K M Kam1, C W Yip. 1. Tuberculosis Reference Laboratory, Yung Fung Shee Memorial Center, Department of Health, Kwun Tong, Kowloon, Hong Kong. kmkam@asiaonline.net
Abstract
OBJECTIVE: To study changing trends in TB epidemiology with emphasis on drug resistance rates in various age groups from 1986-1999. DESIGN: Laboratory-based data on drug susceptibility testing against streptomycin (SM), isoniazid (NH), rifampicin (RMP) and ethambutol (EMB) had been collected continuously in a centralised TB laboratory in Hong Kong. Epidemiological parameters such as sex, age and drug resistance rates in new and retreatment cases were measured and analysed for longitudinal trends. RESULTS: Of 48 924 non-duplicate isolates from new TB cases, 7045 (14.4%) were resistant to one or more drugs, 5773 (11.8%) were resistant to SM and/or INH while 881 (1.8%) were multidrug-resistant (MDR-TB). Of 3857 isolates from retreatment patients, 1176 (30.5%) were resistant to one or more drugs, 616 (16.0%) were resistant to SM and/or [NH, and 467 (12.1%) were MDR-TB. For isolates from new cases, significant declines were observed in the resistance rates against any drug, SM alone, INH alone, SM+INH and INH+RMP. For retreatment isolates, significant declines were also observed in resistance to any drug and INH+RMP. In both new and retreatment cases, isolates from patients aged over 65 years showed significantly lower drug resistance (any drug and INH+RMP) compared with other age groups (16-34 years and 35-65 years). CONCLUSION: With successful implementation of DOTS over a 14-year period, laboratory-based surveillance data showed significant declines in drug resistance, including MDR-TB. This has occurred amidst demographic changes associated with a generally ageing population as well as highly mobile sectors that are in constant exchange with highly endemic areas.
OBJECTIVE: To study changing trends in TB epidemiology with emphasis on drug resistance rates in various age groups from 1986-1999. DESIGN: Laboratory-based data on drug susceptibility testing against streptomycin (SM), isoniazid (NH), rifampicin (RMP) and ethambutol (EMB) had been collected continuously in a centralised TB laboratory in Hong Kong. Epidemiological parameters such as sex, age and drug resistance rates in new and retreatment cases were measured and analysed for longitudinal trends. RESULTS: Of 48 924 non-duplicate isolates from new TB cases, 7045 (14.4%) were resistant to one or more drugs, 5773 (11.8%) were resistant to SM and/or INH while 881 (1.8%) were multidrug-resistant (MDR-TB). Of 3857 isolates from retreatment patients, 1176 (30.5%) were resistant to one or more drugs, 616 (16.0%) were resistant to SM and/or [NH, and 467 (12.1%) were MDR-TB. For isolates from new cases, significant declines were observed in the resistance rates against any drug, SM alone, INH alone, SM+INH and INH+RMP. For retreatment isolates, significant declines were also observed in resistance to any drug and INH+RMP. In both new and retreatment cases, isolates from patients aged over 65 years showed significantly lower drug resistance (any drug and INH+RMP) compared with other age groups (16-34 years and 35-65 years). CONCLUSION: With successful implementation of DOTS over a 14-year period, laboratory-based surveillance data showed significant declines in drug resistance, including MDR-TB. This has occurred amidst demographic changes associated with a generally ageing population as well as highly mobile sectors that are in constant exchange with highly endemic areas.
Authors: Courtney M Yuen; Helen E Jenkins; Carly A Rodriguez; Salmaan Keshavjee; Mercedes C Becerra Journal: Pediatrics Date: 2015-06-01 Impact factor: 7.124
Authors: Helen E Jenkins; Arielle W Tolman; Courtney M Yuen; Jonathan B Parr; Salmaan Keshavjee; Carlos M Pérez-Vélez; Marcello Pagano; Mercedes C Becerra; Ted Cohen Journal: Lancet Date: 2014-03-24 Impact factor: 79.321
Authors: Kai Man Kam; Chi Wai Yip; Lai Wa Tse; Kin Lai Wong; Tak Kam Lam; Kristin Kremer; Betty Kam Yan Au; Dick van Soolingen Journal: J Clin Microbiol Date: 2005-01 Impact factor: 5.948
Authors: Courtney M Yuen; Arielle W Tolman; Ted Cohen; Jonathan B Parr; Salmaan Keshavjee; Mercedes C Becerra Journal: Pediatr Infect Dis J Date: 2013-05 Impact factor: 2.129