Biomedical subjects
A E Ryan
Publications and source records attributed to A E Ryan.
Human trichostrongyliasis in Queensland.
Trichostrongylus infection, an uncommonly reported zoonosis in Australia, is common in parts of the world where there is close human contact with herbivorous animals. We report 5 cases diagnosed in our laboratory since 1992. Over this period the laboratory has conducted over 46,000 parasitological examinations on feces. All 5 cases were investigated for fecal parasites following detection of a blood eosinophilia. Two of the 5 cases complained of mild abdominal discomfort and diarrhea. It is likely that all obtained their infection following ingestion of contaminated unwashed vegetables which had been fertilized with animal manure. Four of the cases acquired their infection in Queensland and the fifth may have become infected in rural Victoria. All were treated with pyrantel embonate with resolution of the eosinophilia. Follow up fecal specimens showed no parasites. Patients were instructed on the mode of transmission and advised to thoroughly wash any uncooked vegetables prior to ingestion. In our cases, goats and horses were possibly implicated. No published reports of Trichostrongylus spp. in humans in Australia have occurred since the 1930s and it may be more common in Australia than is recognized. The infection may be missed because patients are asymptomatic or have mild gastrointestinal symptoms or only a blood eosinophilia. Trichostrongylus eggs may also be mistaken for hookworm eggs. It is important therefore to distinguish these infections from hookworm infection as the modes of transmission, management and advice regarding prevention differ.
Urticaria and acute hepatitis A virus infection.
Urticaria has been described only rarely in patients with hepatitis A virus infection, although its association with acute hepatitis B virus infection is well recognized. A young male homosexual presented with hepatitis and urticaria, which proved to be an acute hepatitis A virus infection. In one study of a foodborne outbreak of hepatitis A virus, 2/130 patients developed hives. A few other isolated cases of presumed hepatitis A virus infection and urticaria have been reported, but this is the first detailed description of a serologically proven hepatitis A virus infection associated with the development of urticaria, in which no other risk factor could be implicated.
Keratomas in horses: seven cases (1975-1986).
The diagnosis of keratoma in 7 horses and their treatment and outcome were evaluated. Horses were 2 to 20 years old, of various breeds, and were intact or castrated males. All were lame, and 6 horses had had previous injuries of the affected hoof that had not responded to prior treatments. Only 1 hoof was affected in each horse. Keratomas were beneath the hoof wall (6 horses) or sole (1 horse). Radiographically, a circular or semicircular defect with a discrete margin was present in the distal portion of the third phalanx in 3 horses. Grossly, keratomas were firm solitary masses (1.5 to 5 cm diameter); gray, tan, or yellow; and oval or conical. Keratomas were excised from beneath the hoof wall by removing a section of hoof wall (5 horses) or by undermining the wall beginning at its junction with the sole (1 horse). A keratoma beneath the sole in 1 horse was excised by excavating the sole to the level of the palmar surface of the third phalanx. Keratoma was verified microscopically by the presence of characteristic rings of squamous epithelial cells with abundant keratin. Purulent exudate and inflammatory infiltrate often were present concurrently, reflecting an associated localized infection. Aftercare included daily application of an antiseptic iodine solution and foot bandages, and shoeing with a treatment plate several weeks after surgery. Hoof and sole defects healed completely between 6 months and 1 year. By 1 year after surgery, 6 horses were sound, and keratoma had not recurred.