Immigrants and tuberculosis in Hong Kong.

Objective: To examine the impact of immigrant populations on the epidemiology of tuberculosis in Hong Kong.

Design: Longitudinal cohort study.

Setting: Hong Kong.

Pyrazinamide susceptibility testing in Mycobacterium tuberculosis: a systematic review with meta-analyses.

Standard culture-based testing of the susceptibility of Mycobacterium tuberculosis to pyrazinamide is difficult to perform. This systematic review with meta-analyses evaluated the roles of molecular assays targeting pncA and of pyrazinamidase assays. PubMed and Embase were searched for relevant publications in English.

Treatment of tuberculosis and optimal dosing schedules.

Intermittent tuberculosis treatment regimens have been developed to facilitate treatment supervision. Their efficacy has been substantiated by clinical trials and tuberculosis control programmes, notwithstanding the lack of head-to-head comparison between daily and intermittent regimens. Recently, there has been opposing evidence from observational studies, pharmacokinetic-pharmacodynamic studies and animal models that intermittent treatment increases the risk of relapse, treatment failure or acquired rifamycin resistance, especially among HIV-infected patients.

Treatment of multidrug-resistant and extensively drug-resistant tuberculosis: current status and future prospects.

Drug resistance in Mycobacterium tuberculosis arises from the man-made selection of mutants that result from spontaneous chromosomal alterations. Preventing the development of drug-resistant TB through a good control program based on directly observed treatment, short-course, is of paramount importance. Established multidrug-resistant (MDR)-TB requires alternative specific chemotherapy, comprising drugs with higher cost and greater toxicity delivered on a programmatic basis.

A systematic review of rapid drug susceptibility tests for multidrug-resistant tuberculosis using rifampin resistance as a surrogate.

Background: The emergence of multidrug-resistant tuberculosis (MDR-TB) has prompted the development of rapid drug susceptibility assays with a focus on rifampin in recent years. Systematic reviews with evaluation of predictive values for different assays are scarce.

Method: MEDLINE was searched on 6 September 2008 for English articles that contain concurrent original data for generating summary measures of sensitivity, specificity and likelihood ratios of rapid rifampin susceptibility assays.

Peak plasma rifampicin level in tuberculosis patients with slow culture conversion.

The clinical utility of therapeutic drug monitoring in tuberculosis has not been adequately evaluated by controlled clinical trials. To examine the relationship between slow culture conversion and peak plasma rifampicin level (Cmax-rfm) in a case-control study, patients with persistence of positive sputum smear despite at least 8 weeks of directly observed treatment with standard pyrazinamide-containing regimens were enrolled prospectively in government chest clinics from 16 December 2005 to 15 November 2006. Patients with multidrug-resistant tuberculosis, human immunodeficiency virus infection, or poor treatment adherence were excluded.

Lower risk of tuberculosis in obesity.

Background: Obesity is increasingly prevalent in both developed and developing areas. Although undernutrition is well associated with tuberculosis, few studies have systematically examined the association with obesity. Method A cohort of 42 116 individuals 65 years or older enrolled at 18 health centers for elderly patients in Hong Kong, China (which has a tuberculosis incidence of approximately 90 per 100,000 population), in 2000 were followed up prospectively through the territory-wide tuberculosis registry for the development of active tuberculosis from 3 months after enrollment until December 31, 2005, using the identity card number as the unique identifier.

4-, 5- and 6-month regimens containing isoniazid, rifampicin, pyrazinamide and streptomycin for treatment of pulmonary tuberculosis under program conditions in Hong Kong.

Setting: Ten full time urban government chest clinics in Hong Kong.

Objective: To assess the effectiveness of 4-, 5- and 6-month fully supervised thrice-weekly regimens containing 4 months of isoniazid, rifampicin, pyrazinamide and streptomycin followed by nil, 1 or 2 months of isoniazid and rifampicin for the treatment of smear-negative culture-negative, smear-negative culture-positive and smear-positive pulmonary tuberculosis.

Design: Retrospective study of the 3 antituberculosis treatment regimens given under program conditions during a 6-month period in 1983.

Serodiagnosis of tuberculosis using an ELISA with antigen 5 and a hemagglutination assay with glycolipid antigens. Results in patients with newly diagnosed pulmonary tuberculosis ranging in extent of disease from minimal to extensive.

Hemagglutination tests with three glycolipid antigens, A1, B1, and C, and ELISA with antigen 5 were done on serum from Chinese patients with pulmonary tuberculosis and from normal subjects in Hong Kong. Tests with all four antigens were of similar efficiency, giving positive results in 30 to 52% of 88 smear-positive patients, in 16 to 22% of 37 smear-negative, culture-positive patients, in 5 to 13% of 76 culture-negative patients with radiologically active disease, in 5 to 11% of 217 culture-negative patients with inactive disease, and in 1 to 4% of 140 normal subjects. If tests were combined so that an overall positive was scored when all tests were positive, there was worse discrimination between patients and normal subjects; however, as suggested by the poor correlation between the results with pairs of the tests, better discrimination was obtained if an overall positive was scored when any of the tests was positive.