No abstract

Increased T cell activation has predictive value for HIV-1 disease progression even before seroconversion. These data support the hypothesis that persistent hyperactivation of the immune system may lead to erosion of the naive T cell pool and CD4 T cell depletion.

Summaryobjective To determine the frequency and determinants of knowledge of dengue infection in three sites in northern Thailand, and to compare prevention measures of people with and without knowledge of dengue.methods In May 2001 we conducted an epidemiological survey among 1650 persons living in three areas in northern Thailand. Knowledge of dengue and the use of prevention measures were measured by means of a structured questionnaire. Differences in knowledge of dengue and the use of prevention measures between risk groups were calculated by chi-square test. Logistic regression was used to identify determinants of knowledge.results Of the 1650 persons, 67% had knowledge of dengue. Fever (81%) and rash (77%) were the most frequently mentioned symptoms. Persons with knowledge of dengue reported a significantly higher use of prevention measures than persons without knowledge of dengue. In multivariate analyses, knowledge of dengue significantly differed by age, sex, occupation and site (P < 0.05). Younger people knew more about dengue than older persons: adjusted odds ratio (aOR) of 6.75 [95% confidence interval (CI): 4.32-10.6] for the 15-29 age group compared with people aged 60 and older. In comparison with farmers (reference group), knowledge of dengue was significantly higher among students (aOR: 10.6, 95% CI: 4.27-26.4), but lower among housewives or unemployed persons (aOR: 0.44, 95% CI: 0.31-0.64).conclusion The overall knowledge of dengue was high, but housewives, unemployed and old persons had relatively little knowledge of dengue. Therefore, these groups may need special attention in future dengue education programmes. Persons with knowledge of the disease more frequently reported the use of preventive measures, indicating the value of education programmes as a tool in dengue prevention.

Mortality among CDI patients is high, even in an endemic situation. Our results show that CDI is associated with to a 2.5-fold increase in 30-day mortality. This highlights the considerable disease burden and clinical impact of CDI, even in absence of an outbreak.

Spatial patterns of and risk factors for seropositivity of dengue infection were studied in three sites in northern Thailand. A survey was conducted in 2001 among 1,750 persons. Potential risk factors for dengue infection were measured by questionnaire and IgM antibodies against dengue were detected by an enzyme-linked immunosorbent assay. The role of landscape as a risk factor was studied using land cover maps and a geographic information system. Logistic regression identified risk factors for dengue seropositivity. Spatial patterns of seropositive cases were determined by cluster analyses. Six percent of the study population was seropositive. Risk factors for dengue seropositivity differed per site, demonstrating variation in local infection patterns. In the periurban site, seropositivity depended on human behavior and factors related to housing quality rather than environmental factors. In both rural sites, older persons had a higher risk of seropositivity and persons living in houses surrounded by natural and agricultural land covers had a lower risk of seropositivity.