Investigations were carried out on eighteen farms in the Province of Gelderland to determine whether it was possible to use biopsy specimens of the tonsils to differentiate between farms with clinical problems caused by Streptococcus suis type 2 and farms without these problems. The proportion of carriers of this organism on the farms was 14 per cent and 2 per cent respectively, so that this differentiation is feasible. It was also studied whether this proportion differed on farms which imported pigs from Great Britain and farms which did not do so; the proportion of carriers on farms having animals imported from Great Britain was found to be higher than that on farms not using these importations, viz., 17 per cent and one per cent respectively.
Animals Carrier State