Concurrent infection with bovine leukaemia virus (BLV) and Theileria annulata was diagnosed in a Friesian calf about 6 months of age at a dairy farm at the Qassim region of central Saudi Arabia. The
disease ended fatally with signs of liver and heart failure. There was anorexia, pyrexia, anaemia, generalized oedema and
jaundice. Haematology showed low RBC counts, PCV percentage and haemoglobin concentration and WBC counts. Lymphocyte differential
was high. Examination of blood smears stained with Giemsa’s stain showed the presence of piroplasms in red blood cells. Autopsy
showed enlarged lymph nodes and lymphosarcoma lesions in the omentum and the heart. There was hydroperitoneum, hydropericardium
and hydrothorax. The liver was pale yellow and friable. Impression smears from sliced lymph nodes and stained with Giemsa’s
stain showed presence of Koch’s blue bodies in lymphoblasts. Histopathological examination revealed fatty degeneration of
hepatocytes and pleomorphic lymphoblasts and giant cells in lymph nodes. Lymphoblasts infiltrated the omentum and heart tissues.
Amyloid was found around blood vessels in the liver, kidneys and lymph nodes. BVL infection was diagnosed by demonstrating
antibodies against the virus in serum using agar gel immunodiffusion and was confirmed with ELISA. 相似文献
AIM: To describe the prevalence and spatial distribution of cattle herds infected with Ikeda and non-Ikeda types of Theileria orientalis in New Zealand between November 2012 and June 2013.
METHODS: Pooled serum samples collected historically between November 2012 and June 2013 were obtained from cattle herds throughout New Zealand. Each pooled sample consisted of approximately 20 individual cattle samples from that herd, and was provided with details of the spatial location of the herd (n=722). DNA from all samples was tested using two quantitative PCR assays for the detection of T. orientalis (all types) and the Ikeda type. The proportion of herds that were positive for T. orientalis and Ikeda type, or that were positive for T. orientalis but negative for Ikeda type (non-Ikeda positive) was determined for different regions of New Zealand.
RESULTS: The highest prevalence of herds infected with Ikeda type was detected in the Northland (33/35; 94%) and Auckland and the Waikato (63/191; 33%) regions. Only 2/204 (1%) herds were positive for the Ikeda type in the South Island. A high percentage of herds that were positive for non-Ikeda types was detected in the Gisborne and Hawkes Bay (23 (95%CI=13–37)%), Auckland and Waikato (22 (95%CI=16–29)%) and Bay of Plenty (24 (95%CI=10–44)%) regions.
CONCLUSIONS AND CLINICAL RELEVANCE: The high prevalence of Ikeda type detected in cattle herds in the Northland, Auckland and Waikato regions represents a risk to naive cattle being introduced into these regions. There is also the potential for resident cattle herds in the Gisborne and Hawkes Bay, Auckland, Waikato and Bay of Plenty regions to experience increased infection with the Ikeda type.
The overall impact experienced by regions will depend on other factors such as the number of herds present and the predominant type of farming, as well as the interplay between tick ecology, cattle immunity and movement patterns of cattle. 相似文献
AIMS: To describe the epidemiology of the epidemic of bovine anaemia associated with Theileria orientalis infection (TABA) in New Zealand between 30 August 2012 and 4 March 2014.METHODS: Blood samples and associated data were obtained from cases of TABA. The case definition for TABA was met when piroplasms were present on blood smears and the haematocrit was ≤0.24?L/L. Samples were analysed using quantitative PCR (qPCR) assays for the detection of T. orientalis Ikeda type. Only cases that were positive in the qPCR assays were included in the analysis. A case herd was defined as a herd that had ≥1 animal positive for T. orientalis Ikeda.Movement records for farms were accessed through the national animal identification and tracing scheme. The OR for cattle movements onto a case farm compared to a non-case farm was estimated using a generalised estimating equation model and the geodesic distance for movements onto case and non-case farms compared using Student's t-test. The kernel-smoothed risk of disease at the farm level was calculated using an extraction map and the clustering of diseased farms in time and space was measured using the spatial temporal inhomogeneous pair correlation function.RESULTS: In the first 18 months there were 496 case herds; 392 (79%) were dairy and 104 (21%) beef herds. Of 882 individual cases, 820 (93.0%) were positive for T. orientalis Ikeda in the qPCR assays. Case herds were initially clustered in the Northland, then the Waikato regions. The OR for a case farm compared to a non-case farm having ≥1 inward cattle movements was 2.03 (95% CI=1.52–2.71) and the distance moved was 26 (95% CI=20.8–31.3) km greater for case farms. The risk of disease was highest in a north, north-eastern to south, south-western belt across the Waikato region. The spatial-temporal analysis showed significant clustering of infected herds within 20–30 days and up to 15?km distant from a case farm.CONCLUSIONS: Theileria orientalis Ikeda type is likely to have been introduced into regions populated with naïve cattle by the movement of parasitaemic cattle from affected areas. Local spread through dispersed ticks then probably became more important for disease transmission between herds once the disease established in a new area.CLINICAL RELEVANCE: Dairy and beef farming in the North Island of New Zealand will be significantly changed in the coming years by the incursion of this new disease. 相似文献
This study was carried out in two observational clinical studies. Study 1 comprised 50 adult crossbred cattle naturally infected
by Theileria annulata. Infected animals were divided into 4 subgroups with different parasitaemia (<1%, 1–3%, 3–5% and >5%). Study 2 comprised
20 adult crossbred cattle naturally infected by Anaplasma marginale. Infected animals were divided into 3 subgroups with different parasitaemia (<10%, 10–20% and 20–30%). In study 1, a significant
negative correlation (P < 0.001) was observed between parasitaemia and superoxide dismutase (SOD). Positive correlations (P < 0.001)
were observed between parasitaemia and lactate dehydrogenase (LDH) and mean corpuscular fragility (MCF). In study 2 positive
correlations (P < 0.05) were observed among parasitaemia and MCF and LDH activity. SOD activity had a negative correlation
with parasitaemia in cattle with parasitaemia lower than 10% but no significant correlation (P > 0.05) was observed between
SOD activity and parasitaemia in cattle with 10–20 and 20–30% parasitaemia. In comparison of both studies we came to the conclusion
that in theileriosis as the severity of disease increased the anaemia, MCF and LDH activity increased and SOD activity decreased
at any parasitaemia, but in anaplasmosis the anaemia, MCF and LDH activity increased at any parasitaemia but SOD activity
decreased only in early but not in advanced stages of disease. 相似文献
The purpose of this study was to determine serum ADA activity in cattle naturally infected with Theileria annulata. In this study, a total of 37 cross-bred cattle which 27 of it showing clinical signs of theileriosis constituted infected group and 10 healthy cattle as control group were used as animal materials. Infected group divided into three groups according to their PCV values. Cattle with PCV > or = 25 were put on group I (n = 9), those with PCV 13-24 were put on group II (n = 11) and those with PCV < or = 12 were put on group III (n = 7). Microscopical diagnosis of the disease was also made. Hematological parameters, serum enzyme activities (ADA, AST, ALT and ALP) were determined in all cattle. Hematological results revealed that significant progressive decreases in HGB, PLT, PBML counts and ratios from group I onwards to group III, whereas the WBC, PBPL counts and ratios showed an increase from group I onwards to group III. The serum ADA, AST, ALT and ALP activity increased significantly in all infected groups compared to control group. However, these parameters were also observed to decrease progressively from group I to group III. Furthermore, the highest increase in enzyme activities observed in the infected group I. But, these enzyme's activities started to decrease in infected group II and III in parallel with PBML and PLT counts. Eventhough, this decrease did not reach to the values obtained from control group. On the contrary, PBPL counts and ratios increased in infected group II and III in contrast to decrease in PCV. As a result, increased serum ADA activity in tropical theileriosis may reflect the involvement of the cellular immune responses. 相似文献