Using caprine arthritis-encephalitis virus antigen in the agar gel immunodiffusion test, 3729 serum samples from goats in over 112 locations around the world were tested for precipitating antibodies. Over 90 per cent of the 1265 positive samples came from Canada, France, Norway, Switzerland and the USA, all of which had 65 per cent reactors or greater. Fiji, Great Britain, Kenya, Mexico, New Zealand and Peru had fewer than 10 per cent positive samples; the majority of these could be traced to importations of goats from countries where there was a high occurrence of precipitating antibody. Somalia, Sudan and South Africa had no reactors among 306 samples. No reactors were found among 1116 samples from domestic and indigenous goats which were known to have had no contact with imported goats from countries which had a high occurrence.

An enzyme-linked immunosorbent assay (ELISA) was developed for the detection of antibodies to caprine arthritis encephalitis virus (CAEV) in goat sera. The system was evaluated using some 1500 sera from flocks of known clinical history. From this data the interpretation limits of the system were determined. The ELISA system was compared with a gel precipitin test using 5800 sera. Of the positive sera, ELISA detected 97.3% and AGPT 61%. Further evaluation was made using 60 sera of known CAEV reactivity from the USA, and results agreed 100%. Indications are that antibody to the envelope glycoprotein gp135 is being detected. The ELISA system is more sensitive than the precipitin test and is presently being used in a CAEV flock accreditation scheme.

Bovine Leukaemia Virus (BLV) infection in New Zealand cattle was investigated. In a national survey of 5000 sera from 500 herds, BLV antibody was not detected. An additional 1062 sera from 140 herds were tested and 3 sera were positive. In the herd of origin of one of these 3 sera, 22.6% of cattle were serologically positive for BLV. Where cases of bovine lymphosarcoma had been diagnosed, 38 of 39 herds tested were negative for BLV antibody. Within the remaining herd, 36% of cows tested were serologically-positive. BLV was isolated from 2 serologically positive cows in this herd.

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