Prevalence and risk of acquisition of methicillin-resistant Staphylococcus aureus among households: A systematic review

Objective: Many studies have reported methicillin-resistant Staphylococcus aureus (MRSA) transmission from patients infected or colonized with MRSA to their household contacts, but the importance of household transmission for persistence of MRSA in the community and reintroduction into healthcare settings is not well understood.

Methods: This review was performed to evaluate evidence on (1) MRSA prevalence, (2) MRSA contact positivity, and (3) MRSA carriage duration in household contacts of MRSA-positive individuals. The MEDLINE and Embase databases were searched covering the period from January 1, 1960 to November 15, 2019 for studies with data on these outcomes. A random-effects model meta-analysis was conducted with included studies to calculate pooled prevalence ratios.

Results: A total 22 relevant articles were included. The meta-analysis showed that the pooled prevalence of MRSA among culture-positive MRSA household contacts was 25.0% (95% confidence interval 20.0-30.0%). A subset of studies with adequate comparison groups reported higher colonization prevalence among household contacts of MRSA-positive individuals compared with household contacts of MRSA-negative individuals. MRSA contact positivity varied between 19.0% and 33.0%, but variation in sampling frequency and follow-up duration made between-study comparisons challenging.

Conclusions: Substantial MRSA transmission occurs in household settings. Improved understanding of household transmission dynamics and the relationship between transmission in healthcare and household settings will be critical to inform improved strategies to control MRSA.