COVID-19 vaccine acceptance and hesitancy among ethnic minorities in Hong Kong.

Ethnic minorities account for 8% of the Hong Kong population, most are Filipino and Indonesian domestic helpers taking care of children and the elderly. To understand the COVID-19 vaccination rates and factors associated with vaccine acceptance of ethnic minorities, we performed a cross-sectional questionnaire study recruiting Hong Kong ethnic minorities aged ≥18 years between 1 July and 18 July 2021 in public areas. Demographics, knowledge about COVID-19, vaccination status, intention and reasons to receive the vaccine, and planning to be re-vaccinated were analyzed. Continuous and categorical variables were compared using unpaired t-test and Chi-square test, respectively. Potential confounders were adjusted using multiple logistic regression. 2,012 ethnic minorities participated, with a mean age of 39 years, of which 97.6% were female, 79.5% were Filipino, and 17.5% were Indonesian. 80.6% of participants were categorized as vaccine acceptance, and 69.2% were willing to be re-vaccinated. There were significantly more Filipinos than Indonesians in the vaccine acceptance group (p < .001). Subjects in the vaccine acceptance group were more likely to have higher education (p < .001), a higher COVID-19 knowledge score (p < .001), received information from the Government website (p = .003) and not from their friends or family members (p = .02), and were more confident in judging the accuracy of the information (p < .001). Logistic regression showed the mean knowledge score (ß = 3.07, p < .001) and receiving information from official Government websites (adjusted OR = 1.37, p = .03) were significant factors that positively influenced vaccine acceptance. The Hong Kong Government should improve COVID-19 vaccination acceptance among ethnic minorities through public education using official channels.

Skin prick testing a better predictor than blood testing for the diagnosis of peanut allergy in Chinese children.

BACKGROUND: Peanut allergy is common in Chinese children, yet the most predictive diagnostic cut-offs for skin prick test (SPT) and blood testing in this population are unclear. OBJECTIVES: We aimed to determine the optimal cut-off values for whole-peanut SPT, specific IgE (sIgE) and component-resolved diagnostics (CRD) for Chinese children based on outcomes of open oral food challenges (OFC) to peanut. METHODS: We recruited ethnic-Chinese patients 1-18 years old who were suspected of having peanut allergy based on a history of reactions after exposure or sensitization although peanut naïve. Considering the AUC value of 0.8, 80% power and 5% level of significance with two tails, 26 patients were needed. Sensitivities, specificities, positive and negative predictive values, and receiver operating characteristic curves (ROCs) and their area-under-curves (AUCs) for SPT, peanut sIgE, and CRD were compared. RESULTS: Thirty-one subjects participated. Only SPT reached statistical significance (AUC 0.91, p = 0.0001), but not the other tests. Seven retrospective data were added to optimize the power. SPT remained to be the best predictor, followed by Ara h 2 sIgE (AUC 0.72, p = 0.02). An SPT wheal size of 3 mm and Ara h 2 sIgE of 0.14 kU(A)/L yielded the highest Youden's index. The specificity of SPT and Ara h 2 sIgE reached 94% at 6 mm and 0.74 kU(A)/L, respectively. Comparisons of ROCs revealed that SPT was significantly better than Ara h 2 sIgE (p = 0.03) and whole-peanut sIgE (AUC 0.61, p = 0.26). CONCLUSION: In Chinese children, SPT appeared to be the best predictor for peanut allergy, followed by Ara h 2 sIgE.

Impact of COVID-19 pandemic on patients with rare disease in Hong Kong.

The COVID-19 pandemic has had significant health, social, and economic consequences internationally. While the pandemic has direct implications on infected patients and families, there is a need to examine the pandemic's effect on patients with non-COVID-19-related diseases. This study examines the impact of the COVID-19 pandemic on 272 rare disease patients with 89 distinct rare diseases in Hong Kong using a cross-sectional online survey between April 10 and April 29, 2020 from the patient and caregiver perspective. The pandemic has impacted patient's health status in 46%, service use patterns in 71%, mental health in 79%, daily living in 82%, social life in 92%, and financial status in 81% of patients. Patient's health status, medical and rehabilitation, and mental health were more impacted by the COVID-19 pandemic in the group of patients with any level of dependency according to the Barthel Index for Activities of Daily Living compared with that in the group of patients who are fully independent (p < 0.0001; p < 0.0001; p = 0.0420). This study is the first study to examine the impact of COVID-19 pandemic on the rare disease population in Hong Kong, and demonstrates the pandemic's effect on service and resource utilization, and patient's physical and mental well-being.

False-positive SARS-CoV-2 serology in 3 children with Kawasaki disease.

BACKGROUND: Kawasaki disease (KD) is an acute febrile and eruptive disease with systemic vasculitis predominantly affecting young East Asian children. Recent reports showed that children with KD-like disease from KD low prevalence regions had positive SARS-CoV-2 serology despite a negative SARS-CoV-2 polymerase chain reaction (PCR) in respiratory samples. OBJECTIVES: To describe 3 pediatric Kawasaki Disease patients with false positive SARS-CoV-2 serology. STUDY DESIGN: We retrospectively recruited children with KD diagnosed during the COVID-19 outbreak in Hong Kong. Clinical characteristics and laboratory test results including SARS-CoV-2 PCR results were retrieved. We performed a microparticle-based immunoassay for the detection of IgG against nucleoprotein (NP) and spike protein receptor binding domain (RBD), and a microneutralization assay for the detection of neutralizing antibodies. RESULTS: Three Chinese children with typical KD were identified. They had no epidemiological links with COVID-19 patients and tested negative for SARS-CoV-2 NPA PCR. They were treated with IVIG and aspirin, and were discharged without complications. Subsequently 2 of them were tested positive against anti-RBD and anti-NP antibodies and 1 was tested positive against anti- RBD antibodies. However, microneutralization assay showed that neutralizing antibodies were absent, suggesting a false-positive IgG result. CONCLUSION: Detection of neutralizing antibodies is recommended to confirm previous SARS-CoV-2 infection in IgG-positive but PCR-negative patients.

Risk factors for drug allergies in Chinese children.

BACKGROUND: Drug allergy, or drug hypersensitivity, is a potentially fatal disorder, and patients labeled with drug allergies have restricted access to first-line treatments. Full knowledge of the characteristics associated with drug allergies and severe reactions during allergy evaluation is beneficial for appropriate risk stratification. OBJECTIVE: We sought to determine whether certain clinical characteristics are associated with drug allergies in Chinese children. METHODS: Charts were reviewed for ethnic Chinese patients less than 18 years old referred to our tertiary allergy center for suspected drug allergies and completed skin and drug provocative testing between 2005 to 2017. Univariate and multivariate analyses were performed on the age of onset of drug allergies, gender, and other atopy versus drug allergies. RESULTS: Out of 75 children, 18 (24%) had IgE-mediated drug allergies, while 8 (10.7%) had delayed drug hypersensitivities, with a cumulative 26 subjects (34.7%) with any drug hypersensitivity. There were positive independent associations between drug hypersensitivities onset age vs IgE-mediated drug allergies (odds ratio (OR) = 14.9, 95% confidence intervals (CIs) = 1.5-148.3, P = 0.017) and between male gender and IgE-mediated drug allergies (OR = 4.4, CIs = 1.2-16.4, P = 0.019). Age 13 years was the best cut-off for IgE-mediated drug allergies according to the receiver operating characteristic curve (P = 0.026). Older age group (OR = 24.0, CIs = 1.4-417.8, P = 0.024) and atopic dermatitis (OR = 8.2, CIs = 1.4-49.8, P = 0.015) were correlated with delayed drug hypersensitivities. CONCLUSIONS: While several previous studies suggested a higher prevalence of IgE-mediated drug allergies in younger adult females, older boys were more likely to have drug allergies for Chinese children.

Clinical spectrum of food allergies: a comprehensive review.

Food allergy is defined as an adverse immune response towards food proteins or as a form of a food intolerance associated with a hypersensitive immune response. It should also be reproducible by a double-blind placebo-controlled food challenge. Many reported that food reactions are not allergic but are intolerances. Food allergy often presents to clinicians as a symptom complex. This review focuses on the clinical spectrum and manifestations of various forms of food allergies. According to clinical presentations and allergy testing, there are three types of food allergy: IgE mediated, mixed (IgE/Non-IgE), and non-IgE mediated (cellular, delayed type hypersensitivity). Recent advances in food allergy in early childhood have highlighted increasing recognition of a spectrum of delayed-onset non-IgE-mediated manifestation of food allergy. Common presentations of food allergy in infancy including atopic eczema, infantile colic, and gastroesophageal reflux. These clinical observations are frequently associated with food hypersensitivity and respond to dietary elimination. Non-IgE-mediated food allergy includes a wide range of diseases, from atopic dermatitis to food protein-induced enterocolitis and from eosinophilic esophagitis to celiac disease. The most common food allergies in children include milk, egg, soy, wheat, peanut, treenut, fish, and shellfish. Milk and egg allergies are usually outgrown, but peanut and treenut allergy tends to persist. The prevalence of food allergy in infancy is increasing and may affect up to 15-20 % of infants. The alarming rate of increase calls for a public health approach in the prevention and treatment of food allergy in children.

Cytokine profiles in human immunodeficiency virus-infected children treated with highly active antiretroviral therapy.

CONTEXT: There have been few longitudinal studies of cytokine production in neonatally acquired HIV-1 infection and none in Asian or Chinese children. OBJECTIVE: To determine whether monitoring cytokine production could contribute to the better management of pediatric patients with HIV-1 infection. SETTING: Clinical Immunology Laboratory and Pediatrics Department, University Hospital, Hong Kong. PATIENTS: Ten Asian and 2 Eurasian children infected with HIV-1 by mother-to-child transmission were followed for up to 5 years while on treatment with highly active antiretroviral therapy (HAART). MAIN OUTCOME MEASURES: Numbers of unstimulated and mitogen-activated cytokine-secreting cells (IFN-gamma, interleukin [IL]-2, IL-4, IL-6, IL-10, IL-12, and TNF-alpha) were measured by ELISPOT assay at frequent intervals, and correlations were sought with CD4+ and CD8+ cell counts and viral loads. RESULTS: Mitogen-stimulated IL-2-secreting cells were directly associated with recovery of CD4+ cells. Correlations with viral load were found for Con A-induced IFN-gamma, Con A-induced IL-4, and unstimulated IL-10, suggesting that these cytokines were either suppressed by high virus levels or that higher cytokine levels suppressed virus. IFN-gamma, IL-2-, IL-4-, and IL-12-secreting cells induced by PHA, Con A, and/or SAC tended to increase for the first 3-4 years of treatment but declined thereafter. CONCLUSION: Alterations in cytokine profiles were not associated with adverse clinical events and there was little evidence to indicate that monitoring cytokine enzyme-linked immunospots (ELISPOTs) could contribute to pediatric patient management.