TABLE 1.

Sera employed in the comparison between the IgM-GIPL ELISA, IFA, and capture ELISA

Group	n	Description
Control	10	Human serum samples collected from healthy individuals without clinical symptoms or positive serological tests for infection with T. gondii, T. cruzi. S. mansoni, Plasmodium spp., or Leishmania spp. All patients in this group were negative for Toxoplasma-specific IgM and by the IgG IFA
Acute toxoplasmosis	20	Human serum samples collected from patients with typical clinical symptoms of infectious mononucleosis-like syndrome, with fever, fatigue, and enlargement of the cervical lymph nodes. The sera from these patients exhibited specific IgM antibodies (titer of ≥64), IgG antibodies (titer of ≥256) by IFA, and low avidity of T. gondii-specific IgG
Chronic toxoplasmosis	14	Human serum samples collected from immunocompetent individuals with asymptomatic toxoplasmosis. These serum samples exhibited specific IgG antibodies (titer of ≥64), negative results for T. gondii specific IgM (titer of <16) in the IFA, and high avidity of T. gondii-specific IgG.
Indeterminate	21	Serum samples collected from patients presenting asymptomatic infections. However, the results of the laboratory assays were unclear for these patients. A high level of discordant results was seen in this group, with IgM antibodies (titer of ≥64) being persistently positive for a long period of time, associated with positive results for IgG (titer of ≥64) in the IFA and high avidity of T. gondii-specific IgG.
Malaria	30	Serum samples collected from patients from areas of malarial endemicity. These samples had specific IgG antibodies for Plasmodium spp. as analyzed in the IFA. From these sera, 14 were negative (titer of <16) and 16 were positive (titer of >64) for Toxoplasma-specific IgG in the IFA.
Chagas' disease	40	Human serum samples collected from patients with specific IgG antibodies to T. cruzi. The patients presented clinic symptoms of the cardiac, digestive, or asymptomatic form of Chagas' disease. Of these sera, 22 were negative (titer of <16) and 18 were positive (titer of ≥64) for Toxoplasma-specific IgG in the IFA.
Schistosomiasis	40	Human serum samples collected from patients in areas of endemic S. mansoni infection. Digestive and hepatosplenic symptoms were the clinical forms presented by this group. The samples had specific IgG antibodies to S. mansoni by the IFA. Of these sera, 23 were negative (titer of <16) and 17 were positive (titer of >64) for Toxoplasma-specific IgG in the IFA.
Leishmaniasis	80	Human serum samples collected from patients from areas of leishmaniasis endemicity. 50% of the patients presented the cutaneous or mucocutaneous form of leishmania infection; the other patients had clinical symptoms of visceral leishmania. All serum samples exhibited specific IgG antibodies to Leishmania spp. in the IFA. Of these sera, 52 were negative (titer of <16) and 28 were positive (titer of >64) for Toxoplasma-specific IgG in the IFA.
Arthritis	16	Serum samples collected from patients with arthritis. All patients had polyarticular or systemic symptoms of rheumatoid arthritis. All samples were positive for IgM rheumatoid factors. All patients from this group were negative for Toxoplasma-specific IgM and IgG in the IFA.