ABSTRACT
Ninety per cent of the 500,000 annual new cases of visceral leishmaniasis (VL) occur in India/Bangladesh/Nepal, Sudan and Brazil. Importantly, 80-90% of human infections are sub-clinical or asymptomatic, usually associated with strong cell-mediated immunity. Understanding the environmental and genetic risk factors that determine why two people with the same exposure to infection differ in susceptibility could provide important leads for improved therapies. Recent research using candidate gene association analysis and genome-wide linkage studies (GWLS) in collections of families from Sudan, Brazil and India have identified a number of genes/regions related both to environmental risk factors (e.g. iron), as well as genes that determine type 1 vs. type 2 cellular immune responses. However, until now all of the allelic association studies carried out have been underpowered to find genes of small effect sizes (odds ratios or OR < 2), and GWLS using multicase pedigrees have only been powered to find single major genes, or at best oligogenic control. The accumulation of large DNA banks from India and Brazil now makes it possible to undertake genome-wide association studies (GWAS), which are ongoing as part of phase 2 of the Wellcome Trust Case Control Consortium. Data from this analysis should seed research into novel genes and mechanisms that influence susceptibility to VL.
Subject(s)
Genetic Predisposition to Disease , Genome, Human , Genome-Wide Association Study , Leishmania donovani/pathogenicity , Leishmaniasis, Visceral/genetics , Animals , Asia, Western/epidemiology , Brazil/epidemiology , Genome-Wide Association Study/methods , Humans , Hypersensitivity, Delayed/genetics , Leishmaniasis, Visceral/epidemiology , Leishmaniasis, Visceral/immunology , Leishmaniasis, Visceral/parasitology , Mice , Mice, Inbred BALB C , Sudan/epidemiologyABSTRACT
PURPOSE: To develop a scale to measure (social) participation for use in rehabilitation, stigma reduction and social integration programmes. METHOD: A scale development study was carried out in Nepal, India and Brazil using standard methods. The instrument was to be based on the Participation domains of the International Classification of Functioning, Disability and Health (ICF), be cross-cultural in nature and assess client-perceived participation. Respondents rated their participation in comparison with a "peer", defined as "someone similar to the respondent in all respects except for the disease or disability". RESULTS: An 18-item instrument was developed in seven languages. Crohnbach's alpha was 0.92, intra-tester stability 0.83 and inter-tester reliability 0.80. Discrimination between controls and clients was good at a Participation Score threshold of 12. Responsiveness after a "life change" was according to expectation. CONCLUSIONS: The Participation Scale is reliable and valid to measure client-perceived participation in people affected by leprosy or disability. It is expected to be valid in other (stigmatised) conditions also, but this needs confirmation. The scale allows collection of participation data and impact assessment of interventions to improve social participation. Such data may be compared between clients, interventions and programmes. The scale is suitable for use in institutions, but also at the peripheral level.