农业部家畜血吸虫病流行病学观测点2011年观测结果情况

2011年对8个家畜血吸虫病观测点血吸虫感染、野粪污染情况以及螺情进行了调查.全年共检测了21091头牛、1425只羊以及1760头(匹)其他家畜,血吸虫病感染率分别为0.42％、0.63％和0％.在97头(只)感染家畜中,90.72％(88头)为牛,9.28％(9只)为羊.江西省吴城镇和湖南省南大膳镇的牛血吸虫感染率超过4％.在湖南省和江西省的观测点中发现家畜粪便有血吸虫虫卵污染,其中96.15％阳性野粪为牛粪.所有观测点都有钉螺分布,但阳性钉螺主要分布在湖南省和江西省的观测点.观测结果显示湖南省洞庭湖和江西省鄱阳湖地区是目前防控家畜血吸虫病的重点地区,且病牛依然是血吸虫病疫区(尤其是湖沼型地区)的主要传染源.     

A Retrospective Study on Antimicrobial Resistance in Mannheimia (Pasteurella) haemolytica,Escherichia coli,Salmonella Species,and Bordetella avium from Chickens in Minnesota

A 5-yr retrospective study (1998 to 2002) was conducted to determine the rate of isolation of 4 different bacterial pathogens and their antimicrobial resistance from chickens submitted to the Minnesota Veterinary Diagnostic Laboratory, St. Paul, Minnesota. The in vitro antimicrobial resistance was evaluated using the disc diffusion method. A total of 218 bacteria were isolated with the frequency of isolation being Mannheimia (Pasteurella) haemolytica 92 (42.2%) > Escherichia coli 80 (36.7%) > Salmonella spp., 42 (19.3%) > Bordetella avium 4 (1.8%). All isolates were resistant to macrolides and tetracycline antimicrobials but showed varied resistance to aminoglycoside and beta-lactam antibiotics. A majority of the isolates showed high resistance to spectinomycin, sarafloxacin, tetracycline, sulfadimethoxine, and sulfachloropyridiazine. These results emphasize the need for continued surveillance of chicken pathogens to monitor their resistance patterns with a view to control the infections caused by these pathogens.     

Molecular testing of adult Pacific salmon and trout (Oncorhynchus spp.) for several RNA viruses demonstrates widespread distribution of piscine orthoreovirus in Alaska and Washington

This research was initiated in conjunction with a systematic, multiagency surveillance effort in the United States (U.S.) in response to reported findings of infectious salmon anaemia virus (ISAV) RNA in British Columbia, Canada. In the systematic surveillance study reported in a companion paper, tissues from various salmonids taken from Washington and Alaska were surveyed for ISAV RNA using the U.S.‐approved diagnostic method, and samples were released for use in this present study only after testing negative. Here, we tested a subset of these samples for ISAV RNA with three additional published molecular assays, as well as for RNA from salmonid alphavirus (SAV), piscine myocarditis virus (PMCV) and piscine orthoreovirus (PRV). All samples (n = 2,252; 121 stock cohorts) tested negative for RNA from ISAV, PMCV, and SAV. In contrast, there were 25 stock cohorts from Washington and Alaska that had one or more individuals test positive for PRV RNA; prevalence within stocks varied and ranged from 2% to 73%. The overall prevalence of PRV RNA‐positive individuals across the study was 3.4% (77 of 2,252 fish tested). Findings of PRV RNA were most common in coho (Oncorhynchus kisutch Walbaum) and Chinook (O. tshawytscha Walbaum) salmon.     

Detection of tilapia lake virus (TiLV) infection by PCR in farmed and wild Nile tilapia (Oreochromis niloticus) from Lake Victoria

Tilapia lake virus disease (TiLVD) has emerged to be an important viral disease of farmed Nile tilapia (Oreochromis niloticus) having the potential to impede expansion of aquaculture production. There is a need for rapid diagnostic tools to identify infected fish to limit the spread in individual farms. We report the first detection of TiLV infection by PCR in farmed and wild Nile tilapia from Lake Victoria. There was no difference in prevalence between farmed and wild fish samples (p = .65), and of the 442 samples examined from 191 fish, 28 were positive for TiLV by PCR. In terms of tissue distribution, the head kidney (7.69%, N = 65) and spleen (10.99%, N = 191), samples had the highest prevalence (p < .0028) followed by heart samples (3.45%, N = 29). Conversely, the prevalence was low in the liver (0.71%, N = 140) and absent in brain samples (0.0%, N = 17), which have previously been shown to be target organs during acute infections. Phylogenetic analysis showed homology between our sequences and those from recent outbreaks in Israel and Thailand. Given that these findings were based on nucleic acid detection by PCR, future studies should seek to isolate the virus from fish in Lake Victoria and show its ability to cause disease and virulence in susceptible fish.     

Expert Opinion to Identify High‐Risk Entry Routes of Canine Rabies into Papua New Guinea

The proximity of Papua New Guinea (PNG) to canine rabies‐endemic countries in South‐East Asia presents a risk of incursion of this disease into PNG and the rest of the Oceanic region. The objective of this study was to identify the highest risk routes for entry of dogs – associated with movement of people – into PNG from canine rabies‐endemic countries. A structured, in‐country expert‐elicitation workshop was used, and 20 entry routes were identified. The highest risk routes were three land routes from Papua, Indonesia (hunters, traditional border crossers and unregulated, unchecked ‘shopper‐crossers’) and two sea routes (fishing and logging). These results will be used to direct more detailed risk assessments to develop surveillance strategies and incursion response plans.     

Clinical screening of horses and early warning for West Nile virus

Clinical presentation of West Nile disease in horses is variable, but ataxia, weakness and muscle fasciculations are often observed, sometimes with abnormal behaviour, teeth grinding and bruxism. Practitioners should be aware that horses are more sensitive to infection than man and serve as sentinels for an early warning of West Nile virus circulation in a given area. This early warning allows the implementation of preventive and control measures such as vaccination of horses and mosquito control.     

麦田天敌监测资料统计标准的研究

通过对麦田天敌消长规律的调查分析,从害虫防治和天敌利用的角度出发,提出天敌的最低利用指标,并作为划分天敌发生盛期的依据。同时提出用天敌高峰日发生量和发生盛期天数、后期网捕天敌量作为划分天敌发生程度的指标,并在麦田天敌监测资料统计中进行了具体应用。     

疯牛病的安全风险评估和监控技术研究动态

为了确保全球畜产品安全处于较高水平,世界动物卫生组织建议所有成员国,将安全风险评价机制引入疯牛病等动物烈性疾病的安全监控管理体系。文中将重点介绍疯牛病安全风险评估和监控技术方面的最新科研成果,具体包括疯牛病安全风险因子识别以及释放风险、暴露风险、后果风险评估等技术的发展动态。     

欧盟动物防疫制度介绍

通过对欧盟现行动物防疫法规、体制的分析,从防疫管理体制、兽医管理、区域化管理、疫病监测、补偿体系等方面详细论述了欧盟先进的动物防疫体系,并提出了对我国动物防疫体系建设的启示,为完善我国动物防疫体系提供借鉴。