Abstract
Background:
The protozoan Toxoplasma gondii is the source of the zoonosis Toxoplasmosis. and causes public health problems throughout the world. Environmental contamination by oocysts excreted by cats as definitive hosts affects the spread of this disease. Wild rats as rodents can be used as an indicator of environmental contamination by oocysts, considering that rats have a habit of living in dirty environments and can be infected by oocysts from the environment.
Aim:
This study aims to detection of toxoplasmosis from tissue cysts and serological test in wild rats as an indicator of environmental contamination in Surabaya.
Methods:
A total of 100 wild rats collected from Surabaya were collected in five areas (west, east, central, north, and south Surabaya) obtained from three trapping locations: housing, dense settlements, and markets. All samples were examined microscopically for parasitological tests through the brain tissue samples, and the serum was examined using the ToMAT (Toxoplasma Modified Agglutination Test) to detect the presence of Ig G and Ig M.
Results:
The results showed that the seroprevalence of T. gondii in wild rats was 31% (30% for Ig G and 1% for Ig M). Tissue cysts in the rat brain samples tested were 19% (19/100).Ig G prevalence rate in female rats was 25% (8/32) while for males it was 32.3% (22/68). The highest seropositive Ig G from densely populated settlements was 50%, markets were 25.8%, and housing was 12.1%. The highest seropositive Ig M from densely populated settlements was 2.8%. Population density and the presence of cats are factors supporting the high seropositive rate at the trapping location.
Conclusion:
This study revealed that there has been Toxoplasmosis contamination in Surabaya with evidance of 31% in serology and active infection with 19% tissue cyst. It is necessery for controling with survailance in cats to prevent transmission in humans.

Key words: Tissue cyst, Public health, ToMAT, Toxoplasmosis, Wild rats