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Biomedical subjects

A C Cheung

Publications and source records attributed to A C Cheung.

8 recordsLinked to original sources
PubMed2005

The SARS outbreak in a general hospital in Tianjin, China -- the case of super-spreader.

Severe acute respiratory syndrome (SARS) is a newly emerged infectious disease with a high case-fatality rate and devastating socio-economic impact. In this report we summarized the results from an epidemiological investigation of a SARS outbreak in a hospital in Tianjin, between April and May 2003. We collected epidemiological and clinical data on 111 suspect and probable cases of SARS associated with the outbreak. Transmission chain and outbreak clusters were investigated. The outbreak was single sourced and had eight clusters. All SARS cases in the hospital were traced to a single patient who directly infected 33 people. The patients ranged from 16 to 82 years of age (mean age 38.5 years); 38.7% were men. The overall case fatality in the SARS outbreak was 11.7% (13/111). The outbreak lasted around 4 weeks after the index case was identified. SARS is a highly contagious condition associated with substantial case fatality; an outbreak can result from one patient in a relatively short period. However, stringent public health measures seemed to be effective in breaking the disease transmission chain.

Adolescent↗
PubMed2001

Aortic valve reoperation after homograft or autograft replacement.

BACKGROUND AND AIM OF THE STUDY: With increasing use of homograft and autograft aortic valves for aortic valve replacement (AVR), more patients will be presenting for aortic valve reoperation due to structural degeneration of the homograft or autograft valve. Management options include homograft re-replacement, which may require extensive surgery, versus AVR with a mechanical valve or a stented xenograft. Here, results are reported in 18 consecutive patients who underwent aortic valve re-replacement (AVreR) after previous homograft or autograft insertion. METHODS: Between May 1976 and March 2001, 18 patients underwent AVR after previous homograft (n = 16) or autograft (n = 2) insertion. The homograft or autograft had been implanted as a full root in eight patients (44%), as a mini-root in one (6%), and in the subcoronary position in nine (50%). Indication for the reoperation was structural valve degeneration (n = 14; 72%) in one occasion combined with aneurysm of the homograft, or endocarditis (n = 4; 22%), and seven (39%) presented as a non-elective procedure. The median interval between the two operations was 5.4 years (range: 0.3-10.8 years). RESULTS: Fourteen patients (78%) received either a mechanical valve (n = 12; 67%) or a stented xenograft valve (n = 2; 11%). Four others (22%) required root re-replacement with either another homograft (n = 3) or a mechanical valved conduit (n = 1) for endocarditis (n = 2) or an associated aneurysm (n = 2). Overall hospital mortality was 11% (n = 2) due to stroke (n = 1) or respiratory failure (n = 1). Two patients died 3.1 and 7.0 years after the procedure. CONCLUSION: Aortic valve reoperation after previous homograft or autograft implantation is a rare operation and presents a high-risk group. A simplified approach was preferred by utilizing mechanical or stented xenograft valves at reoperation, while homograft re-replacement was reserved for endocarditis or an associated aneurysm.

Adult↗