Chagas disease centennial anniversary celebration: historical overview and prospective proposals aiming to maintain vector control and improve patient prognosis - a permanent challenge

Neglected tropical diseases in Brazilian children and adolescents: data analysis from 2009 to 2013

BACKGROUND

Neglected tropical diseases (NTDs) prevail in conditions of poverty and contribute to the maintenance of social inequality. Out of the NTDs prioritized by the Brazilian Ministry of Health, four parasitic infections require mandatory notification: acute Chagas disease, leishmaniasis, malaria, and schistosomiasis. Data on the behaviour of these NTDs in the young population are currently limited. This study seeks to analyse the epidemiological aspects of these parasitic infections in children and adolescents in Brazil.

METHODS

A retrospective exploratory ecological study was conducted. A spatial analysis of the cases reported between 2009 and 2013 in individuals aged between 0 and 19 years that were notified through the Health Notification Aggravation Information System (SINAN) was performed.

RESULTS

In total, 64,567 cases of cutaneous and visceral leishmaniasis, malaria, schistosomiasis, and acute Chagas disease were recorded in the SINAN database, representing a rate of 20.15 cases per 100,000 inhabitants. The average age of the cases was 12.2 years and 62.32% were male. Four hundred and three deaths related to these obligatorily reported parasites were recorded, indicating a case fatality rate of 0.62%. Visceral leishmaniasis and acute Chagas disease had the highest rates of lethality. A heterogeneous spatial distribution of the studied parasites was observed.

CONCLUSIONS

The number of cases and the lethality rate described in this study show that these diseases still represent a serious problem for public health in Brazil. This points to the need to encourage new research and the reformulation of social, economic, and public health policies aimed at ensuring better health and living conditions for all individuals, especially those among the populations considered vulnerable, as is the case of the young.

Spatiotemporal analysis of reported cases of acute Chagas disease in the State of Pernambuco, Brazil, from 2002 to 2013

INTRODUCTION

Control strategies to eliminate the transmission of Chagas disease by insect vectors have significantly decreased the number of reported acute cases in Brazil. However, data regarding the incidence and distribution of acute Chagas disease cases in the State of Pernambuco are unavailable in the literature.

METHODS

A geographical information system was used to delineate the spatiotemporal distribution profile of the cases from 2002 to 2013 in 185 municipalities of Pernambuco based on the municipality where notification occurred. The results were presented in digital maps generated by the TerraView software (INPE).

RESULTS

A total of 302 cases of acute disease were recorded in 37.8% of the municipalities, for a total of 0.13 cases per 1,000,000 inhabitants per year. Out of the 302 cases, 99.3% were reported between 2002 and 2006. The most affected municipalities were Carnaubeira da Penha, Mirandiba and Terra Nova. The risk maps showed a significant decrease in the number of notifications and a concentration of cases in the Midwest region.

CONCLUSIONS

This study highlights a significant decrease in new cases of acute Chagas disease in Pernambuco starting in 2006 when Brazil received an international certification for the interruption of vectorial transmission by Triatoma infestans. However, control strategies should still be encouraged because other triatomine species can also transmit the parasite; moreover, other transmission modes must not be neglected.

Review: surveillance of Chagas disease

After remarkable reduction in prevalence through regional elimination of domestic vectors, the central challenge of Chagas disease control is shifting towards interruption of the disease transmission by non-eliminable vectors in Latin America. Vector surveillance with community participation was cost-effective against the eliminable vectors. But the efforts often failed against the non-eliminable vectors due to lack of surveillance coverage or sustainability. For instance, in El Salvador and Honduras, the operational vector control personnel lost access to many communities under decentralized health systems. To cover wider areas lastingly, the countries implemented the surveillance systems involving non-specialists from locally embedded resources, such as local health services, schools and community leaders. From these experiences, this paper outlines a common structure of the current community-based surveillance systems, consisting of five fundamental sequential functions. To increase scalability and sustainability, four of the five functions could be delegated to the locally available human resources, and the surveillance systems can be integrated into the general health systems. Challenges at national and regional levels are discussed for further evolution of the surveillance systems.

The benefits of using selenium in the treatment of Chagas disease: prevention of right ventricle chamber dilatation and reversion of Trypanosoma cruzi-induced acute and chronic cardiomyopathy in mice

Cardiac damage is a frequent manifestation of Chagas disease, which is caused by the parasite Trypanosoma cruzi. Selenium (Se) is an essential micronutrient, the deficiency of which has been implicated in the development of cardiomyopathy. Our group has previously demonstrated that Se supplementation prevents myocardial damage during acute T. cruzi infection in mice. In this study, we analyzed the effect of Se treatment in cases of T. cruzi infection using prevention and reversion schemes. In the Se prevention scheme, mice were given Se supplements (2 ppm) starting two weeks prior to inoculation with T. cruzi(Brazil strain) and continuing until 120 days post-infection (dpi). In the Se reversion scheme, mice were treated with Se (4 ppm) for 100 days, starting at 160 dpi. Dilatation of the right ventricle was observed in the infected control group at both phases of T. cruzi infection, but it was not observed in the infected group that received Se treatment. Surviving infected mice that were submitted to the Se reversion scheme presented normal P wave values and reduced inflammation of the pericardium. These data indicate that Se treatment prevents right ventricular chamber increase and thus can be proposed as an adjuvant therapy for cardiac alterations already established by T. cruzi infection.

Videofluoroscopic evaluation of swallowing in Chagas' disease

Dysphagia is the most common digestive symptom reported by patients with Chagas' disease. The condition results from abnormalities of esophageal motility. Our hypothesis is that there are also alterations of oral and pharyngeal transit during swallowing. We studied by videofluoroscopy the oral and pharyngeal transit during swallowing in 17 patients with dysphagia, a positive serologic test for Chagas' disease, and radiologic demonstration of esophageal involvement. The study also included 15 asymptomatic healthy volunteers. Each subject swallowed in duplicate 5 and 10 ml of liquid and paste barium boluses. Chagas' disease patients had a longer oropharyngeal transit with the 5-ml liquid bolus (p = 0.03), and a longer oral transit (p = 0.01) and pharyngeal transit (p = 0.04) with the 10-ml liquid bolus than controls. There was no difference between patients and controls with swallows of the 5-ml paste bolus. With swallows of the 10-ml paste bolus, the oropharyngeal transit (p = 0.05), pharyngeal transit (p = 0.04), pharyngeal clearance (p = 0.02), and UES opening (p = 0.01) took a longer amount of time in Chagas' disease patients than in controls. We conclude that the duration of pharyngeal transit is longer in patients with Chagas' disease than in normal subjects, especially with a bolus of pasty consistency and a volume of 10 ml.