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Objective To explore the influence of agricultural mechanization progress on epidemic intensity of hemorrhagic fever with renal syndrome (HFRS) so as to provide reference for prevention and control of HFRS in rural areas.Methods Data of HFRS epidemics and agricultural mechanization progress of Qingdao City and five main epidemic areas of HFRS were collected by retrospective analysis methods.Agricultural mechanization progress,time distribution,incidence rate of HFRS and capture rate of rats were compared,respectively.Risk factors were analyzed by case-control study using simple random sampling method.Cases of case group were selected from HFRS cases of Jiaonan County recovered between 2012 and 2013.The control group was healthy residents with a equal number of the case group.Residential locations,work ways,rodent infestation at work locations and in residential areas and skin injury conditions were surveyed by a household questionnaire survey.Results Agricultural machinery gross power of Qingdao City was developed from 174.76 megawatts of electricity (mwe) in 1985 to 854.00 mwe in 2015.The comprehensive mechanization degree marched from 60.0％ in 1994 to 90.2％ in 2015.HFRS incidence in Qingdao City declined from the first epidemic peak (1986) of 32.97/100 000 to the third peak (2012) of 3.54/100 000.HFRS incidence in Jiaonan,Jiaozhou,Pingdu,Laixi,Jimo cities reduced from the first epidemic peak (1985 or 1986) of 101.25/100 000,86.37/100 000,35.80/100 000,11.55/100 000,8.13/100 000 to the third peak(2012) of 14.68/100 000,4.43/100 000,2.33/100 000,6.02/100 000,3.26/100 000.The platform stage of epidemic peak in autumn and winter shortened from 4 or 5 months to 2 months.The capture rate of rats fluctuated around 2％.The infection risk of small farm implements or handwork was greater than huge mechanization (OR =0.01,P ＜ 0.01).Conclusions Agricultural mechanization changes the agricultural activity patterns to a large extent and lowers the HFRS epidemic by minimizing the risk of infection and shortening the platform stage of epidemic peak.The higher the degree of mechanization,the lower the epidemic intensity.
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ABSTRACT This study was the first to evaluate the efficiency of trapping methods in the study of small mammals in the Carajás National Forest, southeastern Brazilian Amazon. It is an area with a unique vegetation type (metalofilic savannah or Canga). The aims of this study were to compare the efficiency of two trapping methods (i.e. live-traps and pitfalls), the bait types used, and evaluate if trapping success varied seasonally. We used four sampling grids, each with six parallel transects. The trap effort for live-traps and pitfalls was 51,840 trap*nights and 10,800 bucket*nights, respectively. We used three types of bait: a paste of peanut butter and sardines, bacon, and bananas. We placed one type of bait in each trap, alternating between points. We recorded 26 species of small mammals, 11 from the order Didelphimorphia and 15 from the order Rodentia. Pitfalls captured a higher number of species compared with live-traps. The capture rate, the mortality rate and the quantity of juveniles and adults did not differ significantly between methods. Capture rate for pitfalls differed significantly between seasons. The majority of species were captured by a single method. Species were equally attracted to the traps regardless of the type of bait used. Some of our results differed significantly from other studies in Amazonia and such variation should be taken into account when designing survey methods for Amazonian small mammals.
RESUMO Este estudo foi o primeiro a avaliar a eficiência de métodos de captura de pequenos mamíferos não-voadores na Floresta Nacional de Carajás, sudeste da Amazônia brasileira. É uma área que apresenta características fitofisionômicas exclusivas (savana metalófila ou Canga) e sofre pressão da atividade mineradora. Os objetivos desse estudo foram comparar a eficiência de dois métodos de captura e de três tipos de iscas, bem como se a eficiência dos métodos variou sazonalmente. Nós usamos quatro grades de amostragem, cada uma com seis trilhas paralelas. Capturas com armadilhas de gaiola (live-traps) e armadilhas de caída (pitfall traps) foram realizadas durante três estações secas e três úmidas. O esforço total de captura foi de 51.840 armadilhas*noite e 10.800 baldes*noite para live-traps e pitfalls, respectivamente. Três tipos de isca (pasta de amendoim com sardinha, bacon e banana) foram usadas de forma alternada em todas as armadilhas. Nós registramos 26 espécies de pequenos mamíferos, 11 da ordem Didelphimorphia e 15 da ordem Rodentia. Pitfalls capturaram mais espécies que live-traps. As taxas de captura e de mortalidade e a proporção de jovens e adultos não diferiram entre os métodos. O sucesso de captura diferiu sazonalmente apenas para pitfalls. A maioria das espécies foi capturada preferencialmente ou exclusivamente por um dos dois métodos. As espécies foram igualmente atraídas por todos os tipos de iscas. Nossos resultados diferiram de outros obtidos na Amazônia, o que deve ser levado em consideração em desenhos amostrais para pequenos mamíferos na região.
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Amazonian EcosystemABSTRACT
Objective To understand the ecological developmental characteristics of rats in the epidemic areas of hemorrhagic fever with renal syndrome (HFRS) so as to provide a basis for effective control of HFRS.Methods Based on the China National Disease Surveillance Reporting and Management System,data of HFRS cases from 2010 to 2014 were collected and analyzed by retrospective analysis.Meanwhile surveillance data of rats were collected and the capture rates in different seasons,genders and districts were also analyzed.Results Totally 51,92,129,85 and 71 cases of HFRS were reported from 2010 to 2014.Most HFRS cases occurred from October to November which were 43,59,78,37 and 37,respectively.Totally 2902 rats were captured from 2010 to 2014.The five-year average capture rate was 4.87％ (2902/59610).The highest capture rate was 6.94％ (910/13107) in the third quarter and the outdoor capture rate (5.80％,1681/28987) was higher than that of indoor(3.99％,1221/30623,x2 =324.35,P ＜ 0.05).More male rats were captured than female rats and the overall proportion was 62.82％ (348/554) and 37.18％ (206/554),respectively.The outdoor rats were mainly Apodemus agrarius (556),Cricetulus triton (432),Rattus noruegicus (217),Mus musculus (211) and Sorex araneus (139),and the indoor rats were mainly Mus musculus (514),Rattus noruegicus (469) and Sorex araneus (181).The black rat disappeared and White-bellied rat appeared.Conclusions The rat density keeps higher all year round and the type of rats has become increasingly complex.Mixed living of indoor and outdoor rats increased the infection probability of different types of Hantavirus,which has an immediate impact on the spreading pattern of HFRS.