EN
Out of 437 pigs coming from a pig farm trichinellosis was revealed by the digestion method (weight of samples =100 g, phrenic muscles) in 151 pigs (34.6 per cent). The rate of invasion below 1 larva in 1 g of muscles was found in 83 per cent of pigs, i.e. 19.0 per cent of animals under study; 2—3 larvae per 1 g — in 14 animals (3.2 per cent) and over 3 larvae per 1 g in 54 pigs, i.e. in 12.4 per cent. The presence of T. spiralis invasion in the pig farm in question was found already in 1989. The exchange of animals and deratization were done. It was not possible to establish the source of infestation. The larvae of T. spiralis were also stated in two of three rats coming from the same pig farm and the rate of invasion was high. However, it does not seem that rats have been the main source of the invasion.