves as a sobering reminder of the importance of effective hospital infection prevention and control practices, including hand hygiene, environmental cleaning, and standard interventions aimed at curbing Staphylococcal colonization, to halt the spread of resistant bacteria.