Spread of pathogens in the patient transfer network of US hospitals

TL;DR

This study analyzes the US hospital patient transfer network over two years to understand its role in spreading antibiotic-resistant infections, demonstrating its potential as a substrate for infection transmission and proposing early detection strategies.

Contribution

It introduces a network-based analysis of hospital transfers and evaluates sensor placement strategies for early infection outbreak detection.

Findings

Hospital transfer network can facilitate infection spread.

Using 2% of hospitals as sensors detects 80% of C. Diff. cases.

Network in-degree is effective for sensor placement.

Abstract

Emergent antibiotic-resistant bacterial infections are an increasingly significant source of morbidity and mortality. Antibiotic-resistant organisms have a natural reservoir in hospitals, and recent estimates suggest that almost 2 million people develop hospital-acquired infections each year in the US alone. We investigate a network induced by the transfer of Medicare patients across US hospitals over a 2-year period to learn about the possible role of hospital-to-hospital transfers of patients in the spread of infections. We analyze temporal, geographical, and topological properties of the transfer network and demonstrate, using C. Diff. as a case study, that this network may serve as a substrate for the spread of infections. Finally, we study different strategies for the early detection of incipient epidemics, finding that using approximately 2% of hospitals as sensors, chosen based on their network in-degree, results in optimal performance for this early warning system, enabling the early detection of 80% of the C. Diff. cases.