Re-entering the diphtheria laboratory diagnosis

Toxigenic C. diphtheriae pose a serious threat to unvaccinated and immunocompromised individuals, whose numbers have recently increased in Europe. The International system of quality control revealed the poor state of laboratory diagnosis of diphtheria in EU countries, which means Europe is not well prepared for the possible outbreaks. This is mostly due to the absence of simple, standard and reliable laboratory diagnostic methods. The main element in the diphtheria diagnostic scheme is a detection of the bacterial toxin (DT). The common method for detecting the production of DT by corynebacteria, gel immunoprecipitation or Elek test developed in 1949, is vulnerable, time consuming and laborious. PCR for DT gene detection is inaccurate as non-toxigenic C. diphtheriae and C. ulcerans strains carrying the mutated toxin gene circulate worldwide. Rapid immunochemical test (LFIA) for the detection of diphtheria toxin was developed and evaluated.