ABSTRACT This study describes the laboratory investigation of two acute Chagas disease outbreaks that occurred in the riverside communities of Marimarituba and Cachoeira do Arua, in the Santarem municipality, Para State, located in the Northern region of Brazil, and occurred in March 2016 and August 2017, respectively. The generation of data regarding the diversity of Trypanosoma cruzi parasites circulating in the Amazon region is key for understanding the emergence and expansion of Chagas disease. This study aimed to identify T. cruzi Discrete Typing Units (DTUs) involved in two outbreaks of acute Chagas disease (ACD) directly from the patient’s biological sample. Nested and multiplex PCR targeting the 24Sα (rRNA) and mini-exon genes, respectively, were used to identify T. cruzi DTU in blood samples from patients diagnosed with ACD. The samples with positive cPCR were submitted for analysis for T. cruzi DTUs, which included 13 samples from the patients with ACD by oral transmission and two samples collected from two newborns of two women with ACD, from Marimarituba and Cachoeira do Arua. The samples were classified as T. cruzi TcIV, from Marimarituba’s outbreak, and T. cruzi TcI, from Cachoeira do Arua’s outbreak. The molecular identification of T. cruzi may increase understanding of the role of this parasite in Chagas disease’s emergence within the Amazon region, contributing to the improvement of the management of this important, but also neglected, disease.

ABSTRACT This study describes difficulties in the monitoring of a child born during an oral outbreak of Chagas disease, in which there are several indications that the transmission occurred through the congenital route: 1. the mother was in the third trimester of pregnancy when she was infected; 2. She presented high parasitemia at the time of delivery; 3. In both, the mother and her daughter, T. cruzi was classified as DTU TcIV. The parasites were not found in the blood at birth and the infection was detected only three months later in an asymptomatic infant. As the mother and her child live in a highly endemic area, vector transmission could not be excluded during this period.

ABSTRACT Candidemia is a significant cause of bloodstream infections (BSI) in nosocomial settings. The identification of species can potentially improve the quality of care and decrease human mortality. Quantitative PCR (qPCR) was evaluated for Candida albicans detection using culture suspensions containing C. albicans , spiked human blood, the cloned qPCR target fragment (ITS2 region) and the results of these assays were compared. The assays showed a good detection limit: C. albicans DNA extracted from yeast (sensitivity 0.2 CFU/µL), spiked human blood (sensitivity 10 CFU/mL), and cloned fragment of ITS2 region (sensitivity 20 target copies/μL). The efficiency of ITS2 fragment-qPCR ranged from 89.67 to 97.07, and the linearity (R2) of the standard curve ranged from 0.992 to 0.999. The results showed that this ITS2-qPCR has a great potential as a molecular prototype model for the development of a test to be applied in clinical practice, greatly reducing the time of candidemia diagnosis, which is extremely important in this clinical setting.

ABSTRACT Trypanosoma cruzi is the causative agent of Chagas disease. Nowadays, the transmission in Brazil occurs mainly by oral ingestion of contaminated food that has been associated with more severe clinical manifestations. We report a case of Acute Chagas disease caused by oral transmission in a child from Northern Brazil. In the hospital admission, physical examination showed tachycardia, hepatomegaly, bipalpebral edema and anasarca. Trypanosoma cruzi trypomastigotes were found in microscopy during blood cell count. Twenty-three days before hospitalization, the child had ingested the “bacaba palm fruit's wine”. Even with the appropriate diagnosis and starting of treatment, she did not survive. Quantitative analysis of Trypanosoma cruzi DNA in a blood sample resulted in 54,053.42 parasite equivalents/mL and the DTU TcIV was identified. The outcome may have been determined by several factors, including the delay to seek a medical service beyond the high parasitemia, detected by qPCR. DTU TcIV could also have influenced the natural history of the disease.

OBJECTIVES: The impact of Chagas disease (CD) in HIV-infected patients is relevant throughout the world. In fact, the characterization of the adaptive immune response in the context of co-infection is important for predicting the need for interventions in areas in which HIV and Chagas disease co-exist. METHODS: We described and compared the frequency of cytokine-producing T cells stimulated with soluble antigen of Trypanosoma cruzi (T. cruzi) using a cytometric assay for the following groups: individuals with chronic Chagas disease (CHR, n=10), those with Chagas disease and HIV infection (CO, n=11), those with only HIV (HIV, n=14) and healthy individuals (C, n=15). RESULTS: We found 1) a constitutively lower frequency of IL-2+ and IFN-γ+ T cells in the CHR group compared with the HIV, CO and healthy groups; 2) a suppressive activity of soluble T. cruzi antigen, which down-regulated IL-2+CD4+ and IFN-γ+CD4+ phenotypes, notably in the healthy group; 3) a down-regulation of inflammatory cytokines on CD8+ T cells in the indeterminate form of Chagas disease; and 4) a significant increase in IL-10+CD8+ cells distinguishing the indeterminate form from the cardiac/digestive form of Chagas disease, even in the presence of HIV infection. CONCLUSIONS: Taken together, our data suggest the presence of an immunoregulatory response in chronic Chagas disease, which seems to be driven by T. cruzi antigens. Our findings provide new insights into immunotherapeutic strategies for people living with HIV/AIDS and Chagas disease.

A reativação da doença de Chagas em pacientes com a infecção pelo HIV apresenta uma alta morbidade e mortalidade. Neste relato, apresentamos caso confirmado de meningoencefalite chagásica, como doença definidora de aids, em paciente com 318 linfócitos T-CD4+/mm3. Após 2 meses de tratamento seguido de um ano de profilaxia secundária com benzonidazol e início precoce de terapia antirretroviral (HAART), a paciente apresentou boa evolução clínica, parasitológica e radiológica. Utilizamos a reação em cadeia da polimerase qualitativa do T. cruzi, para monitorização da parasitemia por T. cruzi durante e após o tratamento. Ressaltamos o valor potencial das técnicas moleculares associadas aos parâmetros clínicos e radiológicos nos pacientes com doença de Chagas e infecção pelo HIV. A introdução precoce da terapia antirretroviral, a terapia antiparasitária prolongada, manutenção e descontinuação da mesma, são desafios atuais, embora possíveis, no manejo da reativação da doença de Chagas na era das terapias antirretrovirais de alta eficácia.

The reactivation of Chagas disease in HIV infected patients presents high mortality and morbidity. We present the case of a female patient with confirmed Chagasic meningoencephalitis as AIDS-defining illness. Interestingly, her TCD4+ lymphocyte cell count was 318 cells/mm3. After two months of induction therapy, one year of maintenance with benznidazol, and early introduction of highly active antiretroviral therapy (HAART), the patient had good clinical, parasitological and radiological evolution. We used a qualitative polymerase chain reaction for the monitoring of T. cruzi parasitemia during and after the treatment. We emphasize the potential value of molecular techniques along with clinical and radiological parameters in the follow-up of patients with Chagas disease and HIV infection. Early introduction of HAART, prolonged induction and maintenance of antiparasitic therapy, and its discontinuation are feasible, in the current management of reactivation of Chagas disease.