PhD defence Carl Boodman

Supervisors

• Prof. dr. Johan Van Griensven (ITM)

• Prof. dr. Sandra Van Puyvelde (University of Antwerp)

PhD awarding university

University of Antwerp, Faculty of Medical Sciences and Health, Vaccine & Infectious Disease Institute (VAXINFECTIO) 

Abstract

How does a bacterium historically associated with the trenches of the First World War continue to cause severe disease today, and how can its hidden transmission be detected?

This thesis investigates the contemporary epidemiology, clinical manifestations, and detection of Bartonella quintana, a louse-borne bacterium that causes persistent bloodstream infection and endocarditis, an infection of the heart valves. It combines systematic reviews, laboratory studies, outbreak investigations, and community-based surveillance across diverse geographic and socioeconomic settings. 

Systematic reviews establish the global distribution of infection and highlight diagnostic delays and severe complications of endocarditis. Studies of persistent fever in low- and middle-income countries identify evidence of overlooked Bartonella and Coxiella infections, while demonstrating limitations of antibody testing. Canadian investigations document infection in remote Indigenous communities and transmission through organ transplantation, informing changes in donor assessment and recipient management. Community-based studies in Canada and Belgium evaluate testing lice and dried blood samples as practical approaches to detecting hidden bacterial circulation among people experiencing homelessness. In Belgium, B. quintana DNA was detected in lice from approximately one in five participants.

Together, these findings demonstrate that B. quintana remains an underrecognized cause of serious and fatal illness whose persistence reflects social inequalities. The thesis highlights opportunities to improve surveillance while emphasizing that effective prevention requires better access to adequate housing, water, and hygiene.