STUDY OF CONGENITAL CHAGAS' DISEASE

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During this research, 640 out of 2072 (30.8%) of pregnant women showed positive anti-Trypanosoma cruzi (T.cruzi) antibody, and 32 out of 640 (5.00%) newborns were diagnosed as congenital Chagas' disease. Though it is hard to follow them up, 17 out of 32 are still under investigation. They have many environmental factors ; 52 out of 134 (38.8%) of the seropositives live in the house of sun-dried brick (adobe) and 41 out of 134 (30.61%) live in the house of clay wall with cracks. We could find the living environment of inhabitant is the ideal condition for infestation of Triatoma infestans (T.infestans), the main vector of T.cruzi. We could also envision that the ordinary contact with triatomine bugs with high rate of T.cruzi infestation caused the repeated infection and invasion into fetus during their pregnancy. On the other hand, T.cruzi is always found in the blood of chronic phase of Chagas' disease (latent infection), although the density is low.It is possible that T.cruzi invades into fetus through umbilical cord blood. We tried to confirm T.cruzi-DNA from the pregnant seropositives by PCR method, but the result was not consistent with the others'. The diagnosis by PCR needs further study considering the characteristic of this disease. The reliable diagnosis method of this disease seems strout method using umbilical cord blood and method of xenodiagnosis. Most of the seropositives are latent infection, so the establishment of diagnosis by PCR is now expected. Though the cardiac disturbance coursed by this disease has been little reported, we analyzed the Holter E.C.G of 9 newborns diagnosed as congenital Chagas' disease and 4 out of 9 showed rising of average heart rate (P<0.05). We are going to study in further detail from this aspect, and advise to prevent this disease.