RESUMEN
Objective To create a model based on meteorological data to predict the regions at risk of schistosomiasis during the flood season, so as to provide insights into the surveillance and forecast of schistosomiasis. Methods An interactive schistosomiasis forecast system was created using the open-access R software. The schistosomiasis risk index was used as a basic parameter, and the species distribution model of Oncomelania hupensis snails was generated according to the cumulative rainfall and temperature to predict the probability of O. hupensis snail distribution, so as to identify the regions at risk of schistosomiasis transmission during the flood season. Results The framework of the web page was built using the Shiny package in the R program, and an interactive and visualization system was successfully created to predict the distribution of O. hupensis snails, containing O. hupensis snail surveillance site database, meteorological and environmental data. In this system, the snail distribution area may be displayed and the regions at risk of schistosomiasis transmission may be predicted using the species distribution model. This predictive system may rapidly generate the schistosomiasis transmission risk map, which is simple and easy to perform. In addition, the regions at risk of schistosomiasis transmission were predicted to be concentrated in the middle and lower reaches of the Yangtze River during the flood period. Conclusions A schistosomiasis forecast system is successfully created, which is accurate and rapid to utilize meteorological data to predict the regions at risk of schistosomiasis transmission during the flood period.
RESUMEN
Objective To establish the surveillance and risk assessment system of schistosomiasis in Jiangsu Province,so as to provide technical support for timely understanding of the risk of schistosomiasis transmission and implementation of target-ed control measures. Methods The surveillance sites of schistosomiasis were assigned according to the epidemic status and en-demic type of schistosomiasis as well as the characteristics of the water system,and the prevalence of Schistosoma japonicum in humans and domestic animals,and snail status were investigated. In addition,the quality control of serum detection of S. japon-icum infections was performed. The prevalence of human and animal S. japonicum infections,snail status and missing diagnosis of serum detection were analyzed and compared among regions. Results A total of 27 surveillance sites of schistosomiasis were set up in 26 counties of 10 cities,Jiangsu Province,including 14 sites in transmission-interrupted villages and 13 sites in trans-mission-controlled villages,and 15 sites in marshland and lake regions,9 sites in plain regions with water network and 3 sites in mountainous region. In the 27 surveillance sites,a total of 16 617 residents were screened for S. japonicum infection by using dipstick dye immunoassay(DDIA),and 326 were sero-positive,with a sero-prevalence of 1.96%(2.17%for men and 1.8%for women). Of the 326 individuals undergoing parasitological examination,2 positive cases were detected in the marshland and lake region,with a S. japonicum human prevalence of 0.01%. Of the 762 floating population detected,10 were positive for blood test,with a sero-prevalence of 1.31%,and no egg-positive individuals were detected. No infection was found in the 476 do-mestic animals. Of the 746 settings surveyed,a total of 240.7 hm2 snail area was detected,with a mean snail density of 0.06 snails/0.1 m2,and no infected snails were found. There were 780 quality-control sera detected in 26 surveillance sites of schisto-somiasis,and the gross coincidence rate was 95.13%,with misdiagnosis rate of 1.28%and missing diagnosis rate of 19.23%. Conclusion The surveillance sites of schistosomiasis show reasonable distribution in Jiangsu Province,and the endemic situa-tion of schistosomiasis appears a low level in the whole province.
RESUMEN
O controle da requeima da batata requer aplicação freqüente de fungicidas, o que encarece a produção, impactando de modo desnecessário o ambiente. A utilização de modelos de previsão dessa doença permitiria reduzir as aplicações sem afetar a produção. Neste trabalho, objetivou-se avaliar os modelos "Blitecast e Prophy" como referência para o controle da requeima por fungicidas. Os experimentos foram conduzidos na primavera de 2004 e no outono de 2005, em Santa Maria, RS. Os dados meteorológicos foram medidos no centro da área experimental, a 0,10 e a 1,50 m acima da superfície do solo. Utilizaram-se diferentes valores de severidade (VS) acumulada, calculada pelos modelos "Blitecast" (VS= 18, 24, 30, 36 e 42) e "Prophy" (VS= 15, 20, 25, 30 e 35) que se constituíram os tratamentos, adicionando-se o tratamento com aplicação semanal e a testemunha, sem aplicação. O delineamento foi inteiramente casualizado com quatro repetições, sendo cada parcela composta de quatro fileiras de plantas com 5 m de comprimento. Avaliou-se a severidade da requeima por parcela a cada três a cinco dias. Verificou-se que o uso do modelo "Blitecast" com 18 valores de severidade acumulados, incrementou, em pelo menos, 42,6 por cento a produtividade de tubérculos comerciais em relação às áreas sem aplicação de fungicida e reduziu o número de aplicações em 25 por cento nos períodos úmidos e, em 70 por cento nos períodos secos, em relação às aplicações semanais. A eficiência de controle da requeima foi similar à obtida com aplicações semanais de fungicida nos tratamentos Bli18 e Pro15. O uso do modelo "Prophy" requer maior número de aplicações do que o "Blitecast" e não resultou em melhor controle.
The control potato late blight needs a great number of fungicide sprayings. These increase the costs of cropping and cause undesirable environmental impacts. The use of forecast systems to predict disease has the potential of reducing fungicide applications without reducing yield. The objective of this study was to evaluate the performance of Blitecast and Prophy systems as a reference model for predicting late blight potato and support decision of spray fungicides. Experiments were carried out during Spring 2004 and Autumn 2005, in Santa Maria, RS, Brazil. Meteorological data were measured in the center of the experimental area at 0.10 and 1.50 m above soil surface. Different accumulated severity values (VS) were calculated with 'Blitecast' (VS = 18, 24, 30, 36 and 42) and 'Prophy' (VS = 15, 20, 25, 30 and 35) forecast systems. These values were used to perform. Two additional treatments were the weekly sprays and without fungicides. The experimental design was a completely randomized, with four replications. Each plot had four rows plants with 5 m length. Late blight severity was evaluated in each three to five days. The fungicide spraying schedule based on Blitecast system with 18 accumulated severity values increased tuber yield at least 42.6 percent compared to the control without fungicides treatment. It also reduced the number of sprayings by 25 percent during wet periods and 70 percent during dry periods compared to weekly sprayings. The efficiency of controlling late blight was similar to the weekly sprayings treatment in the treatments Bli18 e Pro15. The Prophy model predicted higher number of fungicide sprayings than the Blitecast system and did not improve disease control.