Nursing research summary

Simulating the Spread and Control of Multiple MDROs Across a Network of Different Nursing Homes

This NIH-funded project uses agent-based modeling to simulate how five key multidrug-resistant organisms (MDROs) interact, spread, and respond to control strategies simultaneously across a network of 70 nursing homes in Orange County, CA. The goal is to develop more effective ecosystem-wide infection control approaches by understanding complex transmission dynamics involving multiple pathogens at once.

National Institute of Allergy and Infectious Diseases Published 2026 4 min read
United Statespublic_metadataVery High authorityWound CareResearch Funding

In brief

This NIH-funded project uses agent-based modeling to simulate how five key multidrug-resistant organisms (MDROs) interact, spread, and respond to control strategies simultaneously across a network of 70 nursing homes in Orange County, CA. The goal is to develop more effective ecosystem-wide infection control...

What this article is about

Quick Answer

This NIH-funded project uses agent-based modeling to simulate how five key multidrug-resistant organisms (MDROs) interact, spread, and respond to control strategies simultaneously across a network of 70 nursing homes in Orange County, CA. The goal is to develop more effective ecosystem-wide infection control approaches by understanding complex transmission dynamics involving multiple pathogens at once.

Student takeaways

Key Takeaways

  • The study aims to model how multiple MDROs (MRSA, VRE, ESBL-PE, CRE, C. auris) interact simultaneously within a network of 70 nursing homes across Orange County, CA.
  • The database record does not provide key finding 2.
  • The database record does not provide key finding 3.
  • The database record does not provide key finding 4.
  • The database record does not provide key finding 5.

Student summary

Why This Research Matters

This research project, titled 'Simulating the Spread and Control of Multiple MDROs Across a Network of Different Nursing Homes,' aims to understand how various multidrug-resistant organisms (MDROs) spread within nursing homes in Orange County, California. The study acknowledges that while MDROs are often studied individually, they actually circulate simultaneously, meaning their prevention strategies might affect each other and compound risks.

The core problem addressed is the significant burden of healthcare-associated infections caused by MDROs in US nursing homes (NHs), which lead to nearly 3 million cases annually. The project's main goal is to elucidate two key aspects: first, how multiple MDROs interact and spread simultaneously within a network of NHs; and second, how different infection control policies and interventions might impact the transmission of these various pathogens across the entire region.

The research uses agent-based models (ABMs) as its primary tool. These computational models simulate individual 'agents'—in this case, nursing home residents—and their interactions within a detailed representation of NHs in Orange County, CA. The project is structured into three specific aims: 1. Developing ABMs for each of the 70 nursing homes in OC, CA to simulate how five key MDROs (methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, extended-spectrum beta-lactamase-producing Enterobacterales, carbapenem-resistant Enterobacterales, and Candida auris) interact among carriers and co-carriers. 2. Evaluating how different pathogens, host factors (like comorbidities, wounds, or bedbound status), and room characteristics (such as having roommates, common areas, or shared equipment) simultaneously affect MDRO transmission in NHs across the region using these ABMs. 3. Estimating how various pathogen-specific and non-specific multi-modal strategies may affect the transmission and spread of different MDROs individually and simultaneously within this network of NHs.

For nursing students appraising this research, it's important to consider several aspects: The study is a 'funded research project' rather than a published paper with results. This means its findings are in the form of models and simulations that will likely inform future data collection for other projects (Projects 1 and 2 mentioned in the abstract) or guide further refinement of these models.

The population focus is on residents within nursing homes, specifically those who may be colonized by one or more MDROs. The setting involves a network of NHs across Orange County, CA, which adds complexity due to potential transmission between facilities and shared community resources. The authors frame the problem as understanding how simultaneous spread affects colonization and infection risks for various MDROs at once, rather than just looking at them in isolation. This is crucial because current strategies might not account for these interactions effectively.

Regarding source/rights cautions: The record indicates 'NIH RePORTER public project metadata.' While the abstract provides a clear overview of the research plan and aims, it does not contain actual study results or data analysis outcomes (as would be found in a published paper). Therefore, claims about specific findings from this particular document are limited to its stated objectives. The absence of a DOI means that cross-referencing with other databases might be less straightforward.

A nurse can reason from the evidence presented in the abstract by understanding that MDROs don't exist in isolation within nursing homes and their control requires a comprehensive, ecosystem-wide approach. This project's use of ABMs allows for testing various interventions before they are implemented widely, potentially saving resources and improving patient safety. The focus on multiple pathogens simultaneously is a strength as it reflects real-world complexity.

The research highlights the importance of considering factors like host vulnerabilities (comorbidities, wounds) and environmental aspects (roommates, shared equipment) in MDRO transmission strategies. It also emphasizes that interventions might have different impacts depending on which combination of MDROs are present. The project's iterative nature with other projects suggests a commitment to building robust evidence.

Students should critically evaluate the assumptions built into these agent-based models and consider how well they represent real-world nursing home environments and resident populations. They should also appreciate that this type of modeling is a powerful tool for hypothesis generation and strategy testing, even if it doesn't provide definitive answers on its own. The abstract clearly states that model results will guide data collection for other projects (Projects 1 & 2), implying that the findings from these ABMs are preliminary steps towards more concrete evidence. Therefore, while this project is significant in outlining a research approach and specific aims, students should be aware it's primarily a planning document or grant proposal detailing future work rather than reporting completed study outcomes.

Source abstract

Study Overview

Abstract Project 3: Simulating the Spread and Control of Multiple MDROs Across a Network of Nursing Homes in a Region Multidrug-resistant organisms (MDROs) cause nearly 3 million healthcare-associated infections (HAIs), which are a major cause of death in US nursing homes (NHs), annually. While MDROs are commonly studied in isolation, these pathogens circulate simultaneously, and their spread and prevention may affect and compound each other. Therefore, determining the value of such strategies in NHs requires an understanding of how they would affect colonization and infection risks of various MDROs simultaneously. Moreover, the impact of MDROs and their prevention and control strategies extend beyond individual NHs and involve the dynamic ecosystem of NHs in a region. Computational modeling that integrates epidemiologic, operational, and economic components can help delineate the circulation and impact of multiple MDROs, test various prevention and control strategies, and determine the subsequent ecosystem-wide effects related to transmission and disease burden in ways that can save time, effort, and resources. The overall goal of this proposed project is to elucidate (1) the combined effects of multiple MDROs spreading simultaneously and (2) how policies and interventions (e.g., contact precautions, decolonization) may have an impact across a variety of MDROs at the same time, using agent-based models (ABMs) of NHs in Orange County (OC), California (CA). These detailed representations of NHs will include and help differentiate among various multi-level factors affecting MDRO spread. This modeling Project will proceed in a synergistic, iterative manner with the other two Projects. Model results will guide data collection and analyses for Projects 1 and 2, and data insights from Projects 1 and 2 will guide further refinement of the models. Shifting the focus from one MDRO at a time to various MDROs collectively will help decision makers choose the best overall infection control strategy. Specific Aim 1 will develop ABMs for each of the 70 nursing NHs in OC, CA simulating how multiple MDROs (methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, extended-spectrum beta-lactamase-producing Enterobacterales, carbapenem-resistant Enterobacterales, and Candida auris) interact among carriers and co-carriers to promote spread. Specific Aim 2 will evaluate how different pathogens, host factors (e.g., comorbidities, wounds, bedbound status), and room characteristics (e.g., roommates, common areas, shared equipment) simultaneously affect MDRO transmission in NHs across a region using the various NH ABMs. Specific Aim 3 will estimate how various pathogen-specific and non-specific multi-modal strategies may affect the transmission and spread of different MDROs individually and simultaneously in NHs across a region using the NH ABMs.

Study type: Funded research project

Evidence appraisal

Main Findings

  • The study aims to model how multiple MDROs (MRSA, VRE, ESBL-PE, CRE, C. auris) interact simultaneously within a network of 70 nursing homes across Orange County, CA.
  • The database record does not provide key finding 2.
  • The database record does not provide key finding 3.
  • The database record does not provide key finding 4.
  • The database record does not provide key finding 5.

Practice transfer

Clinical Relevance

  • This research could lead to more effective and efficient infection control strategies by considering the simultaneous spread of multiple MDROs rather than focusing on single pathogens in isolation.
  • Clinical implication 2 should be interpreted cautiously because the database record is limited.
  • Clinical implication 3 should be interpreted cautiously because the database record is limited.
  • Clinical implication 4 should be interpreted cautiously because the database record is limited.
  • Clinical implication 5 should be interpreted cautiously because the database record is limited.

Faculty notes

Educational Relevance

This NIH-funded research project (5U19AI172725-04) titled 'Simulating the Spread and Control of Multiple MDROs Across a Network of Different Nursing Homes' represents a significant methodological advancement in understanding healthcare-associated infections (HAIs), specifically those caused by multidrug-resistant organisms (MDROs). The project's core objective is to move beyond studying individual MDROs in isolation, recognizing that these pathogens co-circulate and their spread/prevention strategies can interact, thereby compounding risks. This approach aims to provide a more holistic understanding of MDRO dynamics within nursing homes (NHs) across Orange County, California.

The study employs agent-based modeling (ABMs), a sophisticated computational tool, to simulate the complex interactions between multiple MDROs and their human hosts within NH environments. The project is structured around three specific aims: 1. **Model Development:** To develop ABMs for each of the 70 nursing homes in Orange County, CA, simulating how five key MDROs (MRSA, VRE, ESBL-PE, CRE, and C. auris) interact among carriers and co-carriers. 2. **Factor Analysis:** To evaluate how different pathogens, host factors (e.g., comorbidities, wounds, bedbound status), and room characteristics (e.g., roommates, common areas, shared equipment) simultaneously affect MDRO transmission in NHs across the region using these ABMs. 3. **Intervention Evaluation:** To estimate how various pathogen-specific and non-specific multi-modal strategies may affect the transmission and spread of different MDROs individually and simultaneously within this network of NHs.

The project's significance lies in its attempt to address a critical gap: current infection control strategies often target single pathogens, potentially overlooking synergistic effects or unintended consequences when multiple MDROs are present. By modeling these complex interactions at the regional level (a 'network' of NHs), it aims to identify more effective and efficient overall infection control strategies that consider ecosystem-wide transmission dynamics.

The research is inherently interdisciplinary, integrating epidemiology, operational data from NHs, and economic considerations into a unified computational framework. This allows for testing various prevention and control strategies in silico before they are implemented widely, potentially saving time, effort, and resources. The project's design acknowledges the dynamic nature of MDRO spread: it's not confined to individual facilities but involves interconnected communities of care. The ABMs will help differentiate among various multi-level factors affecting MDRO spread, from individual resident characteristics to facility infrastructure and regional patterns.

For faculty, this project serves as an excellent example for teaching about: The application of advanced computational modeling (ABM) in public health research. The importance of considering complex interactions between multiple pathogens rather than studying them in isolation. The challenges of controlling MDROs in long-term care settings with vulnerable populations and shared resources. How research can be structured to inform policy and practice, particularly through iterative collaboration between modeling efforts and empirical data collection (as implied by the synergy with Projects 1 & 2).

The project's focus on multiple MDROs simultaneously is a key strength. It reflects real-world conditions where patients are often colonized or infected with more than one resistant organism. The specific choice of pathogens (MRSA, VRE, ESBL-PE, CRE, C. auris) covers a broad spectrum of significant threats in NH settings.

A notable aspect is the integration of various influencing factors: host vulnerabilities and environmental conditions are explicitly included as variables within the models. This allows for a more nuanced understanding of transmission drivers beyond just pathogen characteristics or general infection control measures. The project's iterative nature, where model results will guide data collection (Projects 1 & 2) and vice-versa, is crucial for building robust evidence. It represents a modern approach to research design in complex systems.

Faculty should also consider the limitations inherent in such modeling projects: assumptions built into the ABMs must be carefully scrutinized; while powerful for hypothesis generation and strategy testing, these models are not direct substitutes for clinical trials or observational studies that provide empirical data on real-world outcomes. The project's findings will likely inform future research directions rather than providing immediate actionable protocols.

This funded research project is a valuable resource for illustrating contemporary approaches to tackling complex public health problems in nursing homes and underscores the need for innovative strategies to combat MDROs effectively.

Critical appraisal

Limitations

  • The study is based on simulations (agent-based models) which rely on assumptions about pathogen behavior, host factors, and environmental conditions.
  • Findings are preliminary as this document primarily outlines research aims; actual data from interventions or comprehensive transmission patterns will be generated by subsequent projects (Projects 1 & 2).
  • Generalizability of findings to other regions or types of healthcare settings beyond Orange County nursing homes may require further validation.

Classroom use

Discussion Questions

  • How do the assumptions built into agent-based models for MDRO spread affect their predictive validity and applicability in real-world NHs?
  • What are the most significant host factors (e.g., comorbidities, wounds) identified by such models as drivers of multi-MDRO transmission that could be targeted by nursing interventions?
  • How might room characteristics like shared equipment or common areas disproportionately contribute to MDRO spread compared to direct roommate contact in a networked NH system?
  • What are the potential unintended consequences of implementing broad-spectrum infection control strategies (e.g., universal decolonization) on the simultaneous transmission dynamics of multiple, distinct MDROs as modeled?
  • How can findings from these ABMs be effectively translated into actionable guidelines for nursing staff and administrators in diverse NH settings to improve overall MDRO prevention?
  • Discussion question 6: What does "Simulating the Spread and Control of Multiple MDROs Across a Network of Different Nursing Homes" help nursing students evaluate?
  • Discussion question 7: What does "Simulating the Spread and Control of Multiple MDROs Across a Network of Different Nursing Homes" help nursing students evaluate?
  • Discussion question 8: What does "Simulating the Spread and Control of Multiple MDROs Across a Network of Different Nursing Homes" help nursing students evaluate?
  • Discussion question 9: What does "Simulating the Spread and Control of Multiple MDROs Across a Network of Different Nursing Homes" help nursing students evaluate?
  • Discussion question 10: What does "Simulating the Spread and Control of Multiple MDROs Across a Network of Different Nursing Homes" help nursing students evaluate?

Search-ready answers

Frequently asked questions

What is the main focus of this research project on MDROs in nursing homes?

The primary goal is to understand how multiple multidrug-resistant organisms (MDROs) spread simultaneously and interact within a network of nursing homes, as well as to evaluate how various prevention and control strategies might impact these pathogens collectively across different facilities.

Which specific types of MDROs are being studied in this project?

The research focuses on several key MDROs including methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), extended-spectrum beta-lactamase-producing Enterobacterales, carbapenem-resistant Enterobacterales, and Candida auris.

What kind of modeling approach is used in this study?

The project utilizes agent-based models (ABMs) to simulate the spread and control of these MDROs across a network of nursing homes. This involves creating detailed representations of individual nursing home facilities.

How many nursing homes are included in the Orange County, California model for this research?

Specific Aim 1 outlines developing ABMs for each of the 70 nursing homes located in Orange County (OC), California.

What is one of the key reasons MDROs are studied collectively rather than individually in this project?

MDROs often circulate simultaneously, and their spread and prevention strategies can affect and compound each other. Studying them together provides a more comprehensive understanding of transmission dynamics and control measures.

According to the abstract, what is a major cause of death related to MDROs in US nursing homes?

The abstract states that multidrug-resistant organisms (MDROs) are a major cause of death in US nursing homes annually.

What types of host factors and room characteristics are considered influential for MDRO transmission according to Specific Aim 2?

Specific Aim 2 evaluates how different pathogens, along with host factors such as comorbidities, wounds, and bedbound status, and room characteristics like roommates, common areas, and shared equipment simultaneously affect MDRO transmission.

What is the overarching aim of using computational modeling in this research?

Computational modeling that integrates epidemiologic, operational, and economic components can help delineate the circulation and impact of multiple MDROs, test various prevention and control strategies, and determine subsequent ecosystem-wide effects related to transmission and disease burden.

What is a potential benefit for decision makers from this research?

Shifting the focus from one MDRO at a time to various MDROs collectively will help decision makers choose the best overall infection control strategy.

How does this project plan to interact with other related projects?

The modeling Project will proceed in a synergistic, iterative manner with the other two Projects. Model results will guide data collection and analyses for those projects, and conversely, data insights from them will guide further refinement of these models.