Experimental toxoplasmosis in house sparrows (Passer domesticus)

A total of 31 house sparrows (Passer domesticus) were divided into five gro ups of six to seven birds. Birds were infected per os with 1, 10, 10(2), 10 (3) and 10(4) oocysts of Toxoplasma gondii of the gl strain, respectively. When the general health, production of antibodies against T. gondii and iso lation positivity of the sparrows were examined in weeks 3, 7 and 12 post-i nfection (p.i.), no clinical signs of toxoplasmosis were observed. Seroprev alences ascertained in weeks 3, 7, and: 12 p.i. were 64% (18 positive/28 te sted), 95% (21/22) and 70% (7/10) when tested by indirect immunofluorescenc e (titre greater than or equal to 20); 54% (15/28), 59% (13/22) and 70% (7/ 10) when tested by the latex agglutination test (titre greater than or equa l to 20); and 59% (4/7), 0% (0/12) and 20% (2/10) when tested by the Sabin Feldman dye test (titre 4), respectively. T. gondii was re-isolated from 45 % (13/29) infected sparrows. House sparrows were found to exhibit some resi stance to the K1 strain of T, gondii after oocyst infection, and the result s suggest that sparrows may not, be a significant source of environmental i nfection.