Different serological cross-reactivity of Trypanosoma rangeli forms in Trypanosoma cruzi-infected patients sera

<p>Abstract</p> <p>Background</p> <p>American Trypanosomiasis or Chagas disease is caused by <it>Trypanosoma cruzi </it>which currently infects approximately 16 million people in the Americas causing high morbidity and mortality. Diagnosis of American trypanosomiasis relies on serology, primarily using indirect immunofluorescence assay (IFA) with <it>T. cruzi </it>epimastigote forms. The closely related but nonpathogenic <it>Trypanosoma rangeli </it>has a sympatric distribution with <it>T. cruzi </it>and is carried by the same vectors. As a result false positives are frequently generated. This confounding factor leads to increased diagnostic test costs and where false positives are not caught, endangers human health due to the toxicity of the drugs used to treat Chagas disease.</p> <p>Results</p> <p>In the present study, serologic cross-reactivity between the two species was compared for the currently used epimastigote form and the more pathologically relevant trypomastigote form, using IFA and immunoblotting (IB) assays. Our results reveal an important decrease in cross reactivity when <it>T. rangeli </it>culture-derived trypomastigotes are used in IFA based diagnosis of Chagas disease. Western blot results using sera from both acute and chronic chagasic patients presenting with cardiac, indeterminate or digestive disease revealed similar, but not identical, antigenic profiles.</p> <p>Conclusion</p> <p>This is the first study addressing the serological cross-reactivity between distinct forms and strains of <it>T. rangeli </it>and <it>T. cruzi </it>using sera from distinct phases of the Chagasic infection. Several <it>T. rangeli</it>-specific proteins were detected, which may have potential as diagnostic tools.</p

Coping strategies of women with postpartum depression symptoms in rural Ethiopia: a cross-sectional community study

Background: Most women with postpartum depression (PPD) in low- and middle-income countries remain undiagnosed and untreated, despite evidence for adverse effects on the woman and her child. The aim of this study was to identify the coping strategies used by women with PPD symptoms in rural Ethiopia to inform the development of socio-culturally appropriate interventions. Methods: A population-based, cross-sectional study was conducted in a predominantly rural district in southern Ethiopia. All women with live infants between one and 12 months post-partum (n = 3147) were screened for depression symptoms using the validated Patient Health Questionnaire, 9 item version (PHQ-9). Those scoring five or more, ‘high PPD symptoms’, (n = 385) were included in this study. The Brief Coping with Problems Experienced (COPE-28) scale was used to assess coping strategies. Construct validity of the brief COPE was evaluated using confirmatory factor analysis. Results: Confirmatory factor analysis of the brief COPE scale supported the previously hypothesized three dimensions of coping (problem-focused, emotion-focused, and dysfunctional). Emotion-focused coping was the most commonly employed coping strategy by women with PPD symptoms. Urban residence was associated positively with all three dimensions of coping. Women who had attended formal education and who attributed their symptoms to a physical cause were more likely to use both problem-focused and emotion-focused coping strategies. Women with better subjective wealth and those who perceived that their husband drank too much alcohol were more likely to use emotion-focused coping. Dysfunctional coping strategies were reported by women who had a poor relationship with their husbands. Conclusions: As in high-income countries, women with PPD symptoms were most likely to use emotion-focused and dysfunctional coping strategies. Poverty and the low level of awareness of depression as an illness may additionally impede problem-solving attempts to cope. Prospective studies are needed to understand the prognostic significance of coping styles in this setting and to inform psychosocial intervention development

Antibody response of naturally infected individuals to recombinant Plasmodium vivax apical membrane antigen-1

In the present study, we evaluate the naturally acquired antibody response to the Plasmodium vivax apical membrane antigen 1 (PvAMA-1), a leading vaccine candidate against malaria. the gene encoding the PvAMA-1 ectodomain region (amino acids 43-487) was cloned by PCR using genomic DNA from a Brazilian individual with patent P. vivax infection. the predicted amino acid sequence displayed a high degree of identity (97.3%) with a previously published sequence from the P. viva-v Salvador strain. A recombinant protein representing the PvAMA-1 ectodomain was expressed in Escherichia coli and refolded. By ELISA, this recombinant protein reacted with 85 and 48.5% of the IgG or IgM antibodies, respectively, from Brazilian individuals with patent P. vivax malaria. IgG I was the predominant subclass of IgG. the frequency of response increased according to the number of malaria episodes, reaching 100% in individuals in their fourth malaria episode. the high degree of recognition of PvAMA-1 by human antibodies was confirmed using a second recombinant protein expressed in Pichia pastoris (PV66/AMA-1). the observation that recognition of the bacterial recombinant PvAMA-1 was only slightly lower than that of the highly immunogenic 19 kDa C-terminal domain of the P. vivax Merozoite Surface Protein-1 was also important. DNA sequencing of the PvAMA-1 variable domain from 20 Brazilian isolates confirmed the limited polymorphism of PvAMA-1 suggested by serological analysis. in conclusion, we provide evidence that PvAMA-1 is highly immunogenic during natural infection in humans and displays limited polymorphism in Brazil. Based on these observations, we conclude that PvAMA-1 merits further immunological studies as a vaccine candidate against P. vivax malaria. (C) 2004 Australian Society for Parasitology Inc. Published by Elsevier B.V. All rights reserved.Univ São Paulo, Dept Anal Clin & Toxicol, Fac Ciencias Farmaceut, BR-05508900 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Microbiol Immunol & Parasitol, BR-04023062 São Paulo, BrazilBiomed Primate Res Ctr, Dept Parasitol, NL-2280 GH Rijswijk, NetherlandsUniversidade Federal de São Paulo, Dept Microbiol Immunol & Parasitol, BR-04023062 São Paulo, BrazilWeb of Scienc

Efficacy profile of Cypermethrin and Chlorpyrifos based acaricides on Rhipicephalus microplus control on cattle in the rearing phase, naturally infested and exposed to tick fever agents in central Brazil.

The objective of this work was to evaluate the efficacy of two cypermethrin- and chlorpyrifos-based acaricides in controlling Rhipicephalus microplus in a naturally infested bovine herd and in in vitro tests, as well as to monitor the animals for tick fever. Male bovines in the rearing phase were used, with 30 Brangus and 30 Nellore animals naturally infested. The groups were composed as follows: 15 Nellore treated, 15 Nellore control, 15 Brangus treated and 15 Brangus control. Every 18 days, the animals were monitored for tick count, acaricide treatment, weight, blood pack cell volume, and clinical signs. For in vitro tests, the larval packet test, adult immersion test and DNA amplification for tick fever diagnosis were performed. In the first animal treatment period, product 1 (cypermethrin, 15 g+chlorpyrifos, 25 g+citronellal, 1 g) was used; in the second period, product 2 (cypermethrin, 15 g+chlorpyrifos, 30 g+fenthion, 15 g) was used. In Brangus animals, the mean efficacy was 35.1% and 95.8% in the first and second periods, respectively, for the same animals. For Nellore animals, the efficacy in periods one and two was 51% and 97.1%, respectively. The in vitro results showed efficacy above 95% for the two challenged acaricides. The Brangus animals showed a high production of ticks associated with the presence of tick fever agents, which could generate risks for the disease's enzootic stability.Made available in DSpace on 2018-12-20T23:39:41Z (GMT). No. of bitstreams: 1 31EfficacyprofileofCypermethrinandChlorpyrifosbasedacaricideson.pdf: 311208 bytes, checksum: 537314271e2c7bfe173253ee270f7c42 (MD5) Previous issue date: 2018-12-18bitstream/item/188775/1/31-Efficacy-profile-of-Cypermethrin-and-Chlorpyrifos-based-acaricides-on.pd