Are maternal re-infections with Trypanosoma cruzi associated with higher morbidity and mortality of congenital Chagas disease?
BACKGROUND
Comparing two surveys performed in Bolivia in 1992-1994 and 1999-2001, we reported a significant decrease in the proportions of severe and mortal forms of congenital Chagas disease. This might be due to a reduction of vectorial density (VD) in maternal residence area, raising the question of a possible causal relationship between such VD, maternal parasitaemia and prognosis of congenital infection with Trypanosoma cruzi.


METHODS
Comparisons of haematological and parasitological data obtained from Bolivian mothers infected with T. cruzi, and of clinical and biological data obtained from their infected and uninfected newborns, stratified according to VD in the area of maternal residence.


RESULTS
i) Blood hematocrit rates or hemoglobin amounts were within the normal ranges and similar in all the maternal groups, whatever the VD in their areas of residence; ii) mothers living in high VD areas displayed a higher frequency of hemocultures positive for T. cruzi; iii) newborns congenitally infected with T. cruzi, but not uninfected babies born from infected mothers, displayed higher frequencies of very low Apgar scores, low birth weights, prematurity, respiratory distress syndrome or anasarca, as well as higher mortality rates when their mothers lived in areas of high VD.


CONCLUSIONS
Frequent bites of blood sucking Reduvidae during pregnancy do not induce maternal anaemia, but, likely through multiple maternal re-infections with T. cruzi, increase maternal parasitemia and worsen congenital Chagas disease. Maternal dwelling in areas of high VD is associated with a serious increased risk of severe and mortal congenital Chagas disease.
Torrico
Faustino
F
Centro Universitario de Medicina Tropical, Facultad de Medicina, Universidad Mayor de San Simon, Cochabamba, Bolivia.
Vega
Cristina Alonso
CA
Suarez
Eduardo
E
Tellez
Tatiana
T
Brutus
Laurent
L
Rodriguez
Patricia
P
Torrico
Mary-Cruz
MC
Schneider
Dominique
D
Truyens
Carine
C
Carlier
Yves
Y
D000818:Animals; D001034:Apgar Score; D001838:Bolivia / Q000453:epidemiology; D014355:Chagas Disease / Q000151:congenital* / Q000453:epidemiology / Q000401:mortality; D004199:Disease Vectors; D019353:Endemic Diseases; D005260:Female; D005865:Gestational Age; D006400:Hematocrit; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D018445:Infectious Disease Transmission, Vertical; D009017:Morbidity; D009035:Mothers; D011156:Population Density; D011247:Pregnancy; D012111:Residence Characteristics; D014349:Trypanosoma cruzi
D006454:Hemoglobins