Development of a simple and rapid assay for early diphtheria diagnosis.

ended

During 1990s, there was an epidemic of diphtheria in Russia and other countries of the former USSR affecting about 200, 000 people with 5000 deaths. Although diphtheria incidence in Russia has declined substantially, recent reports from several EU countries indicate circulation of toxigenic C. diphtheriae among migrants from Asia and Africa as well as children’s deaths among indigenous population. Toxigenic C. diphtheriae poses a serious risk for unvaccinated persons and persons with low level of immunological protection, the number of which in recent times in Europe has increased. The International system of quality control revealed poor state of laboratory diagnosis of diphtheria in EU countries, which means we are not prepared for the possible outbreaks. This is mostly due to the absence of simple, standard and reliable diagnostic methods. The leading element in the diphtheria laboratory diagnostic approach is a detection of the bacterial toxin. In this regard, it is proposed to develop non-apparatus immunochromatographic strip (ICS) test for diphtheria toxin (DT) indication. In addition a liquid selective medium for the clinical sample cultivation will be designed. A combination of the ICS test and the medium will represent a novel assay for early diphtheria diagnosis. The reagent kit will be commercially produced. The availability of simple, reliable and affordable ICS assay for DT detection will increase the accuracy of diphtheria diagnosis in EU and other countries and reduce the duration of its execution up to 6 hours (instead of 5-7 days as recommended by the WHO manual). The efficient early diphtheria diagnosis will enable timely initiation of anti-diphtheritic treatment that will save lives, prevent the development of complications (heart failure, paralysis), as well as stop the spread of the disease through initiation of preventive measures (vaccination and antibiotic prophylaxis) in case of disease outbreaks.