Vector-borne zoonotic bacteria in Tunisia: from fragmented data to an integrated One Health surveillance framework

Vector-borne and vector-associated bacterial zoonoses represent an important component of infectious disease epidemiology in Tunisia. This review synthesizes available evidence on major bacterial groups, including Rickettsia, Bartonella, Anaplasma, Ehrlichia, Borrelia, Coxiella burnetii, and other arthropod-associated bacteria, using a One Health framework integrating human, animal, vector, wildlife, and environmental compartments. The available evidence reveals heterogeneous levels of knowledge across bacterial taxa. Rickettsia represents the most established tick-associated zoonotic system, with Rickettsia conorii as the main confirmed human pathogen, while additional species have been detected mainly in arthropods or animal-associated settings. Bartonella has a significant clinical association with blood culture-negative endocarditis, whereas other bacterial groups show predominantly animal- or vector-associated evidence. Coxiella burnetii remains a major zoonotic concern linked to livestock, camels, reproductive materials, and environmental exposure. For Borrelia, Anaplasma, and Ehrlichia, substantial evidence of circulation exists in vectors and animals, but human clinical relevance remains incompletely characterized. Across bacterial groups, a recurrent limitation is the imbalance between molecular detection in vectors or animal hosts and confirmed evidence of transmission or human disease. Detection of bacterial DNA should therefore be interpreted cautiously and not considered equivalent to infection, reservoir competence, or vectorial transmission. Additional arthropod-associated bacteria identified through microbiome studies require further investigation to clarify their ecological significance. The Tunisian evidence base demonstrates active circulation of diverse vector-associated bacteria but remains fragmented across clinical, veterinary, entomological, and ecological domains. Strengthening integrated One Health surveillance through coordinated human diagnosis, animal sentinel systems, vector monitoring, environmental investigations, and advanced molecular approaches is essential to better assess zoonotic risks in Tunisia and the wider North African-Mediterranean region.