Medicine - Medicine
Prevalence of asthma and underlying risk factors in two Peruvian cities.
Asthma was previously considered to be uncommon in Latin America; however, recent studies in different Latin American cities have identified that its prevalence currently ranges between 18% and 27%. These estimates are very high when compared with those reported in other developing countries and are comparable to those in many developed countries. At 21% to 27%, Peru has the highest prevalence of asthma in Latin America and one of the highest worldwide. However, studies reported in the literature were conducted only in the city of Lima and it is unclear if these rates are representative of Peru as a whole. We hypothesize that individuals living in Lima have unique environmental exposures, genetic predispositions, or both that are associated with an increased prevalence of asthma. We plan to conduct an observational study of 1,400 children aged 13 to 15 years in two Peruvian cities, Lima and Tumbes, to determine if there are differences in the prevalence and severity of asthma and if any underlying risk factors can explain these differences. We will assess the prevalence of asthma through a standard questionnaire, spirometry and exercise challenge. We will ask about potential environmental exposures, dietary factors, collect blood for genetic analysis and measurement of total IgE, and perform skin allergen testing. Finally, we will perform measurements of indoor and outdoor particulate matter in 10% of households. This award will help to support pilot studies on genetic analysis, collection of environmental data and laboratory measurement of total IgE in our study populations.Hepatitis E virus (HEV) is the leading global cause of acute viral hepatitis; particularly in South Asia where seasonal floods contaminate drinking water supplies leading to frequent hepatitis E (HE) epidemics. Whereas case-fatality rates in the general population can vary from 0.1-3.0%, elevated mortality (10-40%) in pregnant women infected with HEV genotype 1 has been demonstrated consistently in South Asia. Current methods to confirm infection rely on enzyme immunoassays (EIA) for detection of IgM or IgG antibodies to HEV (anti-HEV) in serum or PCR of HEV RNA in serum or stool. Collection of blood and stool is invasive and suffers practical constraints in children under 5 and pregnant women in resource-limited settings which may impede the ability to make frequent follow-up measurements in epidemiologic studies. This research will serve three purposes. First, to optimize and validate an HEV salivary EIA by evaluating the sensitivity, specificity, and reliability of HEV EIAs in de-identified paired saliva and finger-stick blood samples from patients at Dhaka Shishu Hospital, Dhaka, Bangladesh an area where HEV is endemic. Second, to evaluate the acceptance, usability, and reliability of a saliva self-sampling protocol via a brief survey after patients self-sample saliva. And third, to advance efforts to integrate the optimized HEV salivary EIA into ongoing and future epidemiologic studies which would refine understanding of the time windows of seroconversion and progression of infectious vs subclinical HE symptoms. Future studies building on this pilot research will improve the scientific evidence base about the time windows of HEV exposure and infection in populations with unique susceptibility.
Robert Gilman MD DTMH, Public Health, International Health; Kathleen Barnes PhD, Medicine, Genetic Research Facility; Wiliam Checkley MD PhD, Medicine/Medicine and Publlic Health/International Health; Robert Wise MD, Medicine, Medicine