Background: Ixodid ticks are critical vectors of pathogens affecting human, livestock, and wildlife health. In tropical regions, landscape heterogeneity is a key driver of tick–host associations, yet comprehensive studies across diverse habitats remain limited. Methods: This study investigated tick infestations on a wide range of animal hosts across four major habitat types comprising natural forests, oil palm plantations, rural villages, and urban areas in Peninsular Malaysia from 2022 to 2023. Results: Of 1277 hosts of 38 families and 79 species examined, 270 (21.1%) were infested with 1985 ixodid ticks, representing 16 ixodid species. The most abundant tick species were Haemaphysalis wellingtoni (44.7%), Amblyomma cordiferum (19.7%), and H . semermis (9.6%). Network and correspondence analyses revealed distinct tick–host–habitat associations: A. cordiferum , H. semermis , H . hystricis , and Ixodes granulatus were strongly associated with natural forests, whereas H. wellingtoni predominated in oil palm plantations and rural villages on domestic and jungle fowl ( Gallus gallus domesticus and Gallus gallus ). Wild boar ( Sus scrofa ) hosted the most diverse tick species, particularly in urban and rural settings. Notably, A . varanense exhibited strict specificity to reptiles. Conclusions: These findings demonstrate the influence of habitat on tick–host interactions, offering critical insights for targeted surveillance and integrated One Health strategies to mitigate tick-borne disease risks in rapidly changing tropical ecosystems. Graphical

Chiggers (Acariformes: Trombiculidae) are ectoparasites of small mammals and important vectors of scrub typhus, yet their taxonomy and molecular diversity in Southeast Asia remain poorly resolved. This study represents the first DNA barcoding and phylogenetic assessment of chiggers from small mammals across Peninsular Malaysia, integrating mitochondrial (COI) and nuclear (28 S rDNA) genes. A total of 192 chiggers representing 11 morphospecies from six genera were sequenced, with tree topologies inferred using maximum likelihood and supported by multiple species delimitation methods. The COI gene discriminated five species as monophyletic, while analysis of the 28 S rDNA gene clarified phylogenetic relationships within Walchia and Leptotrombidium. Discordance between morphological and molecular boundaries in several taxa, particularly Gahrliepia fletcheri, Leptotrombidium deliense, and Walchiella oudemansi, suggests the existence of cryptic lineages and potential regional diversification. Importantly, this study provides the first molecular records for eight species, including the only barcodes from the genera Gahrliepia and Walchiella worldwide. These findings provide important resources for the molecular identification of Southeast Asian chiggers and underscore the need for integrative approaches combining morphology, molecular data, and biogeography to resolve complex species boundaries and improve vector surveillance for mite-borne diseases.

Urban stray cats are often associated with ectoparasites and zoonotic pathogens due to their unsanitary living conditions and lack of veterinary care. Fleas, especially Ctenocephalides spp., are competent vectors of Bartonella spp., a genus of emerging bacterial pathogens with both public health and veterinary relevance. This study investigated the presence of Bartonella DNA in ectoparasitic fleas infesting stray cats in various urban habitats within the Klang Valley, Malaysia. A total of 204 fleas were collected from 89 stray cats. Fleas were identified morphologically using established taxonomic keys under a light microscope and further validated through PCR amplification of the mitochondrial cytochrome c oxidase subunit I (cox1) gene. Detection of Bartonella spp. was conducted by targeting the citrate synthase (gltA) gene. All fleas were confirmed as Ctenocephalides felis, with an infestation prevalence of 39.33% among the cats sampled. Of 118 C. felis specimens tested, 86.44% were positive for Bartonella DNA, one of the highest worldwide and significantly surpassing previous Malaysian reports. Sequencing of 12 positive samples showed identities with B. claridgeiae (58.3%), B. henselae (25.0%), an uncultured Bartonella species (8.3%) and a Bartonella isolate from a dog in Chile (8.3%). These results highlight the significant presence of Bartonella, causative agent of cat-scratch disease in stray cats, emphasizing their potential role as urban reservoirs and vectors. The findings underscore the need for ectoparasite surveillance and zoonotic pathogen control as integral components of stray animal management in Malaysia’s urban settings.

Urban stray cats are often associated with ectoparasites and zoonotic pathogens due to their unsanitary living conditions and lack of veterinary care. Fleas, especially Ctenocephalides spp., are competent vectors of Bartonella spp., a genus of emerging bacterial pathogens with both public health and veterinary relevance. This study investigated the presence of Bartonella DNA in ectoparasitic fleas infesting stray cats in various urban habitats within the Klang Valley, Malaysia. A total of 204 fleas were collected from 89 stray cats. Fleas were identified morphologically using established taxonomic keys under a light microscope and further validated through PCR amplification of the mitochondrial cytochrome c oxidase subunit I (cox1) gene. Detection of Bartonella spp. was conducted by targeting the citrate synthase (gltA) gene. All fleas were confirmed as Ctenocephalides felis, with an infestation prevalence of 39.33% among the cats sampled. Of 118 C. felis specimens tested, 86.44% were positive for Bartonella DNA, one of the highest worldwide and significantly surpassing previous Malaysian reports. Sequencing of 12 positive samples showed identities with B. claridgeiae (58.3%), B. henselae (25.0%), an uncultured Bartonella species (8.3%) and a Bartonella isolate from a dog in Chile (8.3%). These results highlight the significant presence of Bartonella, causative agent of cat-scratch disease in stray cats, emphasizing their potential role as urban reservoirs and vectors. The findings underscore the need for ectoparasite surveillance and zoonotic pathogen control as integral components of stray animal management in Malaysia’s urban settings.