PCR-based diagnosis of whooping cough in the Russian Federation

The aim was to determine how often the PCR method is used in different laboratories in Russia. In 2018, we conducted a questionnaire survey in diagnostic laboratories of medical organizations and the Centers of Hygiene and Epidemiology that performed PCR studies to identify microorganisms of the genus Bordetella in all 85 Russian regions. We found that in 2013 the PCR was used in 33 (38.8%) regions, but in 2017 the number of regions increased to 64 (75.3%). During 2013-2017 the study has not been applied in 21 regions. The number of PCR tests performed in the laboratories of medical organizations was significantly different. There has been an increase in the number of tests for the diagnosis of pertussis among people with clinical signs of infection and among contact persons in foci of infection. Compared to the Centers of Hygiene and Epidemiology, in medical organizations the rate of introduction of the PCR was higher. Between 2013 and 2017 the proportion of samples containing DNA B.pertussis decreased, but the proportion of samples containing DNA of other representatives of the genus Bordetella increased. Moreover, in the case of isolation DNA Bordetella spp. clinicians diagnose «Whooping cough, other unspecified organism», since there is no information on the species of the pathogen. Thus, in order to improve the diagnosis of pertussis, it is necessary to optimize PCR tests by including target genes that allow to identify of currently relevant DNAs of different representatives of the genus Bordetella.