We conducted a cross-sectional study of Chagas disease in five endemic areas in Argentina, Bolivia, Honduras, and México to estimate the prevalence of Trypanosoma cruzi–specific antibodies in pregnant women, and to assess the use of a rapid test (Chagas Stat-Pak) to screen for T. cruzi infection at the time of delivery. The prevalence of antibodies to T. cruzi measured by enzyme-linked immunosorbent assay (ELISA) in maternal blood was 5.5% (a range of 0.8–28.8% among the countries) in 2,495 women enrolled. Compared with ELISA in maternal blood samples, the Chagas Stat-Pak rapid test sensitivity and specificity in umbilical cord blood were 94.6% and 99.0%, respectively. These results show the ability for a rapid determination of the presence of T. cruzi–specific antibodies in umbilical cord blood as a pragmatic strategy to screen for infection in pregnant women.

Compared with South America, there is a lack of epidemiologic studies about the risk of congenital transmission of Trypanosoma cruzi in Central America and Mexico. It has been suggested that T. cruzi genotypes might differ by region and that congenital transmission might vary according to the parasite’s genotype. Our objective was to compare T. cruzi congenital transmission rates in three countries. We performed an observational prospective study in 2011–2014 enrolling women at delivery in one hospital in Argentina, two hospitals in Honduras, and two hospitals in Mexico. Congenital T. cruzi infection was defined as the presence of one or more of the following criteria: presence of parasites in cord blood (direct parasitological microscopic examination) with positive polymerase chain reaction (PCR) in cord blood, presence of parasites in infant’s blood at 4–8 weeks (direct parasitological microscopic examination), and persistence of T. cruzi-specific antibodies at 10 months, as measured by at least two tests. Among 28,145 enrolled women, 347 had at least one antibody rapid test positive in cord blood and a positive enzyme-linked immunosorbent assay in maternal blood. PCR in maternal blood was positive in 73.2% of the cases, and genotyping identified a majority of non-TcI in the three countries. We found no (0.0%; 95% confidence interval [CI]: 0.0, 2.0) confirmed congenital case in Honduras. Congenital transmission was 6.6% (95% CI: 3.1, 12.2) in Argentina and 6.3% (95% CI: 0.8, 20.8) in Mexico. Trypanosoma cruzi non-TcI predominated and risks of congenital transmission were similar in Argentina and Mexico.

Reproductive physiology and endocrinology change with the onset of illness and injury in a variety of species, including humans. To assess the human reproductive endocrine response to malaria, serial serum samples were collected from 8 male and 9 female residents of Honduras infected with Plasmodium vivax (plus 19 male and 23 female healthy age-matched controls) and were analyzed for associations between testosterone, parasitemia, and cytokine levels. Because testosterone has been negatively associated with measures of immune function under various circumstances, it was hypothesized that testosterone would be directly associated with P. vivax parasitemia and inversely associated with proinflammatory cytokine levels. The findings presented here suggest that 1) testosterone levels are positively associated with P. vivax parasitemia in adult males, and 2) males infected with P. vivax exhibit significantly lower testosterone levels and significantly higher cortisol levels than healthy individuals. Depressed androgen levels during physiologic perturbations may be an advantageous, adaptive host response to ameliorate immunosuppression by higher testosterone levels and to curb the use of energetic resources for metabolically expensive anabolic functions.

Introduction Zika virus (ZIKV) infection during pregnancy is a known cause of microcephaly and other congenital and developmental anomalies. In the absence of a ZIKV vaccine or prophylactics, principal investigators (PIs) and international leaders in ZIKV research have formed the ZIKV Individual Participant Data (IPD) Consortium to identify, collect and synthesise IPD from longitudinal studies of pregnant women that measure ZIKV infection during pregnancy and fetal, infant or child outcomes. Methods and analysis We will identify eligible studies through the ZIKV IPD Consortium membership and a systematic review and invite study PIs to participate in the IPD meta-analysis (IPD-MA). We will use the combined dataset to estimate the relative and absolute risk of congenital Zika syndrome (CZS), including microcephaly and late symptomatic congenital infections; identify and explore sources of heterogeneity in those estimates and develop and validate a risk prediction model to identify the pregnancies at the highest risk of CZS or adverse developmental outcomes. The variable accuracy of diagnostic assays and differences in exposure and outcome definitions means that included studies will have a higher level of systematic variability, a component of measurement error, than an IPD-MA of studies of an established pathogen. We will use expert testimony, existing internal and external diagnostic accuracy validation studies and laboratory external quality assessments to inform the distribution of measurement error in our models. We will apply both Bayesian and frequentist methods to directly account for these and other sources of uncertainty. Ethics and dissemination The IPD-MA was deemed exempt from ethical review. We will convene a group of patient advocates to evaluate the ethical implications and utility of the risk stratification tool. Findings from these analyses will be shared via national and international conferences and through publication in open access, peer-reviewed journals. Trial registration number PROSPERO International prospective register of systematic reviews (CRD42017068915).

In Honduras, chloroquine and primaquine are recommended and still appear to be effective for treatment of Plasmodium falciparum and Plasmodium vivax malaria. The aim of this study was to determine the proportion of resistance associated genetic polymorphisms in P. falciparum and P. vivax collected in Honduras.