Use of Admail and a geographic information system to send surveys to target populations.

INTRODUCTION: This paper briefly describes the use of Canada Post Unaddressed Admail and a geographic information system (GIS) for survey distribution to a specific target population in a large, sparsely populated geographic area, and the effectiveness of this approach. METHODS: Surveys were sent as Unaddressed Admail via Canada Post to a target population of people living within 5 km of a wind turbine in southwestern Ontario. RESULTS: The overall response rate from 8 wind farms (in 8 counties) was 8.1%. CONCLUSION: This approach has the potential to save time and money, but low response rates are common, distribution is not precise and there is potential for selection bias. Despite these flaws, Unaddressed Admail is worth consideration for delivery of information, study-recruitment materials and surveys to rural, remote and specific target populations.

INTRODUCTION: Nous décrivons brièvement l'utilisation du service Médiaposte sans adresse de Postes Canada et d'un système d'information géographique pour la distribution de sondages à une population cible précise sur un grand territoire peu densément peuplé, ainsi que l'efficacité de cette méthode d'envoi. METHODS: Nous avons utilisé le service Médiaposte sans adresse de Postes Canada pour envoyer des sondages à une population cible habitant dans le sud-ouest de l'Ontario à moins de 5 kilomètres d'une éolienne. RESULTS: Le taux de réponse global pour les 8 parcs éoliens visés (dans 8 comtés différents) était de 8,1 %. CONCLUSION: Bien que cette méthode puisse faire économiser temps et argent, elle n'engendre souvent qu'un faible taux de réponse, est imprécise sur le plan de la distribution et pourrait entraîner un biais de sélection. Malgré ces lacunes, le service Médiaposte sans adresse reste une option à envisager pour l'envoi de renseignements, de documents de recrutement en vue d'études et de sondages à des populations cibles précises vivant en milieu rural et éloigné.

Regional, household and individual factors that influence soil transmitted helminth reinfection dynamics in preschool children from rural indigenous Panamá.

BACKGROUND: Few studies have investigated the relative influence of individual susceptibility versus household exposure factors versus regional clustering of infection on soil transmitted helminth (STH) transmission. The present study examined reinfection dynamics and spatial clustering of Ascaris lumbricoides, Trichuris trichiura and hookworm in an extremely impoverished indigenous setting in rural Panamá over a 16 month period that included two treatment and reinfection cycles in preschool children. METHODOLOGY/PRINCIPLE FINDINGS: Spatial cluster analyses were used to identify high prevalence clusters for each nematode. Multivariate models were then used (1) to identify factors that differentiated households within and outside the cluster, and (2) to examine the relative contribution of regional (presence in a high prevalence cluster), household (household density, asset-based household wealth, household crowding, maternal education) and individual (age, sex, pre-treatment eggs per gram (epg) feces, height-for-age, latrine use) factors on preschool child reinfection epgs for each STH. High prevalence spatial clusters were detected for Trichuris and hookworm but not for Ascaris. These clusters were characterized by low household density and low household wealth indices (HWI). Reinfection epg of both hookworm and Ascaris was positively associated with pre-treatment epg and was higher in stunted children. Additional individual (latrine use) as well as household variables (HWI, maternal education) entered the reinfection models for Ascaris but not for hookworm. CONCLUSIONS/SIGNIFICANCE: Even within the context of extreme poverty in this remote rural setting, the distinct transmission patterns for hookworm, Trichuris and Ascaris highlight the need for multi-pronged intervention strategies. In addition to poverty reduction, improved sanitation and attention to chronic malnutrition will be key to reducing Ascaris and hookworm transmission.