Is vertical transmission the only pathway for Rickettsia felis?

The genus Rickettsia encompasses several species grouped into two main clusters, Typhus and the Transitional groups. The latter group contains Rickettsia felis, an endosymbiont of several arthropods with an uncertain human pathogenicity and whose most efficient transmission mechanism described thus far is transovarial. The aim of this study was to evaluate whether this pathway exists using phylogenetic analysis and partial sequences of the 17kDa and gltA genes and comparing them with host phylogeny using the cytb region. This is the first study that evaluates the vertical transmission of R. felis. In general, both phylogenies of R. felis showed no polytomies, as suspected if this pathway was the only pathway occurring. When phylogenies of the invertebrates and the gltA of R. felis were compared for strong coevolutionary insight, intricate relationships were observed, suggesting that other transmission pathways must occur, such as horizontal transmission. Further studies are needed to determine which other transmission routes occur in hematophagous arthropods.

Fleas (Siphonaptera) of domestic and wild animals in extreme northeastern Algeria: first inventory, hosts, and medical and veterinary importance

Fleas are an important member of the North African entomofauna. An understanding of the risks of flea-borne diseases to public and veterinary health can be gained with surveys of their abundance, distribution, and hosts. The aims of this study were to make an initial assessment of flea (Siphonaptera) species collected from a selected number of mammalian hosts in Algeria and debate their medical and veterinary importance. To do so, an entomological survey was conducted on several animal species (goats, dogs, cats, rabbits, hedgehogs, and mongooses) in six localities of El Tarf region located in extreme northeastern Algeria. During the survey, flea specimens were collected from hosts, stored in alcohol, and identified using a taxonomic key. More than 1,200 specimens were collected and identified; including four species: Ctenocephalides felis, Ctenocephalides canis, Pulex irritans, and Archaeopsylla erinacei (s.l.). Goats and dogs were the most infested animals, followed by cats and hedgehogs. Ctenocephalides felis was the most prevalent flea among all infested animals, with 631 collected specimens, followed by Pulex irritans with 433 samples. Overall, this study is an initial assessment of flea species recovered from selected common mammals in northeastern Algeria.

Cat Owners' Perceptions toward Flea Infestation and Flea-borne Diseases: Impact for Public Health and Community Awareness

A structured questionnaire was distributed to a total of 531 cat owners in Peninsular Malaysia to evaluate their perceptions toward fleas and flea-borne diseases (FBD) using a knowledge-attitude-practice (KAP) approach. This study showed that majority of cat owners (50.5%) had a moderate level of knowledge on fleas, while 65.3% of them had a relatively low level of knowledge on FBD. However, most of them had positive attitudes (87.9%) and good practices (94.5%) toward efforts on prevention from flea infestation and FBD. Statistical analysis showed significant associations between knowledge on fleas and FBD toward demographic and pet ownership profiles of the respondents. Educated cat owners from urban area were more likely to have positive attitudes toward prevention of fleas and FBD. Female cat owners with monthly income of RM 5,001-7,000 ($1143-1600) were more likely to have good practices. Middle-aged cat owners showed the highest odds toward both positive attitudes and good practices. Correlation analyses indicated significant linear relationships between both knowledge, which were also associated with attitudes, but not with practices.

Zoonotic Bacteria in Fleas Parasitizing Common Voles, Northwestern Spain

We detected Francisella tularensis and Bartonella spp. in fleas parasitizing common voles (Microtus arvalis) from northwestern Spain; mean prevalence was 6.1% for F. tularensis and 51% for Bartonella spp. Contrasted vector–host associations in the prevalence of these bacteria suggest that fleas have distinct roles in the transmission cycle of each pathogen in nature.

Assessing Cat Flea Microbiomes in Northern and Southern California by 16S rRNA Next-Generation Sequencing

Flea-borne diseases (FBDs) impact both human and animal health worldwide. Because adult fleas are obligately hematophagous and can harbor potential pathogens, fleas act as ectoparasites of vertebrates, as well as zoonotic disease vectors. Cat fleas (Ctenocephalides felis) are important vectors of two zoonotic bacterial genera listed as priority pathogens by the National Institute of Allergy and Infectious Diseases (NIAID-USA): Bartonella spp. and Rickettsia spp., causative agents of bartonelloses and rickettsioses, respectively. In this study, we introduce the first microbiome analysis of C. felis samples from California, determining the presence and abundance of relevant pathogenic genera by characterizing the cat flea microbiome through 16S rRNA next-generation sequencing (16S-NGS). Samples from both northern (NoCal) and southern (SoCal) California were assessed to expand current knowledge regarding FBDs in the state. We identified Rickettsia and Bartonella, as well as the endosymbiont Wolbachia, as the most abundant genera, followed by less abundant taxa. In comparison to our previous study screening Californian cat fleas for rickettsiae using PCR/digestion/sequencing of the ompB gene, the 16S-NGS approach applied herein showed a 95% level of agreement in detecting Rickettsia spp. There was no overall difference in microbiome diversity between NoCal and SoCal samples. Bacterial taxa identified by 16S-NGS in this study may help to improve epidemiological investigations, pathogen surveillance efforts, and clinical diagnostics of FBDs in California and elsewhere.