Pestforecast: Surveillance and early-warning systems for climate-sensitive diseases in Vietnam and Laos
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Item Seroprevalence of leptospirosis and Japanese encephalitis in swine in ten provinces of Vietnam(Journal Article, 2019-08-01) Hu Suk Lee; To Long Thanh; Nguyen Khanh Ly; Hung Nguyen-Viet; Thakur, Krishna K.; Grace, DeliaBackground Leptospirosis is an important zoonotic disease with a global distribution, affecting a wide range of mammalian animals and humans. Japanese encephalitis (JE) virus is the major vector-borne zoonotic disease in the Asia-Pacific region. The main objective of this study was to evaluate the seroprevalence of serovar-specific Leptospira and JE in swine from 10 provinces in Vietnam. Methods Samples were initially collected for swine influenza surveillance from March to April 2017 at large-scale farms (with at least 50 sows and/or 250 fattening pigs) with pigs that tested positive for influenza in the previous surveillance period (2015–16). Findings A total of 2,000 sera samples were analyzed from 10 provinces. Overall, the seroprevalence of leptospirosis was 21.05% (95% CI: 19.28–22.90) using a cut-off titer of ≥ 1:100. The apparent prevalence of JE was 73.45% (95% CI: 71.46–75.37) while the true prevalence was slightly higher (74.46%, 95% credible interval: 73.73–86.41). We found a relatively high presence of leptospirosis and JE in pigs kept on large farms. Prevalence was comparable with other studies suggesting opportunistic testing of samples collected for other surveillance purposes can be a valuable tool to better understand and prevent the potential transmission of these zoonotic diseases from pigs to people in Vietnam. Conclusion Our study provides evidence to veterinarians and animal health professionals for evidence-based practice such as diagnosis, vaccination and zoonotic control. Further investigation into the possible role of different domestic animals, wildlife species or environmental factors is needed to identify the potential risk factors and transmission routes in Vietnam.Item Assessment of aflatoxin B1 in maize and awareness of aflatoxins in Son La, Vietnam(Journal Article, 2018-01) Xuan Thi Thanh Nguyen; Thuy Thi Thanh Nguyen; Hung Nguyen-Viet; Khanh Ngoc Tran; Lindahl, Johanna F.; Grace, Delia; Thanh Minh Ha; Hu Suk LeeAflatoxin 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 > 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 ethnic group (p = 0.003). Maize in Son La is contaminated with AFB1 at levels which imply better control of aflatoxins in maize for human consumptions and animal feed is needed.Item Surveillance and early warning systems for climate-sensitive diseases in Vietnam (2015–17)(Presentation, 2018-11-28) Hu Suk LeeItem Assessment of aflatoxin B1 contamination in maize and awareness of aflatoxins in Son La province, Vietnam(Presentation, 2018-08-15) Hu Suk Lee; Xuan Nguyen Thi Thanh; Thuy Nguyen Thi Thanh; Hung Nguyen-Viet; Lindahl, Johanna F.; Grace, DeliaItem Climate sensitive diseases in Vietnam: Aflatoxin B1 in maize and zoonotic diseases in pigs(Poster, 2018-03-23) Hu Suk Lee; Hung Nguyen-Viet; Nguyen Viet Khong; Ha Minh Thanh; Bui Nghia Vuong; Nguyen Van Huyen; Lindahl, Johanna F.; Grace, DeliaItem Surveillance and early warning systems for climate-sensitive diseases in Vietnam: Key findings from the Pestforecast project(Brief, 2017-12-30) Hu Suk Lee; Hung Nguyen-Viet; Nguyen Viet Khong; Huyen Nguyen Xuan; Vuong Bui Nghia; Ha Minh Thanh; Mihye Lee; Phuc Pham Duc; Vu Sinh Nam; Hoang Thi Thu Ha; Nguyen Huu Quyen; Xuan Nguyen; Lindahl, Johanna F.; Bett, Bernard K.; Unger, Fred; Grace, DeliaItem Surveillance and early warning systems for climate sensitive diseases in Vietnam(Presentation, 2017-11-20) Hung Nguyen-Viet; Hu Suk Lee; Phuc Pham Duc; Khong, N.V.; Thanh, H.M.; Vuong, B.N.; Huyen, N.V.; Lindahl, Johanna F.; Bett, Bernard K.; Unger, Fred; Grace, DeliaItem Climate sensitive diseases in Vietnam: Aflatoxin B1 in maize and zoonotic diseases in pigs(Poster, 2017-11-23) Hu Suk Lee; Hung Nguyen-Viet; Nguyen Viet Khong; Ha Minh Thanh; Bui Nghia Vuong; Nguyen Van Huyen; Lindahl, Johanna F.; Grace, DeliaItem Seasonal and geographical distribution of bacillary dysentery (shigellosis) and associated climate risk factors in Kon Tam Province in Vietnam from 1999 to 2013(Journal Article, 2017-12) Hu Suk Lee; Ha Hoang T.T.; Phuc Pham Duc; Lee, M.; Grace, Delia; Dac Cam Phung; Vu Minh Thuc; Hung Nguyen-VietBackground: Bacillary dysentery (BD) is an acute bacterial infection of the intestine caused by Shigella spp., with clinical symptoms ranging from fever to bloody diarrhoea to abdominal cramps to tenesmus. In Vietnam, enteric bacterial pathogens are an important cause of diarrhoea and most cases in children under 5 years of age are due to Shigella strains. The serogroups S. flexneri and S. sonnei are considered to be the most common. The main objective of this study was to, for the first time, assess the seasonal patterns and geographic distribution of BD in Vietnam, and to determine the climate risk factors associated with the incidence of BD in Kon Tum Province, where the highest rate of bacillary dysentery was observed from 1999 to 2013. Methods: The seasonal patterns and geographic distribution of BD was assessed in Vietnam using a seasonaltrend decomposition procedure based on loess. In addition, negative binomial regression models were used to determine the climate risk factors associated with the incidence of BD in Kon Tum Province, from 1999 to 2013. Results: Overall, incidence rates of BD have slightly decreased over time (except for an extremely high incidence in 2012 in the north of Vietnam). The central regions (north/south central coast and central highlands) had relatively high incidence rates, whereas the northwest/east and Red River Delta regions had low incidence rates. Overall, seasonal plots showed a high peak in the mid-rainy reason and a second smaller peak in the early or late rainy season. The incidence rates significantly increased between May and October (“wet season”) across the country. In Kon Tum Province, temperature, humidity, and precipitation were found to be positively associated with the incidence of BD. Conclusions: Our findings provide insights into the seasonal patterns and geographic distribution of BD in Vietnam and its associated climate risk factors in Kon Tum Province. This study may help clinicians and the general public to better understand the timings of outbreaks and therefore equip them with the knowledge to plan better interventions (such as improving water, sanitation, and hygiene conditions) during peak seasons. This can, in turn, prevent or reduce outbreaks and onwards transmission during an outbreak.Item Sero-prevalence of specific Leptospira serovars in fattening pigs from 5 provinces in Vietnam(Journal Article, 2017-12) Hu Suk Lee; Nguyen Viet Khong; Huyen Nguyen Xuan; Vuong Bui Nghia; Hung Nguyen-Viet; Grace, DeliaBackground Leptospirosis is a zoonotic bacterial disease with a worldwide distribution. In Vietnam, leptospirosis is considered endemic. In pigs, leptospirosis can result in reproductive problems (such as abortion and infertility) which lead to economic loss. In addition, transmission to people presents a public health risk. In Vietnam, few national studies have been conducted on sero-prevalence of leptospirosis in pigs. The main objective of this study was to evaluate the sero-prevalence and incidence of presumptive infective leptospira serovars in fattening pigs from 5 provinces in Vietnam. Results Blood samples from fattening pigs were randomly collected at slaughterhouses. We collected 1959 sera samples from 5 provinces (Son La, Hanoi, Nghe An, Dak Lak and An Giang) between January and early June 2016. The microscopic agglutination test (MAT) was used to identify the serogroups/serovars. Overall, the sero-prevalence was 8.17% (95% CI: 6.99–9.47) and serovar Tarassovi Mitis (2.19%) had the highest prevalence followed by Australis (1.94%), Javanica (1.68%) and Autumnalis (1.17%) using a cutoff (≥ 1:100). The sero-prevalence among female pigs (5.28%, 95% CI: 3.94–6.93) was slightly higher than among male pigs (4.88%, 95% CI: 3.51–6.58), but this difference was not statistically significant. Conclusions Leptospirosis in pigs may be a useful indicator of the human/animal burden in Vietnam and a risk assessment tool. The presence of some of the identified serovars suggests that wildlife may play an important role in the transmission of leptospirosis to domesticated pigs in Vietnam. Therefore, strengthened monitoring and surveillance systems are needed to better understand the epidemiology of the disease and prevent or reduce infection in humans and animals.Item Seasonal patterns of dengue fever and associated climate factors in 4 provinces in Vietnam from 1994 to 2013(Journal Article, 2017-12) Hu Suk Lee; Hung Nguyen-Viet; Vu Sinh Nam; Lee, M.; Won, S.; Phuc Pham Duc; Grace, DeliaBackground In Vietnam, dengue fever (DF) is still a leading cause of hospitalization. The main objective of this study was to evaluate the seasonality and association with climate factors (temperature and precipitation) on the incidences of DF in four provinces where the highest incidence rates were observed from 1994 to 2013 in Vietnam. Methods Incidence rates (per 100,000) were calculated on a monthly basis from during the study period. The seasonal-decomposition procedure based on loess (STL) was used in order to assess the trend and seasonality of DF. In addition, a seasonal cycle subseries (SCS) plot and univariate negative binomial regression (NBR) model were used to evaluate the monthly variability with statistical analysis. Lastly, a generalized estimating equation (GEE) was used to assess the relationship between monthly incidence rates and weather factors (temperature and precipitation). Results We found that increased incidence rates were observed in the second half of each year (from May through December) which is the rainy season in each province. In Hanoi, the final model showed that 1 °C rise of temperature corresponded to an increase of 13% in the monthly incidence rate of DF. In Khanh Hoa, the final model displayed that 1 °C increase in temperature corresponded to an increase of 17% while 100 mm increase in precipitation corresponded to an increase of 11% of DF incidence rate. For Ho Chi Minh City, none of variables were significant in the model. In An Giang, the final model showed that 100 mm increase of precipitation in the preceding and same months corresponded to an increase of 30% and 22% of DF incidence rate. Conclusion Our findings provide insight into understanding the seasonal pattern and associated climate risk factors.Item Surveillance and early warning systems for climate sensitive diseases in Vietnam and Laos(Presentation, 2016-10-17) Hung Nguyen-Viet; Hu Suk Lee; Grace, DeliaItem Introduction to SaTScan, seasonality and time series analysis(Presentation, 2016-11-28) Hu Suk LeeItem Pestforecast: Surveillance and early warning systems for climate sensitive diseases in Vietnam(Presentation, 2016-09-23) Hu Suk LeeItem Pestforecast: Surveillance and early warning systems for climate sensitive diseases in Vietnam(Presentation, 2016-11-30) Hu Suk LeeItem Seroprevalence of specific Leptospira serovars in pigs from five provinces in Vietnam(Presentation, 2016-12-03) Hu Suk Lee; Hung Nguyen-Viet; Grace, DeliaItem A survey of aflatoxin B1 in maize and awareness of aflatoxins in Vietnam(Journal Article, 2017-05-26) Hu Suk Lee; Hung Nguyen-Viet; Lindahl, Johanna F.; Ha Minh Thanh; Tran Ngoc Khanh; Le Thi Thu Hien; Grace, DeliaVietnam is a tropical country with high temperature and precipitation, which may provide good conditions for fungal growth. A few limited studies have been conducted to evaluate the level of aflatoxin B1 in maize in Vietnam. In addition, no studies have been conducted to evaluate the perception and knowledge of aflatoxins in Vietnam. Therefore, the main objective of this study was to determine the levels of aflatoxin B1 for human and animal consumption in maize and evaluate perceptions and knowledge of aflatoxins among people across the country. A total of 2,370 samples were collected from six provinces and analysed using ELISA. Among collected samples, 799 samples (33.71%, 95% confidence interval (CI): 31.81-35.66%) and 687 samples (28.98%, 95%CI: 27.17-30.86%) had levels above 2 µg/kg and 5 µg/kg, respectively [range from below limit of detection (LOD) to 34.8 µg/kg; of the samples above LOD, the mean was 13.1 µg/kg and median was 11.2 µg/kg]. A total of 551 people were interviewed from 6 provinces. The survey showed that awareness of aflatoxins (question: Have you heard about aflatoxins?) in southern Vietnam [An Giang (25%), Dak Lak (23.23%) and Dong Nai (6%)] was relatively higher than in provinces in northern Vietnam. We believe that this analysed information can be useful to better understand the epidemiology of aflatoxins in different provinces. This study also produces evidence on potential risk to humans and animals in Vietnam as well as demographic factors (such as gender and level of education) significantly influencing knowledge of aflatoxins. In conclusion, this paper points to the importance of raising the awareness of the risks with aflatoxins, bearing in mind the gender aspect during capacity development.Item Seasonality of viral encephalitis and associated environmental risk factors in Son La and Thai Binh provinces in Vietnam from 2004 to 2013(Journal Article, 2017-01-11) Hu Suk Lee; Hung Nguyen-Viet; Lee, M.; Phuc Pham Duc; Grace, DeliaIn Vietnam, Japanese encephalitis virus accounts for 12–71% of viral encephalitis (VE) cases followed by enteroviruses and dengue virus among identified pathogens. This study is the first attempt to evaluate the seasonality of VE and associated environmental risk factors in two provinces from 2004 to 2013 using a seasonal trend-decomposition procedure based on loess regression and negative binomial regression models. We found seasonality with a peak of VE in August and June in Son La and Thai Binh, respectively. In Son La, the model showed that for every 1°C increase in average monthly temperature, there was a 4.0% increase in monthly VE incidence. There was a gradual decline in incidence rates as the relative humidity rose to its mean value (80%) and a dramatic rise in incidence rate as the relative humidity rose past 80%. Another model found that a 100 mm rise in precipitation in the preceding and same months corresponded to an increase in VE incidence of 23% and 21%, respectively. In Thai Binh, our model showed that a 1°C increase in temperature corresponded with a 9% increase in VE incidence. Another model found that VE incidence increased as monthly precipitation rose to its mean value of 130 mm but declined gradually as precipitation levels rose beyond that. The last model showed that a monthly increase in duration of sunshine of 1 hour corresponded to a 0.6% increase in VE incidence. The findings may assist clinicians by improving the evidence for diagnosis.Item Surveillance and early warning systems for climate sensitive diseases in Vietnam and Laos(Presentation, 2015-11-23) Hu Suk LeeItem Climate sensitive diseases in the Mekong Region: Can we predict pests by climate factors?(Presentation, 2015-09-16) Hung Nguyen-Viet; Hu Suk Lee; Unger, Fred; Lindahl, Johanna F.; Bett, Bernard K.; Grace, DeliaA warmer, wetter world is likely to be sicker. TheMekong is a hotspot for human, animal and plant diseases, and some of themost important are highly sensitive to climate and climate changes. These diseases can impose enormous burdens on human health and the agricultural sector and hinder broader development. Better response to climate sensitive disease requires better information and tools. The objective of the project we are presenting here is to develop tools to forecast climate-sensitive animal and plant diseases in Vietnam and Laos. Key work packages will include (among others) developing and disseminating maps of hotspots for selected climate-sensitive animal and zoonotic diseases, piloting a real-time prediction system, and exploring the potential for weather-based forecasting for aflatoxin mitigation (only Vietnam). As climaticsensitive animal diseases and zoonoses leptospirosis and Japanese encephalitis have been identified in stakeholder consultations for Vietnam. Leptospirosis is caused by bacteria hosted by mammals, although the rodent-borne serovars are most often associated with serious human diseases which get infected through contact with contaminated water. Japanese encephalitis is a vector-borne viral disease transmitted by culicine mosquitoes from the amplifying hosts (e.g. pigs) to humans, where disease can be fatal. Aflatoxins, produced by Aspergillus spp in cereals, can cause acute or chronic aflatoxicosis in humans. The association of these diseases and meteorological conditions is evaluated and models will be built to predict future occurrence. If the models are successful in predicting disease, the aim is to provide policymakers and stakeholders with tools to aid in mitigating future disease and to make susceptible societies more resilient to future climate change. The ultimate outcome targets farming communities that are able to take practical action to reduce disease risk and/or benefit from risk-mitigating action provided by health providers. A framework which will guide through the various work packages will be presented and discussed. The project is funded by the CGIAR programme on Climate Change, Agriculture and Food Security (CCAFS).