Chan Chan

Prof. Chan Chan

Department of Microbiology, The Chinese University of Hong Kong
orcid

Research Focus & Metrics

Academic Career Length

34Years (1993-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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15 May 2003 in New England Journal of Medicine
Verified
Journal Article
Open access
PDF file
NLNelson Lee
Nelson Lee
DHDavid Hui
David Hui
AWAlan Wu
Alan Wu
CCChan Chan
Chan Chan
PCPeter Cameron
Peter Cameron
JSJoseph JY Sung
Joseph JY Sung
There has been an outbreak of the severe acute respiratory syndrome (SARS) worldwide. We report the clinical, laboratory, and radiologic features of 138 cases of suspected SARS during a hospital outbreak in Hong Kong. From March 11 to 25, 2003, all patients with suspected SARS after exposure to an index patient or ward were admitted to the isolation wards of the Prince of Wales Hospital. Their demographic, clinical, laboratory, and radiologic characteristics were analyzed. Clinical end points included the need for intensive care and death. Univariate and multivariate analyses were performed. There were 66 male patients and 72 female patients in this cohort, 69 of whom were health care workers. The most common symptoms included fever (in 100 percent of the patients); chills, rigors, or both (73.2 percent); and myalgia (60.9 percent). Cough and headache were also reported in more than 50 percent of the patients. Other common findings were lymphopenia (in 69.6 percent), thrombocytopenia (44.8 percent), and elevated lactate dehydrogenase and creatine kinase levels (71.0 percent and 32.1 percent, respectively). Peripheral air-space consolidation was commonly observed on thoracic computed tomographic scanning. A total of 32 patients (23.2 percent) were admitted to the intensive care unit; 5 patients died, all of whom had coexisting conditions. In a multivariate analysis, the independent predictors of an adverse outcome were advanced age (odds ratio per decade of life, 1.80; 95 percent confidence interval, 1.16 to 2.81; P=0.009), a high peak lactate dehydrogenase level (odds ratio per 100 U per liter, 2.09; 95 percent confidence interval, 1.28 to 3.42; P=0.003), and an absolute neutrophil count that exceeded the upper limit of the normal range on presentation (odds ratio, 1.60; 95 percent confidence interval, 1.03 to 2.50; P=0.04). SARS is a serious respiratory illness that led to significant morbidity and mortality in our cohort.

1 September 2020 in Gastroenterology
Verified
Journal Article
Open access
PDF file
TZTao Zuo
Tao Zuo
FZFen Zhang
Fen Zhang
GLGrace C.Y. Lui
Grace C.Y. Lui
YYYun Kit Yeoh
Yun Kit Yeoh
ALAmy Y.L. Li
Amy Y.L. Li
SNSiew C Ng
Siew C Ng
Background & Aims Although severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infects gastrointestinal tissues, little is known about the roles of gut commensal microbes in susceptibility to and severity of infection. We investigated changes in fecal microbiomes of patients with SARS-CoV-2 infection during hospitalization and associations with severity and fecal shedding of virus. Methods We performed shotgun metagenomic sequencing analyses of fecal samples from 15 patients with Coronavirus Disease 2019 (COVID-19) in Hong Kong, from February 5 through March 17, 2020. Fecal samples were collected 2 or 3 times per week from time of hospitalization until discharge; disease was categorized as mild (no radiographic evidence of pneumonia), moderate (pneumonia was present), severe (respiratory rate ≥30/min, or oxygen saturation ≤93% when breathing ambient air), or critical (respiratory failure requiring mechanical ventilation, shock, or organ failure requiring intensive care). We compared microbiome data with those from 6 subjects with community-acquired pneumonia and 15 healthy individuals (controls). We assessed gut microbiome profiles in association with disease severity and changes in fecal shedding of SARS-CoV-2. Results Patients with COVID-19 had significant alterations in fecal microbiomes compared with controls, characterized by enrichment of opportunistic pathogens and depletion of beneficial commensals, at time of hospitalization and at all timepoints during hospitalization. Depleted symbionts and gut dysbiosis persisted even after clearance of SARS-CoV-2 (determined from throat swabs) and resolution of respiratory symptoms. The baseline abundance of Coprobacillus, Clostridium ramosum, and Clostridium hathewayi correlated with COVID-19 severity; there was an inverse correlation between abundance of Faecalibacterium prausnitzii (an anti-inflammatory bacterium) and disease severity. Over the course of hospitalization, Bacteroides dorei, Bacteroides thetaiotaomicron, Bacteroides massiliensis, and Bacteroides ovatus, which downregulate expression of angiotensin-converting enzyme 2 (ACE2) in murine gut, correlated inversely with SARS-CoV-2 load in fecal samples from patients. Conclusions In a pilot study of 15 patients with COVID-19, we found persistent alterations in the fecal microbiome during the time of hospitalization, compared with controls. Fecal microbiota alterations were associated with fecal levels of SARS-CoV-2 and COVID-19 severity. Strategies to alter the intestinal microbiota might reduce disease severity.

1 July 2003 in The Lancet
Verified
Journal Article
Closed access
PDPadraig Duignan
Padraig Duignan
RFRon Am Fouchier
Ron Am Fouchier
MSMartin Schutten
Martin Schutten
GRGuus F Rimmelzwaan
Guus F Rimmelzwaan
GAGeert van Amerongen
Geert van Amerongen
AOAlbert Dme Osterhaus
Albert Dme Osterhaus

1 October 2006 in Journal of Hospital Infection
Verified
Journal Article
Closed access
JTJulian Tang
Julian Tang
YLYuguo Li
Yuguo Li
IEI. Eames
I. Eames
CCChan Chan
Chan Chan
GRG.L. Ridgway
G.L. Ridgway

1 February 2009 in Journal of Clinical Oncology
Verified
Journal Article
Closed access
WYWinnie Yeo
Winnie Yeo
TCTung C. Chan
Tung C. Chan
NLNancy W.Y. Leung
Nancy W.Y. Leung
WLWai Y. Lam
Wai Y. Lam
FMFrankie K.F. Mo
Frankie K.F. Mo
CCChan Chan
Chan Chan
Purpose: Reactivation of hepatitis B virus (HBV) infection is a well-recognized complication in cancer patients with chronic HBV (hepatitis B surface antigen [HBsAg] positive) undergoing cytotoxic chemotherapy. In patients who have resolved HBV (HBsAg negative and antibody to hepatitis B core antigen [anti-HBc] ± antibody to hepatitis B surface antigen [anti-HBs] positive), such incidence has been much less common until recent use of rituximab. In this study on HBsAg-negative/anti-HBc–positive lymphoma patients, the objectives were to determine the HBV reactivation rate in patients treated with rituximab-containing chemotherapy and to compare it with the rate in patients treated without rituximab. Patients and Methods: Between January 2003 and December 2006, all patients diagnosed with CD20+ diffuse large B-cell lymphoma (DLBCL) had HBsAg determined before anticancer therapy. They were treated with either cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) alone or rituximab plus CHOP (R-CHOP). HBsAg-negative patients had anti-HBc determined; serum was stored for anti-HBs and HBV DNA. All patients were observed for HBV reactivation, which was defined as detectable HBV DNA with ALT elevation during and for 6 months after anticancer therapy. Results: Among 104 CD20+ DLBCL patients, 80 were HBsAg negative. Of the latter, 46 patients (44.2%) were HBsAg negative/anti-HBc positive; 25 of these patients were treated with CHOP, and none had HBV reactivation. In contrast, among the 21 patients treated with R-CHOP, five developed HBV reactivation, including one patient who died of hepatic failure (P = .0148). Exploratory analysis identified male sex, absence of anti-HBs, and use of rituximab to be predictive of HBV reactivation. Conclusion: Among HBsAg-negative/anti-HBc–positive DLBCL patients treated with R-CHOP, 25% developed HBV reactivation. Close monitoring until at least 6 months after anticancer therapy is required, with an alternative approach of prophylactic antiviral therapy to prevent this potentially fatal condition.

1 November 2000 in Journal of Medical Virology
Verified
Journal Article
Closed access
PDF file
WYWinnie Yeo
Winnie Yeo
CCChan Chan
Chan Chan
SZSheng Zhong
Sheng Zhong
WHWing M. Ho
Wing M. Ho
JSJoyce L. Steinberg
Joyce L. Steinberg
PJPhilip J. Johnson
Philip J. Johnson