Based on expert opinion, the global guidelines for management of multidrug-resistant tuberculosis impose lengthy and often poorly tolerated treatments.
This observational study evaluates the ...effectiveness of standardized regimens for patients with proven multidrug-resistant tuberculosis previously untreated with second-line drugs in low-income countries.
Consenting patients were sequentially assigned to one of six standardized treatment regimens. Subsequent cohorts were treated with regimens adapted according to results in prior cohorts. The study was designed to minimize failure and default while reducing total treatment duration without increasing relapse frequency.
We report the treatment outcome of all patients with laboratory-confirmed, multidrug-resistant tuberculosis enrolled from May 1997 to December 2007. The most effective treatment regimen required a minimum of 9 months of treatment with gatifloxacin, clofazimine, ethambutol, and pyrazinamide throughout the treatment period supplemented by prothionamide, kanamycin, and high-dose isoniazid during an intensive phase of a minimum of 4 months, giving a relapse-free cure of 87.9% (95% confidence interval, 82.7-91.6) among 206 patients. Major adverse drug reactions were infrequent and manageable. Compared with the 221 patients treated with regimens based on ofloxacin and commonly prothionamide throughout, the hazard ratio of any adverse outcome was 0.39 (95% confidence interval, 0.26-0.59).
Serial regimen formulation guided by overall treatment effectiveness resulted in treatment outcomes comparable to those obtained with first-line treatment. Confirmatory formal trials in populations with high levels of human immunodeficiency virus coinfection and in populations with a higher initial prevalence of resistance to second-line drugs are required.
Tuberculosis (TB) mortality declined in the northern hemisphere over the last 200 years, but peaked during the Russian (1889) and the Spanish (1918) influenza pandemics. We studied the impact of ...these two pandemics on TB mortality.
We retrieved historic data from mortality registers for the city of Bern and countrywide for Switzerland. We used Poisson regression models to quantify the excess pulmonary TB (PTB) mortality attributable to influenza.
Yearly PTB mortality rates increased during both influenza pandemics. Monthly influenza and PTB mortality rates peaked during winter and early spring. In Bern, for an increase of 100 influenza deaths (per 100,000 population) monthly PTB mortality rates increased by a factor of 1.5 (95%Cl 1.4-1.6, p<0.001) during the Russian, and 3.6 (95%Cl 0.7-18.0, p = 0.13) during the Spanish pandemic. Nationally, the factor was 2.0 (95%Cl 1.8-2.2, p<0.001) and 1.5 (95%Cl 1.1-1.9, p = 0.004), respectively. We did not observe any excess cancer or extrapulmonary TB mortality (as a negative control) during the influenza pandemics.
We demonstrate excess PTB mortality during historic influenza pandemics in Switzerland, which supports a role for influenza vaccination in PTB patients in high TB incidence countries.
Meta-analyses on impact of isoniazid-resistant tuberculosis informed the World Health Organization recommendation of a levofloxacin-strengthened rifampicin-based regimen. We estimated the effect of ...initial rifampicin resistance (Rr) and/or isoniazid resistance (Hr) on treatment failure or relapse. We also determined the frequency of missed initial and acquired Rr to estimate the impact of true Hr.
Retrospective analysis of 7291 treatment episodes with known initial isoniazid and rifampicin status obtained from individual patient databases maintained by the Damien Foundation Bangladesh over 20 years. Drug susceptibility test results were confirmed by the programme's designated supra-national tuberculosis laboratory. To detect missed Rr among isolates routinely classified as Hr, rpoB gene sequencing was done randomly and on a sample selected for suspected missed Rr.
Initial Hr caused a large recurrence excess after the 8-month regimen for new cases (rifampicin for two months), but had little impact on rifampicin-throughout regimens: (6 months, new cases; 3.8%; OR 0.8, 95%CI:0.3,2.8; 8 months, retreatment cases: 7.3%, OR 1.8; 95%CI:1.3,2.6). Rr was missed in 7.6% of randomly selected "Hr" strains. Acquired Rr was frequent among recurrences on rifampicin-throughout regimens, particularly after the retreatment regimen (31.9%). It was higher in mono-Hr (29.3%; aOR 3.5, 95%CI:1.5,8.5) and poly-Hr (53.3%; aOR 10.2, 95%CI 4.4,23.7) than in susceptible tuberculosis, but virtually absent after the 8-month new case regimen. Comparing Bangladesh (low Rr prevalence) with a high Rr prevalence setting,true Hr corrected for missed Rr caused only 2-3 treatment failures per 1000 TB cases (of whom 27% were retreatments) in both.
Our analysis reveals a non-negligible extent of misclassifying as isoniazid resistance of what is actually missed multidrug-resistant tuberculosis. Recommending for such cases a "strengthened" regimen containing a fluoroquinolone provokes a direct route to extensive resistance while offering little benefit against the minor role of true Hr tuberculosis in rifampicin-throughout first-line regimen.
Tuberculosis (TB) is a poverty-related disease that is associated with poor living conditions. We studied TB mortality and living conditions in Bern between 1856 and 1950.
We analysed cause-specific ...mortality based on mortality registers certified by autopsies, and public health reports 1856 to 1950 from the city council of Bern.
TB mortality was higher in the Black Quarter (550 per 100,000) and in the city centre (327 per 100,000), compared to the outskirts (209 per 100,000 in 1911-1915). TB mortality correlated positively with the number of persons per room (r = 0.69, p = 0.026), the percentage of rooms without sunlight (r = 0.72, p = 0.020), and negatively with the number of windows per apartment (r = -0.79, p = 0.007). TB mortality decreased 10-fold from 330 per 100,000 in 1856 to 33 per 100,000 in 1950, as housing conditions improved, indoor crowding decreased, and open-air schools, sanatoria, systematic tuberculin skin testing of school children and chest radiography screening were introduced.
Improved living conditions and public health measures may have contributed to the massive decline of the TB epidemic in the city of Bern even before effective antibiotic treatment became finally available in the 1950s.
Immigrants from regions with a high incidence of tuberculosis (TB) are a risk group for TB in low-incidence countries such as Switzerland. In a previous analysis of a nationwide collection of 520 ...Mycobacterium tuberculosis isolates from 2000 to 2008, we identified 35 clusters comprising 90 patients based on standard genotyping (24-locus mycobacterial interspersed repetitive-unit-variable-number tandem-repeat MIRU-VNTR typing and spoligotyping). Here, we used whole-genome sequencing (WGS) to revisit these transmission clusters. Genome-based transmission clusters were defined as isolate pairs separated by ≤12 single nucleotide polymorphisms (SNPs). WGS confirmed 17/35 (49%) MIRU-VNTR typing clusters; the other 18 clusters contained pairs separated by >12 SNPs. Most transmission clusters (3/4) of Swiss-born patients were confirmed by WGS, as opposed to 25% (4/16) of the clusters involving only foreign-born patients. The overall clustering proportion was 17% (90 patients; 95% confidence interval CI, 14 to 21%) by standard genotyping but only 8% (43 patients; 95% CI, 6 to 11%) by WGS. The clustering proportion was 17% (67/401; 95% CI, 13 to 21%) by standard genotyping and 7% (26/401; 95% CI, 4 to 9%) by WGS among foreign-born patients and 19% (23/119; 95% CI, 13 to 28%) and 14% (17/119; 95% CI, 9 to 22%), respectively, among Swiss-born patients. Using weighted logistic regression, we found weak evidence of an association between birth origin and transmission (adjusted odds ratio of 2.2 and 95% CI of 0.9 to 5.5 comparing Swiss-born patients to others). In conclusion, standard genotyping overestimated recent TB transmission in Switzerland compared to WGS, particularly among immigrants from regions with a high TB incidence, where genetically closely related strains often predominate. We recommend the use of WGS to identify transmission clusters in settings with a low incidence of TB.
We examined the effect of an instructional video about the production of diagnostic sputum on case detection of tuberculosis (TB), and evaluated the acceptance of the video.
Randomized controlled ...trial.
We prepared a culturally adapted instructional video for sputum submission. We analyzed 200 presumptive TB cases coughing for more than two weeks who attended the outpatient department of the governmental Municipal Hospital in Mwananyamala (Dar es Salaam, Tanzania). They were randomly assigned to either receive instructions on sputum submission using the video before submission (intervention group, n = 100) or standard of care (control group, n = 100). Sputum samples were examined for volume, quality and presence of acid-fast bacilli by experienced laboratory technicians blinded to study groups.
Median age was 39.1 years (interquartile range 37.0-50.0); 94 (47%) were females, 106 (53%) were males, and 49 (24.5%) were HIV-infected. We found that the instructional video intervention was associated with detection of a higher proportion of microscopically confirmed cases (56%, 95% confidence interval 95% CI 45.7-65.9%, sputum smear positive patients in the intervention group versus 23%, 95% CI 15.2-32.5%, in the control group, p <0.0001), an increase in volume of specimen defined as a volume ≥3ml (78%, 95% CI 68.6-85.7%, versus 45%, 95% CI 35.0-55.3%, p <0.0001), and specimens less likely to be salivary (14%, 95% CI 7.9-22.4%, versus 39%, 95% CI 29.4-49.3%, p = 0.0001). Older age, but not the HIV status or sex, modified the effectiveness of the intervention by improving it positively. When asked how well the video instructions were understood, the majority of patients in the intervention group reported to have understood the video instructions well (97%). Most of the patients thought the video would be useful in the cultural setting of Tanzania (92%).
Sputum submission instructional videos increased the yield of tuberculosis cases through better quality of sputum samples. If confirmed in larger studies, instructional videos may have a substantial effect on the case yield using sputum microscopy and also molecular tests. This low-cost strategy should be considered as part of the efforts to control TB in resource-limited settings.
Pan African Clinical Trials Registry PACTR201504001098231.
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