Community Transmission of Severe Acute Respiratory Syndrome Coronavirus 2, Shenzhen, China, 2020

Liu, Jiaye; Liao, Xuejiao; Shen, Qian; Yuan, Jing; Wang, Fuxiang; Liu, Yingxia; Wang, Zhaoqin; Wang, Fu Sheng; Liu, Lei; Zhang, Zheng

doi:10.3201/eid2606.200239

Cited by 719 publications

(666 citation statements)

References 7 publications

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“…During the current phase of COVID-19 outbreak in Bolivia, only of imported cases, all of them are being tested by rRT-PCR. However, the question is if the spread occurs rapidly in the country, with communitytransmission as is now observed in other countries in the continent [72][73][74], Bolivia, as well as other low-and middle-income countries in the region, e.g. Haiti, Venezuela [75], Nicaragua, among others, will not be able to afford large-scale diagnostics [24].…”

Section: Discussionmentioning

confidence: 99%

Clinical features of the first cases and a cluster of Coronavirus Disease 2019 (COVID-19) in Bolivia imported from Italy and Spain

Escalera-Antezana

Lizon-Ferrufino²,

Maldonado-Alanoca³

et al. 2020

Travel Medicine and Infectious Disease

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Section: Discussionmentioning

confidence: 99%

Clinical features of the first cases and a cluster of Coronavirus Disease 2019 (COVID-19) in Bolivia imported from Italy and Spain

Escalera-Antezana

Lizon-Ferrufino²,

Maldonado-Alanoca³

et al. 2020

Travel Medicine and Infectious Disease

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“…Transmission via aerosols (< 5 μm) is mediated by expelled particles that are smaller in size than respiratory droplets and can remain suspended in the air for prolonged periods of time, allowing infection of susceptible individuals at a greater distance from the site of expulsion 13 . Current epidemiological data suggest that SARS-CoV-2 is transmitted primarily via respiratory droplets and contact 8–10,14,15 , which is used as the basis for mitigation of spread through physical and social distancing measures. However, scientific evidence that SARS-CoV-2 can be efficiently transmitted via the air is weak.…”

Section: Figurementioning

confidence: 99%

SARS-CoV-2 is transmitted via contact and via the air between ferrets

Richard

Kok

Meulder

et al. 2020

Preprint

129

190

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bioRxiv preprint SARS-CoV-2, a coronavirus that newly emerged in China in late 2019 1,2 and spread rapidly 12 worldwide, caused the first witnessed pandemic sparked by a coronavirus. As the pandemic 13 progresses, information about the modes of transmission of SARS-CoV-2 among humans is critical 14 to apply appropriate infection control measures and to slow its spread. Here we show that SARS-15 CoV-2 is transmitted efficiently via direct contact and via the air (via respiratory droplets and/or 16 aerosols) between ferrets. Intranasal inoculation of donor ferrets resulted in a productive upper 17 respiratory tract infection and long-term shedding, up to 11 to 19 days post-inoculation. SARS-18 CoV-2 transmitted to four out of four direct contact ferrets between 1 and 3 days after exposure 19 and via the air to three out of four independent indirect recipient ferrets between 3 and 7 days 20 after exposure. The pattern of virus shedding in the direct contact and indirect recipient ferrets 21 was similar to that of the inoculated ferrets and infectious virus was isolated from all positive 22 animals, showing that ferrets were productively infected via either route. This study provides 23 experimental evidence of robust transmission of SARS-CoV-2 via the air, supporting the 24 implementation of community-level social distancing measures currently applied in many 25 countries in the world and informing decisions on infection control measures in healthcare 26 settings 3 . In late December 2019, clusters of patients in China presenting with pneumonia of unknown etiology 29 were reported to the World Health Organization (WHO) 1 . The causative agent was rapidly identified 30 as being a virus from the Coronaviridae family, closely related to the severe acute respiratory 31 syndrome coronavirus (SARS-CoV) 2,4,5 . The SARS-CoV epidemic affected 26 countries and resulted in 32 more than 8000 cases in 2003. The newly emerging coronavirus, named SARS-CoV-2 6 , rapidly spread 33 worldwide and was declared pandemic by the WHO on March 11, 2020 7 . The first evidence 34 suggesting human-to-human transmission came from the descriptions of clusters among the early 35 cases 8,9 . Based on epidemiological data from China before measures were taken to control the 36 spread of the virus, the reproductive number R0 (the number of secondary cases directly generated 37 from each case) was estimated to be between 2 and 3 10-12 . In order to apply appropriate infection 38 control measures to reduce the R0, the modes of transmission of SARS-CoV-2 need to be elucidated.39 Respiratory viruses can be transmitted via direct and indirect contact (via fomites), and through the 40 air via respiratory droplets and/or aerosols. Transmission via respiratory droplets (> 5 μm) is 41 mediated by expelled particles that have a propensity to settle quickly and is therefore reliant on 42 close proximity between infected and susceptible individuals, usually within 1 m of the site of 43 expulsion. Transmission via aerosols (< 5 μm) is mediated by expelled parti...

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“…The association of coronavirus disease (COVID)-19 with certain comorbidities suggests that undiagnosed patients will seek medical advice from their GP or at the emergency department for symptoms other than respiratory complaints [5,6]. SARS-CoV-2 is mainly transmitted through respiratory droplets and direct contact with contaminated surfaces [7][8][9]. Many healthcare workers and GPs feel insecure because recommendations for personal protection equipment may vary between public health agencies.…”

Section: Introductionmentioning

confidence: 99%

Transmission risk of SARS-CoV-2 to healthcare workers – observational results of a primary care hospital contact tracing

Canova¹,

Schläpfer²,

Piso³

et al. 2020

Swiss Med Wkly

101

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BACKGROUND The coronavirus disease (COVID)-19 epidemic is evolving rapidly. Healthcare workers are at increased risk for infection, and specific requirements for their protection are advisable to ensure the functioning of the basic healthcare system, including the availability of general practitioners (GPs). Understanding the transmission risk is particularly important for guiding evidence-based protective measures in the primary healthcare setting. METHODS Healthcare worker contacts of an initially undiagnosed COVID-19 case, who were without personal protective equipment, in particular not wearing facemasks, were screened with nasopharyngeal swabs and polymerase chain reaction tests for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), irrespective of respiratory symptoms or fever seven days after initial contact. The details of exposure to the index case were obtained during routine contact investigation after unintentional pathogen exposure. RESULTS Twenty-one healthcare workers reported contacts with the index case. Three healthcare workers reported respiratory symptoms (cough) or low-grade fever within 4 days. None of them tested positive for SARS-CoV-2 at the time of symptom onset. All 21 healthcare workers tested SARS-CoV-2 negative 7 days after initial index case contact, including the three healthcare workers with previous symptoms. Ten of the 21 healthcare workers reported a cumulative exposure time of >15 minutes. Longer cumulative contact times were associated with more individual contacts, reduced contact time per contact and activities with physical patient contact. The closest relative of the index patient tested SARS-CoV-2 positive 2 days after the index case presented at the hospital emergency department. CONCLUSION We found a low risk of SARS-CoV-2 transmission in a primary care setting. These findings are compatible with previous reports of the highest transmission probability in household settings with prolonged close contacts. The current protective measures for healthcare workers, including strict adherence to basic standard hygiene and facemasks, offer considerable protection during short periods of contact with symptomatic COVID-19 cases by diminishing the risk of direct and indirect transmission.

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Community Transmission of Severe Acute Respiratory Syndrome Coronavirus 2, Shenzhen, China, 2020

Abstract: Visit our website to listen:https://tools.cdc.gov/medialibrary/ index.aspx#/media/id/393805

Cited by 719 publications

References 7 publications

Clinical features of the first cases and a cluster of Coronavirus Disease 2019 (COVID-19) in Bolivia imported from Italy and Spain

Clinical features of the first cases and a cluster of Coronavirus Disease 2019 (COVID-19) in Bolivia imported from Italy and Spain

SARS-CoV-2 is transmitted via contact and via the air between ferrets

Transmission risk of SARS-CoV-2 to healthcare workers – observational results of a primary care hospital contact tracing

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