ABSTRACT
OBJECTIVE: Toxoplasma gondii is cause of a wide variety of infections in human. The aim of this study was; to evaluate the frequency of sero-positivity of the members in a family with a positive serologic person. METHODS: A case-control study with 170 enrolled units which was conducted in Iran in 2017. The units were settled into two group: I: the family members of seropositive individuals and II: the family members of seronegative individuals. The level of IgG and IgM anti-toxoplasma antibodies were evaluated by ELISA qualitative manner in both groups. RESULTS: Frequency of individuals with positive serology was 52.9% and 34.1% in group I and II, respectively (P value = 0.01). CONCLUSIONS: Clusters of toxoplasma infection would be an event in the family members. Therefore evaluation of the family members (especially high risk persons) of a patient may be necessary.