Transmission of MDR and XDR Tuberculosis in Shanghai, China

Abstract

BackgroundMultidrug-resistant (MDR) and extensively drug-resistant (XDR) tuberculosis (TB) are global health problems. We sought to determine the characteristics, prevalence, and relative frequency of transmission of MDR and XDR TB in Shanghai, one of the largest cities in Asia.MethodsTB is diagnosed in district TB hospitals in Shanghai, China. Drug susceptibility testing for first-line drugs was performed for all culture positive TB cases, and tests for second-line drugs were performed for MDR cases. VNTR-7 and VNTR-16 were used to genotype the strains, and prior treatment history and treatment outcomes were determined for each patient.ResultsThere were 4,379 culture positive TB cases diagnosed with drug susceptibility test results available during March 2004 through November 2007. 247 (5.6%) were infected with a MDR strain of M. tuberculosis and 11 (6.3%) of the 175 MDR patients whose isolate was tested for susceptibility to second-line drugs, were XDR. More than half of the patients with MDR and XDR were newly diagnosed and had no prior history of TB treatment. Nearly 57% of the patients with MDR were successfully treated.DiscussionTransmission of MDR and XDR strains is a serious problem in Shanghai. While a history of prior anti-TB treatment indicates which individuals may have acquired MDR or XDR TB, it does not accurately predict which TB patients have disease caused by transmission of MDR and XDR strains. Therefore, universal drug susceptibility testing is recommended for new and retreatment TB cases.

Risk Factors for Poor Treatment Outcomes in Patients With MDR-TB and XDR-TB in China: Retrospective Multicenter Investigation

“…The percentage of XDR-TB was higher than in the previous surveillance data in China [16][17][18][19], in Taiwan [20], and in other countries [9,21,22], and it was similar to the 23.9% which was reported from South Africa in TB and HIV co-infected patients [23][24][25], similar to the 23.59% from nationwide population-based survey in China [5] and to 20.0% found in the study from Shandong [6]. The high prevalence of XDR-TB could be explained by the fact that our study subjects were from provincial Tuberculosis Specialized Hospitals, where the patients might tend to be selected as being relatively difficult cases.…”

Transmission of multidrug-resistant and extensively drug-resistant tuberculosis in a metropolitan city

“…Traditionally, acquired drug resistance has been emphasised as the principal mechanism by which drug-resistant TB develops. However, in recent MDR-TB reports, the prevalence of new cases with no previous TB treatment has been rising in both high-prevalence HIV settings (South Africa: 55% [15]) and low-prevalence HIV settings (Shanghai, China: 60% [16]; Latvia: 37% [17]; Japan: 45% [18]). …”

Molecular Characterization of Multidrug- and Extensively Drug-Resistant Mycobacterium tuberculosis Strains in Jiangxi, China

“…These patients were epidemiologically unlinked, and all were living in Jiangxi Province. Of the 97 isolates, 77 were drug-resistant strains, which included 35 simple MDR strains (resistance to INH and RIF, but not an FQ, and one of three second-line injectable drugs), 26 pre-XDR strains (defined as resistance to INH and RIF and either an FQ or one of three second-line injectable drugs, but not both) (55), and 16 XDR strains. However, the remaining 20 isolates were pan-susceptible strains and therefore used as negative controls.…”

“…For the MDR isolates, four second-line drugs were chosen to test. These were done according to the WHO guidelines (48) based on the following drug concentrations: isoniazid (0.2 g/ ml), RIF (40.0 g/ml), streptomycin (STR; 4 g/ml), ethambutol (EMB; 2.0 g/ml), ofloxacin (OFX; 2.0 g/ml), kanamycin (KAN; 30.0 g/ml), capreomycin (CAP; 40.0 g/ml), and amikacin (AMK; 40.0 g/ml) (48,55). Periodic external quality assessment of the performance of DST results was conducted by the Tuberculosis Reference Laboratory at the Beijing Research Institute for Tuberculosis Control.…”