Mechanistic theory predicts the effects of temperature and humidity on inactivation of SARS-CoV-2 and other enveloped viruses

eLife, Journal Year: 2021, Volume and Issue: 10

Published: April 27, 2021

Ambient temperature and humidity strongly affect inactivation rates of enveloped viruses, but a mechanistic, quantitative theory these effects has been elusive. We measure the stability SARS-CoV-2 on an inert surface at nine conditions develop mechanistic model to explain predict how alter virus inactivation. find survives longest low temperatures extreme relative humidities (RH); median estimated half-life is >24 hr 10°C 40% RH, ∼1.5 27°C 65% RH. Our uses fundamental chemistry why rate increases with increased shows U-shaped dependence The accurately predicts existing measurements five different human coronaviruses, suggesting that shared mechanisms may for many viruses. results indicate scenarios high transmission risk, point mitigation strategies, advance study transmission.

Language: Английский

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Contamination of inert surfaces by SARS-CoV-2: Persistence, stability and infectivity. A review

Environmental Research, Journal Year: 2020, Volume and Issue: 193, P. 110559 - 110559

Published: Dec. 1, 2020

Language: Английский

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Heterogeneity in transmissibility and shedding SARS-CoV-2 via droplets and aerosols

eLife, Journal Year: 2021, Volume and Issue: 10

Published: April 16, 2021

Which virological factors mediate overdispersion in the transmissibility of emerging viruses remains a long-standing question infectious disease epidemiology.

Language: Английский

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Environmental Factors Influencing COVID-19 Incidence and Severity

Annual Review of Public Health, Journal Year: 2022, Volume and Issue: 43(1), P. 271 - 291

Published: Jan. 4, 2022

Emerging evidence supports a link between environmental factors—including air pollution and chemical exposures, climate, the built environment—and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission disease 2019 (COVID-19) susceptibility severity. Climate, pollution, environment have long been recognized to influence viral infections, studies established similar associations with COVID-19 outcomes. More limited links exposures COVID-19. Environmental factors were found through four major interlinking mechanisms: increased risk of preexisting conditions associated severity; immune system impairment; survival transport; behaviors that increase exposure. Both data methodologic issues complicate investigation these relationships, including reliance on coarse surveillance data; gaps in mechanistic studies; predominance ecological designs. We evaluate strength for environment–COVID-19 relationships discuss actions might simultaneously address pandemic, determinants health, health disparities.

Language: Английский

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Role of meteorological factors in the transmission of SARS-CoV-2 in the United States

Nature Communications, Journal Year: 2021, Volume and Issue: 12(1)

Published: June 14, 2021

Abstract Improved understanding of the effects meteorological conditions on transmission SARS-CoV-2, causative agent for COVID-19 disease, is needed. Here, we estimate relationship between air temperature, specific humidity, and ultraviolet radiation SARS-CoV-2 in 2669 U.S. counties with abundant reported cases from March 15 to December 31, 2020. Specifically, quantify associations daily mean estimates reproduction number ( R t ) calculate fraction attributable these conditions. Lower temperature (within 20–40 °C range), lower were significantly associated increased . The 3.73% (95% empirical confidence interval [eCI]: 3.66–3.76%), 9.35% eCI: 9.27–9.39%), 4.44% 4.38–4.47%), respectively. In total, 17.5% was factors. fractions factors generally higher northern than southern counties. Our findings indicate that cold dry weather low levels are moderately transmissibility, humidity playing largest role.

Language: Английский

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Evidence for a semisolid phase state of aerosols and droplets relevant to the airborne and surface survival of pathogens

Proceedings of the National Academy of Sciences, Journal Year: 2022, Volume and Issue: 119(4)

Published: Jan. 21, 2022

Significance Ambient humidity can influence the survival of pathogens in respiratory aerosols and droplets, although mechanism optimum level for public health remain unclear. Here, we present evidence a humidity-dependent, semisolid state droplets relevant to pathogen survival. These observations indicate that may protect from inactivation by hindering disinfection reactions at intermediate-to-low levels. The formation was dependent on composition aerosols, which suggests destruction will depend particles released an infected host. be used help interpret laboratory studies inform recommendations.

Language: Английский

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Estimation and worldwide monitoring of the effective reproductive number of SARS-CoV-2

eLife, Journal Year: 2022, Volume and Issue: 11

Published: Aug. 8, 2022

The effective reproductive number R e is a key indicator of the growth an epidemic. Since start SARS-CoV-2 pandemic, many methods and online dashboards have sprung up to monitor this through time. However, these are not always thoroughly tested, correctly placed in time, or overly confident during high incidence periods. Here, we present method for timely estimation , applied COVID-19 epidemic data from 170 countries. We evaluate on simulated data, intuitive web interface interactive exploration. show that, early 2020, majority countries estimated dropped below 1 only after introduction major non-pharmaceutical interventions. For Europe implementation interventions was broadly associated with reductions . Globally though, relaxing had more varied effects subsequent estimates. Our framework useful inform governments general public status epidemics their country, used as official source estimates Switzerland. It further allows detailed comparison between relation covariates such implemented health policies, mobility, behaviour, weather data.

Language: Английский

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Dependence on relative humidity in the formation of reactive oxygen species in water droplets

Proceedings of the National Academy of Sciences, Journal Year: 2024, Volume and Issue: 121(12)

Published: March 15, 2024

Water microdroplets (7 to 11 µm average diameter, depending on flow rate) are sprayed in a closed chamber at ambient temperature, whose relative humidity (RH) is controlled. The resulting concentration of ROS (reactive oxygen species) formed the microdroplets, measured by amount hydrogen peroxide (H 2 O ), determined nuclear magnetic resonance (NMR) and spectrofluorimetric assays after droplets collected. results found agree closely with one another. In addition, hydrated hydroxyl radical cations (•OH-H 3 + ) recorded from using mass spectrometry superoxide anions (•O − radicals (•OH) electron paramagnetic spectroscopy. As RH varies 15 95%, H shows marked rise factor about 3.5 going 50%, then levels off. By replacing water deuterium oxide (D O) but keeping gas surrounding O, spectrometric analysis demonstrates that air plays dominant role producing other ROS, which accounts for variation RH. increases, droplet evaporation rate decreases. These two facts help us understand why viruses both survive better low values, as indoor wintertime, disinfected more effectively higher summertime, thus explaining recognized seasonality airborne viral infections.

Language: Английский

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Survival of MS2 and Φ6 viruses in droplets as a function of relative humidity, pH, and salt, protein, and surfactant concentrations

PLoS ONE, Journal Year: 2020, Volume and Issue: 15(12), P. e0243505 - e0243505

Published: Dec. 8, 2020

The survival of viruses in droplets is known to depend on droplets' chemical composition, which may vary respiratory fluid between individuals and over the course disease. This relationship also important for understanding persistence generated from wastewater, freshwater, seawater. We investigated effects salt (0, 1, 35 g/L), protein 100, 1000 μg/mL), surfactant 10 droplet pH (4.0, 7.0, 10.0) viability 1-μL pipetted onto polystyrene surfaces exposed 20%, 50%, 80% relative humidity (RH) using a culture-based approach. Results showed that MS2, non-enveloped virus, was generally higher than Φ6, an enveloped after 1 hour. composition greatly influenced virus viability. Specifically, MS2 similar at different values, but Φ6 significantly reduced acidic basic compared neutral ones. presence bovine serum albumin protected both inactivation droplets. sodium chloride dodecyl sulfate varied by type RH. Meanwhile, RH affected as shown previously: lowest intermediate high results demonstrate determined carrier droplets, especially content, environmental factors. These findings emphasize importance order predict contained them.

Language: Английский

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Stability and transmissibility of SARS‐CoV‐2 in the environment

Journal of Medical Virology, Journal Year: 2022, Volume and Issue: 95(1)

Published: Aug. 30, 2022

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus causing ongoing global disease 2019 (COVID-19) pandemic, is believed to be transmitted primarily through droplets and aerosols. However, reports are increasing regarding contamination of environmental surfaces, shared objects, cold-chain foods with SARS-CoV-2 RNA possibility fomite transmission raises much concern debate. This study summarizes current knowledge potential mechanisms SARS-CoV-2, including prevalence surface in various settings, viability stability on surfaces or fomites, as well factors affecting survival such temperature relative humidity. Instances transmission, food importance epidemics, discussed. The gaps also briefly analyzed.

Language: Английский

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