Are maternal re‐infections with Trypanosoma cruzi associated with higher morbidity and mortality of congenital Chagas disease?

Abstract

Summary 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. Method 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. Conclusion 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.

Congenital Chagas disease as an ecological model of interactions between Trypanosoma cruzi parasites, pregnant women, placenta and fetuses

“…We reported mortality rates up to 13% in a Bolivian cohort of congenitally infected newborns studied between 1992 and 1994, while such rate dropped to 2% in another study in 1999-2001, when Bolivia benefited from improved socio-economic conditions, better maternal care and extended its vector control programs (limiting re-infections during pregnancy; see Section 9) . Neonatal morbidity and mortality are much higher when acute or reactivated infection (co-infection with HIV) occur during pregnancy (see Section 4; Freilij et al, 1995b;Moretti et al, 2005;Scapellato et al, 2009), as well as, likely, when chronically infected pregnant women suffer from re-infections (see Section 9; Torrico et al, 2006). Experiments in mice also show acute infection and reinfections in chronic phase inducing fetal resorptions and/or pup mortality (Mjihdi et al, 2002;Solana et al, 2002;Cencig et al, 2013; see Section 9), in relation to high blood parasite-and TNF-␣-levels (Mjihdi et al, 2002(Mjihdi et al, , 2004Solana et al, 2009).…”

Reinfections and Trypanosoma cruzi strains can determine the prognosis of the chronic chagasic cardiopathy in mice

“…Several points about this different evolution are still poorly understood (Higuchi et al 2003). People living in endemic areas are exposed to suffer reinfections, a relevant factor even in congenital disease (Rabinovich et al 1990;Catalá et al 2004;Torrico et al 2006). We have previously demonstrated that reinfections with different T. cruzi strains have a potent role in developing early cardiac damage in the acute and indeterminate phase of experimental Chagas' disease (Bustamante et al 2002(Bustamante et al , 2003.…”

Mother-to-Child Transmission of Trypanosoma cruzi

“…Data also suggest vector control programs may potentially decrease the risk of MTCT and the severity of congenital Chagas disease by decreasing maternal parasitic load [18]. Congenital transmission rates are lower in nonendemic countries compared with endemic countries [19], and congenital Chagas disease in Bolivia has been less symptomatic in recent periods [20].…”