Browsing by Autor "Natalie M. Bowman"

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32. Risk Factors for Vertical Transmission of <i>t. Cruzi</i> infection in an Endemic Setting
(Oxford University Press, 2020) Melissa D. Klein; Freddy Tinajeros; Edith Málaga; Manuela Verástegui; Beth Jessy Condori; Federico Urquizu; Robert H. Gilman; Natalie M. Bowman
Abstract Members of the Chagas Disease Working Group in Peru and Bolivia include Edith Hinojosa, Clariza Chavez, Jean Karla Velarde, Carla Chavarria, Victoria Serrudo, Roberto Araya, Alcides Buitron, Rita Mendieta, Holger Mayta, Maritza Calderon, Holger Mayta and Yagahira Castro. Background Vertical transmission of Trypanosoma cruzi infection accounts for a growing proportion of new cases of Chagas disease. Congenital infection is curable if treated promptly, but the majority of infected infants do not receive timely diagnosis or treatment. Better risk stratification is needed to predict which women are more likely to transmit the infection. Methods This study enrolled women who presented for delivery and their infants at the Percy Boland Women’s Hospital in Santa Cruz, Bolivia. Pregnant women were screened for Chagas disease by rapid test. The infants of seropositive mothers underwent diagnostic testing with microscopy (“micromethod”) and quantitative polymerase chain reaction (qPCR) as newborns and at one- and nine-month follow-up. Mothers completed surveys about demographics and medical history. Results Among 5,828 enrolled women, 1,271 (21.8%) screened positive for Chagas disease. Of the 1,325 infants of seropositive mothers, 113 (8.5%) were diagnosed with congenital Chagas disease by microscopy or qPCR. Cesarean delivery was significantly associated with lower odds of vertical transmission (adjusted OR: 0.63, 95% CI: 0.41–0.98, p=0.040). Congenital infection was more common in twins (adjusted OR: 3.30, 95% CI: 1.97–5.54, p&lt; 0.001) and male infants (adjusted OR: 1.50, 95% CI: 1.01–1.22, p=0.045). Conclusion Our findings suggest that Cesarean delivery may be protective against vertical transmission of T. cruzi, while twins and male infants may have an increased risk. A better understanding of risk stratification for congenital Chagas disease may help improve regional initiatives to reduce disease burden. Disclosures All Authors: No reported disclosures
IgG Subclasses and Congenital Transmission of Chagas Disease
(American Society of Tropical Medicine and Hygiene, 2021) Cristian Roca; Edith S. Málaga-Machaca; Manuela Verástegui; Billy Scola; Edward Valencia Ayala; María del Carmen Menduiña; Sassan Noazin; Natalie M. Bowman; Freddy Tinajeros; Robert H. Gilman
The mechanism of vertical transmission of Trypanosoma cruzi is poorly understood. In this study, we evaluated the role of IgG subclasses in the congenital transmission of Chagas disease. We conducted a case-control study in a public maternity hospital in Santa Cruz, Bolivia, enrolling women at delivery. Thirty women who transmitted T. cruzi to their newborns (cases), and 51 women who did not (controls) were randomly selected from 676 total seropositive women. Trypanosoma cruzi-specific IgG1, IgG2, and IgG3 levels were measured by in-house ELISA. The IgG4 levels were unmeasurable as a result of low levels in all participants. Quantitative polymerase chain reaction results and demographic factors were also analyzed. One-unit increases in normalized absorbance ratio of IgG1 or IgG2 levels increased the odds of congenital T. cruzi transmission in Chagas-seropositive women by 2.0 (95% CI: 1.1-3.6) and 2.27 (95% CI: 0.9-5.7), adjusted for age and previous blood transfusion. Odds of congenital transmission were 7.0 times higher in parasitemic mothers (95% CI: 2.3-21.3, P < 0.01) compared with nonparasitemic mothers. We observed that all mothers with IgG1 ≥ 4 were transmitters (sensitivity = 20%, specificity = 100%). Additionally, no mothers with IgG2 < 1.13 were transmitters (sensitivity = 100%, specificity = 21.6%). We demonstrated that IgG subclasses and parasite presence in blood are associated with vertical transmission of T. cruzi and could identify women at increased risk for congenital transmission by measuring IgG subclasses. These measures have potential as objective screening tests to predict the congenital transmission of Chagas.
Risk Factors for Maternal Chagas Disease and Vertical Transmission in a Bolivian Hospital
(Oxford University Press, 2020) Melissa D. Klein; Freddy Tinajeros; María del Carmen Menduiña; Edith Málaga; Beth Jessy Condori; Manuela Verástegui; Federico Urquizu; Robert H. Gilman; Natalie M. Bowman
Although improved access to screening and qPCR increased the number of infants diagnosed with congenital Chagas disease, many infants remain undiagnosed. A better understanding of risk factors and improved access to highly sensitive and specific diagnostic techniques for congenital Chagas disease may help improve regional initiatives to reduce disease burden.
Use of a Chagas Urine Nanoparticle Test (Chunap) to Correlate with Parasitemia Levels in T. cruzi/HIV Co-infected Patients
(Public Library of Science, 2016) Yagahira E. Castro-Sesquen; Robert H. Gilman; Carolina Mejía; Daniel E. Clark; Jeong Won Choi; Melissa Reimer-McAtee; Rosario Castro; Edward Valencia Ayala; Jorge Flores; Natalie M. Bowman
Chunap shows potential for early detection of Chagas reactivation. With appropriate adaptation, this diagnostic test can be used to monitor Chagas disease status in T. cruzi/HIV co-infected patients.