Estudio clínico y determinación de la parasitemia en un grupo de pacientes infectados por Trypanosoma cruzi de la región de Atacama, Chile / Clinical study of measure of parasitemia in patients infected with Trypanosoma cruzi in Atacama, Chile

BACKGROUND: Trypanosoma cruzi infection is endemic in Northern/Central Chile. AIM: To perform a clinical assessment of patients infected with Trypanosoma cruzi. PATIENTS AND METHODS: Two hundred sixty three subjects with a positive serology for Trypanosoma cruzi, were invited by mail to a clinical assessment in a Regional Hospital. In a subsample of these, a polymerase chain reaction for Trypanosoma cruzi, was done. RESULTS: Of all the invited subjects, 183 responded and were assessed at the hospital. Of these, 60 had cardiac affections, 52 had colon problems and 17, esophageal disease. Seventy four were asymptomatic. Of the 64 patients in whom polymerase chain reaction was done, 35 had a positive result. CONCLUSIONS: A high percentage of subjects infected with Trypanosoma cruzi, had clinical consequences of the infection. Polymerase chain reaction showed persistency of the parasite in more than half of the infected patients.

Inmunodiagnóstico de las infecciones por Strongloides stercoralis en Chile utilizando la prueba de ELISA / Immunodiagnosis of Strongyloides stercoralis infections in Chile using ELISA test

BACKGROUND: Strongyloides stercoralis is a world wide distributed small intestinal nematode parasite. In immunocompetent individuals S stercoralis can produce asymptomatic infections or a moderate clinical picture of diarrhea, some cases become chronic. In immunocompromised patients, a disseminated disease may appear, sometimes fatal. In Chile, there is little epidemiological information about S stercoralis infections and appropriate diagnostic techniques are usually not used. AIM: To evaluate the yield of an ELISA test for the diagnosis of strongyloidiasis in Chilean patients. MATERIAL AND METHODS: Ten serum samples from patients with S stercoralis infections confirmed by a positive stool examination, 66 samples from individuals with other infections by tissue helminthes (24 toxocariasis, 15 trichinellosis, 11 hydatidosis, 12 fascioliasis and 4 cysticercosis), 13 samples from subjects with autoimmune diseases and 49 samples from apparently healthy individuals with a normal eosinophil count, were studied. ELISA antigen was prepared using a filariform larval extract obtained from a murine species of Strongyloides, maintained in laboratory animals. RESULTS: Using 0.33 optical density units as a cut off value, 9 of 10 sera of S stercoralis infected individuals, had a positive ELISA test. No cross reactions were observed with sera of patients with other helminthic infections, autoimmune diseases or in healthy individuals. Thus, specificity, positive and negative predictive values were 100 per cent. CONCLUSIONS: The results obtained are similar with those found by other investigators. ELISA test for strongyloidiasis is a useful tool for the diagnosis of clinical cases and for seroepidemiological studies of this nematode infection in Chile.