Atypical trichinellosis without eosinophilia associated with osteomyelitis.

Human trichinellosis is an important food-borne zoonosis caused by a nematode worm, Trichinella. The symptoms of the disease vary widely depending on the infection load, stage of infection and host immunity and include nausea, vomiting, abdominal pain, fever, facial edema and muscle pain. The disease is usually characterized by moderate to high eosinophilia. We hereby discuss an atypical case of trichinellosis, which presented with myositis of the thigh muscles but had no eosinophilia and no facial or periorbital edema and was associated with osteomyelitis of the femur. The diagnosis was made by the demonstration of anti-trichinella antibodies and later confirmed by the presence of larvae of Trichinella in the digested muscle biopsy. Physicians must be aware of trichinosis and should include it in their differential diagnosis when examining patients with fever and myositis with or without eosinophilia.

Unsuccessful treatment of a horse with mandibular granulomatous osteomyelitis due to Halicephalobus gingivalis.

An 8-year-old horse was presented with a submandibular swelling. Biopsy of the lesion indicated granulomatous osteomyelitis due to Halicephalobus gingivalis. In the absence of evidence of involvement of the central nervous system at the time of diagnosis, the horse was treated with ivermectin. Unfortunately, the horse did not survive.

Experimental model of chronic osteomyelitis caused by Leishmania (L) amazonensis.

Experimental animal models have been used for the study of the physiopathogenesis of leishmaniasis, on some occasions with success, while in other situations such as bone alterations that accompany tegumentary leishmaniasis, especially in diffuse cutaneous form (DCL), the mechanisms are still unknown. In the present study, we determined these alterations in an animal model susceptible to Leishmania (L) amazonensis. Amastigotes of L. (L) amazonensis isolated from patients with diffuse cutaneous leishmaniasis (DCL) were inoculated into the hind paws of eight BALB/c mice, macroscopic and histopathological aspects were analyzed. After 90 and 120 days of evolution, histopathological analysis demonstrated a mononuclear cell infiltrate rich in plasma cells and intense parasitism of intra- and extra-medullary macrophages, with areas of bone necrosis and discrete involvement of cartilaginous tissue. The results show that the inflammatory process developed during L. (L) amazonensis infection might cause bone tissue destruction and secondarily affect the joints.

Osteolytic osteomyelitis associated with visceral leishmaniasis in a dog.

A dog was examined with a history of weight loss and lameness of the left hind limb. A painful response to examination of the left hip joint, and lymphadenopathy were noted. Amastigote forms of Leishmania sp. were observed by cytology in samples from the popliteus lymph node, and anti-Leishmania sp. antibodies at a titer of 1:640 were detected in serum by indirect immunofluorescence. Radiological changes included osteolysis and a periosteal proliferative reaction in the left femoral greater trochanter. These changes were histologically characterized as an osteolytic granulomatous osteomyelitis associated with amastigotes within macrophages. Non-decalcified fragments of the periosteum were processed for immunohistochemistry, observed with prominent immunolabelling of amastigotes of Leishmania sp. within macrophages. The diagnosis was further confirmed by positive PCR for Leishmania sp., belonging to the Leishmania donovani complex.

Disseminated Halicephalobus deletrix infection in a horse.

A 13-year-old Quarter Horse gelding was referred for evaluation of a draining tract and fracture of the right hemimandible of 4 weeks' duration. Two days prior to admission, the horse had developed pigmenturia. Radiography of the mandible revealed a fracture of the vertical ramus of the right hemimandible, loss of the right lower second premolar, and osteomyelitis involving an extensive portion of the hemimandible. Ultrasonography of the left kidney revealed loss of normal renal architecture. Histologic examination of tissue obtained from the right hemimandible revealed granulomatous osteomyelitis and multiple metazoan parasites identified as Halicephalobus deletrix. The horse was treated with antimicrobial and deworming agents, and the mandible was surgically debrided. The horse became atactic 8 days after surgery and was euthanatized. Necropsy identified parasitic migration in the right hemimandible, kidneys, and CNS.