福建省水牛巴贝斯焦虫病调查研究 Ⅱ.病原鉴定

1981～1986年调查福建省崇安县水牛巴贝斯焦虫病,该病病原初步鉴定为牛巴贝斯焦虫Babesia boris(Babes,1988)。病原各类虫体形态所占比例分别为:单梨形虫体占37.21％,双梨形虫体占35.03%,椭圆形虫体占16.73%,环形虫体占7.67％,圆形虫体占1.34%和变形虫形虫体占2.01％。红细胞染虫数1～4个,多数1～2个。带虫红细胞平均直径5.25μm。梨形虫体平均长度1.98μm。虫体指数为1:1.04～2.76。红细胞染虫率x4.33%,S1.97％。虫体位于红细胞中部占78.55％,位子红细胞边缘占21.45％。双梨形虫体尖端排列形成钝角、锐角和直线分别为80.19％、14.15％和5.66％。     

Canine babesiosis caused by Babesia canis vogeli in rural areas of the State of Minas Gerais, Brazil and factors associated with its seroprevalence

This epidemiological survey on canine babesiosis was carried out in three distinct rural regions (Lavras, Belo Horizonte and Nanuque) of the State of Minas Gerais, Brazil. Ticks and blood samples were collected during a dry season (Lavras, n = 92; Belo Horizonte, n = 50; Nanuque, n = 102) and the subsequent rainy season (Lavras, n = 71; Belo Horizonte, n = 28; Nanuque, n = 66) from dogs living on farms. Plasma samples were analyzed by the indirect fluorescent antibody test for detection of anti-Babesia canis vogeli antibodies. DNA was extracted from blood of serologically positive dogs and molecular characterization of Babesia species was performed. Rhipicephalus sanguineus, Amblyomma cajennense and Boophilus microplus were the tick species identified in all regions. In Lavras, in addition to those tick species, A. tigrinum and A. ovale were also identified. The most prevalent tick species was A. cajennense (35.3%), followed by R. sanguineus (19%) and B. microplus (4.0%). Dogs living in Nanuque region were more heavily infested with ticks than dogs living in Belo Horizonte and Lavras regions. The overall frequency of anti-B. c. vogeli antibodies in the canine population in rural areas of Minas Gerais was 28.7%, with prevalence rates of 49.0% in Nanuque, 34.0% in Belo Horizonte and 3.3% in Lavras. The age of the animals and tick infestation were associated with seroprevalence of B. c. vogeli. The sequence analysis showed that B. c. vogeli was the only Babesia species present in all three regions. This study showed different rates of prevalence and incidence of canine babesiosis among the three rural regions sampled in Minas Gerais State. The results point to the importance of canine babesiosis in rural areas and to the need for further studies related to its transmission and maintenance in nature.     

犬巴贝斯虫病检测研究

犬巴贝斯虫病是经蜱传播的血液寄生虫病,其临床症状是高热、贫血、血红蛋白尿和脾肿大。通过血涂片检验,血常规检验并结合临床特征,对西安市103只宠物犬进行了巴贝斯虫的感染情况检测。结果显示,犬血液中巴贝斯虫的感染数为16例,占总数的15.53%,其中5月份的感染犬最多,为13例,占感染数的81.25%(13/16)。     

河南省郑州市某宠物医院2例犬巴贝斯虫病的诊治

犬巴贝斯虫病是一种由硬蜱传播的犬血液寄生虫病,以春、夏季节多发,患病犬出现高热、黄疸、尿液发红、严重贫血、消瘦、精神萎靡等临床症状。选取河南省郑州市某宠物医院的2例犬巴贝斯虫病例进行分析,总结了犬巴贝斯虫病的诊治方法。     

Status of Lipid Peroxidation, Antioxidants, and Oxidation Products of Nitric Oxide in Equine Babesiosis: Status of Antioxidant and Oxidant in Equine Babesiosis

Equine babesiosis is a tick-borne protozoal disease of horses caused by Theileria equi and Babesia caballi. The disease is endemic in most tropical and subtropical areas. The aim of this paper is to assess the antioxidant status, lipid peroxidation, and oxidation products of nitric oxide (NO) in horses and mules naturally infected with T. equi and B. caballi. East and Southeast Anatolian horses and mules living in rural region of the Eastern border of Turkey were used as the material for this study. These animals are used as pack animal (3–7 years of age). Infected animals were in acute or subacute infection period. In the current study, malondialdehyde (MDA), oxidation products of NO (nitrate and nitrite), serum glutathione (GSH), vitamin E, and retinol levels were analyzed in 58 equids (horse and mule) infected with T. equi and B. caballi as well as in 44 healthy equids. Compared with controls, the level of MDA and nitrate increased significantly (P < .01, P < .05, respectively), whereas GSH concentration and levels of vitamin E decreased significantly (P < .01). There was no significant change in the level of nitrite and retinol between two groups. The results of the current study suggest that in equids infected with T. equi and B. caballi, this alteration in the lipid peroxidation, oxidants, and antioxidants may be related to the host's defenses against parasitic infection and may play a central role in the pathologic conditions associated with babesiosis.     

CHANGES IN ECHOCARDIOGRAPHIC VARIABLES OF LEFT VENTRICULAR SIZE AND FUNCTION IN A MODEL OF CANINE NORMOVOLEMIC ANEMIA

The objective of this study was to document changes in echocardiographic variables of left ventricular size and function noninvasively during acute normovolemic anemia. This model was developed as a pilot study with the purpose of providing baseline information to investigate the pathophysiology, and more specifically the effect on the heart, of canine babesiosis-induced anemia. The study group comprised of 11 mature healthy Beagle dogs that weighed between 9 and 15 kg. Severe normovolemic anemia was induced over a 3-4-day period by serial bleeding while maintaining normovolemia by autotransfusing plasma and infusing crystalloids. The dogs were then allowed to recover. Preanemic (mean Hct 46.7%, standard deviation [SD] 2.4%) echocardiographic variables of left ventricular performance (Fractional shortening, ejection fraction, end-systolic and end-diastolic ventricular volumes, cardiac index, and heart rate) were compared with those in the severely (mean Hct 15.3%, SD 1.1%), moderately (Hct mean 24.7%, SD 1.5%), and mildly (mean Hct 33.5%, SD 2.5%) anemic states, and between the anemic states. With the exception of end diastolic volume, there was a statistically significant (P < 0.05) increase in all variables in the severely anemic state vs. the preanemic and the mild and moderate anemic states. In concordance with previous invasive models, a hyperdynamic state of the left ventricle develops in response to experimentally induced acute canine normovolemic anemia in the conscious dog. Echocardiography has promise as a noninvasive technique of evaluating the cardiac changes in dogs having canine babesiosis.     

Hematology and some blood chemical parameters as a function of tick-borne disease (TBD) signs in horses

Two statements provide the context within which this investigation was carried out: (i) Apulia is an enzootic region for tick-borne diseases (TBD); (ii) the principles of enzootic stability and the study of resilient/resistant breeds are among the tools for future pest control strategies. Thus, a trial protocol was established to check the amount of variation in hematologic and biochemical parameters serving as a function of TBD signs in resilient horses. Blood samples were collected from 109 horses belonging to the Apulian native Murgese breed. Hematologic and biochemical parameters were screened and microscopic search for the parasites in the red cells was performed. Differences in clinical manifestations and hematological and biochemical responses were recorded. The following disease classification was used: infection-free horses (class 0), infected horses (presence of Theileria equi and/or Babesia spp in the red cells) without clinical signs (class 1), and horses suffering from clinical disease (class 2). Seventy-one horses (65.1%) showed no TBD signs; hemoparasites were found in 38 horses (34.9%), of which only five (4.6%) showed clinical signs. A significant decreasing trend was shown from class 0 to class 2, where animals with clinical signs presented highly reduced values of some relevant blood parameters. The similarity of the blood values of class 0 and 1 animals is the most striking result of this work and calls for more extensive, detailed research into the mechanisms through which infected horses with no clinical signs of disease can cope with the condition.     

Clinical and histopathological aspects of splenectomized foals infected by babesia equi

Clinical and histopathological aspects were studied in two splenectomized foals, naturally or experimentally infected with B. equi. The animals presented pyrexia, pale and icteric mucous membranes, hemoglobinuria, and microcytic hypochromic anemia, which coincided with the peak in parasitemia. Histopathological lesions were observed in the liver, kidneys, lungs and heart, and were suggestive of a serious hemolytic crisis provoked by the high level of parasitemia, causing hypoxy in the tissues.     

Babesia canis rossi infection in a Texas dog

A 5-month-old intact male Boerboel dog, imported from South Africa 1 week previously, was presented to a Texas veterinarian for lethargy, anorexia, and labored breathing. The dog was febrile, anemic, leukopenic, thrombocytopenic, and slightly azotemic. Results of the IDEXX SNAP-4Dx enzyme immunoassay were negative for Dirofilaria immitis antigen and antibodies against Ehrlichia canis, Borrelia burgdorferi, and Anaplasma phagocytophilum. An EDTA blood sample analyzed at Oklahoma State University Center for Veterinary Health Sciences revealed nonregenerative anemia, neutropenia, and large protozoal piroplasms in 0.7% of the RBCs. Piroplasms were 2-5μm long and varied in shape from round to oval to piriform; extracellular merozoites were also observed. Nested PCR was performed on DNA extracted from blood using primers that amplify the 18s rRNA gene from all known Babesia species, and the product was sequenced. Basic Local Alignment Search Tool analysis of the 437 base sequence revealed 99-100% similarity to Babesia canis rossi, 92-93% similarity to Babesia canis canis, and 92% similarity to Babesia canis vogeli. The dog responded well to treatment with imidocarb. PCR analysis of a second blood sample 2 weeks later was negative for Babesia spp. DNA. This case represents the first diagnosis of B. canis rossi infection in the United States.