Infección materna y transmisión transplacentaria del Trypanosoma cruzi en Chile: diagnóstico, tratamiento y control / Trypanosoma cruzi transplacental infection in Chile: diagnosis, treatment and control

Trypanosoma cruzi transplacental infection represents a serious public health concern in all the countries like Chile where recent success of insecticide spraying programs eliminated the vector. Because children infected with T. cruzi are usually asymptomatic, a study was designed including infected mothers and their children. The study was conducted for three years to establish diagnostic, treatment, and clinical observations variables. Mothers were tested for T. cruzi IgG, and the new born were examined for parasite DNA using PCR amplification. They were treated with nifurtimox and it was 100% effective, confirmed by successive PCR tests. It has been determined that there are 800 to 1000 new cases a year of transplacental Chagas' disease in Chile. This level of infection in the population should justify the establishment of a control and follow-up program for transplacental Chagas' disease.

Genetic parameters and trends for milk production of blond-faced Latxa sheep using Bayesian analysis.

The genetic progress attained with the breeding scheme of the blond-faced Latxa dairy sheep in the Spanish Basque Country was assessed by a Bayesian approach based on the marginal posterior distributions of parameters achieved via Gibbs sampling. The data file included 49,056 milk yield records of 22,363 ewes. Normal distributions were assumed for EBV and fixed effects, and scaled inverted chi-square distributions were assumed for variance components or additive, permanent environment, and residual effects. Under vague priors for variance components, the posterior means (SD) for heritability and permanent environment coefficient for milk yield at 120 d were 0.22(0.01) and 0.20(0.01). An important effect on the milk yield (41.6% of the mean) was evident for a genetic group of imported rams. Selection was effective for sheep that were bred by AI and that had known parents. The robustness of results for effect of genetic group and genetic trends was validated using a mildly informative prior constructed from variance components estimated with the related black-faced Latxa breed.