Ana Yecê das Neves Pinto

Analysis of an acute Chagas disease outbreak in the Brazilian Amazon: human cases, triatomines, reservoir mammals and parasites

An outbreak of Chagas disease occurred in Mazagão, Amapá, Brazilian Amazon in 1996. Seventeen of 26 inhabitants presented symptoms compatible with acute Chagas disease and were submitted to parasitological and serological tests. All 17 were positive in at least one parasitological test and 11 were also IgM or IgG anti-Trypanosoma cruzi positive. The nine asymptomatic patients were negative for parasites and one was positive for IgG anti-T. cruzi. Sixty-eight triatomines were captured (66 Rhodnius pictipes; two Panstrongylus geniculatus); 45 were infected with T. cruzi (43 R. pictipes; two P. geniculatus). Thirteen trypanosomatid strains were isolated: eight from humans and five from R. pictipes. Four were genotyped as T. cruzi I (two from humans; two from R. pictipes), seven as T. cruzi Z3 (six from humans; one from R. pictipes) and two as T. cruzi Z3 and T. rangeli (from R. pictipes). Treatment started for all patients leading to a decrease in parasitaemia in 16 during the follow-up period (6 months, 1, 5 and 7 years). All were serologically negative 7 years post-treatment. There was an overlap of genotypes in the same ecotope, raising the possibility of transmission through the oral route and the need for early therapeutic intervention for better patient management in the Brazilian Amazon.

Fase aguda da doença de Chagas na Amazônia brasileira: estudo de 233 casos do Pará, Amapá e Maranhão observados entre 1988 e 2005

Two hundred and thirty-three cases of the acute phase of Chagas disease, from Para, Amapa and Maranhao, were observed between 1988 and 2005. One hundred and sixty were studied retrospectively from 1988 to 2002 and seventy-three were prospectively followed up from 2003 to 2005. Among the cases studied, 78.5% (183/233) formed part of outbreaks, probably due to oral transmission (affecting a mean of 4 individuals), and 21.5% (50/233) were isolated cases. Cases were taken to be acute if they presented positive direct parasitological tests (fresh blood, thick drop or Quantitative Buffy Coat, QBC) and/or positive anti Trypanosoma cruzi IgM. Xenodiagnosis was also performed on 224 patients and blood culturing on 213. All the patients had clinical and epidemiological evaluations. The most frequent clinical manifestations were fever (100%), headache (92.3%), myalgia (84.1%), pallor (67%), dyspnea (58.4%), swelling of the legs (57.9%), facial edema (57.5%), abdominal pain (44.3%), myocarditis (39.9%) and exanthema (27%). The electrocardiogram showed abnormalities of ventricular repolarization in 38.5%, low QRS voltage in 15.4%, left-axis deviation in 11.5%, ventricular ectopic beats in 5.8%, bradycardia in 5.8%, tachycardia in 5.8%, right branch block in 4.8% and atrial fibrillation in 4.8%. The most frequently observed abnormality on the echocardiogram was pericardial effusion, in 46.2% of the cases. Thirteen (5.6%) patients died: ten (76.9%) of them due to cardiovascular involvement, two due to digestive complications and one due to indeterminate causes.

II Consenso Brasileiro em Doença de Chagas, 2015

Chagas disease is a neglected chronic condition that presents high morbidity and mortality burden, with considerable psychological, social, and economic impact. The disease represents a significant public health issue in Brazil, with different regional patterns. This document presents the evidence that resulted in the Brazilian Consensus on Chagas Disease. The objective was to review and standardize strategies for diagnosis, treatment, prevention, and control of Chagas disease in the country, based on the available scientific evidence. The consensus is based on collaboration and contribution of renowned Brazilian experts with vast knowledge and experience on various aspects of the disease. It is the result of close collaboration between the Brazilian Society of Tropical Medicine and the Ministry of Health. This document shall strengthen the development of integrated control measures against Chagas disease in the country, focusing on epidemiology, management, comprehensive care (including families and communities), communication, information, education, and research.

Urban outbreak of acute Chagas disease in Amazon region of Brazil: four-year follow-up after treatment with benznidazole

The objective of this report is to describe treatment outcomes over a four-year period of patients with acute Chagas disease in the Amazon region of Brazil. An outbreak of Chagas disease in a low-income district of urban Belém, in September 2000, affected 11 people simultaneously, indicating the likelihood of indirect, oral transmission of Trypanosoma cruzi. Prior to treatment, patients underwent physical and clinical tests; blood samples were processed with immunofluorescence assay (IFA) and quantitative buffy coat (QBC). Following treatment with benznidazole, parasitological and serologic tests (artificial xenodiagnosis and blood culture for T. cruzi), electrocardiogram, and echocardiogram were administered at intervals over a four-year period. Four years after treatment for acute Chagas disease, all patients presented with negative parasitological tests and persistent IgG anti-T. cruzi antibodies with lowered titers; three patients presented electrocardiogram abnormalities consistent with chronic Chagas disease or sequel of acute disease. The satisfactory response to treatment and relevance of serial parasitological examinations of patients with acute Chagas disease are discussed.

Avaliação da resposta aos esquemas de tratamento reduzidos para malária vivax

Relapses may occur with long standard treatment of vivax malaria, and these are caused by incomplete patients compliance. The use of reduced schedules may further better patient compliance, while maintaining the same efficacy, tolerance and minimal adverse reactions. The objective of this study was to test two schedules with reduced doses of chloroquine for vivax malaria and comparing these with the classical schedule. The authors studied 120 outpatients, with vivax malaria , aged over 12 years, submitted to three therapeutic schemes: scheme I: chloroquine phosphate (150mg) in a dose of 25mg/kg/day for three days (10mg/kg/ day in the first day, 7.5mg/kg/day in the second and third day), plus primaquine (15mg) in a dose of 0.25mg/kg/day for fourteen days; scheme II: chloroquine, in a single dose of 10mg/kg, plus primaquine in a dose of 0.5mg/kg/day for seven days; scheme III: chloroquine, 10mg/kg in a single dose plus primaquine in a dose 0.5mg/kg/ day for five days. The clinical response to all three therapeutic schemes was satisfactory. The disappearance of malarial symptoms occurred after a maximum 96 hours of treatment, while the assexual parasitaemia clearance occurred within 72 hours, in all therapeutic schemes.

Esquemas terapêuticos encurtados para o tratamento de malária por Plasmodium vivax

with the objective of evaluating shortened therapeutic outlines effective in vivax malaria treatment, we accomplished an open, prospective study allocating 234 patients with vivax malaria distributed at random into eight therapeutic groups. Six groups used oral arthemisin as blood esquizonticide at different doses for one day and the other two groups received chloroquine in a single dose. The primaquine was used as a hypnozoiticide in all groups. They received a daily dose of 30mg in the course of five or seven days in all groups. The clearance of parasitaemia in patients treated with arthemisin (independent of dosage) was faster than the chloroquine group (p <0.01). Cure was acheived in 92.3% and 80.2%, in patients treated with primaquine for seven or five days, respectively (p=0.0372).

Importance of clinical and laboratory profiles for the differential diagnosis of malaria and acute viral hepatitis

OBJECTIVE: To establish clinical and diagnostic findings of malaria and acute viral hepatitis in children, stressing similarities and differences, so as to enhance the sensitivity of early malaria diagnosis in childhood. METHODS: Two groups were studied, each including 30 children between 2 and 10 years of age. The patients presented either primary malaria infection or acute viral hepatitis, confirmed by thick blood film and tests for markers of viral hepatitis A and B. The patients were submitted to the following evaluations: erythrocyte, leucocyte and platelet counts, hemoglobin and hematocrit dosage, hepatic enzymes, urea, creatinine and bilirubin dosage. Clinical and laboratory findings were described for both groups and compared. Individuals with alterations on the physical exam in both groups were compared using Fishers exact test. RESULTS: Baseline clinical findings were the same in all patients: fever, headache, digestive problems and dark urine. One half of malaria patients did not present the classical malaria signs, but all of them presented fever, differently from patients with hepatitis. In malaria patients, anemia and thrombocytopenia were significantly more frequent than in hepatitis patients. A remarkable increase of bilirubin and hepatic enzyme levels was found in hepatitis patients. CONCLUSIONS: A detailed physical examination and a thorough evaluation of non-specific laboratory tests are sufficient to allow the presumptive diagnosis of both malaria and viral hepatitis, and to reinforce the early diagnosis and treatment of malaria.

Assessment of chloroquine single dose treatment of malaria due to Plasmodium vivax in Brazilian Amazon

Malaria regions of the Amazon basin have been characterized by difficult access and non-compliance of the patients to treatment. In an attempt to assess the schizonticide efficacy of chloroquine in a single dose of 600 mg, the authors realized a double-blind, placebo-controlled trial in 132 outpatients with vivax malaria. Patients were distributed into two groups: group CPLA, given chloroquine 600 mg (single dose) on the first day of treatment, and two doses of placebo on second and third days. Group CHLO, given chloroquine 600 mg on first day and 450 mg on second and third day. Geometric means of the parasite density during the follow-up was similar in both groups. No differences were observed in the parasitological cure between the two groups (p = 0.442). There was clinical and parasitological efficacy in treatment of patients given a single-dose of chloroquine. This suggests that its restricted use could be indicated in remote areas of Brazilian Amazon Region, nevertheless the inadequate response of three patients indicates the need for further studies.

Resposta de anticorpos IgG anti-Plasmodium vivax em crianças expostas à malária, antes e após tratamento específico

OBJECTIVE: To assess the IgG antibody response against P. vivax (IgG anti-PV), and cytophilic (IgG1 and IgG3) and noncytophilic (IgG2) IgG subclasses in 34 children aged 0 to 15 years old infected with P. vivax malaria. METHODS: IgG levels were determined by indirect fluorescent antibody technique during the acute and therapeutic control phase. Patients were distributed into 2 groups according to the presence or absence of a previous malaria episode. IgG anti-PV levels were measured on the first and last day of treatment, and compared by Studentacute;s t test. Antibody levels were correlated with asexual parasitemia (Spearmańs correlation test). RESULTS AND CONCLUSIONS: Increased IgG levels were observed on the first and on the last day of treatment. The geometric means for IgG subclass titers found in patients with previous history of malaria were: IgG1 (806.35) > IgG3 (28.28) > IgG2 (20). In patients infected for the first time, the responses obtained were: IgG1 (709.21) > IgG3 (39.3) > IgG2 (10.7). There was no association between asexual parasitemia and antibody levels on the first day of treatment. Cytophilic antibodies (IgG1, IgG3) predominated over noncytophilic antibodies (IgG2).

Doença de Chagas congênita por infecção aguda maternal por Trypanosoma cruzi transmitida via oral

A family of four, including a 24-year-old female, presented to our laboratory in December 2006 with a prolonged febrile syndrome of unknown etiology. After extensive laboratory screening, acute Chagas disease was confirmed by positive T. cruzi blood culture, combined with clinical, epidemiological and serological findings. The young female, her parents and husband received a daily dose of benznidazole, but she developed serious drug intolerance and amenorrhea. Her treatment was interrupted by a confirmed pregnancy of about 12 weeks of gestational age. The child was born prematurely on April 18, 2007 with low weight and signs of respiratory distress syndrome. Diagnostic screening tests for congenital infections, including Chagas disease, were negative during the perinatal period. About four months after birth, clinical findings generated the following clinical indicators of congenital disease: convergent strabismus, microcephaly and delayed psychomotor development. Serological tests confirmed seroconversion, and magnetic resonance findings included cystic lesions and intracranial calcifications. The authors discuss the critical nature of this serious public health problem in the region and suggest necessary revisions to the recommended treatment for pregnant patients with acute Chagas disease.