Environmental factors and incidence of dengue fever and dengue haemorrhagic fever in an urban area, Southern Thailand

Abstract

Using the enumeration district (ED) block level this study looked at the incidence of dengue fever and dengue haemorrhagic fever (DF/DHF) within the Songkhla municipality in Thailand. Each of the 146 blocks in this area were considered as study units and surveyed for their environmental characteristics. A total of 287 cases of DH/DHF occurring in the year 1998 were selected for this study and the location of their homes mapped. Clustering analysis showed point clustering of the homes (P<0.0001) which was probably due to high density habitation, without any actual prevalence of case clustering. There was no evidence of clustering of the ED blocks with an incidence of DF/DHF (P=0.32). DF/DHF incidence for each block was strongly associated with the percentages of shop-houses, brick-made houses and houses with poor garbage disposal (all P<0.01). DF/DHF control should be emphasized for the areas which have a predominance of these housing types.

A dengue transmission model in Thailand considering sequential infections with all four serotypes

“…In Thailand, clinically diagnosed cases of DF, DHF and DSS are regularly reported to the Provincial Health Offices [5,6]. The total number of infected persons remains unknown without active detection surveillance because slight or asymptomatic persons rarely visit a hospital for treatment [7].…”

Monitoring the Paraguayan epidemiological dengue surveillance system (2009-2011) using Benford’s law

“…The relationship of these variables to dengue may be due to unclear socioeconomic segmentation in the city and the location of sectors with better conditions near those with poor conditions (38,39). Significant population mobility may also explain the mosquito's unexpected spatial distribution pattern (38).…”

“…Nevertheless, it is accepted that the proliferation of the vector increases when conditions are favorable to its reproduction (20,38,40), including socioeconomic conditions (39).…”

La dengue, maladie complexe

“…Cependant si ces facteurs influencent potentiellement le cycle de contamination, ils ne sont pas systéma-tiquement identifiés comme tels, car le résultat des causalités non linéaires entre ces facteurs dépend des contextes locaux. La connaissance de ces relations permet malgré tout la mise en oeuvre d'actions à différentes échelles pour tenter d'améliorer les conditions de santé publique : contrôle régulier des gîtes en eau (Abe et al, 2005), mesures de protection intra domiciliaires (Singh et al, 2011), amélioration des conditions d'accès à l'eau des populations (Schmidt et al, 2011), interventions selon les types d'usages du sol (Thammapalo et al, 2008) ou encore politiques de planification urbaine (De Mattos Almeida et al, 2007).…”

“…1 contamination locale et de rechercher l'échelle pertinente pour le contrôle vectoriel (Kan et al, 2008). Les zones de concentration des indices vectoriels en milieu urbain ont pu être calculées à partir de facteurs environnementaux tels que la densité de maisons en briques ou l'absence de réseau de collecte des ordures en Thaïlande (Thammapalo et al, 2008). Les corrélations entre des données sociodémographiques (éducation, revenu, taille du ménage) et des données épidémiologiques ont permis d'identifier les populations les plus vulnérables au Brésil (De Mattos Almeida et al, 2007).…”