Institute of Applied Mathematics and Mechanics, University of Warsaw, Warsaw, Poland.
Institute of High Pressure Physics, Polish Academy of Sciences, Warsaw, Poland.
PLoS Comput Biol. 2020 Nov 30;16(11):e1008442. doi: 10.1371/journal.pcbi.1008442. eCollection 2020 Nov.
Inter-hospital patient transfers (direct transfers) between healthcare facilities have been shown to contribute to the spread of pathogens in a healthcare network. However, the impact of indirect transfers (patients re-admitted from the community to the same or different hospital) is not well studied. This work aims to study the contribution of indirect transfers to the spread of pathogens in a healthcare network. To address this aim, a hybrid network-deterministic model to simulate the spread of multiresistant pathogens in a healthcare system was developed for the region of Lower Saxony (Germany). The model accounts for both, direct and indirect transfers of patients. Intra-hospital pathogen transmission is governed by a SIS model expressed by a system of ordinary differential equations. Our results show that the proposed model reproduces the basic properties of healthcare-associated pathogen spread. They also show the importance of indirect transfers: restricting the pathogen spread to direct transfers only leads to 4.2% system wide prevalence. However, adding indirect transfers leads to an increase in the overall prevalence by a factor of 4 (18%). In addition, we demonstrated that the final prevalence in the individual healthcare facilities depends on average length of stay in a way described by a non-linear concave function. Moreover, we demonstrate that the network parameters of the model may be derived from administrative admission/discharge records. In particular, they are sufficient to obtain inter-hospital transfer probabilities, and to express the patients' transfers as a Markov process. Using the proposed model, we show that indirect transfers of patients are equally or even more important as direct transfers for the spread of pathogens in a healthcare network.
医院间患者转移（直接转移）已被证明会促进医疗机构网络中病原体的传播。然而，间接转移（患者从社区重新入院到同一或不同的医院）的影响尚未得到充分研究。这项工作旨在研究间接转移对医疗机构网络中病原体传播的贡献。为了实现这一目标，针对德国下萨克森地区开发了一种混合网络-确定性模型，用于模拟医疗机构中多耐药病原体的传播。该模型考虑了患者的直接和间接转移。医院内病原体的传播由 SIS 模型控制，由一个常微分方程系统表示。我们的研究结果表明，所提出的模型再现了医疗机构相关病原体传播的基本特性。它们还表明了间接转移的重要性：仅将病原体传播限制在直接转移会导致系统范围的患病率仅为 4.2%。然而，增加间接转移会使总患病率增加 4 倍（18%）。此外，我们还证明了个体医疗机构的最终患病率取决于平均住院时间，呈非线性凹函数的方式。此外，我们证明了模型的网络参数可以从行政入院/出院记录中得出。特别是，它们足以获得医院间的转移概率，并将患者的转移表示为马尔可夫过程。使用提出的模型，我们表明在医疗机构网络中，患者的间接转移与直接转移一样重要，甚至更重要，会导致病原体的传播。
