Submitted to: Veterinary Parasitology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 1/5/2010
Publication Date: 5/15/2010
Citation: Garcia-Bocanegra, I., Simon-Grife, M., Sibla, M., Dubey, J.P., Cabezio, O., Martin, G., Almeria, S. 2010. Duration of maternally derived antibodies in Toxoplasma gondii naturally infected piglets. Veterinary Parasitology. 170:134-136. Interpretive Summary: Toxoplasma gondii is a single-celled parasite of all warm-blooded hosts worldwide. It causes mental retardation and loss of vision in children, and abortion in livestock. Cats are the main reservoir of T. gondii because they are the only hosts that can excrete the resistant stage (oocyst) of the parasite in the feces. Humans become infected by eating undercooked meat from infected animals and food and water contaminated with oocysts. Serologic diagnosis of toxoplasmosis in young pigs is uncertain because of the presence of antibodies transferred from the mother. In the present study, scientists document the decline of maternally derived antibodies in pigs. The results will be of interest to biologists, parasitologists, and veterinarians.
Technical Abstract: A longitudinal study was performed to analyze the dynamics of T. gondii antibodies in naturally infected piglets from 1 to 25 weeks of age. Seventy three piglets from 20 seronegative sows (modified agglutination test, MAT <1:25) and 20 naturally infected T. gondii seropositive sows (MAT>/=1:25) were analyzed at 1, 3, 6, 9, 12, 15, 18, 22 and 25 weeks of age. Twenty-six of the 73 piglets analyzed (35.6%; CI 95%: 25.5-45.7) were seropositive at some point during the study. Seroprevalence in piglets at one and three weeks of age was significantly higher in animals born from seropositive sows (P<0.001 and P=0.02, respectively) as indication of maternally derived antibodies. The longest persistence (up to 12 weeks of age) was observed in a piglet whose dam had high T. gondii antibody level (MAT>/=1:500), while persistence of maternally derived antibodies in the piglets born from sows with low antibody titers (maximum 1:50) was much shorter and lasted only up to 3 weeks of age, when the piglets were weaned. The risk of horizontal transmission in piglets increased with age and was higher in piglets during the finishing period. The present results indicate that the decline of T. gondii maternally derived antibodies in naturally infected piglets is associated to the titers of their dams.