Respiratory Pathogens Identified in Patients with a Clinically Suspected Bordetella Pertussis Infection

Abstract

Background: Because of the low sensitivity of the suggested two-weeks cough duration to guide the management of suspected cases of pertussis, using a duration of one week have been recently used instead. The aim of this study was to identify Bordetella pertussis and other respiratory pathogens in patients coughing for at least one week. Methods: Prospective, observational, cohort study of 39 patients (13 males, 33%), aged between 16.5 and 65 years, presenting to Oasis hospital, Al Ain city, United Arab Emirates, between March and July 2017. Nasopharyngeal samples were analysed by real-time multiplex polymerase chain reaction assay. Quantitative determination of serum IgG and IgA antibodies against Bordetella pertussis toxin was performed by enzyme-linked immunosorbent assay. Results: The median duration of cough was 13 days. No Bordetella pertussis or parapertussis were isolated in any patients. Four patients (10%) had serum pertussis-toxin IgA >12 IU/ml (of whom one also had the serum IgG >10 IU/ml), indicating probable pertussis infection. Only two of them had had a cough for more than two weeks. Twenty-four (61%) patients had no detected pathogens and in 15 (39%), at least one pathogen was detected, mainly rhinovirus, coronavirus C43, and Mycoplasma pneumoniae. Discussion: Applying the case definition of a two-weeks cough duration would have missed half of the cases of pertussis. Even with the cut-off of one week of coughing, it remains more often associated with viruses or other bacteria. Funding: The study was funded by a research grant from the United Arab Emirates University (No. 31R074). The funding source did not participate in the study design, data collection, analysis and interpretation of the data, or the decision to submit the manuscript for publication. Declaration of Interest: None to declare. Ethical Approval: The project received ethical approval from the Al Ain Medical District Human Research Ethics Committee (ERH_2016_4264). Informed consent was obtained from all participants.