Experimental Infection of Danish Landrace/Yorkshire Crossbred Pigs with Schistosoma japonicum from the People’s Republic of China

Abstract

This study was undertaken to assess the suitability of Danish Landrace/Yorkshire (L/Y) crossbred pigs as experimental hosts of a Chinese mainland strain of Schistosoma japonicum. Pigs were exposed to 200, 500 or 1000 cercariae and parasite burdens were determined by perfusion after either 8 or 11 weeks. All pigs became infected with onset of faecal egg excretion 6 to 7 weeks following exposure to cercariae. The pattern of faecal egg excretion differed markedly among the individual animals. Gross hepatic pathological lesions of varying degrees were noted in all of the pigs. Schistosome worm recoveries ranged from 1.5–23.4% of the cercarial exposure dose. Most schistosome eggs recovered from the tissues, expressed as eggs/g tissue, were found in the rectum (91%), caecum (3.1%) and liver (5.1%). The results show that Danish L/Y pigs may serve as appropriate experimental final hosts of the Chinese mainland strain of S. japonicum.

Sammendrag

Egnetheden af Dansk Landrace/Yorkshire (L/Y) grise som eksperimentelle værter for et isolat af Schistosoma japonicum fra den Kinesiske Folkerepublik blev undersøgt. Grise eksponeredes for 200, 500 eller 1000 cercarier, og bestemmelse af ormebyrdens størrelse fandt sted ved perfusion 8 eller 11 uger efter infektion. Alle grise inficeredes med fækal ægudskillelse startende 6 til 7 uger efter infektion. Det fækale ægudskillelsesmønster varierede markant mellem grisene. Makroskopiske, lever-patologiske læsioner af forskellig grad sås hos alle grise. Schistosomorme etableringen varierede mellem 1,5% og 23,4% af anvendte cercarier. De fleste schistosomæg, udtrykt som æg/gram væv, fandtes i rektum (91%), med mindre forekomster i caecum (3,1%) og lever (5,1%). Undersøgelsen viste at danske L/Y grise kan fungere som velegnede eksperimentelle slutværter for det anvendte isolat af S. japonicum.