부산대학교 도서관

Background: Mosquito-borne Rift Valley fever virus (RVFV) causes acute, often severe, disease in livestock and humans. To determine the exposure factors and range of symptoms associated with human RVF, we performed a population-based cross-sectional survey in six villages across a 40 km transect in northeastern Kenya. Methodology/Principal Findings: A systematic survey of the total populations of six Northeastern Kenyan villages was performed. Among 1082 residents tested via anti-RVFV IgG ELISA, seroprevalence was 15% (CI95%, 13–17%). Prevalence did not vary significantly among villages. Subject age was a significant factor, with 31% (154/498) of adults seropositive vs. only 2% of children ≤15 years (12/583). Seroprevalence was higher among men (18%) than women (13%). Factors associated with seropositivity included a history of animal exposure, non-focal fever symptoms, symptoms related to meningoencephalitis, and eye symptoms. Using cluster analysis in RVFV positive participants, a more severe symptom phenotype was empirically defined as having somatic symptoms of acute fever plus eye symptoms, and possibly one or more meningoencephalitic or hemorrhagic symptoms. Associated with this more severe disease phenotype were older age, village, recent illness, and loss of a family member during the last outbreak. In multivariate analysis, sheltering livestock (aOR = 3.5 CI95% 0.93–13.61, P = 0.065), disposing of livestock abortus (aOR = 4.11, CI95% 0.63–26.79, P = 0.14), and village location (P = 0.009) were independently associated with the severe disease phenotype. Conclusions/Significance: Our results demonstrate that a significant proportion of the population in northeastern Kenya has been infected with RVFV. Village and certain animal husbandry activities were associated with more severe disease. Older age, male gender, herder occupation, killing and butchering livestock, and poor visual acuity were useful markers for increased RVFV infection. Formal vision testing may therefore prove to be a helpful, low-technology tool for RVF screening during epidemics in high-risk rural settings. Author Summary: Rift Valley fever virus (RVFV) causes serious disease in both animals and humans. Large-scale outbreaks result in devastating economic losses and create many urgent public health concerns. Among humans, the symptoms of RVF are variable, having a broad spectrum of disease that ranges from mild to severe fever symptoms, and can include ocular complications, encephalitis, and sometimes hemorrhagic disease. In this study, 1082 at-risk Kenyan subjects were serum antibody-tested for evidence of prior RVFV infection and their demographic, health, and exposure data were collated. Seroprevalence was moderately high across the study area (15%) but did not differ significantly among villages across the study region. Age, gender, and herding occupation were all significantly associated with being RVFV seropositive. Older age, village and certain animal husbandry activities were associated with more severe disease. Poor visual acuity was more likely in the seropositive group. This better definition of risk factors and associated symptom complexes should prove helpful for RVF screening during future outbreaks in high-risk rural settings. [ABSTRACT FROM AUTHOR]