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Your search keyword '"Viviana, Pinedo-Cancino"' showing total 2 results
Start Over Author "Viviana, Pinedo-Cancino" Publisher public library of science (plos)
2 results on '"Viviana, Pinedo-Cancino"'

1. Detection of toxoplasmic encephalitis in HIV positive patients in urine with hydrogel nanoparticles.

Author

Hannah E Steinberg, Natalie M Bowman, Andrea Diestra, Cusi Ferradas, Paul Russo, Daniel E Clark, Deanna Zhu, Ruben Magni, Edith Malaga, Monica Diaz, Viviana Pinedo-Cancino, Cesar Ramal Asayag, Maritza Calderón, Vern B Carruthers, Lance A Liotta, Robert H Gilman, Alessandra Luchini, and Toxoplasmosis working group in Peru and Bolivia

Subjects
Arctic medicine. Tropical medicine, RC955-962, Public aspects of medicine, RA1-1270
Abstract

BackgroundDiagnosis of toxoplasmic encephalitis (TE) is challenging under the best clinical circumstances. The poor clinical sensitivity of quantitative polymerase chain reaction (qPCR) for Toxoplasma in blood and CSF and the limited availability of molecular diagnostics and imaging technology leaves clinicians in resource-limited settings with few options other than empiric treatment.Methology/principle findingsHere we describe proof of concept for a novel urine diagnostics for TE using Poly-N-Isopropylacrylamide nanoparticles dyed with Reactive Blue-221 to concentrate antigens, substantially increasing the limit of detection. After nanoparticle-concentration, a standard western blotting technique with a monoclonal antibody was used for antigen detection. Limit of detection was 7.8pg/ml and 31.3pg/ml of T. gondii antigens GRA1 and SAG1, respectively. To characterize this diagnostic approach, 164 hospitalized HIV-infected patients with neurological symptoms compatible with TE were tested for 1) T. gondii serology (121/147, positive samples/total samples tested), 2) qPCR in cerebrospinal fluid (11/41), 3) qPCR in blood (10/112), and 4) urinary GRA1 (30/164) and SAG1 (12/164). GRA1 appears to be superior to SAG1 for detection of TE antigens in urine. Fifty-one HIV-infected, T. gondii seropositive but asymptomatic persons all tested negative by nanoparticle western blot and blood qPCR, suggesting the test has good specificity for TE for both GRA1 and SAG1. In a subgroup of 44 patients, urine samples were assayed with mass spectrometry parallel-reaction-monitoring (PRM) for the presence of T. gondii antigens. PRM identified antigens in 8 samples, 6 of which were concordant with the urine diagnostic.Conclusion/significancesOur results demonstrate nanoparticle technology's potential for a noninvasive diagnostic test for TE. Moving forward, GRA1 is a promising target for antigen based diagnostics for TE.

Published
2021
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2. Targeted Screening Strategies to Detect Trypanosoma cruzi Infection in Children

Author

Frank Steurer, Caryn Bern, Vivian Kawai, Natalie M. Bowman, Lance A. Waller, Lilia Cabrera, Viviana Pinedo-Cancino, James H. Maguire, Amy E. Seitz, Juan G. Cornejo del Carpio, Eleazar Cordova-Benzaquen, Michael J. Levy, and Robert H. Gilman

Subjects
Chagas disease, medicine.medical_specialty, lcsh:Arctic medicine. Tropical medicine, lcsh:RC955-962, 030231 tropical medicine, Serology, 03 medical and health sciences, 0302 clinical medicine, Pharmacotherapy, Internal medicine, 11. Sustainability, medicine, Targeted screening, 030212 general & internal medicine, Trypanosoma cruzi, Triatominae, biology, Transmission (medicine), lcsh:Public aspects of medicine, Public Health, Environmental and Occupational Health, lcsh:RA1-1270, biology.organism_classification, medicine.disease, 3. Good health, Infectious Diseases, Vector (epidemiology), Immunology
Abstract

Background: Millions of people are infected with Trypanosoma cruzi, the causative agent of Chagas disease in Latin America. Anti-trypanosomal drug therapy can cure infected individuals, but treatment efficacy is highest early in infection. Vector control campaigns disrupt transmission of T. cruzi, but without timely diagnosis, children infected prior to vector control often miss the window of opportunity for effective chemotherapy. Methods and Findings: We performed a serological survey in children 2–18 years old living in a peri-urban community of Arequipa, Peru, and linked the results to entomologic, spatial and census data gathered during a vector control campaign. 23 of 433 (5.3% [95% CI 3.4–7.9]) children were confirmed seropositive for T. cruzi infection by two methods. Spatial analysis revealed that households with infected children were very tightly clustered within looser clusters of households with parasite-infected vectors. Bayesian hierarchical mixed models, which controlled for clustering of infection, showed that a child’s risk of being seropositive increased by 20% per year of age and 4% per vector captured within the child’s house. Receiver operator characteristic (ROC) plots of best-fit models suggest that more than 83% of infected children could be identified while testing only 22% of eligible children. Conclusions: We found evidence of spatially-focal vector-borne T. cruzi transmission in peri-urban Arequipa. Ongoing vector control campaigns, in addition to preventing further parasite transmission, facilitate the collection of data essential to identifying children at high risk of T. cruzi infection. Targeted screening strategies could make integration of diagnosis and treatment of children into Chagas disease control programs feasible in lower-resource settings.

Published
2007
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