Modeling the hepatitis A epidemiological transition in Brazil and Mexico

Background: Many low- to middle-income countries have completed or are in the process of transitioning from high or intermediate to low endemicity for hepatitis A virus (HAV). Because the risk of severe hepatitis A disease increases with age at infection, decreased incidence that leaves older children and adults susceptible to HAV infection may actually increase the population-level burden of disease from HAV. Mathematical models can be helpful for projecting future epidemiological profiles for HAV. Methods: An age-specific deterministic, dynamic compartmental transmission model with stratification by setting (rural versus urban) was calibrated with country-specific data on demography, urbanization, and seroprevalence of anti-HAV antibodies. HAV transmission was modeled as a function of setting-specific access to safe water. The model was then used to project various HAV-related epidemiological outcomes in Brazil and in Mexico from 1950 to 2050. Results: The projected epidemiological outcomes were qualitatively similar in the 2 countries. The age at the midpoint of population immunity (AMPI) increased considerably and the mean age of symptomatic HAV cases shifted from childhood to early adulthood. The projected overall incidence rate of HAV infections decreased by about two thirds as safe water access improved. However, the incidence rate of symptomatic HAV infections remained roughly the same over the projection period. The incidence rates of HAV infections (all and symptomatic alone) were projected to become similar in rural and urban settings in the next decades. Conclusion: This model featuring population age structure, urbanization and access to safe water as key contributors to the epidemiological transition for HAV was previously validated with data from Thailand and fits equally well with data from Latin American countries. Assuming no introduction of a vaccination program over the projection period, both Brazil and Mexico were projected to experience a continued decrease in HAV incidence rates without any substantial decrease in the incidence rates of symptomatic HAV infections

Metabolism of omeprazole after two oral doses in children 1 to 9 months old

Proton pump inhibitors (PPIs) have been used recently for gastrointestinal esophageal reflux disease (GERD) in children older than one year with good results [1,2]. However, the pharmacokinetics of PPIs have not been studied in children less than two years old. The aim of our study was to evaluate the frequency of the main phenotypes of the metabolizing enzymes CYP2C19 and CYP3A4 in Mexican infants. Our results indicate no significant difference between the 0.5 and the 1.5 mg/kg doses. The percentage of CYP2C19- poor metabolizers was 17% in babies below 4 months and was not detected in children above 3 months. When a combined CYP2C19- and CYP3A4- phenotype was estimated, omeprazole levels were significantly higher in poor metabolizers than in extended metabolizers. The percentage of ultra-extensive metabolizers in children older than 3 months were 20% and 33% for CYP2C19 and CYP3A4 respectively, compared to only 6% and 9% respectively, in babies between 1 and 3 months old. In general children, under 4 months had higher omeprazole levels and an immature metabolism. Studies in children older than 2 years old have showed similar pharmacokinetics to adults. For children between 1 month old and up to 9 months, we suggest the use of the 0.5 mg/kg dose, since it prevents accumulation in poor metabolizers, caution is recommended to identify ultra-fast metabolizers, but this would require new studies

Current pediatric indications for cisapride: A position paper by a panel convened by the European Society for Pediatric Gastroenterology, Hepatology and Nutrition

SCOPUS: re.jinfo:eu-repo/semantics/publishe