Open AccessTiming of exposure is critical in a highly sensitive model of SARS-CoV-2 transmission
Author(s) -
Ketaki Ganti,
Lucas Ferreri,
Chung-Young Lee,
Camden R. Bair,
Gabrielle K. Delima,
Kate E. Holmes,
Mehul S. Suthar,
Anice C. Lowen
Publication year - 2022
Publication title -
plos pathogens
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.719
H-Index - 206
eISSN - 1553-7374
pISSN - 1553-7366
DOI - 10.1371/journal.ppat.1010181
Subject(s) - transmission (telecommunications) , covid-19 , viral load , relative humidity , pandemic , outbreak , disease transmission , biology , transmission rate , virology , medicine , infectious disease (medical specialty) , disease , virus , computer science , meteorology , telecommunications , geography
Transmission efficiency is a critical factor determining the size of an outbreak of infectious disease. Indeed, the propensity of SARS-CoV-2 to transmit among humans precipitated and continues to sustain the COVID-19 pandemic. Nevertheless, the number of new cases among contacts is highly variable and underlying reasons for wide-ranging transmission outcomes remain unclear. Here, we evaluated viral spread in golden Syrian hamsters to define the impact of temporal and environmental conditions on the efficiency of SARS-CoV-2 transmission through the air. Our data show that exposure periods as brief as one hour are sufficient to support robust transmission. However, the timing after infection is critical for transmission success, with the highest frequency of transmission to contacts occurring at times of peak viral load in the donor animals. Relative humidity and temperature had no detectable impact on transmission when exposures were carried out with optimal timing and high inoculation dose. However, contrary to expectation, trends observed with sub-optimal exposure timing and lower inoculation dose suggest improved transmission at high relative humidity or high temperature. In sum, among the conditions tested, our data reveal the timing of exposure to be the strongest determinant of SARS-CoV-2 transmission success and implicate viral load as an important driver of transmission.