Point-of-care testing for Toxoplasma gondii IgG/IgM using Toxoplasma ICT IgG-IgM test with sera from the United States and implications for developing countries

Abstract

BackgroundCongenital toxoplasmosis is a serious but preventable and treatable disease. Gestational screening facilitates early detection and treatment of primary acquisition. Thus, fetal infection can be promptly diagnosed and treated and outcomes can be improved.MethodsWe tested 180 sera with the Toxoplasma ICT IgG-IgM point-of-care (POC) test. Sera were from 116 chronically infected persons (48 serotype II; 14 serotype I-III; 25 serotype I-IIIa; 28 serotype Atypical, haplogroup 12; 1 not typed). These represent strains of parasites infecting mothers of congenitally infected children in the U.S. 51 seronegative samples and 13 samples from recently infected persons known to be IgG/IgM positive within the prior 2.7 months also were tested. Interpretation was confirmed by two blinded observers. A comparison of costs for POC vs. commercial laboratory testing methods was performed.ResultsWe found that this new Toxoplasma ICT IgG-IgM POC test was highly sensitive (100%) and specific (100%) for distinguishing IgG/IgM-positive from negative sera. Use of such reliable POC tests can be cost-saving and benefit patients.ConclusionsOur work demonstrates that the Toxoplasma ICT IgG-IgM test can function reliably as a point-of-care test to diagnose Toxoplasma gondii infection in the U.S. This provides an opportunity to improve maternal-fetal care by using approaches, diagnostic tools, and medicines already available. This infection has serious, lifelong consequences for infected persons and their families. From the present study, it appears a simple, low-cost POC test is now available to help prevent morbidity/disability, decrease cost, and make gestational screening feasible. It also offers new options for improved prenatal care in low- and middle-income countries.

Evaluation of a New Immunochromatography Technology Test (LDBio Diagnostics) To Detect Toxoplasma IgG and IgM: Comparison with the Routine Architect Technique

“…Lastly, the ICT IgG-IgM test could be promoted as a first-line technique in developing countries and could be particularly interesting for the early follow-up of pregnant women. This indication was also mentioned by Begeman et al (9). Indeed, the simple determination of the serological status in early pregnancy compared to the serological status at birth seems simple and feasible in developing countries.…”

“…Another recent study has evaluated this new technique (9). The methodological approach is different and complementary (in relation to our work).…”

Global initiative for congenital toxoplasmosis: an observational and international comparative clinical analysis

“…Furthermore, in the fragmented US healthcare system, uninsured patients often lack adequate access for even legally mandated testing. The advent of novel, more economical point-of-care screening modalities likely will revolutionize testing during gestation 70 . This will address one of the primary arguments against monthly gestational screening at present.…”

Serological and molecular rapid diagnostic tests for Toxoplasma infection in humans and animals

“…The device accurately identified seropositive USA patients with known T. gondii infection and distinguished them from seronegative individuals. Moreover, it has the potential to identify acute infection accurately [34,41]. In the USA, both the diagnostic sensitivity and specificity were found to be 100% [34], while in France, the sensitivity and specificity were reported to be 97% and 96%, respectively, as compared to the Architect fully automated chemiluminescence test (Abbott North, Chicago, IL) [41].…”