Employing digital PCR for enhanced detection of perinatal Toxoplasma gondii infection: A cross-sectional surveillance and maternal-infant outcomes study in El Salvador.

Toxoplasma gondii is a parasitic infection that can be transmitted in utero, resulting in fetal chorioretinitis and other long-term neurological outcomes. If diagnosed early, pregnancy-safe chemotherapeutics can prevent vertical transmission. Unfortunately, diagnosis of acute, primary infection among pregnant women remains neglected, particularly in low-and-middle-income countries. Clinically actionable diagnosis is complex due to the commonality of infection during childhood and early adulthood which spawn long-last antibody titers and historically unreliable direct molecular diagnostics. The current study employed a cross-sectional T. gondii perinatal surveillance study using digital PCR, a next generation molecular diagnostic platform, and a maternal-fetal outcomes survey to ascertain the risk of vertical toxoplasmosis transmission in the Western Region of El Salvador. Of 198 enrolled mothers at the time of childbirth, 6.6% had evidence of recent T. gondii infection-85% of these cases were identified using digital PCR. Neonates born to these acutely infected mothers were significantly more likely to meconium aspiration syndrome and mothers were more likely to experience labor and delivery complications. Multivariable logistic regression found higher maternal T. gondii infection odds were associated with the presence of pet cats, the definitive T. gondii host. In closing, this study provides evidence of maternal T. gondii infection, vertical transmission and deleterious fetal outcomes in a vulnerable population near the El Salvador-Guatemala border. Further, this is the first published study to show clinical utility potential of digital PCR for accurate diagnosis of congenital toxoplasmosis cases.

Chagas Disease Maternal Seroprevalence and Maternal-Fetal Health Outcomes in a Parturition Cohort in Western El Salvador.

Congenital Chagas disease is a growing concern, prioritized by the World Health Organization for public health action. El Salvador is home to some of the highest Chagas disease (Trypanosoma cruzi infection) burdens in the Americas, yet pregnancy screening remains neglected. This pilot investigation performed a maternal T. cruzi surveillance study in Western El Salvador among women presenting for labor and delivery. From 198 consented and enrolled pregnant women, 6% were T. cruzi positive by serology or molecular diagnosis. Half of the infants born to T. cruzi-positive women were admitted to the NICU for neonatal complications. Geospatial statistical clustering of cases was noted in the municipality of Jujutla. Older women and those knowing an infected relative or close friend were significantly more likely to test positive for T. cruzi infection at the time of parturition. In closing, maternal T. cruzi infections were significantly higher than national HIV or syphilis maternal rates, creating an urgent need to add T. cruzi to mandatory pregnancy screening programs.

A Southwestern United States Pilot Investigation of Triatomine-Mite Prevalence.

BACKGROUND: Chagas disease is a leading cause of cardiac failure in Latin America. Due to poor safety profiles and efficacy of currently available therapeutics, prevention is a priority for the millions living at risk for acquiring this clinically important vector-borne disease. Triatomine vectors of the Chagas disease parasite, Trypanosoma cruzi, are found in the southwestern United States, but risk for autochthonous transmission is thought to be low. The role of ectoparasitic mites is under-explored regarding the ecology of triatomines and Chagas disease transmission. METHODS: Triatomine collections were performed using three common entomologic techniques in 2020-2021 from four different locations in southern Arizona and New Mexico. Triatomines were analyzed visually under a 112.5× microscope for the presence of externally attached mites. Following mite removal, triatomines were tested for T. cruzi infection by PCR. RESULTS: Approximately 13% of the collected triatomines had mites securely attached to their head, thorax, abdomen, and legs. More than one mite attached was a common finding among ectoparasitized triatomines. Mite presence, however, did not statistically influence triatomine T. cruzi status. CONCLUSIONS: Our findings add to a growing body of literature demonstrating the sustainability of mite-infested triatomine populations throughout the Western Hemisphere. Future investigations are warranted to better understand the biologic impact of triatomine mites and their potential to serve as a potential biological control tool.