The microepidemiology of wasting syndrome, a common link to diarrheal disease, cancer, rabies, animal models of AIDS, and HIV-AIDS YHAIDS). The feline leukemia virus and rabies virus models.

Infant cats were inoculated intracranially with rabies or feline leukemia viruses in an experimental study of wasting syndrome. The daily pre- and postinoculation body weights were recorded until kittens were moribund. Affected animals in both groups manifested growth failure or wasting syndrome. Immunodepression, manifested by a conspicuous depletion of thymic cortex, the thymus dependent areas of the spleen, and growth hormone producing-alpha adenopituicytes was significantly (p less than 0.01) related to the wasting status of the animals. The ability of pituitary glands from these animals to produce growth hormone was studied by in situ immunoperoxidase staining and showed a significant (p less than 0.01) difference between healthy and wasted animals. Rabies and feline leukemia viruses were each found responsible for the low immunoreactivity of growth hormone producing alpha adenopituicytes. Because the hypothalamus and the hypophysis were both found infected, it was concluded that regardless of the triggering agent in primary wasting, the hypothalamic-hypophyseal-thymic axis was always involved through a decrease in growth hormone production.

Therapeutic responses of piglets to experimentally induced colibacillosis.

The purpose of these experiments was to determine the effects of prior exposure to antimicrobials on subsequent treatment of artificially induced colibacillosis in pigs. One- to two-week-old piglets were given 10(7) multiple antibiotic resistant Escherichia coli orally. Two groups of the piglets received priming doses at different levels of the antimicrobial preparation, ASP-250 before challenge. The remaining group received no antimicrobial. Piglets ill as a result of the challenge were treated with chloramphenicol of chlortetracycline, or received no treatment. Chloramphenicol was significantly more effective than chlortetracycline in terminating colibacillosis in the primed and unprimed groups. There were fewer deaths and relapse cases in those groups which received chloramphenicol treatment. Results in piglets treated with chlortetracycline were not significantly better than those which received no treatment.

Detection of La Crosse (California encephalitis) virus antigen in mouse skin samples.

La Crosse (LAC) viral antigen was detected in the skin of inoculated mice. Antigen was detected principally in the dermis of 102 of 120 (85%) mice with clinical signs of illness. To demonstrate the specificity of the fluorescence, LAC virus was isolated from selected samples and was identified by the complement-fixation test. Antigen was most often detected in skin rich in vascular and nerve tissue and was probably disseminated by hematogenous spread. Antigen was found in muscle, vascular, nervous, and other tissues of the dermis, depending on the age of the mice. Antigen was first detected in the skin of 80% of the mice (5 to 6 days of age) on postinoculation day (PID) 3. On PID 4, 100% of these mice were positive, but on PID 5, only 40% were positive, indicating that clearance or neutralization of antigen had occurred in peripheral areas. The skin biopsy technique may be applicable to diagnosis of arboviral infections in other vertebrates.

Rabies in a litter of skunks predicted and diagnosed by skin biopsy.

Four juvenile skunks were vaccinated against rabies, descented, and then placed in 4 different households. An illness subsequently developed in 3 of the skunks that was confirmed as rabies, by examination of biopsy specimens of muzzle skin using immunofluorescence microscopy. In 1 clinically normal skunk, the skin was found to be test-positive, predicting that rabies would develop; the signs of rabies became evident in 48 hours. the infection was considered to be field acquired rather than vaccine induced.

Modern trends in veterinary public health.

The veterinary profession and its contribution to public health should expand in breadth, depth and flexibility to respond to the changing needs of community and society. This longstanding issue is still the subject of controversy between on the one hand those whose scientific activities contribute to our knowledge of food and environmental hygiene, enteric infections, food-borne diseases and zoonoses in general, and on the other the all too numerous traditionalists (even within the profession) who resist the venture of veterinarians into new territories and resent involvement in public health. Veterinarians are ideally suited to function in public health because of their orientation to populations, disease prevention, and the economic implications of disease.