Project description:We report the nearly complete genome of a norovirus GII.4 Hong Kong[P31] variant (GII strain Hu/HK/2019/GII.4 Hong Kong[P31]/CUHK-NS-2200) that was detected in a patient with gastroenteritis in August 2019. The genome was sequenced by metagenomic next-generation sequencing and was found to have 92.8% nucleotide similarity to the closest GII.4 norovirus sequence in GenBank.
Project description:BACKGROUND: The underlying basis for the seasonality of influenza A viruses is still uncertain. Phylogenetic studies investigated this phenomenon but have lacked sequences from more subtropical and tropical regions, particularly from Southeast Asia. METHODOLOGY/PRINCIPAL FINDINGS: 281 complete hemagglutinin (HA) and neuraminidase (NA) sequences were obtained from influenza A(H3N2) viruses, collected over 10 years (1997-2006) from Hong Kong. These dated sequences were analyzed with influenza A(H3N2) vaccine strain sequences (Syd/5/97, Mos/10/99, Fuj/411/02, Cal/7/04) and 315 other publicly available dated sequences from elsewhere, worldwide. In addition, the NA sequence alignment was inspected for the presence of any naturally occurring, known, neuraminidase inhibitor (NAI) resistance-associated amino acid mutations (R292K and E119V). Before 2001, the Hong Kong HA and NA sequences clustered more closely with the older vaccine sequences (Syd/5/97, Mos/10/99) than did sequences from elsewhere. After 2001, this trend reversed with significant clusters containing HA and NA sequences from different locations, isolated at different times, suggesting that viral migration may account for much of the influenza A(H3N2) seasonality during this 10-year period. However, at least one example from Hong Kong was found suggesting that in some years, influenza A(H3N2) viruses may persist in the same location, perhaps continuing to circulate, sub-clinically, at low levels between seasons, to re-emerge in the influenza season the following year, relatively unchanged. None of these Hong Kong influenza A(H3N2) NA sequences contained any of the known NAI-resistance associated mutations. CONCLUSIONS/SIGNIFICANCE: The seasonality of influenza A(H3N2) may be largely due to global migration, with similar viruses appearing in different countries at different times. However, occasionally, some viruses may remain within a single location and continue to circulate within that population, to re-emerge during the next influenza season, with relatively little genetic change. Naturally occurring NAI resistance mutations were absent or, at least, very rare in this population.
Project description:We have recently described the discovery of a novel coronavirus, coronavirus HKU1 (CoV-HKU1), associated with community-acquired pneumonia. However, the clinical spectrum of disease and the epidemiology of CoV-HKU1 infections in relation to infections with other respiratory viruses are unknown. In this 12-month prospective study, 4,181 nasopharyngeal aspirates from patients with acute respiratory tract infections were subjected to reverse transcription-PCRs specific for CoV-HKU1 and human coronaviruses NL63 (HCoV-NL63), OC43 (HCoV-OC43), and 229E (HCoV-229E). Coronaviruses were detected in 87 (2.1%) patients, with 13 (0.3%) positive for CoV-HKU1, 17 (0.4%) positive for HCoV-NL63, 53 (1.3%) positive for HCoV-OC43, and 4 (0.1%) positive for HCoV-229E. Of the 13 patients with CoV-HKU1 infections, 11 were children and 8 had underlying diseases. Similar to the case for other coronaviruses, upper respiratory infection was the most common presentation of CoV-HKU1 infections, although pneumonia, acute bronchiolitis, and asthmatic exacerbation also occurred. Despite a shorter duration of fever (mean, 1.7 days) and no difference in maximum temperature in children with CoV-HKU1 infections compared to patients with most other respiratory virus infections, a high incidence of febrile seizures (50%) was noted, which was significantly higher than those for HCoV-OC43 (14%), adenovirus (9%), human parainfluenza virus 1 (0%), and respiratory syncytial virus (8%) infections. CoV-HKU1 and HCoV-OC43 infections peaked in winter, although cases of the former also occurred in spring to early summer. This is in contrast to HCoV-NL63 infections, which mainly occurred in early summer and autumn but were absent in winter. Two genotypes of CoV-HKU1 cocirculated during the study period. Continuous studies over a longer period are warranted to ascertain the seasonal variation and relative importance of the different coronaviruses. Similar studies in other countries are required to better determine the epidemiology and genetic diversity of CoV-HKU1.
Project description:ObjectiveTo determine the incidence and prevalence of gout in the general population and the utilisation of urate-lowering therapy (ULT) among patients with gout in Hong Kong.MethodsA total of 2,741,862 subjects who attended any outpatient clinics or accident and emergency department (with or without hospitalisation) in 2005 and did not die before 2006 were identified from the Clinical Data Analysis and Reporting System (CDARS) of the Hospital Authority in Hong Kong. All subjects were followed until the end of 2016 or death. Demographics, diagnosis of gout, serum urate levels, and ULT prescriptions were retrieved from CDARS. Gout was defined by the diagnosis codes in CDARS. The serum urate levels achieved after prescribing ULT were the means of all serum urate levels measured 6 months after prescriptions. Results were analysed by R version 3.3.3 with package 'prevalence' version 0.4.0.ResultsThe crude incidence of gout increased from 113.05/100,000 person-years (PY) in 2006 to 211.62/100,000 PY in 2016. The crude prevalence of gout increased from 1.56% in 2006 to 2.92% in 2016. Only 25.55% of patients with gout were prescribed ULT in 2016. 35.8% of patients treated with ULT were able to achieve the target serum urate level of < 6 mg/dL.ConclusionsPopulation ageing as well as other risk factors contributed to an increase in the incidence and prevalence of gout in Hong Kong. In 2016, the crude prevalence of gout in Hong Kong was comparable to that in many western countries. However, only one in four patients with gout in Hong Kong was prescribed ULT.
Project description:Japanese encephalitis virus (JEV) is a mosquitoborne virus endemic to China and Southeast Asia that causes severe encephalitis in <1% of infected persons. Transmission of JEV via blood transfusion has not been reported. We report transmission of JEV via blood donation products from an asymptomatic viremic donor to 2 immunocompromised recipients. One recipient on high-dose immunosuppressive drugs received JEV-positive packed red blood cells after a double lung transplant; severe encephalitis and a poor clinical outcome resulted. JEV RNA was detected in serum, cerebrospinal fluid, and bronchoalveolar lavage fluid specimens. The second recipient had leukemia and received platelets after undergoing chemotherapy. This patient was asymptomatic; JEV infection was confirmed in this person by IgM seroconversion. This study illustrates that, consistent with other pathogenic flaviviruses, JEV can be transmitted via blood products. Targeted donor screening and pathogen reduction technologies could be used to prevent transfusion-transmitted JEV infection in highly JEV-endemic areas.
Project description:Initial cases of coronavirus disease in Hong Kong were imported from mainland China. A dramatic increase in case numbers was seen in February 2020. Most case-patients had no recent travel history, suggesting the presence of transmission chains in the local community. We collected demographic, clinical, and epidemiologic data from 50 patients, who accounted for 53.8% of total reported case-patients as of February 28, 2020. We performed whole-genome sequencing to determine phylogenetic relationship and transmission dynamics of severe acute respiratory syndrome coronavirus 2 infections. By using phylogenetic analysis, we attributed the community outbreak to 2 lineages; 1 harbored a common mutation, Orf3a-G251V, and accounted for 88.0% of the cases in our study. The estimated time to the most recent common ancestor of local coronavirus disease outbreak was December 24, 2019, with an evolutionary rate of 3.04 × 10-3 substitutions/site/year. The reproduction number was 1.84, indicating ongoing community spread.
Project description:BackgroundHuman coronavirus NL63 (HCoV-NL63) is a recently discovered human coronavirus found to cause respiratory illness in children and adults that is distinct from the severe acute respiratory syndrome (SARS) coronavirus and human coronaviruses 229E (HCoV-229E) and OC43 (HCoV-OC43).MethodsWe investigated the role that HCoV-NL63, HCoV-OC43, and HCoV-229E played in children hospitalized with fever and acute respiratory symptoms in Hong Kong during the period from August 2001 through August 2002.ResultsCoronavirus infections were detected in 26 (4.4%) of 587 children studied; 15 (2.6%) were positive for HCoV-NL63, 9 (1.5%) were positive for HCoV-OC43, and 2 (0.3%) were positive for HCoV-229E. In addition to causing upper respiratory disease, we found that HCoV-NL63 can present as croup, asthma exacerbation, febrile seizures, and high fever. The mean age (+/- standard deviation [SD]) of the infected children was 30.7 +/- 19.8 months (range, 6-57 months). The mean maximum temperature (+/- SD) for the 12 children who were febrile was 39.3 degrees C +/- 0.9 degrees C, and the mean total duration of fever (+/- SD) for all children was 2.6 +/- 1.2 days (range, 1-5 days). HCoV-NL63 infections were noted in the spring and summer months of 2002, whereas HCoV-OC43 infection mainly occurred in the fall and winter months of 2001. HCoV-NL63 viruses appeared to cluster into 2 evolutionary lineages, and viruses from both lineages cocirculated in the same season.ConclusionsHCoV-NL63 is a significant pathogen that contributes to the hospitalization of children, and it was estimated to have caused 224 hospital admissions per 100,000 population aged < or = 6 years each year in Hong Kong.
Project description:Dirofilariasis is globally the commonest manifestation of zoonotic filariasis. We report the detection of a novel canine species causing human and canine dirofilariasis in Hong Kong. Three human cases occurring over 10 months were identified, one presenting with cervical lymphadenopathy, one with an abdominal subcutaneous mass, and one with a subconjunctival nodule. Transected worms recovered from the resected abdominal subcutaneous mass were morphologically compatible with Dirofilaria. The cox1 gene sequences of the three human isolates were identical; however, they were only 96.2% and 89.3% identical to the cox1 gene of Dirofilaria repens and Dirofilaria immitis, respectively. Sequencing of the 18S-ITS1-5.8S gene cluster was successful in the intact worm, and the nucleotide sequences were 94.0% and 94.9% identical to those of D. repens and D. immitis, respectively. Screening of the blood samples from 200 dogs and 100 cats showed the presence of the novel Dirofilaria species in 3% (6/200) of the dogs' but none of the cats' blood samples. Nucleotide sequences of the cox1 gene and 18S-ITS1-5.8S gene clusters of the dogs' samples were identical to those in the human samples. The sera of canines infected by this novel Dirofilaria species were negative when tested with the SNAP 4Dx D. immitis detection kit, except in the case of dogs with a mixed infection with D. immitis as detected by PCR. The results from this study suggest that this novel Dirofilaria species is a cause of filarial infection in humans and dogs in Hong Kong. We propose to name this Dirofilaria species "Candidatus Dirofilaria hongkongensis."