Comparative sensitivities of various tests for diagnosing early Schistosoma mansoni infection in mice

Mahmoud Mohamed Bahgat,Abduallh M Ibrahim,Maha Rizk,Amany Sayed Maghraby,Rehab Abdel Megeed

doi:10.4172/2155-9597.1000116

Abstract

Objective: We compared the diagnostic values of cercarial antigen preparation, cercarial secretions, soluble worm antigen preparation and worm vomit prepared from the parasite Schistosoma mansoni. Methods: Enzyme linked immunosorbant assay was used to detect IgG in plasma from Schistosoma mansoni infected mice. In parallel, specific primers for the parasite genome was used to detect S. mansoni DNA in plasma and urine from infected mice and hemolymph and tissues of infected Biomphalaria alexandrina snails by Polymerase chain reaction. Results: The results showed that all the above diagnostic approaches enabled infection to be diagnosed as early as three days post mice exposure to parasite cercariae. Conclusion: Cercarial secretions and worm vomit represent new useful economic crude antigens for preliminary detection of parasite active transmission or response to therapy in an endemic setting. Also, it was found that the detection of Schistosoma mansoni DNA in urine from infected mice was the most sensitive and specific (although expensive) method for infection diagnosis than all the others.

Highlights

Diagnosis of schistosomiasis infection is conventionally carried out by Kato Katz technique [1,2,3,4] or serologic methods [5,6]
The levels of the anti-worm IgG remained high at 23 weeks post-treatment, the polymerase chain reaction (PCR) results turned negative at week 10 posttreatment [14]
We compared the diagnostic values of several crude antigens prepared from the cercarial and the adult worm stages of the parasite S. mansoni to detect IgG in sera from infected mice with the same parasite kinetically at regular time intervals post infection

Summary

Introduction

Diagnosis of schistosomiasis infection is conventionally carried out by Kato Katz technique [1,2,3,4] or serologic methods [5,6]. We compared the diagnostic values of several crude antigens prepared from the cercarial and the adult worm stages of the parasite S. mansoni to detect IgG in sera from infected mice with the same parasite kinetically at regular time intervals post infection. Of these antigens cercarial secretaions (CS) and worm vomit (WoV) were previously evaluated for their diagnostic value to detect IgG in sera from infected humans [15]. In a trial to improve the sensitivity and specificity of the diagnosis, a PCR based on specific primers for the parasite genome was evaluated for its capacity to detect infection in plasma and urine from infected mice

Methods

Results

Conclusion