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Cetina, Linda Grace Molano

doi:10.7705/biomedica.v31i0.525

Cited by 1 publication

(3 citation statements)

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“…Patients were treated with Bnz (6 mg/kg/day) during 60 continuous days in three daily doses (Alarcoń de Noya et al, 2011;Alarcon de Noya et al, 2016). During follow-up, nine treated patients who remained with evidence of parasite persistence (high values in anti-T. cruzi IgG titers, presence of lytic antibodies, and/or persistence of positive PCR) received a new course of treatment with Bnz (Amato Neto, 1999).…”

Section: Antiparasitic Treatmentmentioning

confidence: 99%

“…ELISA tests involving antihuman IgG alkaline phosphatase conjugates were carried out simultaneously in all sera. ELISA IgG cut-off line was defined as an optical density (OD) value equal to 0.200 to determine a positive sample (Alarcoń de Noya et al, 2011).…”

Section: Immunoenzymatic Assaymentioning

confidence: 99%

“…In these patients, the outcome observed by serological, parasitological and PCR-based monitoring two years after treatment with Benznidazole (Bnz) was disappointing. Around 70% of patients still had positive lytic antibodies; some presented anti-T.cruzi IgG antibody titers and positive T. cruzi PCR findings (Alarcoń de Noya et al, 2011). Considering that Bnz is highly effective in the acute phase and during childhood in other endemic regions where other parasite DTUs prevail (Bianchi et al, 2015;Moscatelli et al, 2019), these data suggested therapeutic failure and consequently a second treatment was administered to people with persistence of lytic antibodies and/or positive PCR results, however without outcome improvement (Garcia-Bournissen, 2019;Molina-Morant et al, 2020).…”

Section: Introductionmentioning

confidence: 99%

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Characterization and Follow-Up of Trypanosoma cruzi Natural Populations Refractory to Etiological Chemotherapy in Oral Chagas Disease Patients

Muñoz-Calderón

Díaz-Bello

Noya

et al. 2021

Front. Cell. Infect. Microbiol.

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We aimed to characterize the genetic constitution of natural T. cruzi populations involved in an Oral Chagas Disease (OCD) outbreak at a rural school of the community of Chichiriviche de la Costa, Venezuela, which affected patients did not respond to the etiological treatment. Peripheral blood samples and/or hemocultures were obtained from twenty-nine OCD patients at time of diagnosis or along nine years of Post-treatment (Tx) follow-up. The IgG serology, T. cruzi discrete typing units (DTU), satellite DNA-qPCR parasitic loads, and minicircle signatures were determined at Pre-Tx and after Tx. The serological titles and parasitic loads changed after treatment, with a significant decrease of IgG titers (Spearman’s r value= -0.961) and median parasite loads from 2.869 [IQR = 2.113 to 3.720] to 0.105 [IQR = -1.147 to 1.761] log10 par eq. /mL at Pre-Tx and Post-Tx, respectively, suggesting infection evolution from acute to chronic phase, without seroconversion or parasitological eradication, which was indicative of treatment failure. All patients were infected with T. cruzi DTU I populations. At Pre-Tx their median Jaccard genetic distances were 0.775 [IQR = 0.708 to 0.882], decreasing in genetic variability towards the end of follow-up (Mann-Whitney U test p= 0.0031). Interestingly, no Post-Tx minicircle signature was identical to its Pre-Tx counterpart population in a same patient, revealing selection of parasite subpopulations between the primary infection and Post-Tx. The parasitic populations isolated from hemocultures showed a lower number of bands in the minicircle signatures with respect to the signatures obtained directly from the patients’ blood samples, demonstrating a process of parasitic selection and reduction of the population variability that initially infected the patients. Decrease of parasitic loads after treatment as well as Pre- and Post-Tx intra-TcI diversity might be a consequence of both, natural evolution of the acute infection to the chronic phase and persistence of refractory populations due to Tx selection.

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Section: Antiparasitic Treatmentmentioning

confidence: 99%

Section: Immunoenzymatic Assaymentioning

confidence: 99%