COVID-19 case fatality rate in Hong Kong has been decreasing due to various timely anti-epidemic measures


8th February 2023 – (Hong Kong) The Centre for Health Protection (CHP) of the Department of Health (DH) and the University of Hong Kong have been performing testing on nucleic acid specimens to monitor COVID-19 variants, and have been sharing the related data with international organisation.

 Surveillance results during January to December 2022 showed that the Omicron sub-lineages were the most common variant. Over half of the total cases with variant detected involved BA.4/BA.5 and its descendent lineages, followed by BA.2 and its descendent lineages; while newly emerging variants like BA.2.75.2, BA.4.6, BF.7, BQ.1.1, XBB and XBD accounted for small proportions. The Government note that there is no significant difference between the percentage distribution of variant amongst death cases and all cases with the aforesaid Omicron sub-lineages detected.

Since April 2020, the Health Bureau and the Health and Medical Research Fund (HMRF) have approved a total of HK$556 million to support 70 COVID-19 related medical research studies from bench to bedside and at the community level through application of new technologies. These studies address important research areas including transmissibility and infectivity of the virus, effective detection and surveillance, prevention strategies of the disease and development of vaccines, treatments and therapies.

 There are a number of studies related to the research of variants, including the applications of sewage surveillance and genomic surveillance approaches to monitor the activities of the variants and their transmission chains in the community, the use of cell lines and animal models to investigate the viral characteristics of different variants, the association between clinical symptoms and variant infection, and the immune protection from different doses and types of COVID-19 vaccines against the variants. Some of these research findings have already been published in top-tier international journals.

A total of 9,343 and 2,347 death cases fulfilling reporting criteria were recorded in the first half and the second half of 2022 by the CHP of the DH respectively. Specifically, a COVID-19 death case is defined as a death in a person tested positive and died within 28 days of the first positive specimen collection day. The underlying cause of death may have been unrelated to COVID-19. In particular, the Hospital Authority (HA) has been categorising the cause of death into related or unrelated to COVID-19 according to preliminary analysis since 4th January this year. As at 29th January this year, among the 1,291 deaths of positive cases in public hospitals reported by the HA, 648 cases or about 50.2 per cent were related to COVID-19 while the remaining 643 cases or about 49.8 per cent were unrelated.

In fact, the COVID-19 case fatality rate in Hong Kong has been decreasing due to various timely anti-epidemic measures (including vaccination and the provision of COVID-19 oral drugs), as well as a substantial number of natural infections brought by the fifth wave of the epidemic. According to figures from the DH, the COVID-19 case fatality rates in the first half and the second half of 2022 were 0.76 per cent and 0.17 per cent respectively. Meanwhile, the Government of the Hong Kong Special Administrative Region (HKSAR) has been reviewing the effectiveness, assessing the impact and drawing the experiences periodically in response to the epidemic development in the past three years, so as to continuously improve the epidemic responses on all fronts. The crude COVID-19 mortality rate in Hong Kong (approximately 180 deaths per 100,000 population) is lower than that of many developed western economies (approximately 200 to more than 300 deaths per 100,000 population).

Starting from 30th January, 2023, the Government of the HKSAR has revised the reporting criteria of COVID-19 under which persons tested positive (including by nucleic acid and rapid antigen tests) are not required to report to the CHP, while doctors are only required to report to the CHP death cases and severe cases. Besides, the announcement of death figures has been adjusted to cover a death in a person tested positive and died within 28 days of the first positive specimen collection day and the underlying cause of death may have been related to COVID-19 upon preliminary assessment. Under the new arrangement, since not all cases tested positive are reported, the Government cannot calculate and should not compare the COVID-19 case fatality rate thereafter. The criteria for the announcement of COVID-19 death cases have also been changed, and hence they cannot be compared with the previous figures.

Furthermore, according to the figures prepared by HA, among the inpatients diagnosed with COVID-19 in public hospitals, 5,220 were in serious or critical conditions in the first half of 2022, and 2,921 in the second half of the year. The above serious or critical situations are not necessarily caused by COVID-19, and the relevant figures do not include death cases.