Bordetella holmesii Prosthetic Valve Endocarditis: A Case Report and Review

Bordetella holmesii: Still Emerging and Elusive 20 Years On

Since the first description of Bordetella holmesii in 1995, almost 100 publications have contributed to the increasing knowledge of this emerging bacterium. Although first reported to induce bacteremia mainly in immunocompromised patients, it has also been isolated in healthy persons and has shown the capacity to induce pertussis-like symptoms and other clinical entities, such as meningitis, arthritis, or endocarditis. Respiratory diseases are generally less severe than those induced by Bordetella pertussis. However, B. holmesii was found to have a higher capacity of invasiveness given the various infection sites in which it was isolated. The diagnosis is difficult, particularly as it is a slow-growing organism but also because respiratory infections are systematically misdiagnosed as B. pertussis. Treatment is delicate, as its susceptibility to macrolides (prescribed in respiratory infections) and ceftriaxone (used in invasive disease) is challenged. Regarding prevention, there is no consensus on prophylactic treatment following index cases and no vaccine is available. Epidemiological data are also sparse, with few prevalence studies available. In this chapter, we provide an overview of the current state of knowledge on B. holmesii.

Invasive Bordetella holmesii infections

Bordetella holmesii is a rare cause of invasive human disease. The fastidious and unusual nature of this organism makes routine isolation and identification challenging. We report two cases of B. holmesii bacteremia that were rapidly identified by matrix-assisted laser desorption-ionization time-of-flight mass spectrometry (MALDI-TOF MS) when standard techniques failed to provide speciation. There are no current standards for susceptibility testing or treatment recommendations. The rare occurrence and challenges in identifying this pathogen led us to perform a comprehensive review of the epidemiology, clinical presentations, and treatment options for this potentially invasive pathogen.

Bordetella holmesii endocarditis: case report and review of literature

The second case of Bordetella holmesii endocarditis in a pediatric patient is presented. This patient had a prosthetic mitral valve and asplenia. He was successfully treated with 6 weeks of intravenous meropenem. We review all 9 other reported cases of endocarditis and summarize treatment and outcome. Five were immunocompromised and 6 had predisposing cardiac conditions.

Bordetella holmesii: an under-recognised Bordetella species

Bordetella holmesii, first described in 1995, is believed to cause both invasive infections (bacteraemia, meningitis, endocarditis, pericarditis, pneumonia, and arthritis) and pertussis-like symptoms. Infection with B holmesii is frequently misidentified as being with B pertussis, the cause of whooping cough, because routine diagnostic tests for pertussis are not species-specific. In this Review, we summarise knowledge about B holmesii diagnosis and treatment, and assess research needs. Although no fatal cases of B holmesii have been reported, associated invasive infections can cause substantial morbidities, even in previously healthy individuals. Antimicrobial treatment can be problematic because B holmesii's susceptibility to macrolides (used empirically to treat B pertussis) and third-generation cephalosporins (often used to treat invasive infections) is lower than would be expected. B holmesii's adaptation to human beings is continuing, and virulence might increase, causing the need for better diagnostic assays and epidemiological surveillance.