Analysis of trend in incidence of trichinellosis in pigs before and after systematic deratization

In the territory of Serbia, the occurrence of trichinellosis in domestic pigs has been present for a long number of years. In a ten-year period, a total of 1,224 pigs were registered in one populated area with the diagnosis of a larval form of the parasite T.spiralis. In the middle of the period of examination, a systematic deratization of the complete settlement was carried out, the neighboring garbage dumps, and a pit grave. The systematic deratization was performed using the preparation Brodisan. This preparation is a liquid concentrate for the preparation of bait with 0.25% bromadiolone (3-(3-/-bromobiphenyl-4- il/-3-hydroxy-1-phenylpropyl)-4-hydroxycoumarin). The total used quantity of bait for one systematic deratization in this populated area was 4,840 kg. Analyzing the tendency of the incidence of positive pigs in the period before the systematic deratization, we established that the average annual increase was around 70 pigs (b=69.30). The best adapted line of movement of the number of positive pigs was a third degree polynomial (Ŷ=185.20- 304.10x + 147.10x2-16.75x3), because its correlation coefficient is the biggest (rxy=0.96). The analysis of the trend in the number of infected pigs after the systematic deratization was performed in the examined area, it was established on the grounds of the negative parameter b of the straight line trend, that the average annual reduction in the number of infected pigs was 39.80. The tendency of a reduction of the number of infected pigs following the systematic deratization is best described by a second degree polynomial (Ŷ=307.2- 109.23x + 11.57x2) because its correlation coefficient is rxy=0.98