Isolation and identification of Babesia ovis in Extremadura (Spain).

A morphological and morphometric comparison was made of a Babesia ovis strain isolated in Extremadura (Spain) and a B. ovis strain from Turkey. Strains were morphologically similar, with a clear predominance of single sub-spherical or anaplasmoid forms. The use of an image analyser to measure B. ovis merozoites revealed significant differences in the long axis, short axis and volume between the two strains. Both strains however behaved in a similar manner in the indirect fluorescent antibody (IFA) test, which suggests a high degree of common antigenicity, despite morphometric differences. Conversely, no cross-reaction was observed between these strains of B. ovis and the other antigens used: B. motasi (The Netherlands), B. motasi (Turkey), B. crassa (Iran) and Theileria ovis (Turkey). B. ovis is therefore considered to be the aetiological agent of babesiosis in the area under study.

Development of Babesia ovata in the haemolymph of the tick, Haemaphysalis longicornis.

The haemolymph of adult tick Haemaphysalis longicornis (H. longicornis) infected with Babesia ovata (B. ovata) was examined at regular intervals. As a result kinetes could be detected in the haemolymph 15 days after engorgement. The kinetes detected could be classified into three types on the basis of their morphological characteristics. They increased gradually in number, reaching a maximum 23 days later. Then they tended to decrease in number, disappearing almost completely from the haemolymph 38 days after the engorgement of ticks.

Studies on a bovine Babesia transmitted by Hyalomma marginatum rufipes Koch, 1844.

A Babesia sp. was recently observed in Hyalomma marginatum rufipes and found to be transmissible to bovines. Further observations were carried out on this parasite and a study made of the morphology of stages in both erythrocytes and tick haemolymph. Apart from Babesia divergens, intra-erythrocytic parasites were not readily distinguishable from bovine Babesia spp. Merozoites in tick haemolymph morphologically resembled those of Babesia bigemina, but they were significantly larger. This Babesia sp. proved to be highly infective for adult H. m. rufipes, with transmission taking place transovarially and next generation nymphae and adults transmitting the infection. Features of the infection were its very low pathogenicity, even in splenectomized animals, and the tendency of parasitized erythrocytes to accumulate in capillaries. Serologically, this species could be differentiated from babesia bigemina, B. divergens, B. bovis and B. major. A serological survey of 25 farms showed a wide distribution of this species in south Africa and its high rate of transmission on most properties. It was concluded that this is a true but hitherto undescribed bovine Babesia sp. and the name Babesia occultans n. sp. is proposed.

Raccoon babesiosis in Connecticut, USA: Babesia lotori sp. n.

A species of Babesia which infects raccoons, Procyon lotor, is described and named Babesia lotori. Twelve of 14 raccoons captured from five counties in Connecticut developed parasitemia after splenectomy. Preoperative levels were subpatent or less than 1%. Parasitemia peaked anywhere from less than 5% to 36.6% in splenectomized raccoons, and all but one survived and possessed low infection rates (less than or equal to 3%) at the end of the experiment. An indirect fluorescent antibody test is described and shown to be useful in detecting antibodies to B. lotori. Seropositive raccoons were obtained from six counties. Two, Babesia-free, splenectomized raccoons developed parasitemia with corresponding increases in antibody titers after they were inoculated with infected blood. Antibody titers of naturally infected raccoons following splenectomy either remained stable or increased fourfold. Babesia was observed in three of four young raccoons which had been naturally confined to chimneys. Two of these four young raccoons were infested with a nest-dwelling tick, Ixodes texanus.

An unidentified Babesia of the domestic cat (Felis domesticus).

An unidentified Babesia was seen in a blood smear from a cat showing signs of anaemia. The cat responded to treatment with diminazene (Berenil). The morphology of the parasite is described and a comparison is made with other Babesia which have been described from the domestic cat and wild felids. This parasite most closely resembled B. herpailuri described from a jaguarundi in South America.

Intraerythrocytic parasitosis in humans with Entopolypoides species (family Babesiidae). Association with hepatic dysfunction and serum factors inhibiting lymphocyte response to phytohemagglutinin.

We have observed two cases of human infection with intraerythrocytic protozoa. The organisms appeared to be in the Entopolypoides group, which had not previously been associated with human infection. One patient was asplenic. Both patients had hepatic dysfunction, and their serum samples contained blocking factors that interfered in vitro with the stimulation of normal lymphocytes by phytohemagglutinin. It appears that in humans, as well as in experimental animals, host factors are important in resistance to infection by intraerythrocytic parasites. These factors include the presence of a spleen and cell-mediated and humoral immunities. Possibly similar infections will be observed in patients with other impairments of T-cell function, such as those induced by malignancy, thymic dysfunction, or immunosuppressive drugs.

A differential diagnostic criterion for Babesia major and Babesia bigemina vermicules from tick haemolymph.

Babesia major mature and immature vermicules in the haemolymph of Haemaphysalis punctata were measured and found to be significantly larger than vermicules of Babesia bigemina. Mature B. major vermicules had a mean length of 15.53 micrometer and mature B. bigemina vermicules had a mean length of 11.79 micrometer. This difference provides a new criterion for the differentiation of the two species.

[Invasiveness and developmental forms of 3 Babesia species and piroplasmids (Piroplasmida) in the eggs of ixodid ticks]. / Invazirovannost' i formy razvitiia trekh vidov Babezii i piroplazmid (Piroplasmida) v iaitsakh iksodovykh kleshchei.

The paper presents the materials on the identification and study of the developmental forms and morphology of B. colchica and P. bigeminum in eggs of Hyalomma anatolicum. The description of developmental forms of B. colchica in eggs of Boophilus calcaratus is given for the first time. P. bigeminum and P. beliceri were detected in eggs of B. calcaratus and H. anatolicum from the first day of egg production up to the emergence of larvae while B. colchica was found beginning from the 4th-5th day of egg production up to the 5th-7th day before larvae emergence. The invasion rate of eggs of B. colchica is considerably smaller than that of B. bigeminum and P. beliceri. In piroplasmids and babesians there were observed sigar--like, roundish, amoebapear-, rod-shaped and oval forms. Some indivisuals of piroplasmids had projections of cytoplasm of different size. Individuals of B. colchica are smaller than those of P. bigeminum and P. beliceri that enables an easy differentiation of babesians from piroplasmids.