Cold-chain-based epidemiology: Scientific evidence and logic in introduction and transmission of SARS-CoV-2

During the COVID-19 pandemic, a series of outbreaks and related investigations have indicated that the virus can be transmitted via cold-chain environment media. The causal relationship between the cold chain and the introduction and spread of viruses has been established. However, due to its stealthy nature, cold-chain environment media is often overlooked. Herein, we aim to provide a systematic review of the existing evidences and logical chains of virus transmission and introduction through cold-chain, from the perspectives of epidemiological investigations, laboratory researches, and molecular epidemiological evidences of cold-chain-related outbreaks. Additionally, scientific evidences also include the survival capacity of the virus in cold-chain environments, as well as modeling of virus transmission and risk assessment. These evidences and the logical framework related to cold-chain transmission put forward the initiation of cold-chain-based epidemiology (CCBE) as one of the important portions of the epidemiology of infectious diseases. Close multidisciplinary collaboration in this field will be essential for the preparation of future pandemics.