An outbreak of Toxoplasmosis amongst squirrel monkeys in an Israeli monkey colony

An outbreak of Toxoplasmosis in a colony of squirrel monkeys (Saimiri sciureus) in Israel is described. Serological, pathological, and molecular findings of monkeys, as well as rodents and pigeons from the vicinity are summarized. Seventy-nine percent (19/24) of monkeys were T. gondii seropositive at titer 1:16 whilst 4% (1/24) were also seropositive at titer 1:64 using the Modified Agglutination Test (MAT). Eighty four percent (21/25) of rats were positive at titer 1:16 and 8% (2/25) of rats were positive at titer 1:32. DNA amplification of a 529bp repeated sequence of T. gondii was detected in the liver and lungs of all monkeys tested, 6/7 in myocardial extractions and 5/6 in brain extractions. Sequence analysis of the SAG2 locus disclosed that T. gondii detected was of Type III genotype. The source of disease was thought to be contamination of feed with infective feline oocysts. As a result of this study, the implementation of a program to capture and remove resident feral cats, to discontinue the feeding of stray cats, and to control rodent populations in the park was introduced.