Concurrent infections of Trichinella spiralis and Toxoplasma gondii in mice.

Concurrent infections with two parasites: a nematode, Trichinella spiralis, and a protozoon. Toxoplasma gondii, were investigated. Antibody production (total immunoglobulin and IgM) was similar in double and single infections. However, the number of Toxoplasma cysts in the brains of mice infected with Trichinella and challenged 1-6 weeks later with Toxoplasma was higher than in mice infected with Toxoplasma alone, while mice infected with Toxoplasma and challenged 4-14 days later with Trichinella had lower worm burdens in the intestine than animals infected with Trichinella alone. Greater loss in body weight was observed in mice infected with both parasites than in those infected with either parasite alone.