MDR-TB

The objective of this study was to compare the diagnostic yield of GeneXpert MTB/RIF with Ziehl-Neelson (ZN) sputum smear microscopy among index TB cases and their household contacts. A cross sectional study was conducted among sputum smear positive index TB cases and their household contacts in Northern Ethiopia. Results: Of 353 contacts screened, 41 (11%) were found to have presumptive TB. GeneXpert test done among 39 presumptive TB cases diagnosed 14 (35.9%) cases of TB (one being rifampicin resistant), whereas the number of TB cases diagnosed by microscopy was only 5 (12.8%): a 64.3% increased positivity rate by GeneXpert versus ZN microscopy. The number needed to screen and number needed to test to diagnose a single case of TB was significantly lower with the use of GeneXpert than ZN microscopy. Of 119 index TB cases, GeneXpert test revealed that 106 (89.1%) and 5 (4.2%) were positive for rifampicin sensitive and rifampicin resistant TB, respectively. GeneXpert test led to increased TB case detection among household contacts in addition to its advantage in the diagnosis of Rifampicin resistance among contacts and index TB cases. There should be a consideration in using GeneXpert MTB/RIF as a point of care TB testing tool among high risk groups.

Early detection and treatment of multidrug-resistant tuberculosis (MDR-TB) is an urgent global priority. Identifying and tracing close contacts of patients with MDR-TB could be a feasible strategy to achieve this goal. However, there is limited experience with contact tracing among patients with drug-resistant tuberculosis both globally and in Ethiopia. Here we present findings on the extent of screening symptomatic contacts and its yield in a tetrtiary hospital in a major urban setting in Ethiopia. Symptomatic household contacts were identified in 29 (5.7%) of 508 index cases treated at the hospital. There were a total of 155 family members in the households traced of whom 16 (10%) had confirmed MDR-TB. At least 1 confirmed MDR-TB case was identified in 15 (51.7%) of the 29 traced households. Tracing symptomatic contacts of MDR-TB cases could be a high yield strategy for early detection and treatment of MDR-TB cases in the community. The approach should be promoted for wider adoption and dissemination.

The aim of this study was to assess the prevalence of MDR-TB and associated risk factors in West Armachiho and Metema districts of North Gondar. A cross-sectional study was conducted between February 1 and June 25, 2014. A total of 124 consecutive smear-positive pulmonary TB patients were included in the study. Socio-demographic and possible risk factor data were collected using a semi-structured questionnaire. Drug susceptibility testing was first performed for rifampicin using GeneXpert MTB/RIF. For those rifampicin resistant strains, drug susceptibility testing was performed for both isoniazid and rifampicin to identify MDR-TB. Of 124 smear-positive pulmonary TB patients, 117 (94.4 %) were susceptible to rifampicin, while 7 (5.7 %) were confirmed to be resistant to rifampicin and isoniazid. History of previous treatment was significantly associated with MDR-TB. Maximizing early case detection and treatment, strengthening TB infection control activities and proper implementation of DOTS are recommended to reduce the burden of MDR-TB.

We set out to evaluate the variation in prevalence of drug resistant tuberculosis (DR-TB) and its determinants across sub-Saharan African (SSA) countries--excluding South Africa--among new and previously treated TB patients. A search of PubMed, EMBASE, Cochrane and bibliographies of DR-TB studies yielded 726 studies published between 2003 and 2013, of which 27 articles fulfilled the inclusion criteria. Studies reported drug susceptibility testing results for a total of 13,465 new and 1,776 previously treated TB patients. The pooled estimate of any DR-TB prevalence among the new cases was 12.6%, while for MDR-TB this was 1.5%. Among previously treated patients, these were 27.2% and 10.3%, respectively. DR-TB (any and MDR-TB) did not vary significantly with respect to study characteristics. The reported prevalence of DR-TB in SSA is low compared to WHO estimates. MDR-TB in this region does not seem to be driven by the high HIV prevalence rates.

To document the prevalence of multidrug resistance among people newly diagnosed with--and those retreated for--tuberculosis in Malawi, we conducted a nationally representative survey of people with sputum-smear-positive tuberculosis between 2010 and 2011. For all consenting participants, we collected demographic and clinical data, two sputum samples and tested for human immunodeficiency virus (HIV).The samples underwent resistance testing at the Central Reference Laboratory in Lilongwe, Malawi. All Mycobacterium tuberculosis isolates found to be multidrug-resistant were retested for resistance to first-line drugs – and tested for resistance to second-line drugs--at a Supranational Tuberculosis Reference Laboratory in South Africa. Overall, M. tuberculosis was isolated from 1777 (83.8%) of the 2120 smear-positive tuberculosis patients. Multidrug resistance was identified in five (0.4%) of 1196 isolates from new cases and 28 (4.8%) of 581 isolates from people undergoing retreatment. Of the 31 isolates from retreatment cases who had previously failed treatment, nine (29.0%) showed multidrug resistance. Although resistance to second-line drugs was found, no cases of extensive drug-resistant tuberculosis were detected. HIV testing of people from whom M. tuberculosis isolates were obtained showed that 577 (48.2%) of people newly diagnosed and 386 (66.4%) of people undergoing retreatment were positive. The prevalence of multidrug resistance among people with smear-positive tuberculosis was low for sub-Saharan Africa--probably reflecting the strength of Malawi’s tuberculosis control programme. The relatively high prevalence of such resistance observed among those with previous treatment failure may highlight a need for a change in the national policy for retreating this subgroup of people with tuberculosis.

Background: Worldwide, there were 650,000 multidrug-resistant tuberculosis (MDR-TB) cases in 2010, and in 2008 the World Health Organization estimated that 150,000 deaths occurred annually due to MDR-TB. Ethiopia is 15th among the 27 MDR-TB high-burden countries.

Printer Friendly Version
Subscribe to RSS - MDR-TB