Space-time trends of community-onset Staphylococcus aureus infections in children: a group-based trajectory modeling approach.

Purpose: Staphylococcus aureus (S. aureus) remains a serious cause of infections in the United States and worldwide. In the United States, methicillin-resistant S. aureus (MRSA) is the leading cause of skin and soft tissue infections. This study identifies 'best' to 'worst' infection trends from 2002 to 2016, using group-based trajectory modeling approach.

Methods: Electronic health records of children living in the southeastern United States with S. aureus infections from 2002 to 2016 were retrospectively studied, by applying a group-based trajectory model to estimate infection trends (low, high, very high), and then assess spatial significance of these trends at the census tract level; we focused on community-onset infections and not those considered healthcare acquired.

Results: Three methicillin-susceptible S. aureus (MSSA) infection trends (low, high, very high) and three MRSA trends (low, high, very high) were identified from 2002 to 2016. Among census tracts with community-onset S. aureus cases, 29% of tracts belonged to the best trend (low infection) for both methicillin-resistant S. aureus and methicillin-susceptible S. aureus; higher proportions occurring in the less densely populated areas. Race disparities were seen with the worst methicillin-resistant S. aureus infection trends and were more often in urban areas.

Conclusions: Group-based trajectory modeling identified unique trends of S. aureus infection rates over time and space, giving insight into the associated population characteristics which reflect these trends of community-onset infection.