Browsing by Autor "Mary Cruz Torrico"

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A simple parasitological technique to increase detection of Strongyloides stercoralis in Bolivian primary health care system
(Research Square (United States), 2022) Ivana Camacho-Alvarez; Elia M. Chavez-Mamani; Philippe Goyens; Jenny Marcela Luizaga-López; Mary Cruz Torrico; Laurent Gétaz; Frédérique Jacobs
Abstract Background: Strongyloides stercoralis is widespread; however, there is limited information on its prevalence owing to laboratory underestimation and low clinical manifestations. The Baermann method and agar culture stand out among the parasitological techniques. Strongyloides stercoralis is present in Bolivia, but its prevalence in children remains unknown. The objective of this study was to estimate the applicability of simple parasitological techniques to increase the detection of this parasite in children living in the tropics. Methods: This cross-sectional study was conducted in a tropical village in Cochabamba, Bolivia. Participants were 304 children aged 5 – 12 years who provided stool samples for different parasitological analyses (direct examination, Ritchie, Barman, and Dancescu techniques), and their parents provided informed consent. Results: Up to 64.8% of pathogenic parasites were detected using the modified Ritchie method. The Baermann technique identified 17.8% of Strongyloides stercoralis cases, and a high sensitivity with respect to the Baermann technique was only for the Dancescu technique (75.9%) that is also specific for Strongyloides stercoralis , followed by 66.7% for the modified Ritchie technique, which is used in second-line care. Discussion: The Baermann technique is the best parasitological option for improving Strongyloides stercoralis diagnosis in the first-line care of the Primary Health Care System. A particular cycle of reinfection, combined with the environment and some other risk factors are related with persistence. Control is difficult without a proper diagnosis, and the Baermann technique is an approach to the solution. We conclude that with a high suspicion of the presence of Strongyloides stercoralis , the use of the Baermann technique is strongly recommended as support for direct examination in primary health care systems especially in tropical areas.
A simple parasitological technique to increase detection of Strongyloides stercoralis in Bolivian primary health care system
(BioMed Central, 2022) Ivana Camacho-Alvarez; Elia M. Chavez-Mamani; Goyens Philippe; Jenny M. Luizaga-López; Mary Cruz Torrico; Laurent Gétaz; Frédérique Jacobs
The Baermann technique is the best parasitological option for improving Strongyloides stercoralis diagnosis in the first-line care of the Primary Health Care System. A particular cycle of reinfection, combined with the environment and some other risk factors are related with persistence. Control is difficult without a proper diagnosis, and the Baermann technique is an approach to the solution. We conclude that with a high suspicion of the presence of Strongyloides stercoralis, the use of the Baermann technique is strongly recommended as support for direct examination in primary health care systems especially in tropical areas.
Additional file 1 of A simple parasitological technique to increase detection of Strongyloides stercoralis in Bolivian primary health care system
(Figshare (United Kingdom), 2022) Ivana Camacho-Alvarez; Elia M. Chavez-Mamani; Goyens Philippe; Jenny M. Luizaga-López; Mary Cruz Torrico; Laurent Gétaz; Frédérique Jacobs
Additional file 1. DATASET CBBA_SS: file containing the digitised database of the questionnaires and laboratory records coded.
AMNIOTIC FLUID IS NOT USEFUL FOR DIAGNOSIS OF CONGENITAL TRYPANOSOMA CRUZI INFECTION
(American Society of Tropical Medicine and Hygiene, 2006) Myrna Virreira; Sabrina Sales Martínez; Cristina Alonso‐Vega; Faustino Torrico; Marco Solano; Mary Cruz Torrico; Rudy Parrado; Carine Truyens; Yves Carlier; Michal Svoboda
Although Trypanosoma cruzi can be transmitted transplacentally and induce congenital infection, no data are available about the presence of this parasite in human amniotic fluid. We examined 8, 19, and 4 amniotic fluid samples (collected at delivery or by aspiration of gastric content of neonates) from control uninfected mothers (M−B−), infected mothers delivering uninfected newborns (M+B−), and mothers of confirmed congenital cases (M+B+), respectively. Polymerase chain reaction (PCR), using nuclear and kinetoplastic DNA primers (Tcz1-Tcz2 and 121–122), were negative for all control M−B− samples, but positive for 5 of 19 M+B− and 2 of 4 M+B+ samples. To determine the number of parasites in the positive samples, real-time PCR using S35/S36 kinetoplastic DNA was performed. Only one M+B+ sample presented a high parasitic DNA amount, whereas the other six PCR-positive samples displayed traces of T. cruzi DNA. In conclusion, the release of parasites in amniotic fluid is probably a rare event that cannot be helpful for the routine diagnosis of congenital Chagas disease.
Artificial Intelligence algorithm for real-time detection and counting of Trypanosoma cruzi parasites using smartphone microscopy
(2025) Lin Lin; A. Solano; Fabiola Gonzales; Mary Cruz Torrico; Daniel Illanes; Nuria Díez; David Bermejo-Peláez; Elena Dacal; Ramón Vallés-López; Luis Pastor
Abstract Chagas disease affects 6–7 million people worldwide and causes approximately 12,000 deaths annually. Diagnostic methods vary by disease stage, with serological tests commonly used in the chronic phase, while microscopy and molecular techniques like PCR and LAMP are employed in the acute phase. While microscopy remains the most accessible tool in resource constrained settings, its effectiveness depends on skilled personnel, creating diagnostic bottlenecks. To overcome these limitations, we developed a portable, smartphone-integrated AI system for real-time Trypanosoma cruzi detection in microscopy images. The platform combines a 3D-printed microscope adapter which aligns the smartphone camera with microscope ocular to digitize images, telemedicine-enabled annotation workflows, and lightweight AI models (SSD-MobileNetV2, YOLOv8) deployed on smartphone for real-time analysis. Trained on a diverse dataset of human samples (478 images from 20 samples), including thick/thin blood smears and cerebrospinal fluid) and murine thin smears (570 images from 33 samples), the SSD-MobileNetV2 model achieved 86% precision, 87% recall, and 86.5% F1-score on human samples, demonstrating robust performance across variable imaging conditions. This system enables rapid, accurate parasite detection in field settings without advanced infrastructure, addressing critical gaps in early diagnosis and monitoring. Its modular design allows adaptation to other pathogens and cellular structures, offering a scalable solution for neglected tropical disease diagnostics. By bridging AI innovation with microscopy, this approach holds promise for advancing equitable healthcare delivery in endemic regions and aligning with global health priorities. Author Summary Chagas disease is a life-threatening illness affecting millions, primarily in Latin America, where access to advanced laboratory equipment and trained specialists is limited. One method of diagnosis is microscopic examination of blood or cerebrospinal fluid samples, it provides immediate results without requiring complex facilities, but its effectiveness depends on the expertise of trained microscopists. We developed a simple, low-cost tool that combines a smartphone, a light microscope, and artificial intelligence (AI) to assist the diagnosis. By attaching a smartphone to a microscope with a 3D-printed adapter, users analyze microscopy images with real-time AI assistance, detecting the parasites causing Chagas disease. Our results show that this approach is accurate and could be useful for regions with limited healthcare infrastructure. It reduces reliance on specialized training and expensive equipment, helping communities diagnose Chagas faster. Beyond Chagas, this approach can be adapted to detect other diseases, offering a versatile tool for fighting neglected tropical illnesses. By bridging gaps in healthcare access, we hope to empower frontline workers and contribute to global efforts to reduce the burden of these diseases on vulnerable populations.
Big is not better: Comparing two alpha-Gal-bearing glycotopes in neoglycoproteins as biomarkers for Leishmania (Viannia) braziliensis infection
(Elsevier BV, 2023) Alba L. Montoya; Eileni R. Gil; Irodiel Vinales; Igor L. Estevao; Paola Taboada; Mary Cruz Torrico; Faustino Torrico; Jorge D. Marco; Igor C. Almeida; Katja Michael
Clinical and immunological characteristics of tegumentary leishmaniasis cases in Bolivia
(Public Library of Science, 2021) Cristina Ballart; Mary Cruz Torrico; Gisela Vidal; Faustino Torrico; Daniel Lozano; Montserrat Gállego; Lilian Pinto; Ernesto Rojas; Ruth Aguilar; Carlota Dobaño
In Bolivia, parasitological diagnosis remains the reference standard in diagnosis of leishmaniasis because of its high specificity, whereas the sensitivity varies over a wide range leading to loss of cases. Until more accurate tools are implemented, all patients should be tested by both smears and culture of lesion aspirates to minimize the risk of false negatives. Our results showed higher concentrations of several cytokines in MCL compared to CL, but no differences were observed between CL and no-cases. In addition, none of the cytokines differed between primary and secondary infections. These results highlight the need of further research to identify biomarkers of susceptibility and disease progression, in addition to looking at the local cellular immune responses in the lesions.
Co-Infection of Leishmania (Viannia) braziliensis and HIV: Report of a Case of Mucosal Leishmaniasis in Cochabamba, Bolivia
(American Society of Tropical Medicine and Hygiene, 2009) Faustino Torrico; Rudy Parrado; Rosario Castro; Carla Jimena Marquez; Mary Cruz Torrico; Marco Solano; Richard Reithinger; Ana Lineth García
We describe the first case of Leishmania/HIV co-infection reported in Bolivia. Initially hospitalized with a diagnosis of pneumonia and bronchitis, the patient had numerous cutaneous and mucosal lesions caused by Leishmania (Viannia) braziliensis. The patient was also diagnosed as severely immunocompromised because of HIV infection.
Cuantificación de niveles de INF-y - IL-13 y células T CD4+, CD8+ en pacientes con leishmaniasis tegumentaria con falla terapéutica
(2013) Amilcar Flores León; Ernesto Rojas Cabrera; Marisol Córdova Rojas; Mary Cruz Torrico; David Paz
Objetivos: se realiza un estudio del estatus inmunologico, cuantificando el perfil de citoquinas Th1 (INF-γ) y Th2 (IL-13) y celulas T CD3+, CD4+ y CD8+ como variables que puedan brindar informacion sobre el vinculo y/o asociacion a la falla terapeutica. Metodos: se cuantifico los niveles de INF-γ , IL-13, CD4 + y CD8+ en tres grupos de estudio: a) Pacientes con LT y falla terapeutica (RESISTENTES), b) Pacientes tratados que respondieron al tratamiento de forma exitosa (SENSIBLES) c) Pacientes sanos (GRUPO CONTROL). Resultados: los resultados indican, que la respuesta especifica inmune de los pacientes Resistentes y Sensibles esta polarizada hacia la respuesta TH1 y los valores de los Linfocitos T CD4+ y CD8+ estaban por debajo de los valores normales en los tres grupos de estudio. Los niveles de produccion de INF- γ fue mayor que la IL-13, siendo mas pronunciada en pacientes Resistentes que Sensibles en respuesta al Ag de Leishmania, la tipificacion de las cepas que fueron aisladas de los pacientes resistentes, identificaron a: Leishmania brasiliensis y Leishmania guayanensis. Conclusiones: en relacion a la falla terapeutica de los pacientes resistentes, estarian tambien involucrados los factores relacionados al parasito y otros factores extrinsecos al huesped. Palabras claves: leishmaniasis cutanea; fracaso del tratamiento; citocinas; recuento de linfocito CD4; interferones. Objectives: is a study of the immune status, quantifying the Th1 cytokine profile (IFN-γ) and Th2 (IL-13) and CD3 + T cells, CD4 + and CD8 + as variables that can provide information on the link and / or association therapeutic failure. Methods: we quantified the levels of INF-γ, IL-13, CD4 + and CD8 + in three study groups: a) patients with LT and therapeutic failure (RESISTANT), b) Treated patients who responded to treatment successfully (SENSITIVE ) c) healthy patients (CONTROL GROUP). Results: the results indicate that the specific immune res ponse of resistant and sensitive patients is polarized toward the TH1 response and values of CD4 + T lymphocytes and CD8 + were below normal values in the thr ee groups. The levels of IFN-γ production was higher than IL-13, being more pronounced in patients resistant to sensitive in response to Leishmania Ag, the typing of the strains that were isolated from patients resistant identified: Leishmania brasi liensis and guayanensis Leishmania. Conclusions: regarding treatment failure resistant patients, would also be involved factors related to the parasite and other extrinsic factors to the host.
Detección de cryptosporidium spp y giardia lamblia en niños inmunodeprimidos del Hospital del Niño Manuel Ascencio Villarroel de Cochabamba en Agosto del 2007
(2008) Patricia Denisse Barrientos Galarza; Mary Cruz Torrico; Eduardo Suárez Barrientos
Detection of cryptosporidium spp and Giardia Lamblia in inmunodepressed children of the niñ@ Hospital Manuel Ascencio Villarroel of Cochabamba in august of 2007
(2008) Patricia Denisse Barrientos Galarza; Mary Cruz Torrico; Eduardo Suárez Barrientos
Estandarización de la técnica para la obtención de trypomastigotes en células 3T3 a partir de una cepa local de epimastigotes de Tripanosoma cruzi
(2015) Marisol Córdova Rojas; Mary Cruz Torrico; Faustino Torrico
Objetivo: evaluar el empleo de cultivos celulares para la obtencion de tripomastigotes en celulas 3T3, a partir de una cepa local de epimastigotes de Tripanosoma cruzi.Metodo: se realizo cultivo in vitro de celulas 3T3 en medio DMEM-SBF al 10% mas penicilina estreptomicina, a 37°C, 95% de humedad y 5% de CO2 al septimo dia, fueron infectados con epimastigotes de T. cruzi cepa TcV, aislados de pacientes con Chagas agudo y cultivados preliminarmente en medios bifasicos como NNN y LIT.Resultados: a los 14 dias de infeccion se observo al parasito en las formas: de amastigotes (forma intracelular), posteriormente la tripomastigote (forma extracelular) que fueron liberados al medio una vez lisadas las celulas infectadas. Posteriores sub cultivos de celulas 3T3 con trypomastigotes obtenidos a partir de los epimastigotes mejoran la obtencion de T. cruzi.Conclusiones: es posible la obtencion de trypomastigotes a partir de una cepa local de epimastigotes recreando el ciclo biologico del parasito in vitro.Palabras claves: cultivos celulares, epimastigotes, trypomastigotes, celulas 3T3, cepa de T. cruzi - TcV.
Estatus inmunológico de las madres infectadas por T. cruzi.
(Université Libre de Bruxelles, 2005) Cristina Alonso‐Vega; Emmanuel Hermann; Carine Truyens; Patricia Rodríguez; Mary Cruz Torrico; Faustino Torrico; Yves Carlier
The mechanisms of congenital transmission of Chagas disease remain largely unknown. To better understand the role of maternal immunology during pregnancy in congenital Chagas transmission, we studied the cytokine production and the parasitic load in three groups of mothers: infected mothers who transmitted the disease to their babies (M+B+-), infected mothers who did not transmit the disease to their babies (M+B-) and not infected mothers as a control group (M-B-). M+B+ mothers produced less IFNgamma and more IL-10 than the M+B- mothers, and they are not able to produce IL-2. M+B+ mothers showed a higher parasitic load. These results, indicated that the congenital Chagas transmission is associated with an immunological imbalance and a high parasitic load in the M+B+ mothers.
[Estimation of the parasitemia in Trypanosoma cruzi human infection: high parasitemias are associated with severe and fatal congenital Chagas disease].
(National Institutes of Health, 2005) Mary Cruz Torrico; Marco Solano; José Miguel Guzmán; Rudy Parrado; Eduardo Suárez; Cristina Alonzo-Vega; Carine Truyens; Yves Carlier; Faustino Torrico
The aim of this study was to validate the method of microhematocrit tube, as a rapid method to estimate the parasitemia in blood and to associate the parasites concentration with the morbidity and mortality of new born children with congenital Chagas diseases. Our results were determined experimentally and shown that the detection limit of the microhematocrit tube method is 40 parasites/ml when at least one of the four observed tubes is positive. Besides, it was also established that when the four examined tubes are positive the parasitemia in blood reaches more than 100 parasites/ml. It is important to highlight the modification made by our laboratory in the microscopic observation of the microhematocrit tubes with respect to the methodology used by previous investigators. A positive association exists between a high number of parasites in blood and the morbi-mortality of the newly born children with congenital chagas. The results of positive association between the parasitic load and the morbility and mortality could constitute an argument to understand the possible role of the parasite in the pathology of the disease.
Evaluation of the Diagnostic Sensitivity of the VIASURE Leishmania Real-Time PCR Detection Kit Prototype for the Diagnosis of Cutaneous and Visceral Leishmaniasis
(Wiley, 2023) Albert Arnau; Alba Abràs; Cristina Ballart; Anna Fernández‐Arévalo; Mary Cruz Torrico; Sílvia Tebar; Teresa Llovet; Montserrat Gállego; Carmen Muñoz
Leishmaniasis is a parasitic disease with clinical presentations that vary from asymptomatic infection to cutaneous, mucocutaneous, or visceral disease. Global change, with migratory movements and travels, among others, has had an impact on the presentation of the clinical forms of leishmaniasis in a given area, hindering its diagnosis. The traditional parasitological techniques have limited sensitivity, and currently, there is no reference or gold-standard molecular diagnostic method. The aim of this study was to evaluate the effectivity of the VIASURE Leishmania Real-Time PCR Detection Kit prototype (CerTest Biotec, Zaragoza, Spain) for the diagnosis of autochthonous and imported leishmaniasis in comparison with two other commercialized molecular kits: STAT-NAT® Leishmania spp. (Sentinel, Milano, Italy) and Leishmania spp. Real-TM PCR Kit (Sacace Biotechnologies, Como, Italy). Four species of Leishmania, L. infantum, L. major, L. braziliensis, and L. panamensis, were targeted to assess analytical sensitivity, whereas diagnostic sensitivity was evaluated by studying a panel of 49 DNA samples from patients with suspected or confirmed Leishmania infection. The prototype could detect all the New and Old World species studied and achieved a limit of detection of 5 × 10-5 ng DNA/μL in all species. Also, it allowed the diagnosis of autochthonous and imported cases of cutaneous and visceral leishmaniasis (VL). Diagnostic sensitivity was 81.8% for the prototype and 100% for the Sacace kit (27 and 33 positive samples detected, respectively). The STAT-NAT® kit failed to detect Vianna species. The VIASURE Leishmania Real-Time PCR Detection Kit prototype was found to have good analytical and diagnostic sensitivity. Using a simple protocol and ready-to-use reagents, results are obtained quickly and are easy to interpret. The evaluation results indicate that the test is a promising candidate for routine diagnosis of cutaneous leishmaniasis and VL in endemic countries, but more studies are necessary to address its sensitivity and specificity.
[Immunological status of mothers infected with Trypanosoma cruzi].
(National Institutes of Health, 2005) Cristina Alonso‐Vega; Emmanuel Hermann; Carine Truyens; Patricia Rodríguez; Mary Cruz Torrico; Faustino Torrico; Yves Carlier
The mechanisms of congenital transmission of Chagas disease remain largely unknown. To better understand the role of maternal immunology during pregnancy in congenital Chagas transmission, we studied the cytokine production and the parasitic load in three groups of mothers: infected mothers who transmitted the disease to their babies (M+B+-), infected mothers who did not transmit the disease to their babies (M+B-) and not infected mothers as a control group (M-B-). M+B+ mothers produced less IFNgamma and more IL-10 than the M+B- mothers, and they are not able to produce IL-2. M+B+ mothers showed a higher parasitic load. These results, indicated that the congenital Chagas transmission is associated with an immunological imbalance and a high parasitic load in the M+B+ mothers.
In vitro promastigote fitness of putative Leishmania (Viannia) braziliensis/Leishmania (Viannia) peruviana hybrids
(Elsevier BV, 1999) Mary Cruz Torrico; Simonne De Doncker; Jorge Arévalo; D. Le Ray; Jean‐Claude Dujardin
Intradomiciliary and peridomiciliary captures of sand flies (Diptera: Psychodidae) in the leishmaniasis endemic area of Chapare province, tropic of Cochabamba, Bolivia
(Elsevier BV, 2015) Cristina Ballart; Gisela Vidal; Albert Picado; Mirko Rojas Cortez; Faustino Torrico; Mary Cruz Torrico; Rodrigo Espíndola Godoy; Daniel Lozano; Montserrat Gállego
Molecular detection and parasite load of Trypanosoma cruzi in digestive tract tissue of Chagas disease patients affected by megacolon
(Elsevier BV, 2022) Lilian Pinto; Alejandro G. Schijman; Julio Alonso-Padilla; Daniel Lozano; Mary Cruz Torrico; Pietro Gamba; Margarita Torrez; Vania Lozada; Karina Cartagena; Jareth Sánchez
Multiprimer PCR System Diagnosis of Pulmonary Tuberculosis in Cochabamba, Bolivia
(American Society for Microbiology, 2007) Rudy Parrado; Daniel Lozano; Lineth García; Mary Cruz Torrico; Raúl Delgado; Faustino Torrico; Monica Laserna; Richard Reithinger
Bolivia has one of the highest incidence rates of tuberculosis (TB) in the Americas. An estimated 15,000 new cases per year are detected ([1][1]), which corresponds to an incidence rate of 112 cases per 100,000 population; 1,600 deaths due to TB are reported to occur annually ([10][2]). The actual