title: Toxoplasma gondii infection: What is the real situation?
abstract: The prevalence of chronic Toxoplasma infections reported in the literature varies enormously. We hypothesize that one factor could be due to the different methods used in the evaluation of infections. Serological evidence of Toxoplasma infections in 450 pregnant women (PW) and 300 HIV-infected patients (HIV) were investigated by the Sabin-Feldman dye test and two other commercial ELISA kits (kit1 and kit2). Anti-Toxoplasma IgG antibodies obtained from the Sabin-Feldman dye test, ELISA kit1 and ELISA kit2 in the PW subjects were 14.7%, 29.6% and 38.7%, and in the HIV subjects were 13%, 34.7% and 36.3%, respectively. So there were significant differences in the seroprevalences when different diagnostic tests were used (P<0.05). Regarding Sabin-Feldman dye test as the gold standard for anti-Toxoplasma antibodies detection, we found that the sensitivity and specificity of the ELISA kit1 and kit2 was in the range of their specification. However as the two ELISA kits used in our study identified a much higher prevalence of Toxoplasma infections which indicated that false positive cases were being reported. Based on results obtained, it is therefore highly recommended that research workers should be aware that the reports of serological studies in terms of high positive results should be treated with some skepticism until additional precise diagnostic tools are developed.
authors.affiliation: Department of Microbiology, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla 90110, Thailand.
authors.forename: Waenurama
authors.initials: W
authors.lastname: Chemoh
authors.forename: Nongyao
authors.initials: N
authors.lastname: Sawangjaroen
authors.forename: Veeranoot
authors.initials: V
authors.lastname: Nissapatorn
authors.forename: Chitkasaem
authors.initials: C
authors.lastname: Suwanrath
authors.forename: Verapol
authors.initials: V
authors.lastname: Chandeying
authors.forename: Thanaporn
authors.initials: T
authors.lastname: Hortiwakul
authors.forename: Hemah
authors.initials: H
authors.lastname: Andiappan
authors.forename: Natthawan
authors.initials: N
authors.lastname: Sermwittayawong
authors.forename: Bunsri
authors.initials: B
authors.lastname: Charoenmak
authors.forename: Pisut
authors.initials: P
authors.lastname: Siripaitoon
authors.forename: Amorn
authors.initials: A
authors.lastname: Lekkla
authors.forename: Yaowalark
authors.initials: Y
authors.lastname: Sukthana
mesh_terms: D000913:Antibodies, Protozoan / Q000097:blood*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D015658:HIV Infections / Q000150:complications*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D008297:Male; D008751:Methylene Blue; D011237:Predictive Value of Tests; D011247:Pregnancy; D015597:Pregnancy Complications, Parasitic / Q000453:epidemiology*; D011933:Reagent Kits, Diagnostic; D012680:Sensitivity and Specificity; D016036:Seroepidemiologic Studies; D012698:Serologic Tests; D013785:Thailand / Q000453:epidemiology; D014122:Toxoplasma / Q000276:immunology*; D014123:Toxoplasmosis / Q000453:epidemiology*
chemical_list: D000913:Antibodies, Protozoan; D007074:Immunoglobulin G; D011933:Reagent Kits, Diagnostic; D008751:Methylene Blue
keywords: ELISA test; Pregnant women and HIV-infected patients; Sabin–Feldman dye test; Seroprevalence; Toxoplasma gondii