Background: Despite high vaccination coverage, pertussis remains prevalent in young infants. Still, its clinical presentation is non-specific therefore warranting laboratory testing. Accordingly, we examined the prevalence of Bp and other respiratory pathogens in a sample of nasopharyngeal (NP) specimens submitted by hospital and clinics to a pertussis laboratory of infants suspected of having pertussis.
Methods: One hundred and forty seven NP samples were collected in this prospective ongoing case-control study, 2/2015-12/2015. Bp Real-time PCR targeting pertussis IS 481, parapertussis IS 1001, ptxS1g, holmesii BHIS 1001 and culture were performed as well as PCR of sixteen respiratory viruses (RV-16).
Results: RV-16 positivity was more common than Bp, 61.22 %( 95% CI: 53.2-68.7%) vs. 32.65% (95% CI: 25.6-40.6%) chi square=24.01, p Among the RV-16 positive samples, Human rhinovirus was the most prevalent virus (51.0%); followed by Adenovirus (24.5%), parainfluenza (16.2%) and metapneumovirus (10.1%). The incidence of respiratory viruses in infants with Bp was significantly lower than the incidence of respiratory viruses in infants without pertussis (OR: 3.87, 95% CI: 1.86-8.04; p<0.001). There were no significant differences in the frequency of pertussis by age, 0-2, 2-4, 4-6, and 6-12 months. Notably, 50% of Bp PCR positive samples were also Bp culture- positive.
Conclusion: In young infants suspected of having pertussis, respiratory viruses frequently mimic Bp`s clinical presentation and are more likely to be the causative agent. Laboratory confirmation of Bp should be pursued to assure the judicious use of antibiotic treatment and chemoprophylaxis
