Ocular Dirofilariasis in Migrant from Sri Lanka, Australia.

We describe a case of imported ocular dirofilariasis in Australia, linked to the Hong Kong genotype of Dirofilaria sp., in a migrant from Sri Lanka. Surgical extraction and mitochondrial sequences analyses confirmed this filarioid nematode as the causative agent and a Dirofilaria sp. not previously reported in Australia.

Antigenic Characterization of Novel Human Norovirus GII.4 Variants San Francisco 2017 and Hong Kong 2019.

Norovirus is a major cause of acute gastroenteritis; GII.4 is the predominant strain in humans. Recently, 2 new GII.4 variants, Hong Kong 2019 and San Francisco 2017, were reported. Characterization using GII.4 monoclonal antibodies and serum demonstrated different antigenic profiles for the new variants compared with historical variants.

Inferring Incidence of Unreported SARS-CoV-2 Infections Using Seroprevalence of Open Reading Frame 8 Antigen, Hong Kong.

We tested seroprevalence of open reading frame 8 antigens to infer the number of unrecognized SARS-CoV-2 Omicron infections in Hong Kong during 2022. We estimate 33.6% of the population was infected, 72.1% asymptomatically. Surveillance and control activities during large-scale outbreaks should account for potentially substantial undercounts.

Effectiveness of Vaccines and Antiviral Drugs in Preventing Severe and Fatal COVID-19, Hong Kong.

We compared the effectiveness and interactions of molnupiravir and nirmatrelvir/ritonavir and 2 vaccines, CoronaVac and Comirnaty, in a large population of inpatients with COVID-19 in Hong Kong. Both the oral antiviral drugs and vaccines were associated with lower risks for all-cause mortality and progression to serious/critical/fatal conditions (study outcomes). No significant interaction effects were observed between the antiviral drugs and vaccinations; their joint effects were additive. If antiviral drugs were prescribed within 5 days of confirmed COVID-19 diagnosis, usage was associated with lower risks for the target outcomes for patients >60, but not <60, years of age; no significant clinical benefit was found if prescribed beyond 5 days. Among patients >80 years of age, 3-4 doses of Comirnaty vaccine were associated with significantly lower risks for target outcomes. Policies should encourage COVID-19 vaccination, and oral antivirals should be made accessible to infected persons within 5 days of confirmed diagnosis.

Prevalence of oral human papillomavirus infection among the general adult population in Hong Kong.

A cross-sectional study in 2021-23 collected oral rinse gargle samples from an human papillomaviruses (HPV) vaccine-naïve general adult population in Hong Kong. HPV was detected by a PCR using SPF10 primers, and genotyped by a linear array covering 25 genotypes. Epidemiologic information including sociodemographics, medical history, oral health, and sexual behavior were collected by a self-administered questionnaire. Altogether, 2323 subjects aged 18-75 (median 47) years with 50.1% male were recruited. The prevalence for oral HPV infection with all genotypes combined, high-risk, and low-risk genotypes was 1.5%, 0.7%, and 0.7%, respectively; and with no statistically significant difference between participant gender. The prevalence increased with age and was highest in women at 45-54 years (2.7% for all genotypes combined), and highest in men aged >64 years (4.1% for all genotypes combined). HPV52 was the most common genotype among all participants. Univariate analysis suggested more lifetime sexual or oral sexual partners as risk factors, but they did not reach statistical significance upon multivariate analysis; whereas higher educational level had an independent protective effect. To conclude, oral HPV prevalence increased with age in Hong Kong. Strategies to prevent oral HPV infection and the associated cancers are urgently needed.

Prognostic performance of Hong Kong Liver Cancer with Barcelona Clinic Liver Cancer staging systems in hepatocellular carcinoma.

BACKGROUND: Accurate staging is necessary for predicting hepatocellular carcinoma (HCC) prognosis and guiding patient management. The Barcelona Clinic Liver Cancer (BCLC) staging system has limitations due to heterogeneity observed among patients in BCLC stages B and C. In contrast, the Hong Kong Liver Cancer (HKLC) staging system offers more aggressive treatment strategies. AIM: To compare the prognostic performance of HKLC and BCLC staging systems in Egyptian patients with HCC. METHODS: We conducted a retrospective study at the National Liver Institute, Menoufia University, Egypt, on 1015 HCC patients. Data was collected from patients' medical records over 10 years (from 2008 to 2018). The BCLC and HKLC stages were identified, and Kaplan-Meier survival analysis was used to compare patients' overall survival rates within each staging system. Additionally, we evaluated the comparative prognostic performance of the two staging systems. RESULTS: Hepatitis C was identified as the underlying etiology in 799 patients (78.7%), hepatitis B in 12 patients (1.2%), and non-viral causes in 204 patients (20.1%). The survival analysis demonstrated significant differences across the various stages within both the BCLC and HKLC systems. The receiver operating characteristic (ROC) curves indicated a marginally superior performance of the HKLC system in predicting survival at 1, 2, and 3 years compared to the BCLC system. Furthermore, the HKLC staging provided a slightly enhanced prognostic capability, particularly for patients classified under BCLC stages B and C, suggesting a potential survival benefit. CONCLUSION: HKLC classification had a slightly better prognostic performance than BCLC staging system and may offer a survival advantage for certain patients with HCC in BCLC stage B and C HCC cases.

Employment conditions and mental health of overseas female migrant domestic workers in Hong Kong: a parallel mediation analysis.

BACKGROUND: Female migrant domestic workers (MDW), approximately 8.5 million globally, often live in their employer's home under vulnerable conditions. In Hong Kong, MDWs currently comprise 5% of the population. This study was conducted to assess the association between employment conditions and mental health, and the mediating roles stress and job satisfaction have, among female MDWs in Hong Kong. METHODS: Participants completed an online cross-sectional survey. A total of 1,965 survey were collected between August 2020 and August 2021. Questions in the survey were related to MDWs background information, employment conditions, stress, job satisfaction, and two mental health outcomes: anxiety and depression. An employment conditions score was created to assess the cumulative effect poor employment conditions had on mental health. A multicategorical parallel mediation analysis was used to assess the direct effect employment conditions have on mental health and the indirect effects through stress and job satisfaction. RESULTS: Overall, 17.7% of MDWs were reported to be suffering from anxiety and 30.8% from depression. An increase in poor employment conditions was statistically associated with an increase in both outcomes, while stress levels and job satisfaction mediated this association. CONCLUSIONS: The findings call for increased scrutiny of employment conditions and mental well-being of MDWs.

Access to civil justice as a social determinant of health: a legal epidemiological cross-sectional study.

BACKGROUND: Although it is widely acknowledged that access to civil justice (ATJ) is a key social determinant of health (SDOH), the existing literature lacks empirical evidence supporting ATJ as a SDOH for specific dimensions of health. METHODS: A legal epidemiological, cross-sectional, postal survey was conducted on n = 908 randomly sampled participants in Hong Kong in March 2023. Data collected were perceptions of the civil justice system, health, and sociodemographics. Perceived ATJ was assessed using a modified version of the Inaccessibility of Justice scale (IOJ) and Perceived Inequality of Justice scale (PIJ), i.e. the "modified IOJ-PIJ", consisting of 12 of the original 13 items from both scales divided into two subdomains: "procedural fairness", and "outcome neutrality". For health data, quality of life was assessed using the Hong Kong version of the Abbreviated World Health Organization Quality of Life questionnaire (WHOQOL-BREF(HK)), psychological distress (including symptoms of anxiety and depression) was assessed using the four-Item Patient Health Questionnaire (PHQ-4), and having comorbidities was assessed using Sangha's Self-Administered Comorbidity Questionnaire (SCQ). Structural equation modelling (SEM) was used to investigate the relationships between perceived ATJ and the measured health outcomes. RESULTS: SEM demonstrated that both subdomains for ATJ had significantly negative associations (B < 0; p < 0.05) with all quality-of-life subdomains, except for between outcome neutrality with social relationships; both subdomains for ATJ had significantly positive association (B > 0; p < 0.05) with both anxiety and depression; and, after adjusting for age, only "procedural fairness" had significantly positive association (B > 0; p < 0.05) with having comorbidities. CONCLUSION: This study provided empirical evidence that ATJ is a SDOH for specific dimensions of health. The results of this study encourage laws, policies, and initiatives aimed at improving ATJ, as well as collaborative efforts from the legal and health sectors through health-justice partnerships, and from the broader community, to safeguard and promote public health by strengthening ATJ.

Radioactivity of inert construction and demolition waste from Hong Kong and environmental assessment for marine trial reclamation in Guanghai Bay.

Inert construction and demolition waste from Hong Kong (HK public fills) has been used for marine trial reclamation in the Guanghai Bay (GHWT) of the Chinese Mainland. However, an environmental assessment of HK public fills is necessary due to higher radioactivity in HK soils than typical global levels. Here, radiation dose rate, gamma radionuclides and gross beta of HK public fills were analyzed. The origin information was explored using natural primordial radionuclides as fingerprints. Our data show that radiation dose rate of HK public fills before disposal was 0.14-0.54 (0.33 ± 0.03) µSv/h (n = 16,722 data with 2787 ships) in 2014, which is less than the GHWT background. Monthly detection of 238U, 226Ra, 210Pb, 232Th, 228Th, 40K, and gross beta in HK public fills was conducted on three random ships. Their specific activities were <6.27-155.5, 58.7-98.7, <7.83-238.2,97.9-168.6, 87.1-136.0, 463.1-1,018, and 1047-1658 Bq/kgDW, respectively. These results suggest that the radioactivity levels of HK public fills are essentially the same as the GHWT background. The study assessed potential risks using various indices icluding Raeq (Radium equivalent activity), Hex (External radiation hazard index), Hin (Internal radiation hazard index), Iγ (Gamma index), AUI (Activity utilization index), AUI (Activity utilization index), E (Annual effective dose), AGDE (Annual gonadal dose equivalent), RLI (Representative level index), Din (Indoor air absorbed dose rate), Dout (Outdoor air absorbed dose rate), and ELCR (Excess lifetime cancer risk). The study suggests that HK public fills should be used for the trial reclamation rather than building-house materials. This provides valuable insights for the resource utilization and minimizing environmental pollution of HK public fills. The aim is to offer fundamental technical assistance for future waste resource utilization, ecological protection, and restoration in the Guangdong-Hong Kong-Macao Greater Bay Area.

How mobility pattern shapes the association between static green space and dynamic green space exposure.

Greenspaces are crucial for enhancing mental and physical health. Recent research has shifted from static methods of assessing exposure to greenspaces, based on fixed locations, to dynamic approaches that account for individual mobility. These dynamic evaluations utilize advanced technologies like GPS tracking and remote sensing to provide more precise exposure estimates. However, little work has been conducted to compare dynamic and static exposure assessments and the effect of individual mobility on these evaluations. This study delves into how greenspaces around homes and workplaces, along with mobility patterns, affect dynamic greenspace exposure in Hong Kong. Data was collected from 787 participants in four communities in Hong Kong using GPS, portable sensors, and surveys. Using multiple statistical tests, our study revealed significant variations in participants' daily mobility patterns across socio-demographic and temporal factors. Further, using linear mixed-effects models, we identified complex and statistically significant interactions between participants' static greenspace exposure and their mobility patterns. Our findings suggest that individual mobility patterns significantly modify the relationship between static and dynamic greenspace exposure and play a critical role in explaining socio-demographic and temporal context differences in the relationship between static and dynamic greenspace exposure.

The prevalence of constipation in adult psychiatric out-patients on clozapine treatment at a regional public hospital in Hong Kong.

OBJECTIVE: To determine the occurrence of constipation in local patients on clozapine treatment, and to compare the demographical and clinical characteristics of patients on clozapine treatment with or without constipation. METHODS: This is a cross-sectional, observational study. All adult psychiatric out-patients on clozapine treatment attending follow-up at a regional hospital were recruited for clinical interview and medical record review. The Enhanced Asian Rome III Questionnaire (EAR3Q) was used to define patients with constipation. The Bristol Stool Form Scale (BSFS) was used to assess stool form. The Brief Psychiatric Rating Scale-Anchored (BPRS-A) was used to measure psychiatric symptoms. The Brief Medication Adherence Scale (BMAS) was used to assess treatment adherence. Logistic regression was conducted to identify independent associating factors of constipation in patients on clozapine treatment. RESULTS: The prevalence of constipation in patients on clozapine treatment was 26.3%, (95% CI [21.5%, 31.6%]). Independent associating factors included disorder of psychological development (aOR = 6.98, 95% CI [1.24, 39.18]), anxiety (very mild: aOR = 9.23, 95% CI [2.59, 32.87]; mild: aOR = 2.66, 95% CI [1.26, 5.62]), prescription with combination of laxatives (aOR = 0.40, 95% CI [0.17, 0.95]), and concomitant use of amisulpride (aOR = 2.52, 95% CI [1.09, 5.82]), quetiapine (aOR = 5.92, 95% CI [1.11, 31.56]) and metamucil (aOR = 9.30, 95% CI [1.53, 56.58]). CONCLUSION: This study examined the prevalence of clozapine-associated constipation in Hong Kong using a validated questionnaire. The identification of independent factors associated with constipation could facilitate better risk stratification and risk modification in clinical practice.

Cross-border healthcare-seeking and utilization behaviours among ethnic minorities: exploring the nexus of the perceived better option and public health concerns.

BACKGROUND: Many ethnic minorities in Hong Kong seek medical tourism after encountering inequalities in access to local healthcare because of language barriers and cultural-religious differences. The present study explored the ethnic minorities' lived experiences of medical tourism and issues arising from cross-border health-seeking relevant to this specific population. METHODS: Qualitative in-depth interviews with 25 ethnic minority informants from five South Asian countries in 2019. RESULTS: The 19 informants out of the 25 have sought assistance from their international networks for home remedies, medical advice and treatments of traditional/Western medicines, for they are more costly or unavailable in Hong Kong and for issues related to racial discrimination, language barriers, transnationalism engagement, cultural insensitivity, and dissatisfaction with healthcare services in Hong Kong. DISCUSSION: Medical tourism can relieve the host country's caring responsibilities from healthcare services, so the government might no longer be hard-pressed to fix the failing healthcare system. Consequently, it could cause public health concerns, such as having patients bear the risks of exposure to new pathogens, the extra cost from postoperative complications, gaps in medical documentation and continuum of care, etc. It also triggers global inequities in health care, exacerbating unequal distribution of resources among the affordable and non-affordable groups. CONCLUSION: Ethnic minorities in Hong Kong sought cross-border healthcare because of structural and cultural-religious issues. The surge of medical tourism from rich and developed countries to poor and developing countries may infringe upon the rights of residents in destination countries. To mitigate such negative impacts, policymakers of host countries should improve hospital infrastructure, as well as train and recruit more culturally sensitive healthcare workers to promote universal health coverage. Healthcare professionals should also strive to enhance their cultural competence to foster effective intercultural communication for ethnic minority groups.

Beyond individual responsibility towards healthy food choices: A qualitative study among Pakistani women in Hong Kong.

While biomedical understandings of food and diet coupled with discourses on individual responsibility towards healthy food choices are nowadays prominent, other social and cultural meanings attached to food and diet are largely devalued. The limits of such a reductionist approach are more evident when related to the experiences of migrant and ethnic populations, whose alternative knowledge(s) and practices about food and health are especially neglected. A multicultural city with a public healthcare system inherited from the British colonial times and largely shaped by biomedical ideas of health, Hong Kong offers a lens into the limits of such a reductionist approach. Due to their vulnerability in the context of Hong Kong as shaped by intersecting social identities, 72 women from Pakistan were recruited to be our community partners in a community-based participatory action research project to investigate their health needs and concerns. 12 focus group discussions were conducted, exploring their experiences of "healthy" food and overweight especially related to their encounters with the Hong Kong public healthcare system, as these issues emerged as key health concerns within the community. Four major themes emerged: unmet expectations of care, health is beyond the individual, constraints to a healthy diet in the context of migration, and beyond health: food as care for diasporic women. This study highlights the limit of a reductionist approach to healthy food as merely based on nutrition and individual responsibility. It stresses the need of a counter-discourse in the field of public health, emphasizing not only alternative cultural ideas of health and food, but also enlarging the field of health in biomedical terms to embrace "care" and acknowledging the structural constraints shaping migrant and ethnic population's vulnerability in making "healthy" food choices.

Urinary metals and their associations with DNA oxidative damage among e-waste recycling workers in Hong Kong.

Recycling electronic waste (e-waste) poses risks of metal exposure, potentially leading to health impairments. However, no previous study has focused on this issue in Hong Kong. Therefore, from June 2021 to September 2022, this study collected urine samples from 101 e-waste workers and 100 office workers in Hong Kong to compare their urinary levels of metals using ICP-MS. Among the 15 included metals (with detection rates above the 70 % threshold), eight showed significantly higher urinary concentrations (unit: µg/g creatinine) in e-waste workers compared to office workers: Li (25.09 vs. 33.36), Mn (1.78 vs. 4.15), Ni (2.10 vs. 2.77), Cu (5.81 vs. 9.23), Zn (404.35 vs. 431.52), Sr (151.33 vs. 186.26), Tl (0.35 vs. 0.43), and Pb (0.69 vs. 1.16). E-waste workers in Hong Kong generally exhibited lower metal levels than those in developing regions but higher than their counterparts in developed areas. The urine level of 8-hydroxy-2-deoxyguanosine (8-OHdG) was determined by HPLC-MS/MS, and no significant difference was found between the two groups. Multiple linear regression models revealed no significant association between individual metal and urinary 8-OHdG concentrations. However, the metal mixture was identified to marginally elevate the 8-OHdG concentrations (1.12, 95 %CI: 0.04, 2.19) by quantile g­computation models, with Mn and Cd playing significant roles in such effect. In conclusion, while the metal levels among Hong Kong e-waste workers compared favorably with their counterparts in other regions, their levels were higher than those of local office workers. This underscores the need for policymakers to prioritize attention to this unique industry.

Study on the impact of air pollution on residents' health expenditures in Guangdong, Hong Kong, and Macao Greater Bay Area.

The Guangdong, Hong Kong, and Macao Greater Bay Area (GHMA) has experienced economic development and rapid growth of transportation infrastructure in recent years. However, the economic advancement is also accompanied by serious atmospheric pollution, which threatens the health of the residents, thus, it is of great significance to explore the impact of atmospheric pollution on the health expenditures of residents in the GHMA. The article establishes a spatial econometric model to study the impact of atmospheric pollution on residents' health expenditure in the GHMA based on panel data from 2014 to 2021, using nine prefectures in the GHMA as research objects. The results show that: (1) Atmospheric pollution in the GHMA has an obvious spatial agglomeration phenomenon and spatial spillover effect, and the impact of atmospheric pollution on the health of the residents is still very serious; (2) PM2.5 emissions are positively and significantly related to the actual health care cost per person, and the rise in air pollution is the main reason for the rise in public health spending; (3) Other factors also have different impacts on residents' health expenditures. Based on the above research, the article puts forward corresponding policy recommendations.

Dynamics of childhood obesity in Hong Kong throughout the COVID-19 pandemic before and after the school closures: a 3-year longitudinal study.

OBJECTIVE: This study is to evaluate if there is any difference in the balance between incidence of and remission from overweight/obesity in Hong Kong school-age children before and during the COVID-19 pandemic over three years. METHODS: This is a retrospective longitudinal study that involved children aged 6-16 years from a database of the School Physical Fitness Award Scheme. RESULTS: 2765 students were longitudinally followed up for two years. The prevalence of childhood overweight/obesity was increased between the 2019 and 2021 academic years (P < 0.001). During the COVID-19 pandemic, the rate of obesity remission significantly reduced by 7.9 % (P = 0.003), at a background of a plateau of obesity among children and adolescents. CONCLUSIONS: Our study provides evidence on the impact of school closure and home confinement as a standard infection control measure for the prevention of COVID-19, which are likely to break the balance between incidence of and remission from childhood obesity.

Impact of COVID-19 pandemic on specialty training in obstetrics and gynaecology in Hong Kong: is there a concern about the future prospect?

INTRODUCTION: The COVID-19 pandemic in the past few years led to major adjustments in the provision of healthcare. This study aimed to investigate trainees' perception of impact of the pandemic on specialty training in Obstetrics & Gynaecology (O&G) in Hong Kong. METHODS: A cross-sectional questionnaire survey was performed on all the O&G trainees and the young fellows of the Hong Kong College of Obstetricians and Gynaecologists (HKCOG). The questionnaires included 5 parts: demographic data, impact on clinical activities, redeployment, educational activities and career progression. RESULTS: A total of 104 questionnaires (92.9%) were received for final analysis. The majority of the participants had reductions in elective and emergency operations, as well as exposure to in-patient admissions and out-patient clinics in both obstetrics and gynaecology. The reduction was most significant in elective gynaecology operations. One-third (34.6%) of the participants had been redeployed to other departments, and educational activities were reduced during the pandemic. Around 58% of the trainees were concerned with the reduction in clinical exposure, and 78% worried they would not be able to log sufficient number of surgical procedures. Basic trainees were significantly more worried than higher trainees. Around half of the trainees had doubts or regrets about choosing to undergo O&G specialty training. CONCLUSION: The O&G trainees in Hong Kong perceived that the COVID-19 pandemic had significant negative impacts on their training. Many trainees were worried they would not be able to attain the required level of competence when they complete their specialist training.

Characteristics of Gambling Helpline Callers in Macao: A Regional Comparison.

Despite the continued focus on profiling gambling helpline callers, little is known about the characteristics of callers in Macao. To address this gap, this study aims to investigate the characteristics of problem gamblers calling the helpline in Macao and explore the regional differences between callers from Macao, mainland China, and Hong Kong. Specifically, the study examined their demographics, helpline usage, and gambling-related characteristics. The study used data collected by SKHSSCO between 2015 and 2021. The results showed that, at the aggregate level, the helpline callers in Macao were male, young, and full-time employees. The majority used the telephone and reported problems with casino table games. In addition, the referral rate was relatively low, while the rate of suicidal ideation was comparatively high. The results also revealed that callers from Macao, mainland China, and Hong Kong were notably distinct in these characteristics. The findings shed light on how to increase helpline accessibility and create tailored interventions and prevention efforts to better support individuals affected by problem gambling.

Impact of a novel pre-hospital stroke notification programme on acute stroke care key performance indicators in Hong Kong: a multicentre prospective cohort study with historical controls.

INTRODUCTION: Early identification and initiation of reperfusion therapy is essential for suspected acute ischaemic stroke. A pre-hospital stroke notification (PSN) protocol using FASE (facial drooping, arm weakness, speech difficulties, and eye palsy) was implemented to improve key performance indicators (KPIs) in acute stroke care delivery. We assessed KPIs and clinical outcomes before and after PSN implementation in Hong Kong. METHODS: This prospective cohort study with historical controls was conducted in the Accident and Emergency Departments of four public hospitals in Hong Kong. Patients were screened using the PSN protocol between August 2021 and February 2022. Suspected stroke patients between August 2020 and February 2021 were included as historical controls. Door-to-needle (DTN) and door-to-computed tomography (DTC) times before and after PSN implementation were compared. Clinical outcomes including National Institutes of Health Stroke Scale score at 24 hours and modified Rankin Scale score at 3 months after intravenous recombinant tissue-type plasminogen activator (IV-rtPA) were also assessed. RESULTS: Among the 715 patients (266 PSN and 449 non-PSN) included, 50.8% of PSN patients and 37.7% of non-PSN patients had a DTC time within 25 minutes (P<0.001). For the 58 PSN and 134 non-PSN patients given IV-rtPA, median DTN times were 67 and 75.5 minutes, respectively (P=0.007). The percentage of patients with a DTN time within 60 minutes was higher in the PSN group than in the non-PSN group (37.9% vs 21.6%; P=0.019). No statistically significant differences in clinical outcomes were observed. CONCLUSION: Although the PSN protocol shortened DTC and DTN times, clinical outcomes did not significantly differ.

The Omicron variant of COVID-19 and its association with croup in children: a single-centre study in Hong Kong.

INTRODUCTION: The fifth wave of the coronavirus disease 2019 (COVID-19) pandemic in Hong Kong was dominated by the Omicron variant, which may cause more upper airway involvement in children. This study was performed to identify any associations between the Omicron variant of COVID-19 and croup in children. METHODS: This retrospective study reviewed the electronic medical records of patients admitted to Tuen Mun Hospital in Hong Kong from 1 January 2018 to 31 March 2022 under the diagnostic code for croup (J05.0 in the International Classification of Diseases 10th Edition). Patients were categorised into three groups according to their admission periods, namely, non-COVID-19, COVID-19-pre-Omicron, and COVID-19-Omicron groups. Disease associations and severity were compared according to incidence, Westley Croup Score, length of hospital stay, medication use, respiratory support, and intensive care unit admissions. RESULTS: The COVID-19 incidence among patients with croup was significantly higher in the COVID-19-Omicron group than in the COVID-19-pre-Omicron group (90.0% vs 2.0%; P<0.001). Compared with patients in the COVID-19-pre-Omicron and non-COVID-19 groups, patients in the COVID-19-Omicron group also had a higher Westley score (moderate and severe disease in the COVID-19-Omicron group: 56.7%; COVID-19-pre-Omicron group: 22.0%, P=0.004; non-COVID-19 group: 24.8%, P<0.001), longer median hospital stay (COVID-19-Omicron group: 3.00 days; COVID-19-pre-Omicron group: 2.00 days, P<0.001; non-COVID-19 group: 2.00 days, P=0.034), and higher mean dexamethasone requirement (COVID-19-Omicron group: 0.78 mg/kg; COVID-19-pre-Omicron group: 0.49 mg/kg, P<0.001; non-COVID-19 group: 0.58 mg/kg, P=0.001). CONCLUSION: The Omicron variant of COVID-19 is associated with croup and can cause more severe disease in Hong Kong children.