In the Santiago area the incidence of Str. agalactiae infection was investigated. In a total of 47 herds including 4,905 milking cows, 95.7 per cent. of the herds and 7.05 per cent. of the cows were infected with Str. agalactiae, 637 quarters out of 1,222 (51.1 per cent.) examined were positive.
In one herd including 25 milking cows all the quarters were examined, 21 cows (84 per cent.) and 55 (57 per cent.) of their quarters were positive.