山羊实验感染伊氏锥虫病理学研究

本文研究了山羊实验感染伊氏锥虫后的血液成分和病理学变化。结果表明:血清中的钾和血糖含量均下降,红细胞数和血红蛋白亦下降,而谷草转氨酶和白细胞数均升高;血清白蛋白、β球蛋白含量下降,γ球蛋白升高,血清总蛋白和血清谷丙转氨酶则无明显变化。组织病理学变化可见支气管肺炎及间质性肺炎、增生性脾炎、肾空泡变性、脑水肿,心肌空泡变性、肝脂肪变性、单纯性淋巴结炎、肾上腺和胰腺空泡变性及慢性肠卡他。     

Reemergence of Dourine in Italy: Clinical Cases in Some Positive Horses

In 2011, Trypanosoma equiperdum reemerged in Italy, almost 10 years after its last appearance. A total of eight infected horses have been observed to date. Six horses were affected by natural outbreaks of the disease, whereas two were infected experimentally. The aim of this study was to offer a recent perspective on clinical cases of dourine in Europe. Investigation of the clinical aspects confirmed the three stages reported in the literature: stage 1 (genital lesions), stage 2 (cutaneous signs), and stage 3 (nervous signs). The most common signs in the horses under study were notable weight loss, edematous skin eruptions and oedemas of the abdomen, mammary glands and hind legs. Three animals presented neurological signs (lip ptosis of lower lip and ataxia). Infections were paucisymptomatic or asymptomatic in some animals. Hyperthermia was not reported in infected animals and considerable anemia was observed. High antibody titers did not always correspond to clinical signs. Positive polymerase chain reaction test results of blood or tissue (skin, eye swab) often correspond to an advanced stage of the disease. Dourine is a variable disease; owing to its low prevalence and chronic manifestation, it can be difficult to make a quick diagnosis when facing a Dourine-positive horse.     

Potential demand for a mixed public-private animal health input: evaluation of a pour-on insecticide for controlling tsetse-transmitted trypanosomiasis in Ethiopia

The new pour-on insecticides that can be used to control tsetse-transmitted trypanosomiasis confer benefits to the owners of the cattle given treatments and other people keeping cattle in areas affected by the control. A study was conducted in southwest Ethiopia to assess farmers' perceptions of the public and private benefits of the pour-on and identify the household-level factors affecting its demand. Ninety-seven percent of the 166 survey respondents had received pour-on treatments when they were free and 67% paid for treatments the month before the survey. Farmers noted public and private benefits from using the pour-on, the most important of which were less trypanosomiasis, fewer problems with biting flies (including tsetse), and fewer problems with ticks. The probit model estimated to quantify the effects of different variables indicates that proportions of cows and oxen, distance to the treatment centre, and seasonal factors were significant determinants of demand.     

PAPS免疫微球快速诊断伊氏锥虫病的研究

本文介绍一种新型的PAPS锥虫快速诊断试剂。PAPS是我组研制成功的一种新型的载体微球,它与伊氏锥虫抗原交联所制备的锥虫快速诊断液具有特异性强、敏感性高、重复性好、快速、简便的特点。我们应用锥虫快诊液检测212头锥虫阳性病牛(见虫),阳性检出率为98.6％。对275头非疫区阴性牛进行检测,阴性符合率为99.6％。PAPS试验与血凝试验的符合率为93.2％。对142头血清和血纸两种血样本进行PAPS试验的阳性结果和反应强度完全吻合,无明显差异。     

Evaluating the use of packed cell volume as an indicator of trypanosomal infections in cattle in eastern Zambia

In this study, packed cell volume-values (PCV) are evaluated as indicator of trypanosomiasis infections in cattle. A total of 734 blood samples were collected in 11 different sampling sites in eastern Zambia: 84 calves (<1 year), 52 young females and 40 young males (between 1 and 3 years), 228 cows, 317 oxen and 13 bulls (>3 years). All samples were subjected to three diagnostic tests: parasitological examination using the buffy coat method, PCR/RFLP and PCV determination. The results were compared and analysed in a Bayesian model, which allowed the estimation of the infection prevalence and the respective test sensitivities and specificities. The presence of a trypanosomal infection significantly reduced the PCV, independently of the age and sex of the infected animal. The estimated prevalence of trypanosomal infections in the study area was 34% (95% credibility interval: 30–38%). While the specificity of both the parasitological and the PCR/RFLP tests were set to 1, the parasitological diagnosis had a low sensitivity (37%) compared to the PCR/RFLP (96%). When using a cut-off value of 24, the PCV had a high specificity (98%) but a rather low sensitivity (53%) for identifying trypanosomiasis infections. Using 26% as a cut-off increased the sensitivity to 76% without much affecting the specificity (94%). A parallel combination of the parasitological diagnosis and the PCV improved the diagnostic sensitivity (74% and 89% for PCV cut-off values of 24% or 26%, respectively) while specificity remained high (98% and 94% for PCV cut-off values of 24% or 26%, respectively). These results suggest that such a combination could advantageously be used for the diagnosis of cattle trypanosomiasis in the field: it is much more sensitive than parasitological examination alone and it is much cheaper than molecular tests. However, the value of this approach depends largely on the determination of an appropriate cut-off value to consider a sample positive, depending on the required test sensitivities and specificities.     

Trypanosomiasis by Trypanosoma vivax in cattle in the Brazilian semiarid: Description of an outbreak and lesions in the nervous system

An outbreak of trypanosomiasis by Trypanosoma vivax is reported in the semiarid of Paraíba, Northeastern Brazil from May to August 2002. Sixty-four cows out of 130 were affected; 11 died and the other recovered after treatment with diminazene aceturate. Affected animals had fever, anemia, weight loss, hypoglycemia, increased serum levels of aspartate aminotransferase and, in nine cows, nervous signs. All cows with nervous signs died; six of them recovered after treatment, but the disease relapsed. Six cows aborted and one delivered a calf that died immediately after parturition. Thirty-two out of 100 calves were affected and five died. Nervous signs were not observed in the calves. Gross lesions were thickening of the meninges, enlarged lymph nodes and prominent white pulp of the spleen. The main histological lesion was meningoencephalitis and malacia in the brain of cows with nervous signs. No antibodies against trypanosomes were found in 33 blood samples collected before the outbreak in the affected farm and in 29 samples collected at the same time in two other neighbor farms. Until January 2003, all 89 animals tested had antibodies against T. vivax, suggesting the occurrence of sub clinical infections in cattle without clinical signs. Only two out of 85 serum samples collected on April 2004 were positive for T. vivax antibodies. Data obtained suggested that the semiarid region is non-endemic for trypanosomiasis and that disease occurred due to introduction of the parasite in a susceptible population after an apparent rise in the Tabanus spp. population.     

患鳠锥体虫病大鳍鳠的血液学和组织学观察

采用血液学和组织学研究了鳠锥体虫病对大鳍鳠(Mystus macropterus)外周血及部分组织器官(鳃、肝脏、肾脏、头肾及脾脏)造成的病理变化。结果显示:在感染的的早期和中期,有虫组的红细胞(RBC)数量和血红蛋白含量(Hb)均有所下降,白细胞(WBC)数目增多,但在感染末期个体三者均显著下降,并且白细胞血式发生改变。各项血清指标显示有虫组的肝脏、肾脏出现一定程度的损伤,感染末期个体损伤较严重。组织切片观察显示,鳠锥体虫病能使大鳍鳠的血液、肝脏、肾脏、头肾和脾脏均发生不同程度的病理变化,主要表现为局部鳃丝断裂、出血;肾脏、头肾和脾脏出现不同程度充血,肝细胞呈水样变性,感染末期个体的肾脏、肝脏等出现细胞空泡化。     

武平县耕牛伊氏锥虫病调查报告

用间接血凝试验法对武平县耕牛伊氏锥虫病流行情况进行随机抽样调查，结果查出阳性率为１８．７％，其中水牛阳性率明显高于黄牛，而水牛又以老年牛和壮年牛的阳性率较高，母牛阳性率高于公牛，营养状况中等的牛阳性率高于上等的和下等的牛。     

Seroprevalence of Antibodies Against the Excreted Antigen Superoxide Dismutase by Trypanosoma Cruzi in Dogs From the Yucatan Peninsula (Mexico)

Numerous studies have shown the role of dogs as a reservoir for the American trypanosomiasis, as the bridge connecting sylvatic and peridomestic cycles. The objective of this study was to determine the prevalence of American trypanosomiasis in the dog population (630 sera) from seven localities in the Yucatan Peninsula (city of Mérida and the towns of Molas, Playa del Carmen, Akumal, Xcalacoop, Xcalac and Xahuachol). These data are key for developing control measures for the disease. The sera were analysed to detect antibodies against Trypanosoma cruzi, using Fe‐SOD excreted as the antigenic fraction by ELISA and Western blot as confirmation. The total prevalence found in the Yucatan Peninsula was some 14.76%, with 10.74% in the state of Yucatan (city of Mérida, towns of Molas and Xcalacoop) and 21.34% in the state of Quintana Roo (towns of Playa del Carmen, Akumal, Xcalac and Xahuachol). However, a more thorough epidemiological study of the dog population, both wild and urban, in the Yucatan Peninsula will be required to design a control strategy for these diseases, paying particular attention to the population affected and even broadening the study to other Mexican states as well as neighbouring countries. These results again confirm that iron‐superoxide dismutase excreted by T. cruzi constitutes a good source of antigen for serodiagnosis in epidemiological studies.     

骆驼锥虫病研究现状

锥虫病是世界卫生组织认定的由锥虫引发的主要的人畜共患原虫病之一。在我国流行的主要是骆驼、马、牛等家畜的伊氏锥虫病。骆驼锥虫病可造成骆驼日渐消瘦、心肌衰竭甚至死亡,随着疾病的蔓延会造成较大的经济损失。通常使用苏拉明、贝尼尔、安锥赛等药物可达到防治该病的目的。为了让更多的人们较为系统地了解和有效防治骆驼锥虫病,从骆驼锥虫病的病原体特征、流行病学、临床症状、病理变化和防治措施等方面进行了综述。此外,对骆驼锥虫病的防治提出了新的方法和思路,为骆驼锥虫病的诊断、治疗及预防提供参考。