Molecular survey on vector-borne pathogens in urban and peri-urban rodents in Spain

Abstract

Rodents are key reservoirs and spillover hosts of major pathogens at the wildlife–domestic–human interface, playing a pivotal role in the eco-epidemiology of vector-borne diseases. Nevertheless, data on rodent infection by pathogens of animal and public health relevance remain limited, particularly in anthropized landscapes. This study aimed to evaluate the circulation of Leishmania infantum, Bartonella spp., and Hepatozoon spp. in rodent populations from anthropized areas in Spain, and to identify potential risk factors associated with infection by these pathogens. Spleen samples from 345 rodents—brown rats (Rattus norvegicus, n = 235), black rats (Rattus rattus, n = 62), and house mice (Mus musculus, n = 48)—collected throughout Spain were molecularly processed. Overall, 8.1 % (28/345; 95 % CI: 5.2–11.0) of rodents tested positive for at least one of the three pathogens. Leishmania infantum and Bartonella spp. were detected in 4.9 % and 3.2 % of the samples analysed, whereas Hepatozoon spp. infection was not detected. A significantly higher prevalence of L. infantum was found in house mice (12.5 %; P = 0.046; OR = 11.0) compared with black rats (1.6 %). Phylogenetic analysis of Bartonella spp. sequences revealed the presence of strains closely related to zoonotic species, particularly B. tribocorum, B. coopersplainsensis, B. rochalimae, and B. elizabethae. These findings indicate that rodents may contribute to the maintenance and transmission of some vector-borne zoonoses in anthropized areas of Spain, underscoring the need for strengthened surveillance and the implementation of control strategies to reduce the impact of rodent-borne pathogens on animal and public health.