| 1. |
- Bett, Bernard, et al.
(författare)
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Spatiotemporal analysis of historical records (2001-2012) on dengue fever in Vietnam and development of a statistical model for forecasting risk
- 2019
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 14:11
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Dengue fever is the most widespread infectious disease of humans transmitted by Aedes mosquitoes. It is the leading cause of hospitalization and death in children in the Southeast Asia and western Pacific regions. We analyzed surveillance records from health centers in Vietnam collected between 2001-2012 to determine seasonal trends, develop risk maps and an incidence forecasting model.METHODS: The data were analyzed using a hierarchical spatial Bayesian model that approximates its posterior parameter distributions using the integrated Laplace approximation algorithm (INLA). Meteorological, altitude and land cover (LC) data were used as predictors. The data were grouped by province (n = 63) and month (n = 144) and divided into training (2001-2009) and validation (2010-2012) sets. Thirteen meteorological variables, 7 land cover data and altitude were considered as predictors. Only significant predictors were kept in the final multivariable model. Eleven dummy variables representing month were also fitted to account for seasonal effects. Spatial and temporal effects were accounted for using Besag-York-Mollie (BYM) and autoregressive (1) models. Their levels of significance were analyzed using deviance information criterion (DIC). The model was validated based on the Theil's coefficient which compared predicted and observed incidence estimated using the validation data. Dengue incidence predictions for 2010-2012 were also used to generate risk maps.RESULTS: The mean monthly dengue incidence during the period was 6.94 cases (SD 14.49) per 100,000 people. Analyses on the temporal trends of the disease showed regular seasonal epidemics that were interrupted every 3 years (specifically in July 2004, July 2007 and September 2010) by major fluctuations in incidence. Monthly mean minimum temperature, rainfall, area under urban settlement/build-up areas and altitude were significant in the final model. Minimum temperature and rainfall had non-linear effects and lagging them by two months provided a better fitting model compared to using unlagged variables. Forecasts for the validation period closely mirrored the observed data and accurately captured the troughs and peaks of dengue incidence trajectories. A favorable Theil's coefficient of inequality of 0.22 was generated.CONCLUSIONS: The study identified temperature, rainfall, altitude and area under urban settlement as being significant predictors of dengue incidence. The statistical model fitted the data well based on Theil's coefficient of inequality, and risk maps generated from its predictions identified most of the high-risk provinces throughout the country.
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| 2. |
- Lee, Hu Suk, et al.
(författare)
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An investigation into aflatoxin M 1 in slaughtered fattening pigs and awareness of aflatoxins in Vietnam.
- 2017
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Ingår i: BMC Veterinary Research. - : Springer Science and Business Media LLC. - 1746-6148. ; 13:1
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Aflatoxin M1 (AFM1) is a hydroxylated metabolite formed after aflatoxin B1 (AFB1) is consumed by humans and animals; it can be detected in urine, milk and blood. It is well recognized that AFB1 is toxic to humans and other animals. The International Agency for Research on Cancer (IARC) classifies aflatoxins as group 1 carcinogens and AFM1 as group 2B carcinogen. The main objective of this study was to evaluate the exposure of pigs to aflatoxins as well as to assess the public awareness of aflatoxins among people in five provinces in Vietnam.RESULTS: A total of 1920 urine samples were collected from slaughterhouses located in five provinces. Overall, the positive rate of AFM1 was 53.90% (95% confidence interval 51.64-56.15) using a cut-off of 0.15 μg/kg (range: limit of detection to 13.66 μg/kg, median: 0.2 μg/kg and mean: 0.63 μg/kg). A total of 252 people from the general population were interviewed from 5 provinces, and overall 67.86% reported being aware of aflatoxins. We also found that men and more highly educated had significantly increased awareness of aflatoxins compared to the females and primary/secondary school group. The respective odds ratios (ORs) were as follows: "male" group (OR: 2.64), "high school educated" group (OR: 3.40) and "college/university or more educated" group (OR: 10.20).CONCLUSIONS: We can conclude that pigs in Vietnam are exposed to aflatoxins to varying degrees, and there may be a risk that pork products could contain AFM1. Further investigation is needed into the possible health impacts as well as to aid in establishing regulations for animal feed to reduce the health impacts in humans and animals.
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| 3. |
- Nguyen, Xuan Thi Thanh, et al.
(författare)
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Assessment of aflatoxin B \textlesssub\textgreater1\textless/sub\textgreater in maize and awareness of aflatoxins in Son La, Vietnam
- 2018
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Ingår i: Infection Ecology & Epidemiology. - : Taylor & Francis. - 2000-8686. ; 8:1
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Tidskriftsartikel (refereegranskat)abstract
- ABSTRACTAflatoxin B1 (AFB1) is a fungal by-product which causes acute and chronic toxicity in humans and many other animals. This research was conducted to evaluate the prevalence of AFB1 contamination in maize and residents’ awareness of aflatoxins in Son La province, Vietnam. Maize samples were randomly collected from Son La province using multi-stage sampling. We used cut-off levels of 5 and 20 μg/kg and calculated the mean, median and range for each district. In addition, a questionnaire collected information from households about their knowledge, attitude and practice related to moldy maize. Out of 378 maize samples from Son La, 204 (54.0%) and 141 (37.3%) were contaminated with AFB1 at more than 5 µg/kg and 20 µg/kg, respectively. Mai Son district had the highest proportion of samples (54.0%) using a cut-off level \textgreater 20 µg/kg, and Yen Chau district the lowest (4%). People from the Thai ethnic group were 30.9 times more likely to consume meat from animals fed moldy maize than people from the Kinh ethn...
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