Experimental bovine hypodermosis in Spain.

An experimental survey was carried out in western Spain to investigate both the chronobiology of Hypoderma spp. and the immunoresponse of their bovine hosts. This study was initiated with a new system of obtaining Hypoderma spp. larvae directly from their host, including the eclosion of adults from their pupae, infestation under natural but controlled conditions, and confirmation of the resulting infection. This survey was carried out over 2 cattle grub seasons; it was possible to infest and reinfest the experimental animals and to monitor them by both parasitological methods and by an enzyme-linked immunosorbent assay. This method permitted the evaluation of the development of anti-Hypoderma antibodies during the experiment. The experimental design also enabled us to establish the period of detectable H. lineatum infection to be from December until the end of April with the largest number of warbles observed during March and April. After a pupal period of < 30 d, adults were seen in April and May. Hypoderma bovis (de Geer) showed a delay of 2 m.o. relative to H. lineatum (de Villiers). This study reports a completed biological life cycle of Hypoderma spp. under controlled conditions in both natural and experimental environments.

Method for collecting Hypoderma spp. (Diptera: Oestridae) larvae from cattle.

A new method for collecting 3rd-instar Hypoderma lineatum (Villers) and Hypoderma bovis (L.) is described. A procedure for carrying out chronobiological and other studies involving the life cycle of these flies is included. The larvae are collected from cattle using a dressing made of a circle of cardboard attached to a piece of tulle similar in color to the coat of the animal. These small cloth cages were attached to the animal skin with fast-drying contact glue wherever the swellings produced by 2nd- or 3rd-instar Hypoderma spp. had been previously detected. Each animal was inspected daily to detect the appearance of new larvae. This procedure allows the collection of each emerged larva without contact with other larvae and avoids friction of the cloth cages or dressing with the larvae, thus reducing larval death and increasing viability of the parasite.

Comparative scanning electron microscopy of third-instar Hypoderma spp. (Diptera: Oestridae).

Scanning electron microscope study of third-instar larvae of four species of Hypoderma revealed differences among species in the pattern of spination, spine morphology and morphology of the spiracular plates. These observations identify characters that enable the differentiation of Hypoderma actaeon and H. diana, parasitizing red deer (Cervus elaphus) in Europe, and provide additional characters for differentiating H. bovis and H. lineatum parasitizing cattle.

Deer hypodermosis.

Hypodermyiasis is a common myiasis which affects a wide variety of deer species in many parts of the world. In this article a great review of the disease is made, treating the different species of flies that cause the myiasis in the different species of hosts. Biologies of deer and flies are also studied, with special dedication to the chronobiology of the life cycle of the parasite. Prevalence and intensity of parasitization in many parts of Europe are recorded like expression of the importance of hypodermyiasis in deer. Finally, some remarks about treatment and control are included.

Comparison of the use of secretory and somatic antigens in an ELISA for the serodiagnosis of hypodermosis.

An antigen was prepared from metabolic products which were produced by maintaining first instar larvae of Hypoderma lineatum in RPMI tissue culture medium for 48 h. Three major proteins were identified in the secretory products and were characterised in terms of their molecular weights and iso-electric points. The antigen compared favourably with a soluble extract of larvae when used in an enzyme-linked immunosorbent assay (ELISA) against a panel of control sera and 2000 bovine sera collected from farms in Andalucia, Spain.

Immunological and histological study of T- and B-lymphocyte activity in canine visceral leishmaniosis.

Lymphocyte activity during canine leishmaniosis was studied by histological and immunological methods in experimental and natural infections. Eight dogs were inoculated with 5 x 10(7) promastigotes of Leishmania infantum, LEM 75, zimodeme MON-1, and maintained for 110 days post-infection. Another eight dogs with advanced natural infection were identified by parasitological and serological methods. Three techniques were used: the lymphocyte transformation test (LTT) to study T-cell activity, immunofluorescence assay and enzyme-linked immunosorbent assay to measure antibody production (B-cell activity), and methyl green-pyronin staining to assess tissue responses of lymphocytes. There was a noticeable B-cell response, reflected both histologically and immunologically. High percentages of activated lymphocytes and plasma cells were evident in lymphoid organs and production of specific antibodies was seen throughout the infection. LTT results showed a T-cell unresponsiveness during canine leishmaniosis. These same immunohistological features were observed, although to different degrees, in both experimental and natural infections.

Sarcocystis jorrini sp. nov. from the fallow deer Cervus dama.

Sarcocystis jorrini sp. nov. isolated from the muscle of naturally infected fallow deer (Cervus dama) from the Doñana National Park (Spain) is described by light and electron microscopy. Sarcocysts were macroscopic (2.7 x 1.4 mm) and were found in all striated muscle, including that of the esophagus and the heart. As visualized by light microscopy, the cyst walls were formed by mammilated protrusions surrounded by a coating of connective tissue measuring 10-35 mm in thickness. Electron microscopy revealed that the parasitophorous vacuole was serrated in appearance, with numerous pinocytic vesicles running along its whole length. Villar protrusions were of varying shape and were square, rectangular, or linguiform in cross section. The core of the villi contained small dense granules and microfilaments, which were more abundant in peripheral areas. Ground substance contained larger dense granules clustered around the base of villi. The sarcocyst was surrounded by a secondary cyst wall composed of collagen fibrils and fibrocytes. S. jorrini is the first macroscopically visible sarcocyst of the genus Cervus reported to have a secondary cyst wall.

Hypodermosis in the red deer Cervus elaphus in Córdoba, Spain.

The prevalence of red deer hypodermosis and the life cycle of Hypodermia diana Brauer 1858 in three provinces of the south of Spain, Córdoba, Jaen and Ciudad Real, were studied by inspecting 254, thirty-eight and thirty-five deer from each province respectively. The prevalence of infestations was: Córdoba, 87.75%; Jaen, 92.10%, Ciudad Real, 91.42%. From this we deduced an overall prevalence of 88.67%, comprising 88.23% in male deer and 89.96% in female deer. The intensity of the parasitism in 213 of the 245 animals from Córdoba varied between one warble per animal to more than 100 in 28 of the inspected animals. The chronology of the life cycle during the hunting period (October to the end of February) was investigated.

Elaeophora elaphi n. sp. (Filarioidea: Onchocercidae) parasite of the red deer (Cervus elaphus). With a key of species of the genus Elaeophora.

We described a new species of nematode filarioid (Onchocercidae) parasiting the hepatic vessels of the red deer Cervus elaphus. This new species is characterized by the number and disposition of the papillae on the genital area of the male, and the presence and characteristics of an "area rugosa" situated just in front of the ventral impair precloacal papilla. We discussed this new species, giving a key to the identification of all the known species of the genus Elaeophora.

Toxoplasmosis in pigs in Córdoba, Spain.

A total of 303 pig sera were examined by the Indirect Fluorescence Antibody Test (IFAT), basic Direct Agglutination Test (AD) and Direct Agglutination Test with 2-mercaptoethanol (AD 2-ME). The percentages of positive sera were 32.0 with IFAT, 37.95 with AD and 32.34% with AD 2-ME. No relationship was evident between sex and the incidence of toxoplasmosis in pigs. There were no significant statistical differences between the IFAT and the AD 2-ME, hence both tests can be recommended equally for serological surveys of toxoplasmosis.