Publications by authors named "Asencios L"

Peru has one of the highest burdens of multidrug-resistant tuberculosis (MDR-TB), but universal drug susceptibility testing (DST) has not yet been achieved. To estimate the proportion of drug resistance among smear-positive TB patients in Peru. From September 2014 to March 2015, we performed a national drug resistance survey of patients aged ≥15 years; TB was diagnosed based on sputum smear positivity.

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Background: Human immunodeficiency virus (HIV)-associated tuberculosis deaths have decreased worldwide over the past decade. We sought to evaluate the effect of HIV status on tuberculosis mortality among patients undergoing treatment for tuberculosis in Lima, Peru, a low HIV prevalence setting.

Methods: We conducted a prospective cohort study of patients treated for tuberculosis between 2005 and 2008 in two adjacent health regions in Lima, Peru (Lima Ciudad and Lima Este).

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Background: Resistance to second-line drugs develops during treatment of multidrug-resistant (MDR) tuberculosis, but the impact on treatment outcome has not been determined.

Methods: Patients with MDR tuberculosis starting second-line drug treatment were enrolled in a prospective cohort study. Sputum cultures were analyzed at a central reference laboratory.

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Background: The "fitness" of an infectious pathogen is defined as the ability of the pathogen to survive, reproduce, be transmitted, and cause disease. The fitness of multidrug-resistant tuberculosis (MDRTB) relative to drug-susceptible tuberculosis is cited as one of the most important determinants of MDRTB spread and epidemic size. To estimate the relative fitness of drug-resistant tuberculosis cases, we compared the incidence of tuberculosis disease among the household contacts of MDRTB index patients to that among the contacts of drug-susceptible index patients.

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Background: Peru holds the fourth highest burden of tuberculosis in the Americas. Despite an apparently well-functioning DOTS control program, the prevalence of multidrug resistant tuberculosis (MDR-TB) continues to increase. To worsen this situation, cases of extensively drug resistance tuberculosis (XDR-TB) have been detected.

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Background: Lost, delayed or incorrect laboratory results are associated with delays in initiating treatment. Delays in treatment for Multi-Drug Resistant Tuberculosis (MDR-TB) can worsen patient outcomes and increase transmission. The objective of this study was to evaluate the impact of a laboratory information system in reducing delays and the time for MDR-TB patients to culture convert (stop transmitting).

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The Mycobacterium avium complex (MAC) is a pathogen found in the environment which causes infections in immunocompetent and immunocompromised patients. One case is presented: an HIV positive, 38 year old male patient, infected with P. jirovecii and apparently infected with Mycobacterium tuberculosis since 2009.

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Setting: Programmatic implementation of decentralized rapid drug susceptibility testing (DST) in Lima, Peru.

Objective: Pre-post analysis compared time to diagnosis, treatment outcome and survival among patients tested with direct nitrate reductase assay (NRA) vs. indirect conventional methods.

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Background: The prevalence of extensively drug-resistant (XDR) tuberculosis is increasing due to the expanded use of second-line drugs in people with multidrug-resistant (MDR) disease. We prospectively assessed resistance to second-line antituberculosis drugs in eight countries.

Methods: From Jan 1, 2005, to Dec 31, 2008, we enrolled consecutive adults with locally confirmed pulmonary MDR tuberculosis at the start of second-line treatment in Estonia, Latvia, Peru, Philippines, Russia, South Africa, South Korea, and Thailand.

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To determine whether spatiotemporal information could help predict multidrug resistance at the time of tuberculosis diagnosis, we investigated tuberculosis patients who underwent drug susceptibility testing in Lima, Peru, during 2005-2007. We found that crude representation of spatial location at the level of the health center improved prediction of multidrug resistance.

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The Genotype®MTBDRplus molecular test is a method that allows identification of the most frequent mutations associated with resistance to major first-line antituberculosis drugs, Isoniazid (INH) and Rifampicin (RFP). The aim of this study was to evaluate the performance of the molecular test with culture and smear- positive sputum samples. We evaluated 95 cultures and 100 sputum samples with resistance profiles previously determined by the reference method "Agar Plate Proportions" (APP).

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In most countries with large drug resistant tuberculosis epidemics, only those cases that are at highest risk of having MDRTB receive a drug sensitivity test (DST) at the time of diagnosis. Because of this prioritized testing, identification of MDRTB transmission hotspots in communities where TB cases do not receive DST is challenging, as any observed aggregation of MDRTB may reflect systematic differences in how testing is distributed in communities. We introduce a new disease mapping method, which estimates this missing information through probability-weighted locations, to identify geographic areas of increased risk of MDRTB transmission.

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The Peruvian National Tuberculosis Control Program issued guidelines in 2006 specifying criteria for culture and drug-susceptibility testing (DST), including district-level rapid DST. All patients referred for culture and DST in 2 districts of Lima, Peru, during January 2005-November 2008 were monitored prospectively. Of 1,846 patients, 1,241 (67.

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Objective: To deliver rapid isoniazid (INH) and rifampicin (RMP) drug susceptibility testing (DST) close to the patient, we designed a decentralisation process for the microscopic observation drug susceptibility (MODS) assay in Peru and evaluated its reliability.

Methods: After 2 weeks of training, laboratory staff processed ≥ 120 consecutive sputum samples each in three regional laboratories. Samples were processed in parallel with MODS testing at an expert laboratory.

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We examined the spatiotemporal distribution of laboratory-confirmed multidrug-resistant tuberculosis (MDR TB) cases and that of other TB cases in Lima, Peru with the aim of identifying mechanisms responsible for the rise of MDR TB in an urban setting. All incident cases of TB in two districts of Lima, Peru during 2005-2007 were included. The spatiotemporal distributions of MDR cases and other TB cases were compared with Ripley's K statistic.

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Objective: To evaluate the time to communicate laboratory results to health centers (HCs) between the e-Chasqui web-based information system and the pre-existing paper-based system.

Methods: Cluster randomized controlled trial in 78 HCs in Peru. In the intervention group, 12 HCs had web access to results via e-Chasqui (point-of-care HCs) and forwarded results to 17 peripheral HCs.

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Objective: To evaluate the impact of the e-Chasqui laboratory information system in reducing reporting errors compared to the current paper system.

Design: Cluster randomized controlled trial in 76 health centers (HCs) between 2004 and 2008.

Methods: Baseline data were collected every 4 months for 12 months.

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Aim: To describe the incidence of extensive drug-resistant tuberculosis (XDR-TB) reported in the Peruvian National multidrug-resistant tuberculosis (MDR-TB) registry over a period of more than ten years and present the treatment outcomes for a cohort of these patients.

Methods: From the Peruvian MDR-TB registry we extracted all entries that were approved for second-line anti-TB treatment between January 1997 and June of 2007 and that had Drug Susceptibility Test (DST) results indicating resistance to both rifampicin and isoniazid (i.e.

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We created a web-based laboratory information system, e-Chasqui to connect public laboratories to health centers to improve communication and analysis. After one year, we performed a pre and post assessment of communication delays and found that e-Chasqui maintained the average delay but eliminated delays of over 60 days. Adding digital verification maintained the average delay, but should increase accuracy.

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Background: Performance characteristics of novel rapid drug susceptibility tests (DST) for Mycobacterium tuberculosis may change when moving from research to implementation in actual public health practice. We describe the performance characteristics of a direct, rapid DST when implemented in Lima, Peru.

Methods: A district laboratory validated conventional proportions and nitrate reductase methods.

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The aim of this work was to obtain the best possible estimate of the relevance of bovine tuberculosis (BTB) in humans in Argentina, Brazil, Chile, Colombia, Costa Rica, Dominican Republic, Ecuador, Peru, Uruguay and Venezuela. Sources of information were a questionnaire filled by the participant laboratories, and a search of published literature (1970-2007). Only four of these countries reported bacteriologically confirmed cases of BTB in humans.

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Background: Multi-drug resistant tuberculosis patients in resource-poor settings experience large delays in starting appropriate treatment and may not be monitored appropriately due to an overburdened laboratory system, delays in communication of results, and missing or error-prone laboratory data. The objective of this paper is to describe an electronic laboratory information system implemented to alleviate these problems and its expanding use by the Peruvian public sector, as well as examine the broader issues of implementing such systems in resource-poor settings.

Methods: A web-based laboratory information system "e-Chasqui" has been designed and implemented in Peru to improve the timeliness and quality of laboratory data.

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Timely diagnosis and effective, safe treatment are essential to reduce transmission and improve outcomes for patients with tuberculosis. Aside from laboratory methods, many programmatic factors influence the overall turnaround time (TAT) in diagnosing multidrug-resistant tuberculosis (MDR-TB). We measured each step in the overall TAT required for MDR-TB in two of five health districts of Lima, Peru.

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