Modelling pathogen spread in a healthcare network: Indirect patient movements

Area of Science:

• Epidemiology
• Mathematical Modeling
• Public Health

Background:

• Inter-hospital patient transfers (direct transfers) are known contributors to healthcare-associated pathogen spread.
• The role of indirect transfers (re-admissions from the community) in pathogen dissemination within healthcare networks remains understudied.

Purpose of the Study:

• To investigate and quantify the contribution of indirect patient transfers to the spread of multiresistant pathogens in a healthcare network.
• To compare the impact of direct versus indirect transfers on overall pathogen prevalence.

Main Methods:

• Development of a hybrid network-deterministic model simulating pathogen spread in Lower Saxony, Germany.
• Incorporation of both direct and indirect patient transfer pathways.
• Utilized a Susceptible-Infected-Susceptible (SIS) model for intra-hospital transmission, described by ordinary differential equations.

Main Results:

• The model accurately reproduces key characteristics of healthcare-associated pathogen spread.
• Excluding indirect transfers resulted in 4.2% system-wide pathogen prevalence.
• Including indirect transfers increased overall prevalence by a factor of 4, reaching 18%.

Conclusions:

• Indirect patient transfers are a critical, often underestimated, factor in pathogen dissemination within healthcare systems.
• Pathogen spread is significantly amplified when indirect transfers are considered alongside direct transfers.
• Network parameters for modeling can be effectively derived from administrative patient admission/discharge data.