Summarybackground To determine the efficacy and acceptability of deltamethrin-impregnated bednets in controlling Chagas disease in South America.

SummaryAfrica is severely affected by a resurgence of human African trypanosomiasis (HAT) at epidemic proportions. We report the results of the first 5 years of a HAT control programme in northern Angola run by the non-governmental organization (NGO) ANGOTRIP. In the period between 1996 and 2001, 13 426 patients were screened for HAT. The mortality rate of patients in stage II who were treated with melarsoprol fell from 7.5% to 2.9%, possibly as a result of training and the standardization of treatment protocols. A total of 191 578 people in three provinces of Angola were screened for HAT. Vector control activities were initiated using Lancien traps. Our experiences reflect the connection between war and the increasing incidence of disease, but also demonstrate that HAT control is possible by dedicated NGOs in close cooperation with national institutions even under extremely difficult circumstances.

Los objetivos del estudio fueron el análisis de la cobertura del programa de tamizaje para Trypanosoma cruzi en bancos de sangre de Colombia, sus estrategias en cuanto a las técnicas utilizadas, las acciones con los donantes positivos y dar algunas recomendaciones para mejorar esta red. De los 180 bancos de sangre de 33 departamentos del país, respondieron la encuesta 103, pertenecientes a 20 departamentos, que recolectaron 291.105 unidades de sangre, lo cual corresponde al 66,6% del total captado en el país en 1997. Los 103 bancos tuvieron un cumplimiento del tamizaje del 99,6%. Se informaron como positivas para anticuerpos antiTrypanosoma cruzi 3.321 unidades de sangre de las 287.048 estudiadas, lo cual corresponde al 1,16%. Los datos se discriminaron para cada uno de los departamentos que contestaron la encuesta, observándose marcadas diferencias geográficas entre las tasas de seroprevalencia, las cuales variaban entre el 0% y el 12,6%. La técnica serológica más utilizada para el tamizaje fue la prueba de ELISA, pero solamente 33,2% de las muestras positivas para anticuerpos se sometieron a una prueba confirmatoria, la gran mayoría a la de inmunofluorescencia indirecta. El 95,1% de los bancos respondieron que utilizaban controles de calidad internos básicos de las pruebas y el 73,8% remitían pruebas positivas a otro laboratorio para control de calidad externo.Palabras clave: banco de sangre, Trypanosoma cruzi, enfermedad de Chagas, Colombia. Screening for Chagas disease in blood banksThe screening programs for the Chagas disease agent, Trypanosoma cruzi, were examined in Colombian blood banks and, as a consequence, several procedural improvements in the blood bank network were recommended. Screening strategies and techniques were examined, as well as the action taken when seropositive donors were discovered. From a total of 180 blood banks in 33 departments, 103 banks in 20 departments answered the survey. The 103 banks collected 291,105 units of blood, corresponding to 66.6% of all units collected in the country in 1997. Of these blood units, 99.6% were screened for Chagas trypanosomes; 3,321 (1.2%) of 287,048 were found positive for anti-T. cruzi. The data were grouped by department; geographical differences for seroprevalence rates varied markedly between 0% and 12.6%. The most commonly used serological technique was ELISA, but only 33.2% of the positive samples for anti-T. cruzi underwent further confirmatory testing, mainly through indirect immunofluorescent test. Most (95.1%) of the blood banks used basic, internal quality control procedures, and 73.8% sent positive samples to other laboratories for external quality control.