Overview: The history and pediatric perspectives of severe acute respiratory syndromes: Novel or just like SARS.

Many respiratory viral infections such as influenza and measles result in severe acute respiratory symptoms and epidemics. In the spring of 2003, an epidemic of coronavirus pneumonia spread from Guangzhou to Hong Kong and subsequently to the rest of the world. The WHO coined the acronym SARS (severe acute respiratory syndrome) and subsequently the causative virus as SARS-CoV. In the summer of 2012, epidemic of pneumonia occurred again in Saudi Arabia which was subsequently found to be caused by another novel coronavirus. WHO coined the term MERS (Middle East respiratory syndrome) to denote the Middle East origin of the novel virus (MERS-CoV). In the winter of 2019, another outbreak of pneumonia occurred in Wuhan, China which rapidly spread globally. Yet another novel coronavirus was identified as the culprit and has been named SARS-CoV-2 due to its similarities with SARS-CoV, and the disease as coronavirus disease-2019. This overview aims to compare and contrast the similarities and differences of these three major episodes of coronavirus outbreak, and conclude that they are essentially the same viral respiratory syndromes caused by similar strains of coronavirus with different names. Coronaviruses have caused major epidemics and outbreaks worldwide in the last two decades. From an epidemiological perspective, they are remarkably similar in the mode of spread by droplets. Special focus is placed on the pediatric aspects, which carry less morbidity and mortality in all three entities.

Impact assessment of non-pharmaceutical interventions against coronavirus disease 2019 and influenza in Hong Kong: an observational study.

BACKGROUND: A range of public health measures have been implemented to suppress local transmission of coronavirus disease 2019 (COVID-19) in Hong Kong. We examined the effect of these interventions and behavioural changes of the public on the incidence of COVID-19, as well as on influenza virus infections, which might share some aspects of transmission dynamics with COVID-19. METHODS: We analysed data on laboratory-confirmed COVID-19 cases, influenza surveillance data in outpatients of all ages, and influenza hospitalisations in children. We estimated the daily effective reproduction number (Rt) for COVID-19 and influenza A H1N1 to estimate changes in transmissibility over time. Attitudes towards COVID-19 and changes in population behaviours were reviewed through three telephone surveys done on Jan 20-23, Feb 11-14, and March 10-13, 2020. FINDINGS: COVID-19 transmissibility measured by Rt has remained at approximately 1 for 8 weeks in Hong Kong. Influenza transmission declined substantially after the implementation of social distancing measures and changes in population behaviours in late January, with a 44% (95% CI 34-53%) reduction in transmissibility in the community, from an estimated Rt of 1·28 (95% CI 1·26-1·30) before the start of the school closures to 0·72 (0·70-0·74) during the closure weeks. Similarly, a 33% (24-43%) reduction in transmissibility was seen based on paediatric hospitalisation rates, from an Rt of 1·10 (1·06-1·12) before the start of the school closures to 0·73 (0·68-0·77) after school closures. Among respondents to the surveys, 74·5%, 97·5%, and 98·8% reported wearing masks when going out, and 61·3%, 90·2%, and 85·1% reported avoiding crowded places in surveys 1 (n=1008), 2 (n=1000), and 3 (n=1005), respectively. INTERPRETATION: Our study shows that non-pharmaceutical interventions (including border restrictions, quarantine and isolation, distancing, and changes in population behaviour) were associated with reduced transmission of COVID-19 in Hong Kong, and are also likely to have substantially reduced influenza transmission in early February, 2020. FUNDING: Health and Medical Research Fund, Hong Kong.