Detection and incidence of Bordetella holmesii in respiratory specimens from patients with pertussis-like symptoms in New South Wales, Australia

Winkie Fong; Verlaine Timms; Nadine Holmes; Vitali Sintchenko

doi:10.1016/j.pathol.2017.10.014

Detection and incidence of Bordetella holmesii in respiratory specimens from patients with pertussis-like symptoms in New South Wales, Australia

Pathology. 2018 Apr;50(3):322-326. doi: 10.1016/j.pathol.2017.10.014. Epub 2018 Feb 15.

Authors

Winkie Fong¹, Verlaine Timms², Nadine Holmes¹, Vitali Sintchenko³

Affiliations

¹ Centre for Infectious Diseases and Microbiology - Public Health, Institute of Clinical Pathology and Medical Research - NSW Health Pathology, Westmead Hospital, NSW, Australia; Marie Bashir Institute for Infectious Diseases and Biosecurity, The University of Sydney, Sydney, NSW, Australia.
² Centre for Infectious Diseases and Microbiology - Public Health, Institute of Clinical Pathology and Medical Research - NSW Health Pathology, Westmead Hospital, NSW, Australia.
³ Centre for Infectious Diseases and Microbiology - Public Health, Institute of Clinical Pathology and Medical Research - NSW Health Pathology, Westmead Hospital, NSW, Australia; Marie Bashir Institute for Infectious Diseases and Biosecurity, The University of Sydney, Sydney, NSW, Australia. Electronic address: wfon4473@uni.sydney.edu.au.

PMID: 29455870
DOI: 10.1016/j.pathol.2017.10.014

Abstract

Bordetella pertussis, the aetiological agent of whooping cough is routinely diagnosed by polymerase chain reaction (PCR) directed at IS481, an insertion sequence target also found in Bordetella holmesii. Recent reports have suggested that B. holmesii infections can be misdiagnosed as pertussis, which can have a significant impact on public health surveillance. This study investigated the presence of B. holmesii in B. pertussis positive clinical samples, in order to determine the incidence of B. holmesii. Clinical cases of pertussis diagnosed by IS481-specific PCR between October 2008 and March 2016 in New South Wales were included. Bordetella holmesii was detected through the simultaneous amplification of IS481 and B. holmesii specific insertions sequence, hIS1001. A total of 46 of 802 patients were identified to be positive for B. holmesii rather than B. pertussis, suggesting an incidence rate of 6.5% in 2009, 16.8% in 2010, 7.6% during 2013 and 8.1% during 2015. Bordetella holmesii infections were diagnosed during and between pertussis epidemics, however cases of B. holmesii and B. pertussis co-infections were not found. The predominant age group of B. holmesii infection was 11-18 years old, which was significantly different to the mean age of B. pertussis infections (0-6 years, p = 0.023). These findings revealed that B. holmesii was co-circulating alongside the B. pertussis epidemic for seven years, hidden from view, as B. holmesii infections have been diagnosed as B. pertussis. Confirmatory testing of B. pertussis positive samples for the presence of B. holmesii, especially during pertussis epidemics, should improve the quality of laboratory diagnosis and laboratory surveillance for pertussis. The presence of B. holmesii in Australia highlights the importance of testing for this pathogen and ongoing molecular surveillance that can guide the control of whooping cough.

Keywords: Bordetella holmesii; Bordetella pertussis; PCR; Pertussis.

MeSH terms

Bordetella / genetics*
Bordetella / isolation & purification
Bordetella Infections / diagnosis*
Bordetella Infections / epidemiology*
Bordetella Infections / microbiology*
Bordetella pertussis
DNA, Bacterial / analysis
Humans
Incidence
New South Wales / epidemiology
Retrospective Studies

Substances

DNA, Bacterial