Toxoplasma gondii,one of the most common parasitic infections of man and other warm-bloodedanimals, is an obligate intracellular parasite and a memberof the Apicomplexa phylum. 1 The Felidae family have prominent roles in theepidemiology of T. gondii infection because they repel millions ofoocysts in a short time period (1-2 weeks) in feces2 and pollutedthe soil, food or water.
Oocysts of T. gondii have been detected in thefeces of less than 1% of cats3. Based on serological studies, Aboutone third of the world’s population has been exposed to this widespreadzoonotic agent 1.
It has caused a major public health concern in recent times due to theimmunosuppressive effects of HIV/AIDS 4.Toxoplasmagondii infection induces a powerful IFN-? drivencell-mediated immune response in the mammalian hosts. IFN-? plays a role indriving the transformation of tachyzoites to bradyzoites and blocks reactivationtachyzoites 5.
This is an essential response for the resolution ofacute infection and control of a chronic, latent infection in the CNS6.Recently, somestudies have been showed that ELISA-based on IFN-?assay could be used as useful diagnostic tool for acute and chronic T.gondii infection7-9. Several differentdiagnostic methods such as serological testes, fecal flotation technique andPCR are used for determining T. gondii infection incats. In Iran, large numbers of cats are foundroaming residential streets and can be an important potential source oftransition of zoonotic diseases such as T. gondii infection .
The results of the epidemiological studies showeda high prevalence of Toxoplasma infection in cats of Iran 10, 11, 12,13, 14, 15. There is noinformation about the prevalence of T. gondii infection in cat in Mashhad area., Iran. Theaim of the present survey was to determine the seroprevalence of T.gondii infectionin stray cats in the Mashhad area and the relationship of seropositivestatus of cat with oocyst shedding and the serum IFN-? concentration.