Aspectos parasitológicos y epidemiológicos de los donantes de sangre seropositivos para Trypanosoma cruzi, en un hospital universitario / Parasitological and epidemiological aspects of Trypanosoma cruzi seropositive blood donors

Background: After the interruption of the transmission of Chagas disease via vector insects in Chile, there is little available epidemiological information about this parasitosis in blood banks. Aim To update the rates of T cruzi positive blood donors. To measure parasitological and epidemiological parameters in blood donors with anti T cruzi antibodies. Material and Methods: An ELISA-T cruzi test was carried out in 30,309 blood donors between 2000 and 2004. In 75 blood donors with an ELISA-T cruzi positive test and 79 donors with negative ELISA (controls), a survey about personal or parental history of biting by a kissing bug (Triatomine), was performed. A blood sample was also obtained to perform Polymerase Chain Reaction (PCR) for T cruzi and a xenodiagnostic test. Results: Annual frequency of positive ELISA for T cruzi serum antibodies in blood donors varied from 0.31 percent to 0.45 percent. Twenty eight percent of subjects with positive and 6 percent of subjects with negative specific antibodies answered the survey about biting. PCR and xenodiagnostic test were positive in 52 (69 percent) and 16 (21 percent) of positive ELISA-T cruzi test blood donors, respectively. Xenodiagnostic was also positive in 5 individuals who had a negative PCR. Conclusions: Seroprevalence of T cruzi antibodies decreased from 3 percent in 1968 to 0.3 percent in 2004.

Secuencia de Pierre Robin / Pierre Robin sequence

La secuencia de Pierre Robin constituye un desafío diagnóstico antenatal, el cual se transforma en un desafío terapéutico posterior al nacimiento por la multiplicidad de presentaciones al asociarse con otros síndromes más o menos complejos que provocan problemas en las decisiones de los distintos actores llamados a evaluar la necesidad de corrección quirúrgica o manejo conservador de los niñosque se presentan en forma esporádica en nuestros hospitales. Esta revisión pretende actualizar en forma sucinta los conocimientos sobre patogenia, fisiopatología, manifestaciones clínicas y herramientas terapéuticas con que se cuenta para enfrentar este cuadro.

Rendimiento del xenodiagnótico y el PCR para evaluar el tratamiento quimioterápico específico de la enfermedad de Chagas en niños / Yielding of skin diagnosis and PCR for the evaluation of specific chemotherapy of Chagas's disease in children

Amplification by the polymerase chain reaction (PCR) of Trypanosoma cruzi kinetoplastic DNA was used to enhance sentitivity in the detection of the parasite in blood, with the ultimate goal of improving the parasitological diagnosis of Chagas' disease in 0-10 year-old infected children. Twenty eight children were evaluated by using xenodiagnosis (XD) and PCR. Whereas XD detected 75,0 percent of the cases PCR was positive in 96,8 percent. The usefulness of the PCR was further investigated in the 28 children who have received specific treatment with nifurtimox. Negativetion of XD after three and six months post treatment respectively. These observations suggest that PCR is the most sensitive and quick technique available for direct detection of T. cruzi in chagasic children and that it can be a very useful tool for the follow-up of infected subjects after specific chemotherapeutical treatment