Vallée Julie auteur aut IRD Dubot Pérès Audrey auteur aut IRD Ounaphom P. auteur aut IRD Sayavong C. auteur aut IRD Bryant J.E. auteur aut IRD Gonzalez Jean-Paul auteur aut IRD text journalArticle eng text/pdf born digital access OBJECTIVES To evaluate the prevalence of flavivirus infection in Vientiane city (Lao PDR), to describe the spatial distribution of infection within this city, and to explore the link between flavivirus seroprevalence and urbanization levels of residential neighbourhoods. METHODS A seroprevalence survey was carried out in 2006 including 1990 adults (35 years) and 1568 children (>= 6months and < 6 years) randomly selected. RESULTS The prevalence of individuals with previous flavivirus infection (i.e. negative for both DEN and JE IgM but positive for DEN IgG) was 57.7%, with a significantly (P < 0.001) higher prevalence among adults (84.6%; 95% confidence interval (CI) = 82.4-86.8) than children (9.4%; 95% CI = 7.2-11.6). The prevalence of individuals with recent flavivirus infection (i.e. positive for DEN and/or JE IgM) was 6.5% and also significantly (P < 0.001) higher among adults (10.0%; 95% CI = 8.3-11.7) than children (2.5%; 95% CI = 1.5-3.5). In terms of spatial distribution, IgG prevalence was significantly (P < 0.001) higher among individuals living in the central city (60.1%; 95% CI = 56.2-64.1) than among those living in the periphery (44.3%; 95% CI = 41.5-47.2). In contrast, seroprevalence of recent flavivirus infections was significantly (P < 0.001) higher among individuals living in the periphery (8.8%; 95% CI = 6.9-10.7) than in the central city (4.0%; 95% CI = 2.9-5.2). This association was also statistically consistant (P < 0.01) in multivariate logistic regression after controlling for individual risk factors. CONCLUSIONS Our findings indicate that the level of urbanization of residential neighbourhoods influences the risk of flavivirus infection. The spatial distribution of flavivirus infection varies, even within a small city of less than 300 000 habitants such as Vientiane. specialized Vientiane spatial distribution urbanization residential neighbourhood serosurvey Dengue and Japanese encephalitis LAOS 052 102 14 9 1134-1142 2009 1360-2276 https://www.documentation.ird.fr/hor/fdi:010048322 10.1111/j.1365-3156.2009.02319.x 1360-2276 [F B010048322] https://www.documentation.ird.fr/hor/fdi:010048322 https://www.documentation.ird.fr/intranet/publi/2009/11/010048322.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2009-12-03 2017-08-23 fdi:010048322 fre