4 research outputs found
Estimates of dengue force of infection in children in Colombo, Sri Lanka.
No full textDengue is the most important vector-borne viral disease worldwide and a major cause of childhood fever burden in Sri Lanka, which has experienced a number of large epidemics in the past decade. Despite this, data on the burden and transmission of dengue virus in the Indian Subcontinent are lacking. As part of a longitudinal fever surveillance study, we conducted a dengue seroprevalence survey among children aged <12 years in Colombo, Sri Lanka. We used a catalytic model to estimate the risk of primary infection among seronegative children. Over 50% of children had IgG antibodies to dengue virus and seroprevalence increased with age. The risk of primary infection was 14.1% per year (95% CI: 12.7%-15.6%), indicating that among initially seronegative children, approximately 1 in 7 experience their first infection within 12 months. There was weak evidence to suggest that the force of primary infection could be lower for children aged 6 years and above. We estimate that there are approximately 30 primary dengue infections among children <12 years in the community for every case notified to national surveillance, although this ratio is closer to 100:1 among infants. Dengue represents a considerable infection burden among children in urban Sri Lanka, with levels of transmission comparable to those in the more established epidemics of Southeast Asia
Impacts of Irrigation and Drainage Development Projects in Pakistan: Farmers’ Perceptions
No full textUsing well-designed sample, anecdotal evidence from farmers of a recently completed irrigation and drainage project in Bhawalnagar Pakistan, valuable impact indicators could be assessed. The case study suggests that although this simple and quick method is not a substitute for the detailed scientific survey, yet it can be handy, sufficient, and could be usefully used at a nominal cost as a supplementary method. The parameters approached were the depth to water-table, crop yields, cropping pattern, abandoned lands, water distribution, and seepage reduction, etc. The results showed that some of these, including the depth to water-table, seepage reduction, and cropping pattern compared well with previous technical studies, while some others did not. The physical interventions of the project under quick evaluation comprised concrete lining of about 170 kms of the distributary canals and 352 kms of surface drains. The paper concludes that the farmers’ perceptions, when carefully designed and analysed, offer substantial feedback for remedial actions and for planning future projects.
