HKUMed researchers discovered a mechanism that may explain the temporary loss of smell by using a golden hamster animal model

Members of the research team from HKUMed include: (from left to right) Dr Alex Chin Wing-hong, Investigator, School of Public Health; Ms Sia Sin-fun, Senior Technical Officer, School of Public Health; Dr Yen Hui-ling, Associate Professor, School of Public Health; Professor John Nicholls, Clinical Professor, Department of Pathology; Professor Malik Peiris, Tam Wah-Ching Professor in Medical Science and Chair Professor of Virology, School of Public Health; and Professor Leo Poon Lit-man, Professor and Head of Division of Public Health Laboratory Sciences, School of Public Health.

Researchers at the School of Public Health and the Department of Pathology, LKS Faculty of Medicine of the University of Hong Kong (HKUMed) used golden hamsters to study SARS-CoV-2 pathogenesis and transmission. The study shows that SARS-CoV-2 infection in golden hamsters resembles that found in humans with mild COVID-19 symptoms, and that the infected animals can efficiently transmit the disease to other hamsters by direct contact or through the air. This study not only demonstrates that this animal model may be useful in future studies of the effectiveness of vaccines and drugs to fight novel coronavirus, but is also the first study among research teams worldwide to make use of an animal model to study virus-mediated damage of the olfactory epithelium and neurons needed for the sense of smell in humans, providing a possible explanation of the temporary loss of olfactory senses in some of the infected patients. The findings are now published in Nature.

Read more: https://www.med.hku.hk/en/News/HKUMed-researchers-studied-the-modes-of-transmission-of-novel-coronavirus

HKUMed researchers discovered novel coronavirus (SARS-CoV-2) can infect more efficiently than SARS-CoV in human airways and eyes

Members of the research team from HKUMed include: (from left to right) Professor Malik Peiris, Tam Wah-Ching Professor in Medical Science and Chair Professor of Virology, School of Public Health; Professor John Nicholls, Clinical Professor, Department of Pathology; Dr Michael Chan Chi-wai, Associate Professor, School of Public Health; and Dr Kenrie Hui Pui-yan, Research Assistant Professor, School of Public Health.

Understanding how SARS-CoV-2 infects humans is essential in optimising measures for infection prevention and control of transmission. Over the past 15 years, researchers at the School of Public Health, LKS Faculty of Medicine of the University of Hong Kong (HKUMed) has developed methods for culturing tissues from the human respiratory tract and eyes in the laboratory and applied them to study respiratory viruses such as avian flu H5N1, H5N6, H7N9, the 2009 pandemic H1N1 and MERS-CoV. In a recent study, the team applies the methods to study novel coronavirus (SARS-CoV-2) and becomes the first among research teams worldwide to provide evidence that SARS-CoV-2 can infect both the upper human airways and conjunctiva (the cells lining the surface of the eye), and that SARS-CoV-2 is much more efficient than SARS coronavirus (SARS-CoV) in infecting human airways and the conjunctival surfaces of the eye. The findings are now published in The Lancet Respiratory Medicine, a leading prestigious journal.

In this study, Dr Michael Chan Chi-wai, Associate Professor of the School of Public Health, HKUMed and his research team compared the infection of SARS-CoV-2, SARS-CoV and the influenza viruses H5N1 and H1N1pdm2009 using human upper respiratory tract and eye tissues in a Biological Safety Level-3 (BSL-3) laboratory. They found that SARS-CoV-2 is much more efficient in infecting the human conjunctiva and the upper respiratory airways than SARS-CoV, and its level of infection is comparable to what is observed in the 2009 pandemic H1N1. Taken together, this explains the higher transmissibility of the novel pandemic SARS-CoV-2 than that of SARS-CoV. “This study also highlights the fact that eyes may be an important route of SARS-CoV-2 human infection,” said Dr Chan.

Read more: https://www.med.hku.hk/en/News/HKUMed-Novel-coronavirus-can-infect-more-efficiently-than-SARS-CoV-in-human-airways-and-eyes

HKUMed research examines how Hong Kong managed first wave of COVID-19 without resorting to complete lockdown

Study suggests testing, contact tracing and population behavioural changes—measures which have less disruptive social and economic impact than total lockdown—can meaningfully control COVID-19

Hong Kong appeared to have averted a major COVID-19 outbreak up to March 31, 2020, by adopting far less drastic control measures than most other countries, with a combination of border entry restrictions, quarantine and isolation of cases and contacts, together with some degree of social distancing, according to a new study conducted by researchers at the WHO Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, LKS Faculty of Medicine of the University of Hong Kong (HKUMed). The findings are now published in The Lancet Public Health journal.

Read more: https://www.med.hku.hk/en/News/HKUMed-research-examines-how-Hong-Kong-managed-first-wave-of-COVID-19-without

HKUMed research shows that stroke patients are presenting to hospitals one hour later during COVID-19

Members of HKU Stroke (from left to right): Dr William CY Leung, Dr Gary Lau Kui-kai, Dr Anderson Tsang Chun-on and Dr Teo Kay-cheong highlight the importance of recognising stroke symptoms and seeking medical help as soon as possible despite COVID-19 pandemic to ensure best chance of recovery from acute stroke.

HKUMed research shows that stroke patients are presenting to hospitals one hour later during COVID-19, potentially jeopardising the patients’ eligibility for treatments and affecting the outcome. 

Researchers at The Stroke Research and Prevention Group (HKU Stroke), LKS Faculty of Medicine of The University of Hong Kong (HKUMed) analysed 73 patients who presented to the Accident and Emergency (A&E) Services of Queen Mary Hospital with symptoms of a stroke during the first two months of COVID-19 locally (January 23, 2020 – March 24, 2020), and compared these with 89 patients during a similar period in 2019 (January 23, 2019 – March 24, 2019). They found that, despite similar clinical characteristics between the two groups, patients who presented during the COVID-19 pandemic sought medical attention via the A&E on average 60 minutes later, compared with patients in 2019 (154 vs 95 minutes). Importantly, during the period, only 55% of patients with stroke were presented to hospitals within the therapeutic time window for thrombolysis treatment (4.5 hours from symptom onset), which was ~20% lower compared with the preceding year (55% vs 72%). Furthermore, much fewer patients with a mini-stroke or transient ischaemic attack (TIA) were presented to hospitals during COVID-19 (4% vs 16%). Reassuringly, during COVID-19, it appeared that in-hospital stroke services at Queen Mary Hospital, flagship teaching hospital of HKUMed, were nevertheless not affected and timings of in-patient stroke pathways, such as those from hospital admission to giving treatment, remained similar during and before COVID-19.

Read more: https://www.med.hku.hk/en/News/stroke-patients-are-presenting-to-hospitals-one-hour-later-during-COVID-19

1st-wave COVID-19 transmissibility and severity in China outside Hubei after control measures, and 2nd-wave scenario planning

Timeline of events between Jan 23 and Feb 17, 2020. Photo credit: The Lancet

A research co-led by HKUMED was published in the Lancet medical journal is based on modeling of the epidemic in China. It shows that the death rate in mainland China was far lower, at less than 1%, than in Hubei province where the epidemic began, which had a death rate of nearly 6%. It also varied according to the economic prosperity of each province, which was related to the healthcare available.

Read full research paper on The Lancet: https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(20)30746-7/fulltext

HKUMed research suggested surgical masks could prevent transmission of seasonal coronaviruses from symptomatic people

A research team led by HKUMed and the University of Maryland recruited people with suspected respiratory viral infections to breathe into a machine, the Gesundheit II, to compare the relative amount of virus in exhaled breath with or without a surgical face mask. Photo credit: HKUMED

Surgical face masks may be effective in preventing the transmission of seasonal coronaviruses and influenza virus from symptomatic individuals, based on a study conducted by researchers at the WHO Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, LKS Faculty of Medicine of the University of Hong Kong (HKUMed) and the University of Maryland. In the study, masks were shown to reduce the detection of influenza virus in respiratory droplets and seasonal coronaviruses in droplets and aerosols. Further research is needed to determine whether masks can specifically prevent the transmission of SARS-CoV-2, which is closely related to seasonal coronaviruses. The findings are now published in the journal Nature Medicine.

Previous research had shown that respiratory viral infections, including those caused by coronaviruses, spread between humans mostly through close contact. However, there is no direct evidence of how influenza and coronaviruses spread between individuals who are in close proximity – whether by direct contact, large respiratory droplets, or through breathing another person’s exhaled breath. Respiratory viruses can also survive in the environment and potentially spread through indirect contact. Larger respiratory droplets, which fall near the source, as well as aerosols of smaller fine particles can both contain virus and cause short-range transmission. In addition, aerosols can remain in the air for longer and potentially transmit infection over longer distances, particularly if they are generated at higher concentration or if there is little ventilation.

Non-pharmaceutical measures, such as social distancing, handwashing, ventilation, and the use of face masks, could be important measures to prevent viral transmission. Although the use of face masks has been suggested as a strategy to slow down the transmission of influenza virus, little is known about the relative importance of this strategy in the transmission of other respiratory viruses, including seasonal coronaviruses.

Dr Nancy Leung Hiu-lan, Research Assistant Professor of School of Public Health, HKUMed and the research team recruited 246 people with suspected respiratory viral infections to breathe into a machine — the Gesundheit II — to compare the relative amount of virus in exhaled breath with or without a surgical face mask. The research team provided the same type of surgical mask to all the participants and ensured it was worn correctly.

“In 111 people infected by either coronavirus, influenza virus or rhinovirus, masks reduced detectable virus in respiratory droplets and aerosols for seasonal coronaviruses, and in respiratory droplets for influenza virus. In contrast, masks did not reduce the emission of rhinoviruses.” said Dr Leung.

SARS-CoV-2 and seasonal coronaviruses are closely related and may be of similar particle size. Professor Benjamin Cowling, Division Head of Epidemiology and Biostatistics, School of Public Health, HKUMed, and Co-Director of the WHO Collaborating Centre for Infectious Disease Epidemiology and Control, expressed, “the ability of surgical masks to reduce seasonal coronavirus in respiratory droplets and aerosols implies that such masks can contribute to slowing the spread of SARS-CoV-2 when worn by infected people.”

HKU to Start Clinical Trial of Drug for COVID-19

To help identify possible treatments for tackling COVID-19, The University of Hong Kong Clinical Trials Centre join forces with Queen Mary Hospital, Prince of Wales Hospital, Princess Margaret Hospital and the manufacturer of remdesivir, an investigational antiviral drug, in arranging for two clinical trials targeting for the treatment of moderate to severe COVID-19 patients. With a common goal of accelerating the preparation for the trials, the parties have been working hard in the past few weeks and quickly obtained the approvals from the research ethics committees. It is anticipated that the trials will be initiated within this month (i.e. March 2020).

HKUMed: HKUMed WHO Collaborating Centre for Infectious Disease Epidemiology and Control releases case fatality risk of COVID-19

A press conference was held by HKUMed WHO Collaborating Centre for Infectious Disease Epidemiology and Control on the case fatality risk of COVID-19 release.

The presentation slides can be found here.

Professor Gabriel Leung, Chair Professor of Public Health Medicine, HKUMed, and Founding Director of the WHO Collaborating Centre for Infectious Disease Epidemiology and Control; and Professor Joseph Wu, Division of Epidemiology and Biostatistics, School of Public Health, HKUMed, at the press conference.

HKUMed: Pseudo-colour scanning electron micrograph of SARS-CoV-2 grown in culture from a patient isolate

After 24 hours in culture there are large numbers of orange viral particles on the surface of the cell (blue). Image courtesy of LKS Faculty of Medicine,  Department of Electrical and Electronic Engineering (K.Tsia, K.Lee and Q.Lai), and Electron Microscopy Unit, The University of Hong Kong

HKUMed: Thin-section electron micrographs of the 2019 novel coronavirus grown in cells at HKU

The image shows part of a virus infected cell grown in culture with multiple virus particles being released from the cell surface. Each infected cell produces thousands of new infectious virus particles which can go on to infect new cells. Image credit: John Nicholls, Leo Poon and Malik Peiris, The University of Hong Kong

HKUMed: Short Video of the new Novel Coronavirus Growing in Culture

As many people in the general population are not familiar with what viruses are and what they look like, the University of Hong Kong has released a short video on the new novel Coronavirus growing in culture.

HKUMed: HKUMed WHO Collaborating Centre for Infectious Disease Epidemiology and Control releases real-time nowcast

"Nowcasting and forecasting the potential domestic and international spread of the 2019-nCoV outbreak originating in Wuhan, China: a modelling study" is now published in The Lancet. Read the publication here.

Presentation slides of the press conference can be found here.

Professor Gabriel Leung, Chair Professor of Public Health Medicine, HKUMed, and Founding Director of the WHO Collaborating Centre for Infectious Disease Epidemiology and Control; and Professor Joseph Wu, Division of Epidemiology and Biostatistics, School of Public Health, HKUMed, at the press conference.

Content and image credits to HKU LKS Faculty of Medicine

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