The contribution of syndromic diagnostic tests to pertussis epidemiology

Abstract

Objective: Pertussis is a vaccine-preventable, contagious respiratory in-fection. It can cause serious morbidity and mortality especially in young children. In this study, we aimed to investigate the effect of syndromic polymerase chain reaction (PCR) in the diagnosis of pertussis and the clinical features of the patients. Material and Methods: Nasopharyngeal swab specimens of patients who presented with pertussis-like illness between April and December 2017 were sent to Public Health Microbiology Reference Laboratory for Borde-tella pertussis culture and PCR. Between April and December 2018, naso-pharyngeal swab specimens were tested with the FilmArray® Multiplex PCR (BioFire, Biomerieux Diagnostics, France) in Microbiology Laboratory of our hospital The number of patients diagnosed with pertussis was com-pared between April-December 2017 and April-December 2018. The clinical features of patients were examined. Nasopharyngeal swab specimens of 7 patients between April and December 2017 were sent to Public Health Microbiology Reference Laboratory. B. pertussis culture and PCR positivity were detected in two patients in this period. Between April and December 2018, nasopharyngeal swab specimens of 17 patients were found to be positive for B. pertussis with FilmArray® Multiplex PCR (BioFire, Biomerieux Di-agnostics, France). In 2017, there were two definite pertussis cases. With the introduction of the syndromic PCR in 2018, all 17 patients were recorded as definite pertussis cases. Results: Between April and December 2018, of all patients with B. pertussis infections, 10 (59%) were female, 7 (41%) were male. The mean age was 1.9 months (range, 1 to 3 months). 59% (n= 10) of cases were unvaccinated and 41% (n= 7) had one dose of pertussis vaccine. The cocoon strategy was implemented to none of the parents. The mean time between send-ing nasopharyngeal swab samples and obtaining results was 2.7 (range, 1 to 6) hours. The mean length of hospitalization was 5.6 (range, 3 to 11) days. One case (6%) required non-invasive mechanical ventilation. Conclusion: Pertussis may cause severe clinical conditions especially in infants under 6 months. Rapid diagnosis of pertussis with syndromic PCR makes a significant contribution to pertussis epidemiology. It also improves the timely diagnosis, postexposure prophylaxis and management.