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Sanchez-Camargo C.L.,Medecins Sans Frontieres | Sanchez-Camargo C.L.,Autonomous University of Barcelona | Sanchez-Camargo C.L.,Antonio Narino University | Albajar-Vinas P.,WHO Program on Control of Chagas Disease | And 13 more authors.
Journal of Clinical Microbiology | Year: 2014

Chagas disease is one of the main public health issues in Latin America. Increasingly during the past few decades, Trypanosoma cruzi infection has been detected in North America, Europe, and the Western Pacific, mainly as a result of population movement. The limited availability of rapid serological diagnostic tests hinders rapid diagnosis and early treatment in areas of endemicity and nonendemicity. In collaboration with 11 national reference laboratories (NRLs) from different geographical areas, we evaluated the performances of commercialized serological rapid diagnostic tests (RDT) for T. cruzi infection. Eleven commercialized T. cruzi infection RDTs were evaluated on a total of 474 samples extensively tested with at least three different techniques for Chagas disease, maintained at controlled low temperatures, and stored in the serum banks of the 11 NRLs. We measured the sensitivity, specificity, and concordance of each RDT and provided an additional questionnaire to evaluate its ease of use. The selected RDTs in this study were performed under controlled laboratory conditions. Out of the 11 RDTs, we found 8 of them to be useful, with the cassette format favored over the strip. We did not observe significant differences in RDT performances in the different regions. Overall, the performance results were lower than those disclosed by the manufacturers. The results of this evaluation validate the possibility of using RDTs to diagnose Chagas disease, thereby decreasing the time to treatment at a primary health care facility for patients who are willing to be treated. Further studies should be conducted in the laboratory and in the field to confirm these data, expressly to evaluate reproducibility in resource-limited settings, or using whole blood in clinical settings in areas of endemicity and nonendemicity. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Sanchez L.V.,University Militar Nueva Granada | Bautista D.C.,University Militar Nueva Granada | Corredor A.F.,University Militar Nueva Granada | Herrera V.M.,Autonomous University of Bucaramanga | And 5 more authors.
Microbes and Infection | Year: 2013

Chagas disease caused by Trypanosoma cruzi is a public health problem in Latin America. This parasite displays a high genetic diversity evidenced in six Discrete Typing Units (DTUs) namely TcI-TcVI. The aim of this study was to observe the temporal variation of the DTUs in asymptomatic patients at three different times (10 days interval). The results showed that intermittence is the rule in the bloodstream of Chagas disease patients. The patients showed different detectable DTUs with short time intervals, which favors the clonal histiotropic model and the multiclonality structure of this parasite. © 2013 .

Leon N.,Cayetano Heredia Peruvian University | Padilla C.,Instituto Nacional Of Salud Ins | Pajuelo M.,Cayetano Heredia Peruvian University | Sheen P.,Cayetano Heredia Peruvian University | Zimic M.,Cayetano Heredia Peruvian University
Revista Peruana de Medicina Experimental y Salud Publica | Year: 2013

Taenia solium is a plane helminth responsible for taeniasis and human cysticercosis, the latter being the result of the consumption of infective eggs. Cysticerci can develop in different human tissues, often in the central nervous system, causing neurocysticercosis (NCC). For the diagnosis of NCC, an adequate interpretation of clinical data, neuroimaging results and serological tests are required. However, serological tests could be improved by developing candidate antigens able to increase their sensibility and specificity. In the last years, a series of surface and secretory proteins of T. solium essential for the parasite-host interaction have been described. One of these families is cathepsin L cysteine proteases, which have a predominant role in the development and survival of the parasite. They take part in the tissue invasion, immune response evasion, excystation and encystment of cysticercus. They are considered potential antigens for the immunodiagnosis of neurocysticercosis.

Caicedo Y.,Hospital Universitario del Valle | Paez A.,Instituto Nacional Of Salud Ins | Kuzmin I.,Centers for Disease Control and Prevention | Kuzmin I.,Medical College of Wisconsin | And 7 more authors.
Pediatric Infectious Disease Journal | Year: 2015

Background: Rabies is an acute fatal encephalitis caused by all members of the Lyssavirus genus. The first human rabies survivor without benefit of prior vaccination was reported from Milwaukee in 2005. We report a second unvaccinated patient who showed early recovery from rabies and then died accidentally during convalescence, providing an unparalleled opportunity to examine the histopathology as well as immune and virological correlates of early recovery from human rabies. Methods: Case report, rapid fluorescent focus inhibition test, enzyme-linked immunosorbent assay, indirect and direct fluorescent antibody assays, reverse-transcriptase polymerase chain reaction, phylogenetic reconstruction, isolation in tissue culture, pathology and immunohistochemistry. Results: The 9 year old died 76 days after presenting with rabies of vampire bat phylogeny transmitted by cat bite. Antibody response in serum and cerebrospinal fluid was robust and associated with severe cerebral edema. No rabies virus was cultured at autopsy. Rabies virus antigen was atypical in size and distribution. Rabies virus genome was present in neocortex but absent in brainstem. Conclusions: Clinical recovery was associated with detection of neutralizing antibody and clearance of infectious rabies virus in the central nervous system by 76 days but not clearance of detectable viral subcomponents such as nucleoprotein antigen or RNA in brain. © 2015 Wolters Kluwer Health, Inc.

Fitzwater S.P.,Cayetano Heredia Peruvian University | Sechler G.A.,Cayetano Heredia Peruvian University | Sechler G.A.,The New School | Jave O.,Estrategia Sanitaria Nacional de Prevencion y Control de la Tuberculosis | And 7 more authors.
European Respiratory Journal | Year: 2013

Multidrug-resistant tuberculosis (TB) threatens TB control worldwide. The microscopic observation drug susceptibility (MODS) assay is a low-cost, high-performance TB diagnostic tool for rapid liquid culture and direct isoniazid and rifampicin drug susceptibility testing (DST). The objective of this study was to explore the potential for extending the MODS assay to rapid second-line DST and to identify critical concentrations of candidate drugs for prospective testing. Sputum samples from 94 TB culture-positive patients receiving second-line TB agents were cultured following standardised MODS protocols, with a range of titrations of antimicrobial drugs added. Critical concentrations were determined using a modified Kaplan-Meier survival curve analysis. Candidate critical concentrations were determined for capreomycin (10 μg·mL-1), ciprofloxacin (1.25 μg·mL -1), cycloserine (40 μg·mL-1), ethambutol (10 μg·mL-1), ethionamide (5 μg·mL-1), kanamycin (5 μg·mL-1), para-aminosalicylic acid (10 μg·mL-1) and streptomycin (10 μg·mL -1). No cut-off point was identified for the other second-line drugs or for pyrazinamide. At particular concentrations of some second-line TB drugs this novel Kaplan-Meier analysis clearly differentiated populations that were susceptible or resistant. These candidate critical concentrations should now be tested in a range of epidemiological settings to define the performance of direct, second-line TB DST with MODS, offering potential low-cost second-line TB DST capacity. Copyright©ERS 2013.

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