荣昌县生猪肠道寄生虫感染情况调查

蒋庆等于2007年4—11月,共检查了832份集约化饲养的猪粪便、1133份农户散养猪的粪便,并检查了200头屠宰肥猪的肠道。结果:13.1%的集约化饲养猪感染猪蛔虫,5.4%感染猪鞭虫,14.6%感染食道     

江西部分地市集约化猪场主要肠道寄生虫病流行情况调查

随机采集来自于江西省樟树、丰城、上高、高安、南昌县、新建、新干等8个地市的15个规模不同的集约化猪场不同阶段猪的新鲜粪样共计1301份,采用饱和盐水漂浮法、直接涂片法及临床检查法对其肠道寄生虫感染情况进行调查,发现猪场小袋纤毛虫的感染较严重,其次是球虫、猪蛔虫、食道口线虫、类圆线虫,鞭虫感染率最低。不同生长阶段猪肠道寄生虫的感染情况也不一样,小袋纤毛虫和球虫在各阶段的猪群中均有感染,而鞭虫仅在育肥猪的肠道中被发现;在哺乳仔猪肠道中没有发现猪蛔虫和食道口线虫,在种公猪肠道中没有发现类圆线虫。     

规模化养猪场常用驱虫药的合理选用

在规模化养猪生产过程中，由于猪群的密度高．饲养量大寄生虫容易流行传播．通常情况下，规模化养猪场感染流行的寄生虫主要有三类．即线虫类螨类和原虫类．常见的寄生虫有猪蛔虫结肠小袋纤毛虫食道口线虫猪球虫、毛首线虫和疥螨．     

当前猪用驱虫药的种类及应用

一、猪寄生虫病的现状及危害 据近年对集约化猪场的数千个粪样进行普查的资料显示，猪的肠道寄生虫如仅以感染率统计．结肠小袋纤毛虫和猪球虫的感染率为最高，其次是猪蛔虫和毛首线虫（鞭虫）．但以它的危害所造成的经济损失而言，则猪蛔虫占据首位．一般猪群猪蛔虫的感染率达50％～75％。猪的外寄生虫病则以猪疥螨的感染和危害最为严重，当前我同猪疥螨的感染率除SPF猪场或猪群外，可达到100％。     

禄劝某猪场肠道寄生虫感染情况调查与分析

禄劝某猪场猪使用复方中药驱虫前后进行2次采集粪便,并进行肠道寄生虫检查,结果表明:用药前18份样品全部具有食道口线虫虫卵(100%),6份具有猪蛔虫虫卵(33.3%),有4份同时检出食道口线虫虫卵与猪蛔虫虫卵,混合感染率为22.2%,未见幼虫和原虫。用药后18份样品中9份具有食道口线虫虫卵(50%),3份具有猪蛔虫虫卵(16.7%),有1份检出食道口线虫虫卵与猪蛔虫虫卵混合感染,混合感染率为5.6%,未见幼虫和原虫。说明该猪场驱虫有一定效果,但未达到彻底驱虫的效果。结合该猪场寄生虫感染情况,提出了一些肠道寄生虫感染的防制措施和建议。     

广东和浙江部分地区集约化猪场肠道寄生虫感染情况调查

笔者于2008年6—8月对广东和浙江部分地区7个集约化猪场猪群进行寄生虫感染情况调查。结果显示,7个猪场中有6个猪场存在寄生虫感染,场阳性率为85.71%;主要感染虫种有食道口线虫、猪球虫、小袋纤毛虫、鞭虫等,其中猪球虫感染率达到24.74%,食道口线虫感染率为7.22%,小袋纤毛虫感染率为2.06%,鞭虫感染率为1.03%,且不同年龄阶段猪群寄生虫感染情况不一。     

酒泉市部分地区猪肠道寄生虫感染情况调查与分析

为了解酒泉市猪肠道主要寄生虫感染情况,试验采用水洗沉淀法、饱和盐水漂浮法和卢戈氏碘液法对酒泉4个地区473份猪新鲜粪便样品进行检测。结果显示,共检测出8种肠道寄生虫,总检出率为47.57%,以球虫和小袋纤毛虫为优势感染虫种,检出率分别为41.23%和32.56%,其次为隐孢子虫和圆线虫,分别为4.65%和2.75%,猪蛔虫、猪鞭虫、绦虫和吸虫检出率分别为2.11%、1.06%、0.85%和0.42%。酒泉市猪肠道寄生虫感染情况较为严重,相关防控措施应尽早制定与实施。     

槐山羊肠道寄生虫流行病学调查

为了解河南省槐山羊肠道寄生虫的感染情况,应用寄生虫常规检测方法对周口市某规模化养羊场150份粪样进行寄生虫感染情况调查。结果共检出5类虫卵和卵囊,其中原虫2类（球虫、隐孢子虫）、线虫2类（类圆线虫、鞭虫）、绦虫1类。调查150份粪便样品全部为寄生虫阳性,寄生虫总感染率为100％,其中隐孢子虫感染率为5．33％,球虫的感染率为100％,鞭虫的感染率为10．67％,类圆线虫的感染率为57．33％,绦虫的感染率为44．67％。调查结果说明槐山羊肠道寄生虫混合感染现象较严重,寄生虫感染率呈随着年龄增长而降低的趋势。     

河南郏县大尾寒羊肠道寄生虫感染情况调查

为了解大尾寒羊肠道寄生虫感染情况和保护河南省地方品种资源,采用离心沉淀法、卢戈氏碘液染色法和饱和蔗糖溶液漂浮法对河南省郏县某养殖场和散养的大尾寒羊进行了肠道寄生虫感染情况调查。共检查162份新鲜粪便样品,发现大尾寒羊肠道寄生虫感染率高达98．8％,检出10种寄生虫,其中艾美耳球虫（6种）、贾第虫、圆线虫、鞭虫和绦虫感染率分别为95．7％、1．9％、87．0％、27．8％和4-3％,混合感染率88．3％,圆线虫感染严重,平均EPG值3760．9。表明河南郏县大尾寒羊肠道寄生虫感染较为普遍和严重,并可携带人兽共患寄生虫,应加强其肠道寄生虫病的综合防治。     

规模化猪场驱虫药的合理选用

在规模化养猪生产过程中，由于猪群的密度高、饲养量大，寄生虫容易流行传播。通常情况下，规模化养猪场感染流行的寄生虫主要有三类，即线虫类、螨类和原虫类。常见的寄生虫有猪蛔虫．结肠小袋纤毛虫、食道口线虫．猪球虫、毛首线虫和疥螨．而且不少猪群的寄生虫感染还相当严重，给养猪生产造成巨大的经济损失。为了更好的做好驱虫工作，必须正确认识各类驱虫药物的作用特点，根据本猪场寄生虫的感染流行情况，合理选用驱虫药。     

Survey of intestinal parasites in pigs from intensive farms in Guangdong Province, People's Republic of China

The prevalence of intestinal parasites was investigated in intensive pig farms in Guangdong Province, China between July 2000 and July 2002. Faecal samples from 3636 pigs (both sexes and five age groups) from 38 representative intensive pig farms employing different parasite control strategies were examined for the presence of helminth ova and protozoan oocysts, cysts and/or trophozoites using standard techniques. Of the 3636 pigs sampled, 209 (5.7%) were infected with Trichuris suis, 189 (5.2%) with Ascaris, 91 (2.5%) with Oesophagostomum spp., 905 (24.9%) with coccidia (Eimeria spp. and/or Isospora suis) and 1716 (47.2%) with Balantidium coli. These infected pigs were mainly from farms without a strategic anti-parasite treatment regime. Concurrent infection of multiple parasites was common, and T. suis was the most common nematode infecting breeding, young and mature pigs. The results of the present investigation provide relevant 'base-line' data for assessing the effectiveness of control strategies against intestinal parasitism in intensively raised pigs in Guangdong Province, China.     

Some aspects of nematode infection in pigs from small herds

Two traditionally maintained, small herds from southern Poland, with 8 and 12 sows, respectively, were surveyed coprologically during 2006-2007. In one of the herds, while deworming a group of sows with levamisole, faecal samples were collected on Day -7, Day 0 (the day of treatment) and Day 10, in order to assess the therapeutic effect of the drug. Coprological investigation was performed also in 26 fatteners originating from other small farms and slaughtered in a local abattoir, with their intestines washed through for the presence of roundworms. In both herds examined, Ascaris suum and Oesophagostomum spp. were prevalent, whilst Trichuris suis appeared only very rarely. Mainly fatteners, replacement gilts and young sows were highly infected with A. suum. The roundworm occurrence in 2- 3-week-old piglets, with the intensity of 300 eggs per gram of faeces (EPG), indicated the possibility of parasite transmission to offspring very early in age. The highest level of Oesophagostomum spp. infection was observed in sows, but weaners were also much affected. For the group of dewormed sows, the mean faecal egg count reduction (FECR) was estimated to be 77.1- 80.4%, suggesting the presence of resistant nodular worms. A very high false-positive A. suum egg counts found in slaughtered animals (240 to 320 EPG) testified to a high contamination level of the environment of small piggeries, as well. Since the reciprocal transmission of parasites between pigs and poultry might occur, it implies that the flocks should be raised separately.     

Parasite transmission in confined hogs

Examinations of fecal specimens from swine of all ages maintained in a totally enclosed confinement facility in south Georgia were conducted in a 5-year survey (1977-1981) to determine the prevalence, intensity, and transmission patterns of intestinal nematode and protozoan parasites. Weaned pigs in the nursery had no detectable parasitic infections except sporadic Isospora suis in newly weaned pigs. Growing-finishing hogs had a low prevalence of Ascaris suum, Oesophagostomum spp. and Balantidium suis. Mean A. suum prevalence and mean eggs per gram feces (EPG) increased until about 200 days of age and then declined. Oesophagostomum spp. and B. suis prevalence and intensity tended to increase throughout life. Gilts (mean age 273 days) in the gestation unit had a higher (P less than 0.01) prevalence of A. suum and lower (P less than 0.01) prevalences of Oesophagostomum spp. and B. suis than sows (mean age 706 days). Similarly, A. suum EPG was higher (P less than 0.01) and Oesophagostomum spp. EPG and B. suis cysts per gram feces (CPG) were lower (P less than 0.01) in gilts than in sows. No evidence for a peri-parturient increase in parasite eggs or cysts was found. Instead, there was a higher prevalence of B. suis (P less than 0.01) in gestating than in lactating animals and more lactating sows than gestating sows were negative for parasites (P less than 0.01). Apparent differences due to location (gestation unit or farrowing unit) were largely attributable to age differences. Trichuris suis infections were rare and not shown to be established in the herd. Strongyloides ransomi in suckling piglets was controlled by anthelmintic therapy. I. suis occurred in piglets throughout the study but was never found in sows in the farrowing unit, either before or after birth of a subsequently infected litter of piglets. No parasites requiring intermediate hosts occurred.     

Prevalence of helminth infections in swine in Denmark

During 1982-1984 the occurrence of helminths in 66 sow herds was determined by examining faecal samples from swine of different age groups. Ascaris suum was found in 88% of the herds, while Oesophagostomum spp. and Trichuris suis were found in 58 and 23% of the herds, respectively. Strongyloides ransomi and Hyostrongylus rubidus was not identified in any of the herds. The occurrence of both A. suum and Oesophagostomum spp. was strongly related to the age of the animals. A. suum was most frequently found in growing pigs (30% of the fatteners and 25% of the gilts), whereas only 11-19% of the animals of the adult stock were excreting eggs. In contrast the prevalence of Oesophagostomum spp. increased with the age of the hosts, from 10% of the fatteners to 35 and 44% of the sows and boars, respectively. T. suis occurred only very sporadically, with the highest prevalence being 3% in the gilts. In comparison to previous Danish surveys the present mean prevalences of A. suum and Oesophagostomum spp. were low. Extremely low herd prevalences were found among large herds with intensive management and housing. In these herds, the pigs were infected at a later stage in life than pigs in more traditionally managed herds.     

Prevalence of common gastrointestinal nematode parasites in scavenging pigs of different ages and sexes in eastern centre province, Burkina Faso

The range and infestation intensities of gastrointestinal parasitic nematode species depend on the type of swine production system. The present study focused mainly on nematodes of veterinary importance in scavenging pigs in Burkina Faso, and aimed at determining the prevalence of gastro-intestinal nematode parasites by means of faecal egg per gram (EPG) counts. Between November 2001 and October 2002, faecal samples from 383 pigs of different sexes and ages (< 5 months, 5-12 months and > 12 months) were collected from the rectum and examined for gastrointestinal nematodes parasites using the Mc Master method. Of the 383 pigs examined, 91% were infected by one or more parasites. Ascaris suum (40%; 100-1 400 EPG) was the most prevalent parasite followed by Strongyloides ransomi (21%; 100-4200 EPG), Oesophagostomum spp. (18%; 100-1000 EPG), Hyostrongylus rubidus (11%; 100-1 800 EPG), Globocephalus spp. (10%; 100-400 EPG) and Trichuris suis (1 %; 100-200 EPG). The prevalence was significantly higher in female pigs (n = 239) than in males. In addition, females excreted significantly (P < 0.05) more eggs in their faeces than males, except in the case of Globocephalus spp. The age of the animal had no effect on the prevalence of A. suum whereas there were significant differences in age categories concerning S. ransomi, H. rubidus, Oesophagostumum spp. and Globocephalus spp. Unexpectedly, the high prevalence of these common parasites was not accompanied by elevated EPG values, which suggests the existence of moderate infestations. The present work indicates that the common nematode infestations in pigs do not necessarily need a systematic herd anthelmintic treatment, as only a small number of worms is required to induce immunity. A further study is needed to formulate appropriate and cost-effective strategies for the control of gastro-intestinal nematode parasites in pigs in Burkina Faso.     

Helminth infections in Danish organic swine herds

In nine organic swine herds, faecal excretion and pasture contamination by parasite eggs/larvae were studied in a period from March to October 1999. It was shown that the organic pigs were infected with Ascaris suum (28% of weaners, 33% of fatteners, 4% of sows), Trichuris suis (4% of weaners, 13% of fatteners, <1% of sows) and Oesophagostomum spp. (5% of weaners, 14% of fatteners, 20% of sows) whereas no infections with Hyostrongylus rubidus, Metastrongylus spp. or Strongyloides ransomi were detected. Moreover, no pigs showed clinical signs of infestations with scabies or lice. In the soil samples, very few Trichuris eggs were found throughout the season, whereas Ascaris eggs were found in 14% of the soil samples from sow pastures and in 35% from slaughter pig pastures, with the first infective eggs being recorded in July and the maximum number in August. Infective Oesophagostomum larvae were found in the grass samples in increasing numbers from May to October. Single herd cases of exceptionally high parasite infection levels are described in relation to herd management procedures.     

Efficacy of an in-feed ivermectin formulation against gastrointestinal helminths, lungworms, and sarcoptic mites in swine

The efficacy of ivermectin as an in-feed formulation was evaluated against naturally acquired gastrointestinal helminths, lungworms, and sarcoptic mites (experiment 1; n = 24) and against induced infection with intestinal nematodes (experiment 2; n = 24) in pigs. Treatments consisted of ivermectin administered in feed at concentrations calculated to provide 100 or 200 micrograms/kg of body weight/d for 7 days or of nonmedicated feed (controls) for 7 days. At concentration of 100 micrograms of ivermectin/kg/d, efficacy against naturally acquired infections was 97.7% for Ascaris suum, 97.8% for Metastrongylus spp, greater than 99% for Oesophagostomum spp, 100% for Macracanthorhynchus hirudinaceus, and 89.7% for Ascarops strongylina. Against induced infections (fourth-stage larvae), efficacy was 100% for A suum and 96.9% for Oesophagostomum spp. At concentration of 200 micrograms of ivermectin/kg/d, efficacy against naturally acquired infections was 100% for A suum, Hyostrongylus rubidus, Metastrongylus spp, and Ascarops strongylina; greater than 99% for Oesophagostomum spp; and 85.9% for Macracanthorhynchus hirudinaceus. Against induced infections (fourth-stage larvae), efficacy was 100% for A suum and 95% for Oesophagostomum spp. At concentrations of 100 and 200 micrograms of ivermectin/kg/d, efficacy against Sarcoptes scabiei var suis was evidenced by elimination of the mite by posttreatment day 14.     

Evaluation of a serodiagnostic test using Ascaris suum haemoglobin for the detection of roundworm infections in pig populations

The significant economical consequences of infections with Ascaris suum in pigs are already well documented. However, due to the subclinical nature of the disease and the lack of practical diagnostic means, ascariasis often remains undiagnosed. Here we describe the development and evaluation of a novel indirect ELISA using the purified A. suum haemoglobin (AsHb) molecule as an antigen. Initial validation using sera from 190 pigs experimentally infected twice a week with A. suum and Trichuris suis (25 and 5eggskg(-1)day(-1) respectively) demonstrated that the AsHb ELISA is able to detect long-term exposure to A. suum with a high sensitivity and specificity (99.5% and 100.0% respectively). Furthermore, this serological technique proved to be more sensitive than faecal examination on week 7 and 14 of the experiment (99.5% and 100% compared to 59.5% and 68.4% respectively). Cross-reactivity caused by T. suis infection was shown to be limited after analysing sera from pigs with an experimental T. suis mono-infection. Seroconversion was shown to occur from week 6 onwards in pigs receiving 100 A. suum eggs 5 times a week. Preliminary testing of the ELISA on six randomly selected farms confirmed the results obtained in the artificial infection trials, showing a higher sensitivity of the serologic method compared to faecal examination. Finally, the ELISA was used to investigate Ascaris infection rates on 101 conventional Flemish pig farms. The results showed that on 38.6% of the farms less than 20% of the tested samples were seropositive, while in 19.8% of the farms 80-100% of all pigs were seropositive. The results of this study suggest that the AsHb ELISA could provide pig farmers and veterinarians with an easier and more sensitive way to estimate the overall prevalence of A. suum on their farm.     

Parasites of domestic and wild animals in South Africa. VII. Helminths in pigs slaughtered at the Pretoria municipal abattoir

A total of 52 pigs slaughtered at the Pretoria Municipal Abattoir over a period of 1 year was examined for parastitic helminths. Twenty-six of these pigs were marketed by farmers and 26 by speculators. Of the pigs marketed by farmers 73,1% were found to be infested:--30,8% with Ascaris suum, 65,4% with Ascarops strongylina, 3,8% with Metastrongylus apri, 26,9% with Oesophagostomum spp., 15,4% with Trichostrongylus colubriformis and 15,4% with Trichuris suis. All the pigs marketed by speculators were infested:--7,7% with A. suum, 92,3% with A. strongylina, 11,5% with Oesophagostomum spp., 65,4% with Physocephalus sexalatus, 7,7% with T. colubriformis and 11,5% with T. suis. The findings obtained in surveys conducted in Canada, Greece, India, the Philippines, the United Kingdom and the United States of America are quoted for comparison. Trichostrongylus colubriformis and Oesophagostomum quadrispinulatum are recorded for the first time in pigs in the Republic of South Africa.     

Occurrence of helminths in pig fattening units with different management systems in Northern Germany

The helminth infections on 13 pig fattening farms with different management systems (complete or partial all-in-all-out system or continuous fattening) in North-Western Germany were investigated over at least three fattening periods. Pooled faecal samples were taken from pens once before and three times after anthelmintic treatment. At the beginning of fattening 34.9% of the samples contained helminth eggs, mainly from Oesophagostomum spp. (27.5%). Ascaris suum eggs were found in 10.5% of the samples, while other parasites were only rarely found. The number of pig-supplying farms was positively correlated with the helminth infection prevalence. Immediately after deworming, all pen samples were free of helminth eggs. However, the prevalences increased again, and by the end of fattening A. suum was found in 33.0% and strongylids in 6.0% of the samples. Pens harbouring A. suum-excreting pigs at the beginning of fattening had higher infection levels at the end, and this was also the case for nodular worms. The final prevalence of Ascaris was higher in partial exchange systems than in complete all-in-all-out systems and in old pig houses compared to new ones. Transmission of both Ascaris and Oesophagostomum was highest in autumn and winter. Thus, a single anthelmintic treatment at the beginning of fattening could not prevent infection during fattening, and the state of infection at the beginning was associated with the helminth burden at slaughter. Therefore, the purchase of parasite-free pigs in combination with appropriate hygiene management may minimise the initial infection pressure and keep subsequent infection of the herd at a minimum.