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Background The magnitude and risk factors of progression of atherosclerosis in Asian HIV-infected individuals were unknown. This study aimed to evaluate: (1) the rate of progression of atherosclerosis in HIV-infected individuals, and (2) metabolic and inflammatory parameters that may predict atherosclerosis progression in HIV-infected individuals in an Asian cohort. Setting A prospective, longitudinal study was performed among adults attending an HIV Metabolic clinic in Hong Kong. Methods Carotid intima media thickness (cIMT) was measured at baseline and 24 months. Body composition, metabolic, and inflammatory biomarkers [including homeostasis model assessment of insulin resistance, LDL (low-density lipoprotein) cholesterol particle size, high-sensitive C reactive protein, adiponectin] associated with cIMT change were analyzed; their predictive performances were estimated using receiver operating characteristic analyses. Results Sixty-one HIV-infected individuals (mean ± SD age 49.8 ± 11.4 years, 89% men, 97% Chinese, diabetes 39%, hypertension 30%, and dyslipidemia 85%) were recruited. Annual rate of change of cIMT was +0.0075 (0.0000-0.0163) mm/yr, and 19% developed new plaque at 24 months. Two patients died during the study period, 1 because of sudden cardiac death. Using receiver operating characteristic analyses, combination of lower limb fat percentage, LDL cholesterol subclass pattern B, and lower adiponectin level, but not Framingham score, predicted greater cIMT progression in HIV-infected individuals. Conclusions Asian HIV-infected individuals had atherosclerosis progression. Limb fat percentage, LDL cholesterol particle size, and adiponectin level may identify at-risk Asian HIV-infected individuals for early intervention.

The first human H5N1 case was diagnosed in Hong Kong in 1997. Since then, experience in effective preparedness strategies that target novel influenza viruses has expanded. Here, we report on avian influenza preparedness in public hospitals in Hong Kong to illustrate policies and practices associated with control of emerging infectious diseases. The Hong Kong government's risk-based preparedness plan for influenza pandemics includes 3 response levels for command, control, and coordination frameworks for territory-wide responses. The tiered levels of alert, serious, and emergency response enable early detection based on epidemiological exposure followed by initiation of a care bundle. Information technology, laboratory preparedness, clinical and public health management, and infection control preparedness provide a comprehensive and generalizable preparedness plan for emerging infectious diseases.

We aimed to describe disease burden, characteristics, and outcomes of methicillin-resistant Staphylococcus aureus (MRSA) bloodstream infection (BSI) in Hong Kong. A retrospective, observational study was conducted in 26 Hong Kong public hospitals between January 2010 and December 2012. The primary outcome measures were 30-day mortality rate and infection-related hospital cost. Of 1133 patients reviewed, 727 (64.17%) were male, 1075 (94.88%) had health care-associated community-onset and 44 (3.88%) had hospital-onset MRSA infection. The mean age of patients was 76 (SD = 15) years, including 172 (15.18%) aged 20 to 59 years and 961 (84.8%) aged ≥60 years. The annual incidence rates in age groups of 20 to 59 years and ≥60 years were 0.96 to 1.148 per 100 000 and 22.7 to 24.8 per 100 000, respectively. The 30-day mortality was 367 (32.39%). Older patients (79 years), chronic lung disease, and prior hospitalization were associated with increased mortality. The mean cost was US$10 565 (SD = 11 649; US$1 = HK$7.8). MRSA BSI was a significant burden in Hong Kong.

Introduction − Macrolides can ameliorate inflammation in respiratory diseases, providing clinical benefits. Data in influenza is lacking. Method − A randomized, open-label, multicenter trial among adults hospitalized for laboratory-confirmed influenza was conducted. Study treatments of oseltamivir and azithromycin (500 mg/day), or oseltamivir alone, both for 5 days, were allocated at 1:1 ratio. The primary outcome was plasma cytokine/chemokine concentration change over time (Day 0–10); secondary outcomes were viral load and symptom score changes. Generalized Estimating Equation (GEE) models were used to analyze longitudinal data. Results − Fifty patients were randomized to the oseltamivir-azithromycin or oseltamivir groups, with comparable baseline characteristics (age, 57 ± 18 years; A/H3N2, 70%), complications (72%), and viral load. Pro-inflammatory cytokines IL-6 (GEE: β −0.037, 95%CI-0.067,-0.007, P = 0.016; reduction from baseline −83.4% vs −59.5%), CXCL8/IL-8 (β −0.018, 95%CI-0.037,0.000, P = 0.056; −80.5% vs −58.0%), IL-17 (β −0.064, 95%CI-0.117,-0.012, P = 0.015; −74.0% vs −34.3%), CXCL9/MIG (β −0.010, 95%CI-0.020,0.000, P = 0.043; −71.3% vs −56.0%), sTNFR-1, IL-18, and CRP declined faster in the oseltamivir-azithromycin group. There was a trend toward faster symptom resolution (β −0.463, 95%CI-1.297,0.371). Viral RNA decline (P = 0.777) and culture-negativity rates were unaffected. Additional ex vivo studies confirmed reduced induction of IL-6 (P = 0.017) and CXCL8/IL-8 (P = 0.005) with azithromycin. Conclusion − We found significant anti-inflammatory effects with adjunctive macrolide treatment in adults with severe influenza infections. Virus control was unimpaired. Clinical benefits of a macrolide-containing regimen deserve further study. [ClinicalTrials.gov NCT01779570]

Objective.To determine the prevalence, risk factors, and molecular epidemiology of methicillin-resistantStaphylococcus aureus(MRSA) colonization at the time of admission to acute medical units and to develop a cost-effective screening strategy.Methods.Nasal and groin screening cultures were performed for patients at admission to 15 acute medical units in all 7 catchment regions in Hong Kong. All MRSA isolates were subjected tospatyping.Results.The overall carriage rate of MRSA was 14.3% (95% confidence interval [CI], 13.5–15.1). MRSA history within the past 12 months (adjusted odds ratio [OR], 4.60 [95% CI, 3.28–6.44]), old age home residence (adjusted OR, 3.32 [95% CI, 2.78–3.98]), and bedbound state (adjusted OR, 2.19 [95% CI, 1.75–2.74]) were risk factors selected as MRSA screening criteria that provided reasonable sensitivity (67.4%) and specificity (81.8%), with an affordable burden (25.2%).spatyping showed that 89.5% (848/948) of the isolates were clustered into the 4spaclonal complexes (CCs):spaCC1081,spaCC032,spaCC002, andspaCC4677. Patients colonized with MRSAspatypes t1081 (OR, 1.77 [95% CI, 1.49–2.09]) and t4677 (OR, 3.09 [95% CI, 1.54–6.02]) were more likely to be old age home residents.Conclusions.MRSA carriage at admission to acute medical units was prevalent in Hong Kong. Our results suggest that targeted screening is a pragmatic approach to increase the detection of the MRSA reservoir. Molecular typing suggests that old age homes are epicenters in amplifying the MRSA burden in acute hospitals. Enhancement of infection control measures in old age homes is important for the control of MRSA in hospitals.

Background. Better understanding of complications and outcomes of adults hospitalized with respiratory syn-cytial virus (RSV) infection is necessary.Methods. A retrospective cohort study was conducted on all adults (≥18 years) admitted to 3 acute care generalhospitals in Hong Kong with virologically confirmed RSV infection during 2009–2011 (N=607). Adults hospital-ized forseasonal influenza during the period wereused forcomparison (n=547). Both infections were prospectivelydiagnosed following a standard protocol. Independent reviews of chest radiographs were performed by radiologists.Main outcome measures were all-cause death, respiratory failure requiring ventilatory support, and hospitalizationduration. Cox proportional hazards models were used foranalyses.Results. Themeanage ofRSV patients was75 (SD,16) years; 87% hadunderlyingconditions. Lower respiratoryand cardiovascularcomplications were diagnosed in 71.9% (pneumonia, 42.3%; acute bronchitis, 21.9%; chronic ob-structive pulmonary disease/asthma exacerbation, 27.3%) and 14.3% of patients, respectively; 12.5% had bacterialsuperinfections. Supplemental oxygen and ventilatory support were required in 67.9% and 11.1%, respectively.Crude all-cause mortality was 9.1% and 11.9% within 30days and 60 days, respectively; mean length ofstayof survi-vors was 12 (SD, 13) days. Advanced age, radiographic pneumonia, requirement for ventilation, bacterial superin-fection, and elevated urea level and white blood cell count were independently associated with poorer survival.Systemic corticosteroid use was associated with longer hospitalization and secondary infections. The overall out-comes of survival and length of stay were not significantly different from those in influenza.Conclusions. RSV can cause severe lower respiratory complications in older adults, resulting in respiratoryfailure, prolonged hospitalization, and high mortality similar to seasonal influenza. Corticosteroids did not seem toimprove outcomes. The unmet need forantiviral therapy and vaccination against RSV in adults should be promptlyaddressed.Keywords. RSV; hospitalization; respiratory failure; lower respiratory tract infection; adults.Respiratory syncytial virus (RSV) is known to be animportant cause of lower respiratory tract infection ininfants and young children, leading to hospitalizationsand deaths [1]. Its impact in adults, however, has onlybeen appreciated in recent years. It has been estimatedthat RSV infects 3%–10% of adults annually; althoughmost infections are mild, increasing evidence suggeststhat severe lower respiratory tract infections can occur,especially among older adults and those with underlyingconditions [2–4].RSV may have accounted for 5%–15%of community-acquired pneumonia, 9%–10% of hospi-tal admissions for acute cardiorespiratory diseases, andexcessive deaths duringseasonalpeaks [3,4].Thedisease

Background Beginning from late 2011 and early 2012, increasing circulation of antigenically drifted influenza A/Victoria/361/2011-like H3N2 viruses within genotype 3 of the A/Victoria/208/2009 clade have been reported in multiple European countries and elsewhere. Whether these emerging viruses are associated with increased disease severity is unclear. Objectives To report the clinical and virological findings of a moderately severe hospital outbreak of A/Victoria/361/2011-like viruses that occurred in November 2011 in Hong Kong. Study design Clinical and virological hospital outbreak investigation. Results The outbreak occurred in an adult psychiatric ward in November 2011, a time well before the usual local seasonal influenza winter peak. Altogether, 7 patients and 1 healthcare-worker were affected (mean age, 47 [range, 34–61] years). The attack rates among patients and healthcare-workers were 33% (7/21) and 7% (1/15), respectively. Pneumonia developed in 38% (3/8) of cases; none had underlying immunocompromised conditions. High nasopharyngeal viral loads were detected. All cases responded to antiviral treatment. Multiple amino acid mutations with reference to earlier A(H3N2) vaccine strains were mapped to key antigenic sites on hemagglutinin; however, no critical mutations on receptor binding sites were detected. Viral sequence variations jeopardized the performance of molecular diagnostic assays. Conclusions Severe disease and pneumonia occurred in a substantial proportion of non-immunocompromised adults in a hospital outbreak attributed to the emerging antigenically drifted A/Victoria/361/2011-like H3N2 viruses. Close monitoring of the transmission of this drift variant is required. Further studies are also necessary to determine virus virulence.

We evaluated the acceptability of an additional ad hoc influenza vaccination among the health care professionals following seasons with significant antigenic drift. Self-administered, anonymous surveys were performed by hard copy questionnaires in public hospitals, and by an on-line platform available to all healthcare professionals, from April 1st to May 31st, 2015. A total of 1290 healthcare professionals completed the questionnaires, including doctors, nurses, and allied health professionals working in both the public and private systems. Only 31.8% of participating respondents expressed an intention to receive the additional vaccine, despite that the majority of them agreed or strongly agreed that it would bring benefit to the community (88.9%), save lives (86.7%), reduce medical expenses (76.3%), satisfy public expectation (82.8%), and increase awareness of vaccination (86.1%). However, a significant proportion expressed concern that the vaccine could disturb the normal immunization schedule (45.5%); felt uncertain what to do in the next vaccination round (66.0%); perceived that the summer peak might not occur (48.2%); and believed that the summer peak might not be of the same virus (83.5%). Furthermore, 27.8% of all respondents expected that the additional vaccination could weaken the efficacy of previous vaccinations; 51.3% was concerned about side effects; and 61.3% estimated that there would be a low uptake rate. If the supply of vaccine was limited, higher priority groups were considered to include the elderly aged ≥65 years with chronic medical conditions (89.2%), the elderly living in residential care homes (87.4%), and long-stay residents of institutions for the disabled (80.7%). The strongest factors associated with accepting the additional vaccine included immunization with influenza vaccines in the past 3 years, higher perceived risk of contracting influenza, and higher perceived severity of the disease impact. The acceptability to an additional ad hoc influenza vaccination was low among healthcare professionals. This could have a negative impact on such additional vaccination campaigns since healthcare professionals are a key driver for vaccine acceptance. The discordance in perceived risk and acceptance of vaccination regarding self versus public deserves further evaluation.

Background We aimed to study the pathogenic roles of High-Mobility Group Box 1 (HMGB1) / Receptor-for-Advanced-Glycation-End-products (RAGE) signaling and pro-inflammatory cytokines in patients with active pulmonary tuberculosis (PTB). Methods A prospective study was conducted among non-HIV adults newly-diagnosed with active PTB at two acute-care hospitals (n = 80); age-and-sex matched asymptomatic individuals (tested for latent TB) were used for comparison (n = 45). Plasma concentrations of 8 cytokines/chemokines, HMGB1, soluble-RAGE, and transmembrane-RAGE expressed on monocytes/dendritic cells, were measured. Gene expression (mRNA) of HMGB1, RAGE, and inflammasome-NALP3 was quantified. Patients’ PBMCs were stimulated with recombinant-HMGB1 and MTB-antigen (lipoarabinomannan) for cytokine induction ex vivo. Results In active PTB, plasma IL-8/CXCL8 [median(IQR), 6.0(3.6–15.1) vs 3.6(3.6–3.6) pg/ml, P

In an observational cohort study, we found that adults hospitalized for oseltamivir-resistant (H275Y) seasonal H1N1 influenza (n = 46) were older than those infected with oseltamivir-susceptible strains (n = 31) [74(IQR 59–83) versus 64(IQR 48–76) years; P = 0·045], and most had major comorbidities (78% versus 65%). Disease severity and clinical outcomes were comparable between the two groups: radiographic pneumonia 40–42%, supplemental oxygen use 47–48%, critical illness 11–13%, median duration of hospitalization 5–6 days, death rate 6–9%. Failure to receive effective antiviral therapy was associated with progression to critical illness (23% versus 0%, P = 0·016) and death (20% versus 0%, P = 0·033) in hospitalized patients with seasonal H1N1 influenza.

It is unclear whether pandemic 2009 influenza A (pH1N1) infection caused more significant disease among hospitalized adults than seasonal influenza.A prospective, observational study was conducted in adults hospitalized with polymerase chain reaction-confirmed pH1N1 infection in 2 acute-care general hospitals from June 2009 to May 2010 (n = 382). Complications and outcomes were described and compared with those in a seasonal influenza cohort (2007-2008, same hospitals; n = 754).Hospitalized patients with pH1N1 influenza were younger than those with seasonal influenza (mean age ± standard deviation, 47 ± 20 vs 70 ± 19 years) and fewer had comorbid conditions (48% vs 64%). The rate of positive immunofluorescence assay results was low (54% vs 84%), and antiviral use was frequent (96% vs 52%). Most patients in both cohorts developed complicated illnesses (67.8% vs 77.1%), but patients with pH1N1 influenza had higher rates of extrapulmonary complications (23% vs 16%; P = .004) and intensive care unit admission and/or death (patient age35 years, 2.3% vs 0%; 35-65 years, 12.4% vs 3.2%;65 years, 13.5% vs 8.5%; adjusted odds ratio [OR] 2.13; 95% confidence interval [CI], 1.25-3.62; P = .005). Patients who received antiviral treatment within 96 h after onset had better survival (log-rank test, P.001). However, without timely treatment, the mortality risk was higher with pH1N1 infection (9.0% vs 5.8% for seasonal influenza; adjusted OR, 6.85; 95% CI, 1.64-28.65; P = .008]. Bacterial superinfection worsened outcomes.Adults hospitalized for pH1N1 influenza had significant complications and mortality despite being younger than patients with seasonal influenza. Antiviral treatment within 96 h may improve survival.

BACKGROUND: We examined the role of aerosol transmission of influenza in an acute ward setting. METHODS: We investigated a seasonal influenza A outbreak that occurred in our general medical ward (with open bay ward layout) in 2008. Clinical and epidemiological information was collected in real time during the outbreak. Spatiotemporal analysis was performed to estimate the infection risk among patients. Airflow measurements were conducted, and concentrations of hypothetical virus-laden aerosols at different ward locations were estimated using computational fluid dynamics modeling. RESULTS: Nine inpatients were infected with an identical strain of influenza A/H3N2 virus. With reference to the index patient's location, the attack rate was 20.0% and 22.2% in the "same" and "adjacent" bays, respectively, but 0% in the "distant" bay (P = .04). Temporally, the risk of being infected was highest on the day when noninvasive ventilation was used in the index patient; multivariate logistic regression revealed an odds ratio of 14.9 (95% confidence interval, 1.7-131.3; P = .015). A simultaneous, directional indoor airflow blown from the "same" bay toward the "adjacent" bay was found; it was inadvertently created by an unopposed air jet from a separate air purifier placed next to the index patient's bed. Computational fluid dynamics modeling revealed that the dispersal pattern of aerosols originated from the index patient coincided with the bed locations of affected patients. CONCLUSIONS: Our findings suggest a possible role of aerosol transmission of influenza in an acute ward setting. Source and engineering controls, such as avoiding aerosol generation and improving ventilation design, may warrant consideration to prevent nosocomial outbreaks.

Background Influenza virus infections are causing substantial morbidity and mortality, despite availability of antiviral treatments. Macrolides have been shown to ameliorate inflammation in respiratory diseases and provide clinical benefits. Data in influenza, however, are scarce. We aimed to assess the anti-inflammatory effects of macrolide treatment in patients with influenza, and its effects on viral clearance and symptom resolution. Methods In this open-label, multicentre, randomised controlled trial, we recruited adults admitted to hospital for laboratory-confirmed influenza in Hong Kong. Key inclusion criteria were age 18 years or older, influenza A and B virus infections confirmed by PCR or immunofluorescence assays, and presentation within 4 days from illness onset. Patients were randomly assigned (1:1) using a computer-generated sequence to oseltamivir (75 mg twice daily) plus azithromycin (500 mg per day) or oseltamivir (75mg twice daily) alone, both given orally for 5 days. The primary outcome was change in plasma cytokine and chemokine concentration over time (day 0–10), analysed by intention to treat. Generalised estimating equation (GEE) models were used to analyse longitudinal data, and were adjusted for potential confounders. Ethics approvals were obtained from the institutional review bodies of all participating institutes. All patients provided written informed consent. This trial is registered with ClinicalTrials.gov, number NCT01779570. Findings During the influenza seasons beginning from 2013–14 through to 2015–16, 50 patients were randomly assigned to the oseltamivir-azithromycin (n=25) or oseltamivir (n=25) groups, with similar baseline characteristics (mean age 54·7 years [SD 18·5] in the oseltamivir-azithromycin group vs 58·6 years [18·1] in the oseltamivir group; 16 [64%] of 25 patients in the oseltamivir-azithromycin group were men vs 15 [60%] of 25 in the oseltamivir group). Three key pro-inflammatory cytokines declined faster in the oseltamivir-azithromycin group than in the oseltamivir group: interleukin (IL)-6 (GEE β=–0·037 [95% CI −0·067 to −0·007], p=0·016; change from baseline −83·4% vs −59·5%), IL-17 (β=–0·064 [–0·117 to −0·012], p=0·015; −74·0% vs −34·3%), and CXCL9 (β=–0·010 [–0·020 to 0·000], p=0·043; −71·3% vs −56·0%). Non-significant differences in the following cytokines were observed between treatment groups: CXCL8 (β=–0·018 [–0·037 to 0·000], p=0·056; −80·5% vs −58·0%), sTNFR-1 (β=–0·003 [–0·006 to 0·000], p=0·084; −40·1% vs −24·8%), IL-18 (β=–0·006 [–0·015 to 0·003], p=0·197; −29·1% vs 30·2%), and C-reactive protein (β=–0·033 [–0·088 to 0·022], p>0·10; −77·5% vs −48·2%). Two serious adverse events (SAEs) occurred in the oseltamivir-azithromycin group (Pseudomonas aeruginosa pneumonia, post-influenza vestibular neuronitis onset after stopping treatment for 1 week) versus one SAE in the oseltamivir group (increased ascites; p>0·99); all SAEs were considered unrelated to treatment. Other common adverse events were gastrointestinal or hepatic symptoms (five [20%] of 25 in the oseltamivir-azithromycin group vs four [16%] of 25 in the oseltamivir group; p>0.99) and dizziness or hearing symptoms (two [8%] vs two [8%]; p>0·99). All events were transient and reversible, and no participants died in this study. Interpretation We found significant anti-inflammatory effects with adjunctive macrolide treatment in adults with severe influenza infection. The clinical benefits of a macrolide-containing regimen deserve further study. Funding Research Grant Council of the Government of the Hong Kong Special Administrative Region, China (468112).

BackgroundThe goal of this study was to characterize viral loads and factors affecting viral clearance in persons with severe influenza MethodsThis was a 1-year prospective, observational study involving consecutive adults hospitalized with influenza. Nasal and throat swabs were collected at presentation, then daily until 1 week after symptom onset. Real-time reverse-transcriptase polymerase chain reaction to determine viral RNA concentration and virus isolation were performed. Viral RNA concentration was analyzed using multiple linear or logistic regressions or mixed-effect models ResultsOne hundred forty-seven inpatients with influenza A (H3N2) infection were studied (mean age ± standard deviation, 72±16 years). Viral RNA concentration at presentation positively correlated with symptom scores and was significantly higher than that among time-matched outpatients (control subjects). Patients with major comorbidities had high viral RNA concentration even when presenting >2 days after symptom onset (mean ± standard deviation, 5.06±1.85 vs 3.62±2.13 log10 copies/mL; P=.005; β, +0.86 [95% confidence interval, +0.03 to +1.68]). Viral RNA concentration demonstrated a nonlinear decrease with time; 26% of oseltamivir-treated and 57% of untreated patients had RNA detected at 1 week after symptom onset. Oseltamivir started on or before symptom day 4 was independently associated with an accelerated decrease in viral RNA concentration (mean β [standard error], −1.19 [0.43] and −0.68 [0.33] log10 copies/mL for patients treated on day 1 and days 2–3, respectively; P

Purpose To determine whether the initial chest radiograph is helpful in predicting the clinical outcome of patients with severe acute respiratory syndrome (SARS). Methods Of 343 patients who met the World Health Organization's case definition of probable SARS and who had been admitted to a regional hospital in Hong Kong, 201 patients had laboratory evidence of SARS coronavirus infection. The initial frontal chest radiographs of these 201 patients were assessed in a blinded fashion by 3 radiologists; individual findings were accepted if at least 2 of the radiologists concurred. Independent predictors of an adverse outcome, defined as the need for assisted ventilation, death, or both, were identified by multivariate analysis. Results Bilateral disease and involvement of more than two zones on the initial chest radiograph were associated with a higher risk of liver impairment and poor clinical outcome. Forty-two patients (21%) developed an adverse outcome. Multivariate analysis showed that lung involvement of more than two zones (odds ratio [OR] = 7.0; 95% confidence interval [CI]: 2.7 to 17.9), older age (OR for each decade of life=1.5; 95% CI: 1.1 to 2.0), and shortness of breath on admission (OR = 2.8; 95% CI: 1.1 to 7.4) were independent predictors of an adverse outcome. Conclusion Frontal chest radiographs on presentation may have prognostic value in patients with SARS.

Liver impairment is commonly reported in up to 60% of patients who suffer from severe acute respiratory syndrome (SARS). Here we report the clinical course and liver pathology in three SARS patients with liver impairment. Three patients who fulfilled the World Health Organization case definition of probable SARS and developed marked elevation of alanine aminotransferase were included. Percutaneous liver biopsies were performed. Liver specimens were examined by light and electron microscopy, and immunohistochemistry. Reverse‐transcriptase polymerase chain reaction (RT‐PCR) using enhanced real‐time PCR was applied to look for evidence of SARS‐associated coronavirus infection. Marked accumulation of cells in mitosis was observed in two patients and apoptosis was observed in all three patients. Other common pathologic features included ballooning of hepatocytes and mild to moderate lobular lymphocytic infiltration. No eosinophilic infiltration, granuloma, cholestasis, fibrosis, or fibrin deposition was noted. Immunohistochemical studies revealed 0.5% to 11.4% of nuclei were positive for proliferative antigen Ki‐67. RT‐PCR showed evidence of SARS‐associated coronavirus in the liver tissues, but not in the sera of all 3 patients. However, electron microscopy could not identify viral particles. No giant mitochondria, micro‐ or macro‐vesicular steatosis was observed. In conclusion, hepatic impairment in patients with SARS is due to SARS‐associated coronavirus infection of the liver. The prominence of mitotic activity of hepatocytes is unique and may be due to a hyperproliferative state with or without disruption of cell cycle by the coronavirus. With better knowledge of pathogenesis, specific therapy may be targeted to reduce viral replication and modify the disease course. (Hepatology 2004;39:302–310.)

Severe acute respiratory syndrome (SARS) has caused a major epidemic worldwide. A novel coronavirus is deemed to be the causative agent. Early diagnosis can be made with reverse transcriptase-polymerase chain reaction (RT-PCR) of nasopharyngeal aspirate samples. We compared symptoms of 156 SARS-positive and 62 SARS-negative patients in Hong Kong; SARS was confirmed by RT-PCR. The RT-PCR–positive patients had significantly more shortness of breath, a lower lymphocyte count, and a lower lactate dehydrogenase level; they were also more likely to have bilateral and multifocal chest radiograph involvement, to be admitted to intensive care, to need mechanical ventilation, and to have higher mortality rates. By multivariate analysis, positive RT-PCR on nasopharyngeal aspirate samples was an independent predictor of death within 30 days.

SummaryThe seasonality of influenza infections can be affected by virus subtypes, climate, and social networking in populations. While these factors are well known, their relative influences in specific age groups have not been fully investigated. During 2010–2011, patients aged 65 years and above with influenza virus infections were recruited from a regional hospital in Hong Kong. They were either residents of homes for the elderly (n=60) or living with their family (n=75). Two seasons were distinguished, the summer season of 2010 dominated by H3N2 and the winter season of 2011 dominated by H1N1. The patients’ clinical presentations and patterns of inter-personal connectivity were assessed. Overall, more elderly people living with their family were diagnosed with H1N1 compared to those in the homes for the elderly, and the former had visited a more diverse range of places 1 week prior to diagnosis. A higher proportion of patients living with family presented with lower respiratory tract symptoms, but these patients were less likely to have pre-existing chronic diseases. The results suggest that elderly patients infected during an influenza season could vary by virus subtype, which in turn is dependent on exposure locations and the pattern of social connectivity.

Fecal viral concentrations of 40 patients infected with norovirus genogroup GII.4 correlated with diarrhea duration and frequency of vomiting. Higher viral concentration and older age were independently associated with prolonged diarrhea (> or =4 days). These findings provide information on the pathogenesis and transmission of norovirus infections.

Background Studying cytokine/chemokine responses in severe influenza infections caused by different virus subtypes may improve understanding on pathogenesis. Methods Adults hospitalized for laboratory-confirmed seasonal and pandemic 2009 A/H1N1 (pH1N1) influenza were studied. Plasma concentrations of 13 cytokines/chemokines were measured at presentation and then serially, using cytometric-bead-array with flow-cytometry and ELISA. PBMCs from influenza patients were studied for cytokine/chemokine expression using ex-vivo culture (Whole Blood Assay,±PHA/LPS stimulation). Clinical variables were prospectively recorded and analyzed. Results 63 pH1N1 and 53 seasonal influenza patients were studied. pH1N1 patients were younger (mean±S.D. 42.8±19.2 vs 70.5±16.7 years), and fewer had comorbidities. Respiratory/cardiovascular complications were common in both groups (71.4% vs 81.1%), although severe pneumonia with hypoxemia (54.0% vs 28.3%) and ICU admissions (25.4% vs 1.9%) were more frequent with pH1N1. Hyperactivation of the proinflammatory cytokines IL-6, CXCL8/IL-8, CCL2/MCP-1 and sTNFR-1 was found in pH1N1 pneumonia (2–15 times normal) and in complicated seasonal influenza, but not in milder pH1N1 infections. The adaptive-immunity (Th1/Th17)-related CXCL10/IP-10, CXCL9/MIG and IL-17A however, were markedly suppressed in severe pH1N1 pneumonia (2–27 times lower than seasonal influenza; P−values

Background Little is known about the virological and inflammatory responses of severe pandemic 2009 influenza A(H1N1) virus pneumonia during antiviral treatment. Methods In a prospective observational study, we recruited consecutive adults hospitalized with confirmed pandemic 2009 H1N1 infection during a 16-week period. Nasopharyngeal aspirate and non-respiratory samples (blood, stool and urine) were collected at presentation, and serial nasopharyngeal flocked swabs (NPFS) and tracheal aspirates (TA) were collected after initiating oseltamivir treatment for quantitative viral RNA assay, using real-time reverse transcriptase-PCR. Serial plasma samples were collected for cytokine/chemokine assay using cytometric bead array. Patients with severe pneumonia (lung infiltrates and hypoxaemia) were compared to those with milder illnesses. Results A total of 66 patients were studied (mean age 43 ±20 years); 28 (42%) developed severe pneumonia, of whom 10 (15%) required intubation. Severe pneumonia was associated with older age, dyspnoea, delayed presentation >2 days from onset, extrapulmonary virus detection (13–28%) and higher viral concentration despite late-presentation (multiple linear regression, β=0.94, 95% confidence interval 0.15–1.74; P=0.02). Patients with severe pneumonia exhibited slow viral clearance with oseltamivir treatment, particularly in the lower respiratory tract (median [interquartile range] durations of RNA positivity after antiviral initiation were NPFS 6.0 days [3.0–8.0], TA 11.0 days [7.8–14.3] versus milder illness group NPFS of 2.0 days [1.0–3.0] days; PConclusions In severe 2009 H1N1 pneumonia, viral clearance is slow with treatment, particularly in the lower respiratory tract. A more sustained antiviral regime appears warranted.

Summary Objectives Early diagnosis of smear-negative tuberculosis remains challenging. The role of an interferon-gamma release assay (IGRA) in discriminating active pulmonary tuberculosis (PTB) among cases of ‘pneumonia' was investigated. Methods Consecutive patients admitted to an acute hospital in Hong Kong (intermediate TB burden) during 2006–2008 because of pneumonia and suspected PTB were recruited for IGRA (Quantiferon-TB Gold, QFN-G) study. Diagnosis of tuberculosis was confirmed by mycobacterial culture or histology. Results Altogether 179 patients were recruited (median (IQR) age 59 (44–75), 68.7% male); active PTB was confirmed in 63 (35.2%). Among the AFB-smear-negative ‘pneumonias' ( n = 152), age>50 (OR 0.27, 95% CI 0.09–0.84), absence of weight loss (OR 0.30, 95% CI 0.10–0.88), and negative IGRA (OR 0.08, 95% CI 0.03–0.25) were independently associated with lower risks of PTB. The overall sensitivity, specificity, positive and negative predictive values for the IGRA in diagnosing active PTB were 60%, 87%, 72% and 80% respectively. Among smear-negative ‘pneumonias' ( n = 152), the performance values of IGRA were 64%, 87%, 62% and 88% respectively; in the absence of characteristic clinical or radiographic features of PTB, the negative predictive value (NPV) improved to 90–95%. Conclusions The high NPV of QFN-G among smear-negative ‘pneumonias' can be useful for risk stratification in hospitalized patients suspected of PTB. Further investigation on the role of these assays in patient management is warranted.

Background Aspartic acid to glycine substitution (D222G) of haemagglutinin subunit (HA1) was associated with adverse outcomes in 2009 pandemic influenza A (H1N1) infections. Objectives To characterize the virological profile and antiviral response of patients infected with the HA1 D222G mutant. Study design Sixty-three adults admitted for pandemic influenza in Hong Kong were tested for D222G mutation by direct sequencing. Nasopharyngeal viral concentration on presentation was measured by real-time PCR to evaluate shedding from the upper respiratory tract. Serial upper and lower respiratory tract specimens were monitored to determine preferential tropism and document virological response to treatment. Results The frequency of D222G infection was 17.4% among cases with severe pneumonia, and 26.7% among cases requiring intensive care. Altogether, four sporadic D222G cases spread across the first and second waves in Hong Kong were detected. A significant association between D222G infection with severe pneumonia (100% vs. 32.2%, P = 0.015) and intensive care admission (100% vs. 18.6%, P = 0.002) was observed. D222G was associated with lower concentrations of virus in the upper respiratory tract compared to wildtype, but persisted in the lower respiratory tract at high concentrations, despite clearance from the upper respiratory tract following antiviral treatment. Conclusions These observations suggest that D222G can arise de novo , sheds less virus from the upper respiratory tract and may be less transmissible, but more pneumotropic and more resistant to antiviral treatment. D222G is associated with a higher chance of developing critical disease. Lower respiratory tract specimen is needed for a reliable detection of this mutant.

Background Fever is an undifferentiated clinical feature that may enhance the sensitivity of syndromic surveillance systems. By studying the spatiotemporal associations of febrile patients, it may allow early detection of case clustering that indicates imminent threat of infectious disease outbreaks in the community. Methods We captured consecutive emergency department visits that led to hospitalization in a district hospital in Hong Kong during the period of 12 Sep 2005 to 14 Oct 2005. We recorded demographic data, provisional diagnoses, temperature on presentation and residential location for each patient-episode, and geocoded the residential addresses. We applied Geographical Information System technology to study the geographical distribution these cases, and their associations within a 50-m buffer zone spatially. A case cluster was defined by three or more spatially associated febrile patients within each three consecutive days. Results One thousand and sixty six patient-episodes were eligible for analysis; 42% of them had fever (>37°C; oral temperature) on presentation. Two hundred and four patient-episodes (19.1%) came from residential care homes for elderly (RCHE). We detected a total of 40 case clusters during the study period. Clustered cases were of older age; 57 (33.3%) were residents of RCHE. We found a median of 3 patients (range: 3 - 8) and time span of 3 days (range: 2 - 8 days) in each cluster. Twenty five clusters had 2 or more patients living in the same building block; 18 of them were from RCHE. Conclusions It is technically feasible to perform surveillance on febrile patients and studying their spatiotemporal associations. The information is potentially useful for early detection of impending infectious disease threats.

We retrospectively analyzed 92 cases of severe rickettsial infections in patients (median age = 49 years, 57% male, 37.0% with scrub typhus) in Hong Kong. Immunofluorescence assay was used for diagnostic confirmation. Identification ofor = 1 diagnostic sign (exposure history, rash, or eschar) was possible in 94.6% of the cases. Multivariate analysis suggested that pulmonary infiltrates (odds ratio [OR] = 25.2, 95% confidence interval [CI] = 3.9-160.9, P = 0.001) and leukocytosis (OR = 1.3, 95% CI = 1.0-1.5 per unit increase, P = 0.033) were independent predictors of admission to an intensive care unit (14.1%). Delayed administration of doxycycline was independently associated with major organ dysfunction (23.9%; oxygen desaturation, renal failure, severe jaundice, encephalopathy, cardiac failure) (OR = 1.2, 95% CI = 1.0-1.5 per day delay, P = 0.046; adjusted for age and rickettsia biogroup) and prolonged hospitalization10 days (25%) (OR = 1.4, 95% CI = 1.1-1.9 per day delay, P = 0.014). Treatment with fluoroquinolone/clarithromycin did not correlate with clinical outcomes (P0.05). Early empirical doxycycline therapy should be considered if clinico-epidemiologic signs of rickettsial infections are present.

Understanding factors affecting length of hospital stay (LOS) in patients with severe influenza may improve their management.A retrospective cohort study on laboratory-confirmed, adult influenza patients hospitalized in 2004 and 2005 was conducted. For all influenza cases during that period, immunofluorescence assay on nasopharyngeal aspirate was used for rapid diagnosis, and oseltamivir (75 mg twice daily for 5 days) prescribed if the patient presented within 2 days of symptom onset. Independent factors associated with time to discharge were identified using Cox proportional hazards models. An adjusted hazard ratio (aHR)1 signifies a higher chance of early discharge. Viral shedding and influenza vaccination history were studied during one 'flu' season.A total of 356 patients (influenza A 93.5%) were studied. The majority of patients were old (70.2 +/- 8.4 years), hador = 1 comorbid illness (69.1%) and developed respiratory or cardiovascular complications (69.4%). Oseltamivir initiated within 2 days of illness was associated with shorter total LOS (Kaplan-Meier estimated median 4 versus 6 days [-33%]; aHR for discharge 1.54, 95% confidence intervals [95% CI] 1.23-1.92, P0.0001). Older age (or = 70 years), comorbidities and complications were associated with prolonged LOS. Prolonged viral RNA detectionday 4 of illness (23 out of 99 consecutive patients) was also independently associated with longer LOS (aHR 0.36 [95% CI 0.19-0.71], P = 0.003), whereas influenza vaccination within 6 months was associated with shorter LOS (aHR 2.14 [95% CI 1.18-3.85], P = 0.012).Our analyses suggest that timely oseltamivir treatment is independently associated with shorter LOS in patients hospitalized for severe influenza. Efforts to ensure early diagnosis and therapeutic intervention are warranted.

Background It has been postulated that genetic predisposition may influence the susceptibility to SARS-coronavirus infection and disease outcomes. A recent study has suggested that the deletion allele (D allele) of the angiotensin converting enzyme (ACE) gene is associated with hypoxemia in SARS patients. Moreover, the ACE D allele has been shown to be more prevalent in patients suffering from adult respiratory distress syndrome (ARDS) in a previous study. Thus, we have investigated the association between ACE insertion/deletion (I/D) polymorphism and the progression to ARDS or requirement of intensive care in SARS patients. Method One hundred and forty genetically unrelated Chinese SARS patients and 326 healthy volunteers were recruited. The ACE I/D genotypes were determined by polymerase chain reaction and agarose gel electrophoresis. Results There is no significant difference in the genotypic distributions and the allelic frequencies of the ACE I/D polymorphism between the SARS patients and the healthy control subjects. Moreover, there is also no evidence that ACE I/D polymorphism is associated with the progression to ARDS or the requirement of intensive care in the SARS patients. In multivariate logistic analysis, age is the only factor associated with the development of ARDS while age and male sex are independent factors associated with the requirement of intensive care. Conclusion The ACE I/D polymorphism is not directly related to increased susceptibility to SARS-coronavirus infection and is not associated with poor outcomes after SARS-coronavirus infection.

Sir—We performed a cross-sectional study to assess the physical symptoms in and abnormal laboratory findings for survivors of severe acute respiratory syndrome (SARS) at their first follow-up visit after discharge from Princess Margaret Hospital (Hong Kong, China). Sixty-two patients who experienced the onset of SARS symptoms during the period from 18 March 18 2003 through 30 March 2003 were recruited. All patients had pneumonia and positive SARS-associated coronavirus (SARS-CoV) seroconversion. The mean age (� SD) was 37.07 � 12.96 years, the ratio of male subjects to female subjects was 0.82, and the intubation rate was 9.6%. In this cohort, 90.3% of patients received treatment with ribavirin and corticosteroids [1]. The median interval (� SD) between the onset of SARS symptoms and the first follow-up visit was weeks. 6.59 � 1.07 Symptoms reported at the first followup visit included palpitation (45.1% of patients), exertional dyspnea (41.9%), malaise (40.3%), easy forgetfulness (30.6%), chest discomfort (22.5%), hand tremor (21%), dizziness (17.7%), depression (16.1%), myalgia (12.9%), headache (9.6%), diarrhoea (8.1%), cough (8.1%), insomnia (6.5%), and hair loss over the scalp (3.2%). No patient reported sputum production. Patients described palpitation as a paroxysmal, fast heart beat or extra heart beat sensation. A sinus tachycardia with resting heart rate of 100–110 beats/ min was identified in 18% of patients complaining of palpitation. Laboratory findings included the fol

To the Editor: Severe acute respiratory syndrome (SARS) is an emerging infectious disease worldwide, and relapsing SARS is a major concern. We encountered a 60-year-old woman who was admitted to the Princess Margaret Hospital in Hong Kong on March 29, 2003, with a fever of 39°C, chills, cough, malaise, and sore throat for 2 days before admission. She had no history of travel within 2 weeks of admission. She also had no close contact with patients who had a diagnosis of suspected or confirmed SARS. Chest radiograph on admission indicated consolidation over the right middle zone. In accordance with the diagnostic criteria proposed by the World Health Organization (WHO), this patient’s condition was diagnosed as SARS in view of her symptoms, temperature, and chest radiograph findings (1). Standard microbiologic investigations to exclude common respiratory virus and bacterium for community-acquired pneumonia, including Mycobacterium tuberculosis, were negative in our patient. Reverse transcriptase–polymerase chain reaction (RT-PCR) of nasopharyngeal aspirate samples was negative for coronavirus twice. The coronavirus antibody titer was less than 1/25. The patient was initially treated with oral clarithromycin (500 mg twice a day) and intravenous amoxycillin-clavulanate combination (1.2 g three times a day). Despite the negative evidence for coronavirus infection, she was treated with intravenous ribavirin (24 mg/kg once a day) and hydrocortisone (10 mg/kg once a day) after 48 hours of antibiotics therapy (2). The patient’s symptoms were relieved, and she remained afebrile 3 days after admission. Tolerance for medication was good except for a moderate degree of hemolytic anemia (her hemoglobin level dropped to 9.1 g/dL) and hypokalemia that developed during treatment. On day 15, the chest radiography was clear. The patient was discharged after 3 weeks of hospital stay. The patient attended outpatient clinic on day 35, complaining of exertional dyspnea, low-grade fever, and malaise since her discharge. Her chest radiography showed extensive shadowing. Computer tomographic scan of the thorax indicated widespread ground-glass shadowing in both lung fields, which was especially prominent at left lower and lingular lobes. Her hemoglobin level had dropped further to 8.4 g/dL. Sputum culture yielded substantial growth of methicillin-sensitive Staphylococcus aureus and Pseudomonas aeruginosa. RT-PCR results of throat and nasal swabs were positive twice for coronavirus, but coronavirus cultures from these areas were negative. One month after onset, her coronavirus antibody titer was 200. In view of possible relapse of SARS, she was treated with oral ribavirin (1,200 mg a day) and lopinavir (133.3 mg a day)/ritonavir (33.3 mg) combination (3 capsules twice a day) in addition to intravenous piperacillin/tazobactam combination. The patient was afebrile, and symptoms improved 3 days after admission. Serial chest radiograph showed gradual resolution of shadowing. Subsequent RT-PCR and sputum culture were negative. This case illustrates several important issues regarding problems of infection control, diagnosis, and management of SARS. As the definition of SARS is nonspecific, patients with upper respiratory infection or community-acquired pneumonia could be mislabeled as having SARS. Accommodating confirmed SARS patients and patients mislabeled as having SARS in the same facility may be disastrous. Unfortunately, isolating every single case is impossible, particularly when a large number of patients are admitted. Our patient may have acquired the disease after admission since she was placed in the same ward with other patients confirmed to have SARS. For this reason, special cohorting of SARS patients with closely related signs and symptoms should be strictly implemented at admission. Since fever is the most common feature of SARS, isolating febrile cases with respiratory or gastrointestinal symptoms may be appropriate. Even patients with fever alone should be quarantined since the other symptoms of SARS may not be clinically obvious. Secondly, the sensitivity of diagnosing a coronavirus infection on admission is only 32% to 50% by nasopharyngeal RT-PCR test (3,4). Many infected cases will be missed as a result. Our patient may have had a relapse of disease during her second admission, although she had positive RT-PCR and antibody surge only 1 month after onset. However, we could not conclude whether the first RT-PCR on admission was a false negative or whether the patient acquired coronavirus infection in the hospital. Our study showed that sensitivity for diagnosing coronavirus infection could be increased by performing RT-PCR on samples from different parts of the body (4). Unfortunately, these samples were not taken from our patient. Furthermore, the chest infection with organisms recovered from her sputum could be the sole reason for her second admission, especially when her immune system was weakened by the administration of a high-dose steroid. The presence of genetic material for coronavirus from her nasal cavity and throat might not suggest that the virus is active. The absence of coronavirus growth in this patient might indicate that the virus is no longer viable, although the culture technique itself might not be sensitive enough to justify this claim. Therefore, further refinement of the diagnostic techniques for SARS is essential, especially for diagnosis during early onset. Thirdly, giving treatment to a patient without a legitimate diagnosis may be inappropriate, especially when the treatment carries substantial adverse effects, as illustrated in our patient, and a universally accepted therapy has not been available. Whether lopinavir/ritonavir combination is the key to a cure remains to be clarified, despite the satisfactory response that we observed, since the clinical and radiologic improvement in our patient might be the natural course of the disease.

Severe acute respiratory syndrome (SARS) has become a global public health emergency.To evaluate the characteristics and outcomes of patients with SARS in Hong Kong and to identify predictors of mortality.Retrospective cohort study.Quarantine hospital for patients with SARS in Hong Kong.267 consecutive patients hospitalized from 26 February to 31 March 2003 for probable or confirmed SARS.Clinical, laboratory, and radiographic measures; 3-month mortality rate.According to our case definition, there were 227 cases of confirmed SARS and 40 cases of probable SARS. Common presenting symptoms were fever (99% of patients), chills (74%), malaise (63%), and myalgia (50%). Laboratory findings included lymphopenia (73%), thrombocytopenia (50%), hyponatremia (60%), and elevated levels of lactate dehydrogenase (47%) and C-reactive protein (75%). During hospitalization, incidence of diarrhea (53%), anemia (53%), and acute renal failure (6%) increased. Sixty-nine patients (26%) required intensive care because of respiratory failure. The 3-month mortality rate was 12% (95% CI, 8% to 16%). Factors contributing to mortality were respiratory failure, acute renal failure, and nosocomial sepsis. On multivariate Cox regression, age older than 60 years (relative risk, 5.10 [CI, 2.30 to 11.31]; P0.001) and lactate dehydrogenase level greater than 3.8 micro kat/L at presentation (relative risk, 2.20 [CI, 1.03 to 4.71]; P = 0.04) were independent predictors of mortality.Because of the longer follow-up period in our cohort, the mortality rate in these patients is higher than rates reported in previous studies. Advanced age and high lactate dehydrogenase level at presentation predict mortality. *For members of the Princess Margaret Hospital SARS Study Group, see the Appendix.

Background Understanding factors affecting length of hospital stay (LOS) in patients with severe influenza may improve their management. Methods A retrospective cohort study on laboratory-confirmed, adult influenza patients hospitalized in 2004 and 2005 was conducted. For all influenza cases during that period, immunofluorescence assay on nasopharyngeal aspirate was used for rapid diagnosis, and oseltamivir (75 mg twice daily for 5 days) prescribed if the patient presented within 2 days of symptom onset. Independent factors associated with time to discharge were identified using Cox proportional hazards models. An adjusted hazard ratio (aHR) >1 signifies a higher chance of early discharge. Viral shedding and influenza vaccination history were studied during one ‘flu’ season. Results A total of 356 patients (influenza A 93.5%) were studied. The majority of patients were old (70.2 ±8.4years), had ≥1 comorbid illness (69.1%) and developed respiratory or cardiovascular complications (69.4%). Oseltamivir initiated within 2 days of illness was associated with shorter total LOS (Kaplan-Meier estimated median 4 versus 6 days [-33%]; aHR for discharge 1.54, 95% confidence intervals [95% CI] 1.23–1.92, Pday 4 of illness (23 out of 99 consecutive patients) was also independently associated with longer LOS (aHR 0.36 [95% CI 0.19–0.71], P=0.003), whereas influenza vaccination within 6 months was associated with shorter LOS (aHR 2.14 [95% CI 1.18–3.85], P=0.012). Conclusion Our analyses suggest that timely oseltamivir treatment is independently associated with shorter LOS in patients hospitalized for severe influenza. Efforts to ensure early diagnosis and therapeutic intervention are warranted.