Serodiagnosis of Schistosoma japonicum infection: genome-wide identification of a protein marker, and assessment of its diagnostic validity in a field study in China.

Abstract

BACKGROUND:

Schistosomiasis remains a highly prevalent and serious parasitic disease. A major factor preventing its effective management is the scarcity of effective diagnostic tools. We did a genome-wide identification of diagnostic protein markers for schistosome infection and assessed their diagnostic validity in a field study.

METHODS:

We predicted putative secreted proteins of Schistosoma japonicum (SjSPs) and expressed them as glutathione S-transferase (GST)-fusion proteins. The fusion proteins were arrayed on glutathione (GSH)-immobilised microplates and screened with serum samples from patients with schistosomiasis diagnosed by the Kato-Katz method. We further assessed an identified protein marker for sensitivity and specificity, first in infected serum samples collected from Jiangxi and Hunan Provinces, China, and then through a field study, done in two villages located in a high schistosomiasis-endemic area of the southeast of China.

FINDINGS:

Of 204 recombinant proteins, 35 yielded seropositive reactions, eight showed strong immunoreactivity, and only one (SjSP-13) reacted to the entire panel of 14 archived samples. The reactivity of SjSP-13 to 476 serum samples showed 90·4% (95% CI 86·5-93·5) sensitivity and 98·9% (95% CI 95·9-99·9) specificity. Of 1371 residents enrolled in a field study from Dec 6, 2010, to June 23, 2011, only 74 individuals were identified as being egg-positive, whereas 465 were diagnosed as positive by the SjSP-13-based ELISA kit (rSP13-ELISA). Of the 394 individuals found egg-negative but rSP13-ELISA-positive, 363 (92·4%) were confirmed to be positive for schistosome infection by PCR detection of S japonicum SjR2 retrotransposon.

INTERPRETATION:

The application of this sensitive, specific, and affordable rSP13-ELISA method should help reduce schistosomiasis transmission through targeted treatment of individuals, particularly with low intensity infections, and therefore support schistosomiasis control and elimination strategies.

FUNDING:

National 973 project in China.

• Authors: Xindong Xu, Yuanbin Zhang, Dandan Lin, Jinjin Zhang, Jin Xu, Yue-Min Liu, Fei Hu, Xiaoxing Qing, Chaoming Xia, Weiqing Pan
• Journal: The Lancet. Infectious diseases (Lancet Infect Dis) Vol. 14 Issue 6 Pg. 489-97 (Jun 2014) ISSN: 1474-4457 [Electronic] United States
• PMID: 24656567 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2014 Elsevier Ltd. All rights reserved.

Chemical References

• Anthelmintics
• Antibodies, Helminth
• Biomarkers
• Helminth Proteins
• Recombinant Fusion Proteins
• Praziquantel
• Glutathione Transferase

Topics

• Adolescent
• Adult
• Aged
• Animals
• Anthelmintics (therapeutic use)
• Antibodies, Helminth (blood)
• Biomarkers (metabolism)
• Child
• Child, Preschool
• China
• Enzyme-Linked Immunosorbent Assay (methods)
• Feces (parasitology)
• Female
• Gene Expression
• Glutathione Transferase (immunology)
• Helminth Proteins (genetics, immunology)
• Humans
• Male
• Middle Aged
• Praziquantel (therapeutic use)
• Prevalence
• Recombinant Fusion Proteins (immunology)
• Schistosoma japonicum (genetics, immunology, isolation & purification)
• Schistosomiasis japonica (diagnosis, drug therapy, parasitology)
• Sensitivity and Specificity
• Young Adult