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Quantitative diagnosis of schistosoma infections by detection of circulating antigens in serum and urine

Objective



THE DIAGNOSIS OF SCHISTOSOME INFECTIONS IS STILL MAINLY BASED ON THE DETECTION OF THE PARASITEEGGS IN FAECES OR URINE. HOWEVER, THE STRONG FLUCTUATION OF EGG EXCRETION NECESSITATES RPEATED EXAMINATIONS TO RELIABLY DETERMINE THE INTENSITY OF THE INFECTION, WHILE LIGHT INFECTIONS ARE EASILY MISSED. FOR QUANTITATIVE DIAGNOSIS OF ACTIVE SCHISTOSOME INFECTIONS, DETECTION OF SPECIFIC HOST ANTIBODIES IS NO REALISTIC ALTERNATIVE WHEREAS DETECTION OF ANTIGENS EXCRETED BY THE PARASITE IS A PROMISING APPROACH. DURING THE STD-2 FUNDED COLLABORATIVE RESEARCH PROJECT ON CIRCULATING SCHISTOSOME ANTIGENS IT WAS STUDIED WHETHER ANTIGENS DERIVED FROM THE SCHISTOSOME GUT (CCA, CCA) COULD BE ASSAYED AS MARKERS FOR ACTIVE INFECTION ,INTENSITY OF INFECTION AND FOLLOW-UP OF CHEMOTHERAPY. IN THE FIRST PHASE OF THAT RESEARCH PROJECT, AN ELISA AND A TR-IFMA FOR CAA WERE DEVELOPED, DURING THE SECOND PHASE AN ELISA FOR CCA A DOTIMMUNOBINDING ASSAY FOR CCA IS NOW BEING EVALUATED. IN A NUMBER OF PILOT STUDIES (S MANSONI IMMUNDOBID IMMUNOBINDING S JAPANICUM S INTERCALATUM IT WAS SHOWN THAT CIRCULATING ANTIGEN DETECTION CAN BE USED TO QUANTITATE ACTIVE INFECTION AND TO MONITOR CHEMOTHERAPY. IN ADDITION, IT WAS SHOWN THAT DETECTION OF CCA IN URINE, ALLOWING NON INVASIVE SAMPLING, IS A PROMISING TECHNIQUE.
THE PRESENT PROPOSAL IS BQSED ON THE RESULTS REAGENTS AND EXPERTISE GENERATED DURING THE FIRST NETWORK STUDY AND HAS THE FOLLOWING OBJECTIVES. IT HAS BEEN FOUND THAT DETECTION OF MORE THAN ONE ANTIGEN WILL PROVIDE ADDITIONAL DIAGNOSTIC PARAMETERS MONOCLONAL ANTIBODY PANELS WILL THEREFORE BE SCREENED FOR DIAGNOSTIC ANTIBODIES WITH SPECIAL EMPHASIS ON JAPONICUM. TO ACHIEVE OPTIMAL DETECTION LEVELS AND TO ALLOW TESTING OF SMALL SAMPLES HIGHLY SENTITIVE ASSAYS (ELISA TRIFMA) ARE NEEDED ALTERNATIVE ELISA PROCEDURES WILL BE INVESTIGATED AND A TRIFMA FOR CCA WILL BE DEVELOPED A FIELD APPLICABLE DIP STICK ASSYA OR DOT IMMUNOBINDING ASSAY WILL DEVELOP ADDITIONAL AND MORE DETAILED STUDIES ON ANTIGEN LEVEL FLUCTUATIONS IN SERUM AND URINE ON ANTIGEN LEVELS FOLLOWING CHEMOTHERAPY ON CORRELATION BETWEEN ANTIGEN LEVELS ABD EGG OUTPUT "FALSE POSITIVES AND FALSE NEGATIVES" AND ON ANTIGEN LEVELS AND MORBIDITY WILL BE UNDERTAKEN. A MAJOR ASPECT OF THE PROPOSALIS CONSTUTUED BY TRAINING AND TECHNOLOGY TRANSFER TO COLLABORATING INSTITUTES IN ENDEMIC AREAS BY THE APPLICATION OF THE ASSAUYS IN SEROEPIDEM IOLOGICAL STUDIES. IT IS ANTICIPATED THAT BY AN EFFECTIVE USE OF REAGENTS

Funding Scheme

CSC - Cost-sharing contracts

Coordinator

LEIDEN UNIVERSITY
Address
62,Wassenaarseweg 62
2300 RC Leiden
Netherlands

Participants (7)

Cooperacio Tecnica Espanola Bata
Equatorial Guinea
Address

Bata
Fundação Oswaldo Cruz
Brazil
Address
1715,Avenida Augusto De Lima
30190 Belo Horizonte
Hôpital 'Dr A.Schweitzer' Lambarene
Gabon
Address

20 Lambarene
Landesinstitut für Tropenmedizin
Germany
Address
Königin Elisabeth Straße 32
14059 Berlin
Medical Research Station Kumba
Cameroon
Address

Kumba
Research Institute for Tropical Medicine
Philippines
Address
Alabang, Muntinlupa
Metro Manila
Shanghai Second Medical University
China
Address
280,South Chongging Road
200025 Shanghai