Seasonal Stability of SARS-CoV-2 in Biological Fluids.

Taeyong Kwon,Juergen A Richt,Natasha N Gaudreault

doi:10.3390/pathogens10050540

Abstract

The transmission of SARS-CoV-2 occurs by close contact with infected persons through droplets, the inhalation of infectious aerosols, and the exposure to contaminated surfaces. Previously, we determined the virus stability on different types of surfaces under indoor and seasonal climatic conditions. SARS-CoV-2 survived the longest on surfaces under winter conditions, followed by spring/fall and summer conditions, suggesting the seasonal pattern of stability on surfaces. However, under natural conditions, the virus is secreted in various biological fluids from infected humans. In this respect, it remains unclear how long the virus survives in various types of biological fluids. This study explores SARS-CoV-2 stability in virus-spiked human biological fluids under different environmental conditions by determining the virus half-life. The virus was stable for up to 21 days in nasal mucus, sputum, saliva, tear, urine, blood, and semen; it remained infectious significantly longer under winter and spring/fall conditions than under summer conditions. In contrast, the virus was only stable up to 24 h in feces and breast milk. These findings demonstrate the potential risk of infectious biological fluids in SARS-CoV-2 transmission and have implications for its seasonality.

Highlights

IntroductionSince its first emergence in China, SARS-CoV-2 has rapidly spread worldwide and poses a tremendous threat to global public health and the economy
SARS-CoV-2 in Biological Fluids.Since its first emergence in China, SARS-CoV-2 has rapidly spread worldwide and poses a tremendous threat to global public health and the economy
We estimated SARS-CoV-2 half-life (t1/2 ) values in human nasal mucus, sputum, saliva, tears, blood, and semen under both liquid and a non-porous surface setting, as well as human urine in liquid only, by spiking 5 × 104 50% tissue culture infectious dose (TCID50 ) of SARS-CoV-2 into biological fluids from healthy donors

Summary

Introduction

Since its first emergence in China, SARS-CoV-2 has rapidly spread worldwide and poses a tremendous threat to global public health and the economy. The efficient transmission of SARS-CoV-2 is primarily mediated through close contact with infected individuals who shed respiratory droplets when exhaling, talking, sneezing, and coughing [1]. The expelled droplets span a wide size spectrum, but the majority of them are generally considered >5 μm in diameter. In airborne transmission, smaller droplets, size ≤5 μm, evaporate quickly to generate infectious aerosols that can remain suspended in air for several hours and travel over a long distance [2]. A potential third route of transmission may be exposure to the infectious virus on surfaces. Large droplets settle down to the ground or surfaces within a limited distance and contaminate the environment with the virus. The infectious virus can survive for several days on various types of surfaces and the half-life is the longest under winter conditions, followed by spring/fall and summer conditions, suggesting a seasonal pattern of virus survival on contaminated surfaces [3,4]

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Conclusion