Control of bovine ringworm by vaccination in Norway.

Bovine ringworm caused by Trichophyton verrucosum is a notifiable disease in Norway. New infected herds are reported to the Norwegian Food Safety Authority. To limit spread of the disease, restrictions are imposed on holdings including access to common pastures and sale of live animals. Bovine ringworm has been endemic in the Norwegian dairy population for decades. Since 1980 a vaccine (Bovilis Ringvac LTF-130, Merck Animal Health) has been available. The vaccine contains an attenuated strain of T. verrucosum and stimulates humoral and cellular immune responses conferring protection. Efficacy and safety of the vaccine have been evaluated in experimental and field studies. Vaccination campaigns in densely populated counties have contributed to a substantial decrease in number of ringworm outbreaks. The annual incidence of new infected herds decreased from 1.7% in 1980 to 0.043% in 2004. Few herds remained with restrictions and a "mopping up" project was established to offer assistance specifically to these holdings. A milestone was achieved in 2009; no new herds with cases of clinical ringworm caused by T. verrucosum were reported to the authorities. By end of 2012, there are only two herds with restrictions. Vaccination during the last 30 years has been a key control measure in the effort to prevent disease outbreaks and eradicate bovine ringworm in Norway.

Persistence of antibodies in blood and body fluids in decaying fox carcasses, as exemplified by antibodies against Microsporum canis.

To assist in evaluating serological test results from dead animals, 10 silver foxes (Vulpes vulpes) and 10 blue foxes (Alopex lagopus), 6 of each species previously vaccinated against and all challenged with Microsporum canis, were blood sampled and euthanased. Fox carcasses were stored at +10 degrees C, and autopsy was performed on Days 0, 2, 4, 7, and 11 post mortem during which samples from blood and/or body fluid from the thoracic cavity were collected. Antibodies against M. canis were measured in an enzyme-linked immunosorbent assay (ELISA) as absorbance values (optical density; OD). To assess the degradation of antibodies, the ratio between post mortem and ante mortem absorbance was calculated. The mean absorbance from samples collected during autopsy was generally lower than from samples from live animals. In blood samples, this difference increased significantly with time (P = 0.04), while in body fluid samples the difference decreased (not significant; P = 0.18). We suggest that a positive serological result from testing blood or body fluid of a dead animal may be regarded as valuable, although specific prevalences obtained by screening populations based on this type of material may represent an under-estimation of the true antibody prevalence. Negative serological test results based on material from carcasses may be less conclusive, taken into account the general degradation processes in decaying carcasses, also involving immunoglobulin proteins.