The epidemiology of Moraxella catarrhalis

Abstract

Moraxella catarrhalis is a pathogen of increasing importance and is recognised as one of the most common causes of respiratory tract infection. In particular, it is known for its role in causing otitis media (OM) in children and exacerbation of chronic obstructive pulmonary disease (COPD) in adults. Increasing interest in the development of vaccines against M. catarrhalis necessitates a better understanding of carriage and disease epidemiology; to inform both vaccine development and implementation strategies. To that end a community wide carriage study (the Solent SMART Study) was designed and undertaken to investigate the epidemiology of M. catarrhalis, including risk factors for carriage. As the acquisition of new strains of M. catarrhalis is a known risk factor for exacerbation of COPD, a better understanding of the carriage of M. catarrhalis in those with COPD is of benefit. Care/nursing home residents are a cohort with no prior data related to M. catarrhalis. As a cohort who often suffer from COPD and frequent RTI, there is certainly a need to investigate M. catarrhalis carriage in this vulnerable group. Carriage of M. catarrhalis was therefore investigated in these cohorts of interest. In total 1701 participants were recruited, from which 228 isolates of M. catarrhalis were obtained. In total 8% (CI: 6.7-9.4%) of community-based participants, 19% (CI: 11.0-29.4%) of care/nursing home residents and 4.7% (CI: 1.6-10.7%) of those with COPD carried M. catarrhalis. Carriage site, age, microbial co-carriage, up-to-date vaccination status, recent/concurrent cold and recent use of antibiotics were all significantly associated with the carriage of M. catarrhalis. Antimicrobial resistance was investigated amongst the M. catarrhalis isolated from this study and isolates from disease, providing data which could inform public health strategies. Both carriage and disease isolates showed low levels of resistance, with the most resistance seen for ciprofloxacin. Lastly the prevalence of carriage and AMR over time was investigated using supplementary data from another study. A significant increase in carriage was observed over recent years, however prevalence of AMR remained low with no significant change. This study is important as it provides an insight into the epidemiology of M. catarrhalis, as well as factors that perhaps impact the disease potential of this common pathogen. It also addresses the paucity of data in certain ages and cohorts and helps provide clarity where existing research is inconsistent.

More information

Identifiers

ORCID for Stuart C. Clarke: orcid.org/0000-0002-7009-1548

Catalogue record

Export record