THE MANIFESTATIONS AND DIAGNOSIS OF BABESIA INFECTIONS

In spite of a considerable literature on the Babesia infections of animals, there are comparatively few references to atypical manifestations of the disease. The existing references are reviewed in this paper. They include cases manifested by ocular, respiratory, digestive, nervous, and rheumatic symptoms. Since the causal agents are not always demonstrable in smears of the peripheral blood, and since the disease picture can be so very variable, the criteria of diagnosis are laid down and discussed. A number of cases studied at the Onderstepoort Veterinary Institute, Onderstepoort, Union of South Africa, are described according to the body systems mainly involved. Respiratory symptoms include a range from simple catarrhs to intense dyspnea simulating pneumonia. A striking group is made up by the involvement of the circulatory system, presenting such symptoms as severe ascites, asymmetrical edemas, and purpuric lesions. In the nervous system, Babesia infections are represented in animals by the manifestation of epileptiform fits, aberrations of the gait, abnormal actions and postures, and peripheral nerve palsies. Enteritis and gastritis indicate involvement of the digestive system. The pathogenesis of the atypical lesions is discussed in considerable detail in the light of the pathological and clinicopathological changes that take place in the babesioses. These changes include blocking of the capillaries by agglomerations of parasitized red blood corpuscles with consequent local tissue anoxia and intoxication, anemia, hypoalbuminemia, degeneration of the liver and kidneys, capillary fragility, and marked coagulation defects of the blood. In all these changes and manifestations there is a close parallel with those encountered in malaria from time to time, particularly in the malignant tertian form. Important references from the literature of malaria are cited in support of this observation.