Spatial distribution of, and risk factors for, Opisthorchis viverrini infection in southern Lao PDR

Forrer, A. and Sayasone, S. and Vounatsou, P. and Vonghachack, Y. and Bouakhasith, D. and Vogt, S. and Glaser, R. and Utzinger, J. and Akkhavong, K. and Odermatt, P.. (2012) Spatial distribution of, and risk factors for, Opisthorchis viverrini infection in southern Lao PDR. PLoS neglected tropical diseases, Vol. 6, H. 2 , e1481.

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Official URL: http://edoc.unibas.ch/dok/A6094386

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BACKGROUND: Opisthorchis viverrini is a food-borne trematode species that might give rise to biliary diseases and the fatal cholangiocarcinoma. In Lao PDR, an estimated 2.5 million individuals are infected with O. viverrini, but epidemiological studies are scarce and the spatial distribution of infection remains to be determined. Our aim was to map the distribution of O. viverrini in southern Lao PDR, identify underlying risk factors, and predict the prevalence of O. viverrini at non-surveyed locations. METHODOLOGY: A cross-sectional parasitological and questionnaire survey was carried out in 51 villages in Champasack province in the first half of 2007. Data on demography, socioeconomic status, water supply, sanitation, and behavior were combined with remotely sensed environmental data and fed into a geographical information system. Bayesian geostatistical models were employed to identify risk factors and to investigate the spatial pattern of O. viverrini infection. Bayesian kriging was utilized to predict infection risk at non-surveyed locations. PRINCIPAL FINDINGS: The prevalence of O. viverrini among 3,371 study participants with complete data records was 61.1%. Geostatistical models identified age, Lao Loum ethnic group, educational attainment, occupation (i.e., rice farmer, fisherman, and animal breeder), and unsafe drinking water source as risk factors for infection. History of praziquantel treatment, access to sanitation, and distance to freshwater bodies were found to be protective factors. Spatial patterns of O. viverrini were mainly governed by environmental factors with predictive modeling identifying two different risk profiles: low risk of O. viverrini in the mountains and high risk in the Mekong corridor. CONCLUSIONS/SIGNIFICANCE: We present the first risk map of O. viverrini infection in Champasack province, which is important for spatial targeting of control efforts. Infection with O. viverrini appears to be strongly associated with exposure the second intermediate host fish, human behavior and culture, whereas high transmission is sustained by the lack of sanitation
Faculties and Departments:09 Associated Institutions > Swiss Tropical and Public Health Institute (Swiss TPH) > Department of Epidemiology and Public Health (EPH) > Eco System Health Sciences
UniBasel Contributors:Vounatsou, Penelope and Utzinger, Jürg and Odermatt, Peter
Item Type:Article, refereed
Article Subtype:Research Article
Publisher:Public Library of Science
Note:Publication type according to Uni Basel Research Database: Journal article
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Last Modified:31 Dec 2015 10:53
Deposited On:16 Aug 2013 07:29

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