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Close contact behavior in indoor environment and transmission of respiratory infection
Author(s) -
Zhang Nan,
Chen Wenzhao,
Chan PakTo,
Yen HuiLing,
Tang Julian WeiTze,
Li Yuguo
Publication year - 2020
Publication title -
indoor air
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.387
H-Index - 99
eISSN - 1600-0668
pISSN - 0905-6947
DOI - 10.1111/ina.12673
Subject(s) - transmission (telecommunications) , airborne transmission , range (aeronautics) , social contact , body contact , contact tracing , environmental science , simulation , computer science , environmental health , covid-19 , physics , telecommunications , communication , medicine , psychology , aerospace engineering , engineering , disease , optoelectronics , pathology , infectious disease (medical specialty)
Close contact was first identified as the primary route of transmission for most respiratory infections in the early 20th century. In this review, we synthesize the existing understanding of the mechanisms of close contact transmission. We focus on two issues: the mechanism of transmission in close contact, namely the transmission of the expired particles between two people, and the physical parameters of close contact that affect the exposure of particles from one individual to another, or how the nature of close contact plays a role in transmission. We propose the existence of three sub‐routes of transmission: short‐range airborne, large droplets, and immediate body‐surface contact. We also distinguish a “body contact,” which is defined with an interpersonal distance of zero, from a close contact. We demonstrate herein that the short‐range airborne sub‐route may be most common. The timescales over which data should be collected to assess the transmission risk during close contact events are much shorter than those required for the distant airborne or fomite routes. The current paucity of high‐resolution data over short distances and timescales makes it very difficult to assess the risk of infection in these circumstances.