Experimental infection of calves with Haemonchus placei or Haemonchus contortus: Assessment of clinical, hematological and biochemical parameters and histopathological characteristics of abomasums.

The present study had the primary objective of evaluating clinical, hematological and biochemical parameters, as well as observing anatomical and histopathological characteristics of abomasums, from calves prime-infected with Haemonchus contortus or H. placei. Ten male Holstein newborns were subdivided in three groups (GI placebo; GII infected with H. contortus; GIII inoculated with H. placei). Eye mucosa staining was evaluated. Hematological and biochemical tests were performed on animals. The euthanasia of all ten experimental calves was performed on the 42nd day post-inoculation. Fragments were collected from each of all 10 abomasums for histopathological analysis. Discrete submandibular edema was diagnosed in animals from both infected groups (H. contortus or H. placei). However, there were no significant changes (P > 0.05) in the color of the ocular mucosa of calves from all three experimental groups across the entire experimental period. Hematological and biochemical changes diagnosed on animals could not be linked to infections by species of Haemonchus spp. Regarding histopathological exams, it was possible to diagnose hypertrophy, hyperplasia, binucleated cells, inflammatory infiltrate, multifocal hemorrhage and edema in abomasums from calves of both groups infected with H. placei and H. contortus. It can, thus, be concluded that not only are calves susceptible to infections by both Haemonchus species, but they can also present clinical changes and similar anatomic histopathological lesions independent of being infected by Haemonchus placei or Haemonchus contortus. These results reflect a negative effect on helminth control by mixed grazing between sheep and cattle, especially when using calves.

Dietary assessment in five cases of allergic reactions due to gastroallergic anisakiasis.

BACKGROUND: Anisakis simplex can cause allergic reactions in sensitized patients. Some of these reactions are related to acute parasitism, as is shown in gastroallergic anisakiasis (anisakiasis with digestive and predominantly allergic symptoms). At present, a nonseafood diet is recommended for all patients with any kind of A. simplex allergy. We wished to confirm the clinical suspicion that patients with allergic symptoms after ingestion of raw or undercooked seafood who are sensitized to A. simplex, and diagnosed with gastroallergic anisakiasis, can tolerate the ingestion of seafood when the parasites are dead and noninfective. METHODS: We included patients diagnosed with gastroallergic anisakiasis (positive skin prick test or/and serum specific IgE to A. simplex, with one or more parasites found by gastroscopy in the stomach). Patients included in the study gave written, informed consent. Specimens of A. simplex about 2 cm long were selected, placed in capsules, and frozen at -20 degrees C for more than 48 h to make them noninfective. We administered 11 specimens to every patient at the hospital. If they tolerated the larvae, they were told to eat well-frozen seafood (-20 degrees C at least 48 h). After 6 months, the patients were re-evaluated. RESULTS: Five patients accepted the challenge with noninfective A. simplex larvae. All tolerated the noninfective larvae. After eating deep-frozen seafood for 6 months, no patient suffered a reaction. CONCLUSIONS: In gastroallergic anisakiasis, the antigens of the live parasite probably cause the allergic symptoms. Patients with this disease can tolerate deep-frozen seafood, in which the parasites are dead.