Cluster analysis of the clinical histories of cattle affected with bovine anaemia associated with Theileria orientalis Ikeda type infection

Abstract

AIM To determine the most commonly used words in the clinical histories of animals naturally infected with Theileria orientalis Ikeda type; whether these words differed between cases categorised by age, farm type or haematocrit (HCT), and if there was any clustering of the common words in relation to these categories. METHODS Clinical histories were transcribed for 605 cases of bovine anaemia associated with T. orientalis (TABA), that were submitted to laboratories with blood samples which tested positive for T. orientalis Ikeda type infection by PCR analysis, between October 2012 and November 2014. χ tests were used to determine whether the proportion of submissions for each word was similar across the categories of HCT (normal, moderate anaemia or severe anaemia), farm type (dairy or beef) and age (young or old). Correspondence analysis (CA) was carried out on a contingency table of the frequency of the 28 most commonly used history words, cross-tabulated by age categories (young, old or unknown). Agglomerative hierarchical clustering, using Ward's method, was then performed on the coordinates from the correspondence analysis. RESULTS The six most commonly used history words were jaundice (204/605), lethargic (162/605), pale mucous membranes (161/605), cow (151/605), anaemia (147/605), and off milk (115/605). The proportion of cases with some history words differed between categories of age, farm type and HCT. The cluster analysis indicated that the recorded history words were grouped in two main clusters. The first included the words weight loss, tachycardia, pale mucous membranes, anaemia, lethargic and thin, and was associated with adult (p<0.001), severe anaemia (p<0.001) and dairy (p<0.001). The second cluster included the words deaths, ill-thrift, calves, calf and diarrhoea, and was associated with young (p<0.001), normal HCT (p<0.001), beef (p<0.001) and moderate anaemia (p<0.001). CONCLUSIONS AND CLINICAL RELEVANCE Cluster analysis of words recorded in clinical histories submitted with blood samples from cases of TABA indicates that two potentially different disease syndromes were associated with T. orientalis Ikeda type infection. One was consistent with the affected cattle suffering from a severe regenerative extravascular haemolytic anaemia, the second displaying as ill thrift and diarrhoea, particularly in young beef cattle.

Diagnosis of Liver Neoplasms by Computational and Statistical Image Analysis

“…For hierarchical clustering, Ward’s method was employed which merged pairs of clusters at each step by minimizing the total within-cluster variance and generated a dendrogram for estimation of the number of likely clusters within the studied population (Fig. 4) [19]. The estimates of hierarchical clustering were used to develop centroids for the k-means clustering.…”

Review of the New Zealand Theileria orientalis Ikeda Type Epidemic and Epidemiological Research since 2012

“…Later, Giemsa staining was mostly replaced by PCR testing. The most common clinical signs recorded for cattle with acute infection in New Zealand are jaundice, lethargy, pale mucous membranes, anaemia, and reduced milk production [21]. In the chronic phase, infection is asymptomatic except for the hypothesised syndrome of ill thrift, diarrhoea, and death reported in weaned beef calves [21].…”

“…The most common clinical signs recorded for cattle with acute infection in New Zealand are jaundice, lethargy, pale mucous membranes, anaemia, and reduced milk production [21]. In the chronic phase, infection is asymptomatic except for the hypothesised syndrome of ill thrift, diarrhoea, and death reported in weaned beef calves [21]. In the earlier 1982-1986 T. orientalis epidemic the two most common presenting signs from 101 cases, were ill-thrift (29/101) and diarrhoea (23/101) [22]; it is noteworthy that anaemia and jaundice were not commonly reported in that epidemic [22].…”

“…Whereas in the chronic phase T. orientalis Ikeda type infection now interacts with these contributory causes, leading to potentially more severe effects resulting from stress (physiological or nutritional) or concurrent disease, on milk production and liveweight gain than would be seen in uninfected cattle, i.e., the chronic T. orientalis Ikeda infection decreases the fitness of the animal to tolerate other endemic diseases and deficiencies. This reduction in fitness brought on by chronic infection is the likely explanation for the hypothesised syndrome of ill thrift, chronic diarrhoea and death reported in weaned beef calves [21]. These calves present with quite vague illnesses which are likely related to parasitism, concurrent infections such as BVD or Yersinia pseudotuberculosis and poor nutrition exacerbated by the chronic Theileria infection.…”

Epidemiology, Clinical Signs, and Risk Factors Associated with Theileriosis in Australian Cattle (2006–2022)

“…Being a parasite that proliferates within erythrocytes, it is not surprising that anaemia is one of the most frequently cited clinical signs of theileriosis, along with related observations, such as mucous membrane pallor and jaundice. Clinical signs that have been reported around the world also include pyrexia, depression, inappetence, weakness, and reduced lactation [ 10 , 11 , 12 , 37 , 38 ]. In Australia, commonly cited clinical signs include, but are not limited to, anaemia, jaundice, lethargy, and abortions [ 8 , 13 , 22 , 31 , 39 ].…”