Hospitalizations among family members increase the risk of MRSA infection in a household

Abstract

Objective:

Estimate the risk for household transmission of Methicillin-Resistant Staphylococcus aureus (MRSA) following exposure to infected family members or family members recently discharged from a hospital.

Design:

Analysis of monthly MRSA incidence from longitudinal insurance claims using the Merative MarketScan Commercial and Medicare (2001–2021) databases.

Setting:

Visits to inpatient, emergency department, and outpatient settings.

Patients:

Households with ≥2 family members enrolled in the same insurance plan for the entire month.

Methods:

We estimated a monthly incidence model, where enrollees were binned into monthly enrollment strata defined by demographic, patient, and exposure characteristics. Monthly incidence within each stratum was computed, and a regression analysis was used to estimate the incidence rate ratio (IRR) associated with household exposures of interest while accounting for potential confounding factors.

Results:

A total of 157,944,708 enrollees were included and 424,512 cases of MRSA were identified. Across all included enrollees, exposure to a family member with MRSA in the prior 30 days was associated with significantly increased risk of infection (IRR: 71.03 [95% CI, 67.73–74.50]). After removing enrollees who were hospitalized or exposed to a family member with MRSA, exposure to a family member who was recently discharged from the hospital was associated with increased risk of infection (IRR: 1.44 [95% CI, 1.39–1.49]) and the risk of infection increased with the duration of the family member’s hospital stay (P value < .001).

Conclusions:

Exposure to a recently hospitalized and discharged family member increased the risk of MRSA infection in a household even when the hospitalized family member was not diagnosed with MRSA.

Miller AC, Arakkal AT, Sewell DK, Segre AM, Adhikari B, Polgreen PM. Hospitalizations among family members increase the risk of MRSA infection in a household. Infection Control & Hospital Epidemiology. 2024;45(7):826-832. doi:10.1017/ice.2024.106