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

Abstract

Infection by Toxoplasma gondii is prevalent worldwide. The parasite can infect a broad spectrum of vertebrate hosts, but infection of fetuses and immunocompromised patients is of particular concern. Easy-to-perform, robust, and highly sensitive and specific methods to detect Toxoplasma infection are important for the treatment and management of patients. Rapid diagnostic methods that do not sacrifice the accuracy of the assay and give reproducible results in a short time are highly desirable. In this context, rapid diagnostic tests (RDTs), especially with point-of-care (POC) features, are promising diagnostic methods in clinical microbiology laboratories, especially in areas with minimal laboratory facilities. More advanced methods using microfluidics and sensor technology will be the future trend. In this review, we discuss serological and molecular-based rapid diagnostic tests for detecting Toxoplasma infection in humans as well as animals.

Molecular prevalence of Toxoplasma gondii in sheep from Isfahan, Iran as detected in heart samples by loop-mediated isothermal amplification (LAMP)

“…The prevalence recorded in this study is based on a molecular method and is higher than those previously reported in small ruminants of Iran: 37.5% (sheep) and 22.7% (goat) in southwest Iran (Asgari et al, 2011), 34.32 % (sheep) in south of Iran (Armand et al, 2016), and 56.66% (sheep) and 44.16 (goat) in Eastern Iran (Tavakoli-Kareshk et al, 2017). This prevalence could reflect the LAMP is 10-1000 times more sensitive compared with conventional nested PCR (Khan and Noordin, 2019;Kong et al, 2012).…”

“…A wide range of serological methods including indirect fluorescent antibody tests, enzyme-linked immunosorbent assay, immunosorbent agglutination assay, indirect hemagglutination assay, modified agglutination test, Sabin-Feldman dye test, and Western blot have been applied in extensive epidemiological surveys (Dard et al, 2016). Although serological tests are used extensively in epidemiologic studies, because they are time-consuming, lack in diagnosing primary infections, present antigen cross-reactivity, and antibodies disappear in the long-term, these tests are not reliable when compared to molecular techniques (Sun et al, 2017 for direct detection of T. gondii DNA in tissues (Khan and Noordin, 2019). The first PCR assay for the detection of T. gondii was founded based on the amplification of the 35-repeat B1 gene of the T. gondii genome (Burg et al, 1989).…”

“…Till now, LAMP has been used for the detection of different parasitic protozoan diseases, including cryptosporidiosis, piroplasmosis, and trypanosomosis (Sun et al, 2017). This method is a favorable molecular technique to be used for the diagnosis of toxoplasmosis, specifically in developing countries with a high prevalence rate (Khan and Noordin, 2019). In a comparative study the sensitivity of the LAMP-based on the 529 bp-RE genes was 1000-and 100-fold higher than that of the RE-nested PCR and B1-LAMP, respectively (Kong et al, 2012).…”

Development and Evaluation of Recombinant GRA8 Protein for the Serodiagnosis of Toxoplasma Gondii Infection in Goats

“…Serological methods play a major role in the diagnosis of T. gondii infection in humans and animals [4,5]. Several serological tests have been developed using either live tachyzoites or native soluble antigens; however, they are expensive, laborious, and nonspeci c [6].…”

Development and evaluation of recombinant GRA8 protein for the serodiagnosis of Toxoplasma gondii infection in goats

“…Serological methods play a major role in the diagnosis of T. gondii infection in humans and animals [5,6]. Several serological tests have been developed using either live tachyzoites or native soluble antigens; however, they are expensive, laborious, and nonspeci c [7].…”