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Updated: Aug 14, 2026
3-D Imaging and Analysis of Neurons Infected In Vivo with Toxoplasma gondii
Published on: December 9, 2014
[Immunodiagnosis in 647 suspected clinical cases of toxoplasmosis]
M C Contreras1, S Gallo, P Salinas
1Departamento de Parasitología, Facultad de Medicina, Universidad de Chile, Santiago, Chile.
Insights
Distinguishing acute from chronic toxoplasmosis is crucial. This study found that combining indirect hemagglutination test (IHAT), dye test (DT), and complement fixation test (CFT) can help identify recent or acute Toxoplasma gondii infections, especially in patients with adenopathies, ophthalmopathies, and AIDS.
Area of Science:
- Medical Parasitology
- Immunology
- Infectious Diseases
Context:
- Toxoplasma gondii infections often present asymptomatically, complicating diagnosis.
- Differentiating acute from chronic infections is vital for appropriate patient management and treatment.
- Serological tests are essential for diagnosing toxoplasmosis, but distinguishing infection stages can be challenging.
Purpose:
- To evaluate the utility of indirect hemagglutination test (IHAT), dye test (DT), and complement fixation test (CFT) in differentiating acute from chronic Toxoplasma gondii infections.
- To assess the correlation between serological test results and various clinical manifestations of toxoplasmosis.
- To determine the prevalence of toxoplasmosis across different patient groups.
Summary:
- A study of 647 sera from patients suspected of toxoplasmosis utilized IHAT, DT, and CFT.
- Global positivity rates were 49.5% for IHAT/DT and 4.5% for CFT.
- A high agreement in concordant and discordant titers between IHAT/DT and CFT indicated recent or acute infections, particularly noted in adenopathies, ophthalmopathies (uveitis), and AIDS patients.
- Low and median titers for IHAT/DT were observed in 81.3% of cases, suggesting a significant proportion of acute or recent infections.
Impact:
- The findings provide a basis for improved diagnostic strategies to differentiate acute from chronic toxoplasmosis.
- This can lead to more timely and effective interventions for patients with symptomatic toxoplasmosis.
- Understanding serological patterns aids in managing diverse clinical presentations, including those in immunocompromised individuals and pregnant women.
Abstract:
Though Toxoplasma gondii can cause severe pathology in human, in most of the cases it produces only asymptomatic infection. So, it is important to dispose some methods capables to discriminate between acute and chronic infections. An indirect hemagglutination test (IHAT), dye test (DT) and complement fixation test (CFT) were performed in 647 sera from patients suspected of having toxoplasmosis infection. IHAT and DT titer > or = 4 and CFT > or = 5 were considered positive. Titers were classified as follows: low (4-16), median (64-512) and high (> or = 1000) for IHAT and DT. The pathologies for demanding these serological tests were: adenopathies (58), nephropathies (72), neuropathies (30), obstetrical problems (65), opthalmopathies (147), AIDS (237) and miscellaneous (37). Global positivity of 49.5% and 4.5% for IHAT/DT and CFT respectively were found. The positivity for the different groups were: adenopathies (48.3% and 13.8%), nephropathies (43.1% and 1.4%), neuropathies (26.7% and 3.3%), obstetrical problems (40.0% and 0.0%), ophthalmopathies (59.9% and 8.2%), AIDS (52.1% and 2.5%) and miscellaneous (40.5% and 2.7%) for IHAT/DT and CFT respectively. Low and median titers for IHAT/DT were found in 81.3% of cases. A high agreement in frequency of concordant and discordant titers of IHAT/DT and CFT, indicating a recent or acute infection was observed. This fact was more relevant in adenopathies, ophthalmopathies (uveitis) and AIDS groups.
