Abstract
BackgroundCongenital transmission is a major source of new Trypanosoma cruzi infections, and as vector and blood bank control continue to improve, the proportion due to congenital infection will grow. A major unanswered question is why reported transmission rates from T. cruzi-infected mothers vary so widely among study populations. Women with high parasite loads during pregnancy are more likely to transmit to their infants, but the factors that govern maternal parasite load are largely unknown. Better understanding of these factors could enable prioritization of screening programs to target women most at risk of transmission to their infants.Methodology/Principal FindingsWe screened pregnant women presenting for delivery in a large urban hospital in Bolivia and followed infants of infected women for congenital Chagas disease. Of 596 women screened, 128 (21.5%) had confirmed T. cruzi infection; transmission occurred from 15 (11.7%) infected women to their infants. Parasite loads were significantly higher among women who transmitted compared to those who did not. Congenital transmission occurred from 31.3% (9/29), 15.4% (4/26) and 0% (0/62) of women with high, moderate and low parasite load, respectively (χx2 for trend 18.2; p<0.0001). Twin births were associated with higher transmission risk and higher maternal parasite loads. Infected women without reported vector exposure had significantly higher parasite loads than those who had lived in an infested house (median 26.4 vs 0 parasites/mL; p<0.001) with an inverse relationship between years of living in an infested house and parasite load.Conclusions/SignificanceWe hypothesize that sustained vector-borne parasite exposure and repeated superinfection by T. cruzi may act as an immune booster, allowing women to maintain effective control of the parasite despite the down-regulation of late pregnancy.
Highlights
Regional initiatives to control Chagas disease by eliminating blood-borne transmission and domestic vector infestation have had a remarkable impact on the burden of this neglected disease [1]
Studies have consistently shown that women with high parasite loads during pregnancy are more likely to transmit to their infants, but the factors that govern maternal parasite load are largely unknown [15,16,17]
We evaluated factors associated with maternal parasite load during pregnancy and implications for congenital transmission
Summary
Regional initiatives to control Chagas disease by eliminating blood-borne transmission and domestic vector infestation have had a remarkable impact on the burden of this neglected disease [1]. Studies have consistently shown that women with high parasite loads during pregnancy are more likely to transmit to their infants, but the factors that govern maternal parasite load are largely unknown [15,16,17] Better understanding of this phenomenon could enable prioritization of screening programs to target women most at risk of transmission to their infants. Women with high parasite loads during pregnancy are more likely to transmit to their infants, but the factors that govern maternal parasite load are largely unknown Better understanding of these factors could enable prioritization of screening programs to target women most at risk of transmission to their infants
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
