Inflammatory Myopathy in Horses With Chronic Piroplasmosis.

Horses affected by chronic piroplasmosis may develop poor performance and muscle atrophy. Here we investigate the pathological and immunopathological aspects of myopathy occurring in chronic equine piroplasmosis. The study included 16 horses serologically positive for equine piroplasms presenting with clinical signs and supporting serum biochemical evidence of a myopathy. Skeletal muscle was evaluated by histopathology, immunohistochemistry, indirect immunofluorescence, and molecular detection of piroplasms and inflammatory cytokines in skeletal muscle. Histologic lesions included muscle fiber atrophy (100% of cases), degenerative changes (13/16, 81%), and perivascular perimysial and endomysial lymphocytic infiltrates (81% of cases). In 15 cases (94%), muscle fibers had strong immunostaining for major histocompatibility complex classes I and II. T lymphocyte populations were mainly CD3+, CD8+, and CD4+ in equal proportions, with a lower number of CD79α+ cells. The serum from affected horses was tested by indirect immunofluorescence for binding of IgG, IgM, or IgA to sections of normal equine muscle to detect circulating autoantibodies against muscle antigen(s). In all cases, distinct sarcolemmal staining was detected in sections incubated with serum from affected horses, in contrast to sections incubated with phosphate-buffered saline or equine control sera. Reverse transcription polymerase chain reaction (RT-PCR) testing of muscles from affected animals revealed a significant increase of interferon-γ, interleukin-12, and tumor necrosis factor-α gene expression compared to healthy controls. Theileria equi or Babesia caballi was not detected in samples of affected muscle by RT-PCR. Thus, inflammatory myopathy associated with equine piroplasmosis may involve an autoimmune pathogenesis with upregulation of inflammatory cytokines that may cause myofiber atrophy and degeneration.

Spurious reticulocyte profiles in a dog with babesiosis.

A 9-year-old, female Maltese dog was referred to the Veterinary School of Toulouse with a 2-day history of anorexia and weakness. On clinical examination, the dog had hyperthermia (39.7°C), abdominal discomfort, and polypnea. Significant laboratory findings included pigmenturia, hyperbilirubinemia, hypercreatininemia, hyperfibrinogenemia, abnormal Snap canine pancreas-specific lipase, and pancytopenia with a nonregenerative anemia. A peripheral blood smear revealed numerous intraerythrocytic large Babesia but no polychromasia. There was a discrepancy between the absolute automated reticulocyte count (Sysmex reticulocyte count: 60 × 109 /L; RI 19.4-150.1 × 109 /L) and the manual reticulocyte count (3.6 × 109 /L) as well as the absence of polychromasia. The optical red blood cell scattergram showed an abnormal isolated reticulocyte cluster at the location of low-fluorescence ratio cells. These findings were interpreted as erythrocytes parasitized by large Babesia. The discrepancy between the Sysmex reticulocyte count and the manual reticulocyte count has been reported previously in people with falciparum malaria and numerous intra-erythrocytic Plasmodium falciparum organisms. This spurious reticulocyte profile and reticulocyte count were observed with the Sysmex XT-2000iV and the ProCyte using the same fluorescent dye polymethine but not with the LaserCyte using new methylene blue which does not stain Babesia organisms on a blood smear performed for manual reticulocyte counting.

Epidemiological, clinical, and laboratory characteristics of 48 cases of "Babesia venatorum" infection in China: a descriptive study.

BACKGROUND: Human babesiosis is an emerging zoonosis. "Babesia venatorum" has been identified in only four asplenic men and a child so far. We aimed to describe the epidemiological, clinical, and laboratory characteristics of a series of cases with "B venatorum" infection identified in a sentinel hospital in China. METHODS: We recruited participants with a recent tick bite at Mudanjiang Forestry Central Hospital, Heilongjiang province, China. Cases were diagnosed through PCR followed by sequencing, microscopic identification, or isolation by animal inoculation, or both. FINDINGS: 48 individuals (30 women or girls; median age 45 years, range 7 months to 75 years) with "B venatorum" infection were identified. 32 of these individuals were confirmed cases and 16 were probable cases. None of the 48 cases had received a blood transfusion or had a splenectomy. Geographically, cases were distributed diffusely throughout the hospital catchment area. Of the 32 confirmed cases, 21 (66%) presented with a fever, 13 (41%) with a headache, 12 (38%) with myalgia or arthralgia, and three (9%) with chills. 14 (44%) patients had fatigue, eight (25%) had dizziness, and eight (25%) had hypersomnia. Six (19%) patients had an erythematous non-pruritic rash around the tick-bite site and two (6%) had lymphadenopathy. Seven (22%) and four (13%) patients had anaemia and thrombocytopenia, respectively, and seven (50%) of 14 patients with confirmed infection had increased hepatic transaminase concentrations. In the confirmed cases, concentrations of intercellular adhesion molecule 3 (p<0·001), P-selectin (p<0·05), and platelet endothelial cell adhesion molecule 1 (p<0·001) were significantly reduced, whereas tumour necrosis factor α (p<0·01) and vascular cell adhesion molecule 1 (p<0·001) were significantly increased. INTERPRETATION: "B venatorum" infection should be included in the differential diagnosis of patients with a tick-exposure history in areas where this pathogen has previously been identified in ticks or people. FUNDING: Natural Science Foundation of China and Mega-Project for Infectious Diseases.

The effect of Babesia divergens infection on the spleen of Mongolian gerbils.

Babesiosis is caused by intraerythrocytic protozoan parasites transmitted by ticks and affects a wide range of domestic and wild animals and occasionally humans. The current study aimed to investigate the effect of B. divergens infected erythrocytes on spleen histopathology, cell cycle alteration, and the presence of oxidative stress. Mongolian gerbils were challenged with 5 × 10(6) Babesia divergens infected erythrocytes. Parasitemia reached approximately 77% at day 5 postinfection. Infection also induced injury of the spleen. This was evidenced with (i) increases in cellular damage of the spleen, (ii) decrease in antioxidant capacity as indicated by decreased glutathione, catalase, and superoxide dismutase levels, (iii) increased production of malondialdehyde and nitric oxide derived products (nitrite/nitrate), and (iv) increased lactic acid dehydrogenase activity and protein carbonyl content in the spleen. Infection interfered with normal cell cycle of the spleen cells at G0/G1, S, and G2/M phases. On the basis of the above results it can be hypothesized that B. divergens infected erythrocytes could alter the spleen histopathology and cause cell cycle alteration and induce oxidative stress in splenic tissue.

Loss of neurovirulence is associated with reduction of cerebral capillary sequestration during acute Babesia bovis infection.

BACKGROUND: Severe neurological signs that develop during acute infection by virulent strains of Babesia bovis are associated with sequestration of infected erythrocytes in cerebral capillaries. Serial passage of virulent strains in cattle results in attenuated derivatives that do not cause neurologic disease. We evaluated whether serial passage also results in a loss of cerebral capillary sequestration by examining brain biopsies during acute disease and at necropsy. FINDINGS: Cerebral biopsies of spleen intact calves inoculated intravenously with a virulent or attenuated strain pair of B. bovis were evaluated for capillary sequestration at the onset of babesiosis and during severe disease. In calves infected with the virulent strain, there was a significant increase in sequestration between the first and second biopsy timepoint. The attenuated strain was still capable of sequestration, but at a reduced level, and did not change significantly between the first and second biopsy. Necropsy examination confirmed the second biopsy results and demonstrated that sequestration identified at necropsy reflects pathologic changes occurring in live animals. CONCLUSIONS: Loss of neurovirulence after serial in vivo passage of the highly virulent T2Bo strain of B. bovis in splenectomized animals is associated with a significant reduction of cerebral capillary sequestration. Previous genomic analysis of this and two other strain pairs suggests that this observation could be related to genomic complexity, particularly of the ves gene family, rather than consistent gene specific differences. Additional experiments will examine whether differential gene expression of ves genes is also associated with reduced cerebral sequestration and neurovirulence in attenuated strains.

Levantamento da prevalência da babesiose bovina no município de Umuarama, Paraná, Brasil / Assessment of bovine babesiosis, prevalence in the municipality of Umuarama, Paraná, Brazil / Levantamiento de prevalencia de babesiosis bovina en el município de Umuarama, Paraná, Brasil

A babesiose bovina é uma hemoparasitose causada por duas espécies de protozoários, Babesia bovis e Babesia bigemina, que atinge os rebanhos de bovinos em praticamente todo território nacional, sendo responsável por grandes perdas na produtividade dos rebanhos. A transmissão ocorre, principalmente, pelo carrapato Rhipicephalus Boophillus microplus. Os sinais clínicos se caracterizam por anemia intensa, por hemólise extravascular, febre, hemoglobinúria, icterícia e morte. O diagnóstico da babesiose pode ser por meio do exame microscópico de esfregaços de sangue periférico. O objetivo desse trabalho foi estudar a prevalência da babesiose bovina no município de Umuarama. Foram analisados 325 prontuários clí-nicos de bovinos provenientes do município de Umuarama atendidos no Hospital Veterinário da Universidade Paranaense no período de janeiro de 2003 a dezembro de 2010. A análise revelou que 32,4% foram positivos e 68,6% foram negativos para Babesia spp. Em relação ao sexo dos animais, 30,5% das fêmeas (n=243) e 34,1% dos machos (n=82) foram positivos. Segundo a aptidão zootecnica 27,4% dos bovinos com aptidão para corte (n=164) e 35,4% dos bovinos com aptidão para leite (n=161) foram positivos. Não houve diferença significativa entre os sexos e entre as aptidões (p>0,05). Segundo a subespécie bovina, 23% dos bovinos Bos taurus indicus (n=107) e 37,4% dos bovinos Bos taurus taurus (n=179) foram positivos. Houve diferença significativa entre as subespécies (p<0,05), ocorrendo maior prevalência de babesiose nos Bos taurus taurus. De acordo com os resultados encontrados pode-se concluir que nao houve diferença na prevalência de babesiose quando se comparou o sexo e a aptidão zootécnica. Foi observada uma maior prevalÇencia de babesiose em Bos taurus quando comparado com Bos indicus.

Bovine babesiois is a hemoparasitosis, this disease is caused by two protozoa species, Babesia bovis and Babesiabigemina, and afflicts bovine herds on the entire country, being, responsible for great losses in productivity of the herds.Transmission happens mainly by the tick Rhipicephalus Boophilus microplus. Clinical signs are intense anemia by extravascularhemolysis, fever, hemoglobinuria, jaundice and death. The diagnosis for babesiosis may be through microscopic examinationof peripheral blood smears. It is a disease of great importance for bovine production. The aim of this paper was to studythe prevalence of babesiosis in the municipality of Umuarama. It was analyzed 325 clinical charts from Umuarama, treatedat the Universidade Paranaense (UNIPAR) Veterinary Hospital, from January 2003 to December 2010. The analysis showedthat 32.4% were positive and 68.6% were negative for Babesia spp. Considering gender, 30.5% of the female (n=243) and34.1% of male (n=82) were positive. Concerning productive aptitude 27.4% of the bovines with beef aptitude (n=164) and35.4% of bovines with dairy aptitude (n=161) were positive. There was no significant difference between genders and aptitude(p>0.05). Concerning bovine subspecies 23% of Bos taurus indicus (n=107) and 37.4% of Bos taurus taurus (n=179) werepositive. There was significant difference between subspecies (p<0,05), with greater prevalence of babesiosis in Bos taurustaurus.. According to the results found, it is possible to conclude that there was no difference in the prevalence of babesiosiswhen compared gender and productive aptitude. It was observed a higher prevalence of babesiosis in Bos taurus taurus whencompared to Bos indicus.

Hematologic and bone marrow changes in dogs experimentally infected with Rangelia vitalii.

BACKGROUND: Rangelia vitalii is a tick-transmitted piroplasm that causes both hemolytic and hemorrhagic disease in dogs in Brazil. OBJECTIVE: The aim of this study was to evaluate the response of the bone marrow in dogs experimentally infected with R vitalii during the acute stage of the disease. METHODS: For this study, 2 groups of a total of 12 young dogs were used. Group A was composed of healthy dogs (n = 5), and group B consisted of animals infected with R vitalii (n = 7). Blood samples were collected on days 0, 10, 20, and 30 post-inoculation and stored in EDTA tubes for a full hematology profile, including a reticulocyte count. On days 10 and 20, bone marrow samples were collected, stained, and examined. RESULTS: In infected dogs anemia was identified on days 10 and 20 post-inoculation (P < .01), and on day 20 reticulocytosis was present. Infected dogs had leukopenia due to neutropenia and eosinopenia, along with lymphocytosis and monocytosis, when compared with control animals. In bone marrow, the myeloid:erythroid ratio was significantly decreased (P < .05) in infected dogs due to increased erythroid precursors. CONCLUSIONS: Dogs experimentally infected with R vitalii develop regenerative extravascular hemolytic anemia accompanied by erythroid hyperplasia in the bone marrow. During the acute phase of the disease, leukopenia due to neutropenia and eosinopenia suggests intense tissue recruitment of these cells in response to the endothelial damage caused by this parasite.

NT-ProBNP and cardiac troponin I in virulent canine babesiosis.

Although cardiac pathology and consequently elevated serum cardiac troponin I (cTnI) have been reported, clinically it remains difficult to diagnose cardiac involvement in canine babesiosis. Thus the use of cardiac biomarkers would be useful in determining if a dog with babesiosis also has concurrent cardiac dysfunction. The objectives of this study were to determine plasma N terminal brain natriuretic peptide (NT-proBNP) in canine babesiosis and if it is correlated with cTnI. Three groups of dogs with babesiosis were used: mild uncomplicated (Group 1), severe uncomplicated (Group 2), and complicated (Group 3), and a control group (Group 4) with 15 dogs per group. Each animal had the following determined: serum urea and creatinine, urea: creatinine ratio, cystatin-C, cTnI, blood lactate, plasma NT-proBNP, fractional shortening (FS), and blood pressure. The median NT-proBNP value in Groups 1-4 was 246, 650, 638, and 106 pmol/l. All 3 babesiosis groups had a statistically elevated NT-proBNP level compared to the control group and Groups 2 and 3 showed significantly higher values compared to Group 1. Median cTnI in Group 1-3 was 0.39, 0.4, and 1.45 ng/ml, respectively with the control group having concentrations below the detection limit (0.2 ng/ml). There was a significant difference in cTnI concentration between the control group and group 3 but no statistical difference between the other babesiosis groups. The study concluded that dogs with babesiosis showed elevated levels NT-proBNP and the more severe the disease process the greater the elevation. This elevation is earlier or independent of the increased cTnI.

First case of human babesiosis in Germany - Clinical presentation and molecular characterisation of the pathogen.

Babesiosis is a common infection of animals and is gaining increasing attention as an emerging tick-borne zoonosis of humans in Europe. Here we report on the first case of human babesiosis in Germany in a 63-year-old splenectomised German patient with a relapse of nodular lymphocyte-predominant Hodgkin's lymphoma. After treatment with a chimeric anti-CD20 antibody preparation (Rituximab), the patient was hospitalised because of anaemia and dark urine from haemoglobinuria. Presumptive diagnosis of babesiosis was made based on piriform parasitic erythrocytic inclusions in peripheral blood smears and confirmed by Babesia-specific 18S rDNA PCR. Sequence analysis revealed a >99% homology of the amplicon with the recently described EU1 organism clustering within the Babesia divergens/Babesia odocoilei complex. Despite treatment with quinine and clindamycin the patient relapsed and developed chronic parasitaemia requiring re-treatment and long-term maintenance therapy with atovaquone before he eventually seroconverted and the parasite was cleared. Our findings suggest that human babesiosis occurs in Germany and can take a chronic course in immunocompromised individuals.

Absence of erythrocyte sequestration in a case of babesiosis in a splenectomized human patient.

BACKGROUND: The importance of vascular occlusion in the pathogenesis of human haemoprotozoal disease is unresolved. METHODS: Giemsa-stained tissue sections from a human case of Babesia microti infection in a splenectomized patient with chronic lymphocytic leukaemia and colon cancer were examined to ascertain the distribution of parasitized erythrocytes within the vascular lumen. RESULTS: No evidence of sequestration was observed. CONCLUSION: This first report on the vascular location of B. microti in human tissue suggests that severe multi-organ failure due to babesiosis is independent of sequestration of parasitized erythrocytes. A similar pathogenesis may also cause multi-organ failure in other intraerythrocytic protozoal infections, including falciparum malaria.

Dermatologic aspects of tick bites and tick-transmitted diseases.

Dermatologic manifestations of tick bites and tickborne disease are not commonly encountered. However, recognition of the signs and histopathologic conditions of tick bites can be important to the diagnosis and management of small animal diseases. Understanding the local nodular inflammatory reaction to a tick bite can allay the owner's fear that a newly recognized nodule may be a malignant growth. Additionally, recognition of tick bites and pathognomonic dermatologic changes may provide important evidence in making a diagnosis of tick-transmitted diseases.

Effects of Trypanosoma brucei and Babesia microti infections on the primary granulomatous reaction to Schistosoma eggs in mice.

Mouse infection with the blood protozoa Trypanosoma brucei suppressed significantly the frequency and intensity of the primary granulomatous inflammatory response to eggs of the blood flukes Schistosoma mansoni and S. bovis injected into the pulmonary microvasculature. In addition, the dynamics of the cellular infiltrate of the egg granuloma were strongly affected. It is suggested that the modulation of the granulomatous response is a result of impairment of the cell-mediated immunological responsiveness induced by T. brucei. Infection with Babesia microti did not induce similar effects on the granulomatous response.

Systemic babesiosis. Another cause of the hemophagocytic syndrome.

Hemophagocytosis is a pathologic finding in a variety of infectious diseases associated with peripheral pancytopenia. In addition, hemophagocytosis is a prominent finding in malignant histiocytosis, a primary disorder of the monocyte-macrophage system. Systemic babesiosis is a rare parasitic disorder associated with intraerythrocytic parasites in the peripheral blood. There has been no description of the marrow findings in this disorder. A patient is described who had systemic babesiosis and prominent hemophagocytosis that disappeared after appropriate antiparasitic therapy. Systemic babesiosis should be considered in the differential diagnosis of hemophagocytosis.

Response of babesiosis to pentamidine therapy.

Three nonsplenectomized patients were infected with Babesia microti. One had fever, abdominal pain suggesting gallbladder disease, and evidence of disseminated intravascular coagulation; another was considered to have lymphoma, partly because two smears for Babesia before admission were negative. All three patients were treated with pentamidine isethionate and improved clinically. Parasites were no longer seen on smears after 5 days of therapy, but Babesia could still be recovered by hamster inoculation 5 weeks after therapy in one of the patients tested, underscoring the need for this test to properly evaluate eradication of the organism. In one patient, pentamidine was stopped after 7 days because of increased creatinine concentration, and this amount of drug appeared adequate to control the parasitemia. Pain at drug injection sites was a major side effect in all three patients. Pentamidine appears to be useful in controlling clinical manifestations of babesiosis and decreasing parasitemia, but it does not eradicate the organism.

An electron microscopic study of intra-erythrocytic stages of Babesia bovis in the brain capillaries of infected splenectomized calves.

Splenectomized vaccine donor calves undergoing primary reactions to Babesia bovis infections may develop cerebral babesiosis which leads to death if not treated in time. A brain biopsy was performed on an artificially-infected animal showing nervous symptoms and the tissue was immediately processed for electron microscopic examination. Virtually every erythrocyte in the brain capillaries sectioned was infected with B. bovis. Intra-erythrocytic merozoites, trophozoites and dividing trophozoites were indentified. Important features of the piriform merozoites included a reduced apical complex consisting of the anterior polar ring, microtubules, rhoptries and micronemes. Unidentified membrane-bound bodies, mostly spherical in shape, were observed anterior to the nucleus. The trophozoites showed very little structural differentiation and no food vacuoles or micropores could be detected. Each trophozoite produced 2 identical merozoites and the parent cell became totally incorporated in the daughter merozoites in the multiplication process. Projections were seen radiating from the surface of infected erythrocytes which appeared to adhere to other surfaces on contact. This probably resulted in the sludging of infected erythrocytes in the capillaries. The latter observations coincide with those described for Babesia argentina.