More than 200 diseases can be represented in differential diagnosis of fever of unknown origin
(FUO). The mainstay for the proper diagnosis of FUO took right path for the correct investigations.
Globally, Toxoplasma gondii infection persists lifelong within the affected host organs in
the dormant bradyzoites form. Once the host immunity decreases, it can be converted back to
the activate tachyzoite form that attach the host cells. The aim of our study is to estimate the
frequency of toxoplasmosis in patients with fever of unknown origin, concerning the etiology.
A cross-sectional study was done from November 2017 to May 2018, including 140 patients
chosen with FUO (100 males &40 females), recruited from Port Said Fever Hospital/ Egypt.
Their ages ranged between 16 and 70 years old. Patients were subjected to comprehensive history
taking, laboratory investigations, clinical and radiologic examination. Detection of anti-
Toxoplasma IgM&IgG antibodies was done by the Electrochemiluminescence immunoassay.
Patients had fever with known origin proved by investigations, were excluded from the study.
The results showed that 7.1% of the FUO cases were serologically positive for Toxoplasma
IgG. Of them, 80% were females and 20% were males. About 70% of Toxopl-asma-IgG positive
cases were represented with fever for 3weeks, and 30% were represented with fever for
more than 3weeks. The 70% of the target group had cervical lymphadenopathy and all of them
had hepatosplenomegaly. Moreover, all cases were eating fast food.