PCR-based diagnosis is not always useful in the acute acquired toxoplasmosis in immunocompetent individuals.

Toxoplasmosis is the most prevalent zoonosis in the world and is associated with a large spectrum of diseases. Acute acquired toxoplasmosis (AAT) is considered a benign and self-limiting disease but severe postnatal infections have been reported, particularly in South America. Laboratory diagnosis is based on the detection of anti-Toxoplasma gondii IgM, IgG, and presence of low IgG avidity. However, these assays present limitations, and therefore, PCR has been suggested as an alternative diagnostic tool. In this study, we performed real-time and nested PCR in DNA blood samples from 59 individuals with AAT lasting less than 80 days. None of the patients had parasitic DNA detected by PCR, even in the more severe cases or when blood was collected early after disease onset. These negative results indicate that the parasitemia kinetics needs investigation to determine the best time for blood sampling, especially in immunocompetent individuals. Thus, we emphasize that a negative PCR result does not exclude recent T. gondii infection, and serological criteria are still decisive for the laboratory diagnosis of AAT.

Ocular toxoplasmosis: adverse reactions to treatment in a Brazilian cohort.

Background: The purpose of this study was to estimate the frequency and describe the adverse drug reactions (ADRs) associated with the classic treatment of ocular toxoplasmosis (OT), namely sulfadiazine, pyrimethamine, corticosteroids and folinic acid. Methods: We performed a descriptive study of a prospective cohort of patients with OT treated with the classic therapy. Data were collected during medical consultations and treatment. Results: Of the 147 patients studied, 85% developed one or more ADR. Women presented more ADRs than men (95% vs 77%). Of the total reactions (n=394), 82% were mild, but we found one life-threatening event (Stevens-Johnson syndrome). The most frequent types (71%) of ADRs were gastrointestinal, skin and neurological or psychiatric. The majority of ADRs (90.3%) occurred before the second week of treatment. A third of the patients were treated for the ADR and 10% dropped out of OT treatment. Most (70%) of the ADRs were characterized as being probably caused by the drugs and may be associated with prednisone, sulfadiazine and sulfadiazine/prednisone. Six percent of ADRs were not previously described, such as taste alteration, constipation/bloating, dyspnoea, sweating and somnolence. Conclusions: Our results suggest a high rate of ADRs to OT classic treatment, which requires careful follow-up in order to identify and treat ADRs early.