Incidence, molecular characterisation and epidemiology of Oriental rat flea, Xenopsylla cheopis (Rothschild, 1903) in synanthropic rodent hosts.

Background objectives: Rodents and arthropod vectors transmit zoonotic pathogens like Yersinia pestis, Rickettsia typhi etc. posing a threat to both veterinary and public health. The primary aim of this study was to record the incidence of rat fleas, a vector for plague and murine typhus on synanthropic rodents, their epidemiology and molecular characterization.

Methods: A comprehensive survey of synanthropic rodents viz. Bandicota bengalensis (190), Rattus rattus (201), and Tatera indica (180) across various habitats, including crop fields, poultry farms, fish markets, residential areas, shops, and railway stations in different seasons, was conducted to record the incidence of rat fleas. Fleas collected were identified morphologically, followed by molecular confirmation through PCR amplification of 28S rRNA gene and phylogenetic analysis.

Results: Morphological and molecular analyses confirmed the flea species as Xenopsylla cheopis. The nucleotide sequence obtained was submitted to GenBank (LC626773). The infestation rate varied among rodent species, with R. rattus exhibiting the highest prevalence (55.72%), followed by B. bengalensis (37.36%) and T. indica (6.67%). Adult male rodents were more frequently infested. Seasonal variations revealed peak infestations during winter (36.41%), particularly among rodents from poultry farms (63.33%). R. rattus posed the highest risk for disease transmission (8.35), followed by B. bengalensis (5.60).

Interpretation conclusion: This study highlights the critical role of R. rattus and B. bengalensis in spreading pathogens as primary hosts for X. cheopis. These findings emphasize the need for integrated vector surveillance and targeted control measures to reduce the risk of flea-borne zoonoses in urban and peri-urban areas.