[Study of the factors determining an unexpected occurrecne of Chagas cardiomyopathy in Sucre, Bolivia]. / Etude des facteurs determinant la survenue d'une myocardiopathie chagasique a Sucre, Bolivie.

The purpose of this case-control study carried out between February 1, 1994 and December 22, 1994 at the "Instituto de Gastroenterologia Boliviano-Japonés" in Sucre, Bolivia was to determine risk factors for chronic Chagas cardiomyopathy in adult patients with positive serological tests for Trypanosoma cruzi. A total of 196 subjects were included. Inclusion criteria were positive serological tests for Trypanosoma cruzi, residence in the city of Sucre, Bolivia for at least 3 months, and age over 14 years. There were 62 cases presenting electrocardiographic findings consistent with Chagas cardiomyopathy and 134 controls presenting normal electrocardiographic findings. Both cases and controls underwent a standardized protocol including physical examination and laboratory tests. Interviews were set up to evaluate personal and familial history of Chagas disease, socioeconomic status, and presence of Triatoma infestans in the home. Bivariate analysis of data indicated that Chagas cardiomyopathy was associated with the following risk factors: heart rate (p < 0.05), fecaloma (p < 0.05), occupation requiring strenuous physical exertion (p < 0.001), proximity with domestic animals (p < 0.005), especially pigs (p < 0.005), dwelling features including outbuildings, more than 2 bedrooms, and inside ceilings (p < 0.001). Multivariate analysis revealed the following risk factors: occupation requiring strenuous physical exertion (p < 0.005), a yard around the house (p < 0.05), and inside ceilings (p < 0.05). The results of this study show that prevention of chronic Chagas cardiomyopathy in Sucre, Bolivia will depend on improvement of living conditions.

[Risk approach in the diagnosis of malaria in high altitude regions]. / L'approche de risque dans le diagnostic du paludisme-maladie en régions d'altitude.

Sixteen cases of malaria are reported per thousand inhabitants per year in Kayanza, a province in the High Plateaux of Burundi. A case control study was conducted between October 1990 and March 1991 to better document this phenomenon. The majority of confirmed cases presented in persons who had recently sojourned in an endemic area (relative risk = 18). All except one of the other patients were carriers of plasmodium species that can cause late recurrences, which is compatible with the absence of local transmission. The presumptive diagnosis of malaria, as it is routinely made in the health centres, is not very specific (60%) and it has a positive predictive value of only 10%. This implies that an anti-malaria treatment is useless for 90% of the patients who receive it. It also means that the true malaria incidence rate in Kayanza can be estimated at less than 1 per thousand per year. We propose an alternative diagnostic strategy based on the risk differences between population sub-groups. It should permit an adequate patient management and a satisfactory surveillance of malaria in non-endemic epidemiological strata.