Outbreak of Chagas disease in Brazil: Validation of a molecular diagnostic method.

Chagas disease (CD), caused by the protozoan Trypanosoma cruzi (T. cruzi), affects millions of people worldwide. Polymerase Chain Reaction (PCR) and real-time quantitative PCR (qPCR) have been used as tools to monitor parasitic levels in the bloodstream of individuals exposed to infection, thus enabling the monitoring of relapses and the effectiveness of therapy, for example. The aim of this study was to evaluate the TcSAT-IAM system, developed by our research group, on samples from patients with suspected Chagas disease infection. Initially, primer systems were developed for the detection of the nuclear DNA (SAT-DNA) from T. cruzi (TcSAT-IAM). The Cruzi system, predicted in the literature, and TcSAT-IAM were then evaluated in relation to their analytical sensitivity, specificity and efficiency. Afterwards, the applicability of the qPCR technique using both systems (separately) for the diagnosis of acute CD was evaluated in samples from 77 individuals exposed to the outbreak that occurred in Pernambuco-Brazil, relating the results obtained to those of the classical diagnostic methods recommended for this stage of the infection. TcSAT-IAM and Cruzi had a detection limit of 1 fg of target DNA (0,003 parasites). Thirty-eight cases were recorded, 28 by laboratory criteria and 10 by clinical and epidemiological criteria. Blood samples from 77 subjects were submitted to qPCR by both systems, reaching an agreement of 89.61% between them. After analyzes between systems and diagnostic criteria, the TcSAT-IAM showed sensitivity and specificity of 52.36% (CI 37.26-67.52) and 92.31% (CI 79.68-97.35), respectively, accuracy of 72.73% and moderate agreement. The TcSAT-IAM showed an accuracy of 72.58% and 75% in relation to parasitological and serological tests (IgM anti-T. cruzi), respectively. Therefore, quantitative PCR should be incorporated into the diagnosis of suspected acute cases of Chagas disease.

Mapping the morbidity and mortality of Chagas disease in an endemic area in Brazil.

Chagas disease is among the 21 neglected diseases according to the World Health Organization. This study aimed to investigate the morbidity and mortality distribution of Chagas disease for identifying areas with greater prevalences and deaths of the disease in Northeast Brazil. A population-based ecological study was performed from 2016 to 2018 using data on acute Chagas disease patients from the Disease Notification Information System, chronic cases from the Chagas Disease and the referral Heart Failure Outpatient Clinic in Pernambuco, and Chagas disease-related mortality from the Mortality Information System. The unit of analysis were Pernambuco State mesoregions. The indicators were spatialized into thematic maps on the occurrence and mortality of the disease per 100,000 inhabitants. No cases of acute disease were reported in the period analyzed. Data on 801 chronic Chagas disease patients were analyzed. The population showed an average age of 62 years, with female predominance. The most prevalent comorbidity was systemic arterial hypertension and cardiologic involvement without ventricular dysfunction. The average chronic disease occurrence rate was 3.2/ 100,000 people/ year. As for deaths in the mortality system; in total, 350 deaths were recorded, showing male predominance, age ≥ 60 years, and chronic disease with cardiac involvement as the main mortality cause. The annual average mortality proportion was 1.6/100,000 people. The chronic case distribution showed spatial heterogeneity, with the highest rates of chronic disease and deaths observed in two mesoregions, with the main cause of death being heart-related. This highlights the need for more specialized services in areas with higher burden of the disease to avoid delay in the patients' care.

Mapping the morbidity and mortality of Chagas disease in an endemic area in Brazil

ABSTRACT Chagas disease is among the 21 neglected diseases according to the World Health Organization. This study aimed to investigate the morbidity and mortality distribution of Chagas disease for identifying areas with greater prevalences and deaths of the disease in Northeast Brazil. A population-based ecological study was performed from 2016 to 2018 using data on acute Chagas disease patients from the Disease Notification Information System, chronic cases from the Chagas Disease and the referral Heart Failure Outpatient Clinic in Pernambuco, and Chagas disease-related mortality from the Mortality Information System. The unit of analysis were Pernambuco State mesoregions. The indicators were spatialized into thematic maps on the occurrence and mortality of the disease per 100,000 inhabitants. No cases of acute disease were reported in the period analyzed. Data on 801 chronic Chagas disease patients were analyzed. The population showed an average age of 62 years, with female predominance. The most prevalent comorbidity was systemic arterial hypertension and cardiologic involvement without ventricular dysfunction. The average chronic disease occurrence rate was 3.2/ 100,000 people/ year. As for deaths in the mortality system; in total, 350 deaths were recorded, showing male predominance, age ≥ 60 years, and chronic disease with cardiac involvement as the main mortality cause. The annual average mortality proportion was 1.6/100,000 people. The chronic case distribution showed spatial heterogeneity, with the highest rates of chronic disease and deaths observed in two mesoregions, with the main cause of death being heart-related. This highlights the need for more specialized services in areas with higher burden of the disease to avoid delay in the patients' care.

Detection of antibodies against Leishmania infantum in cats (Felis catus) from the State of Pernambuco, Brazil.

INTRODUCTION: Little information is available concerning infection by Leishmania infantum in cats. Therefore, the aim of this study was to perform a serological study in domestic cats. METHODS: Serum samples (n=153) obtained from animals living in the Cities of Recife and Petrolina, State of Pernambuco, Brazil, were tested by ELISA/S7® (Biogene). RESULTS: Anti-L. infantum antibodies were detected in 3.9% (6/153) of the cats. All seroreagent animals were from Petrolina. CONCLUSIONS: These results serve as an important alert, and future studies are needed to better understand the possible role of cats in the epidemiology of visceral leishmaniasis (VL) in this area.

Detection of antibodies against Leishmania infantum in cats (Felis catus) from the State of Pernambuco, Brazil

Introduction: Little information is available concerning infection by Leishmania infantum in cats. Therefore, the aim of this study was to perform a serological study in domestic cats. Methods: Serum samples (n=153) obtained from animals living in the Cities of Recife and Petrolina, State of Pernambuco, Brazil, were tested by ELISA/S7® (Biogene). Results: Anti-L. infantum antibodies were detected in 3.9% (6/153) of the cats. All seroreagent animals were from Petrolina. Conclusions: These results serve as an important alert, and future studies are needed to better understand the possible role of cats in the epidemiology of visceral leishmaniasis (VL) in this area. .