Serological evidence of exposure to Rickettsia felis and Rickettsia typhi in Australian veterinarians

Abstract

Background Rickettsia felis and Rickettsia typhi are emerging arthropod-borne zoonoses causing fever and flu-like symptoms. Seroprevalence and risk factors associated with exposure to these organisms was explored in Australian veterinarians.MethodsOne hundred and thirty-one veterinarians from across Australia were recruited to participate in a cross-sectional survey. Veterinarians provided a single blood sample and answered a questionnaire on potential risk factors influencing their exposure to R. felis and R. typhi. Indirect microimmunofluorescence antibody testing (IFAT) was used to identify evidence of serological exposure of the participants to R. felis and R. typhi. Results were analyzed and a logistical regression model performed to predict risk factors associated with seropositivity.ResultsIn total, 16.0% of participants were seropositive to R. felis, 4.6% to R. typhi and 35.1% seropositive to both, where cross-reactivity of the IFAT between R. felis and R. typhi precluded a definitive diagnosis. Veterinarians residing within the south-eastern states of Victoria and Tasmania were at a higher risk of exposure to R. felis or generalised R. felis or R. typhi exposure. Older veterinarians and those that recommended flea treatment to their clients were found to be significantly protected from exposure.ConclusionsThe high exposure to R. felis amongst veterinary professionals suggests that flea-borne spotted fever is an important cause of undifferentiated fever conditions that may not be adequately recognized in Australia.

The epidemiology of Rickettsia felis infecting fleas of companion animals in eastern Australia

“…Given the growing significance of R. felis in Australia, the aim of this study was to ascertain the prevalence, primary species and genotype(s) of R. felis infecting fleas isolated from dogs and cats in coastal eastern Australia. In our previously published study, veterinarians from temperate, cooler regions of south-eastern Australia were found to be at significantly higher odds of exposure to R. felis than their counterparts in warmer regions [ 13 ]. We therefore hypothesize that geographical or climatic variables influence R. felis infection rates in fleas, which in turn could influence transmission risk to humans across coastal eastern Australia.…”

The molecular detection of Anaplasma phagocytophilum and Rickettsia spp. in cat and dog fleas collected from companion animals

“…In our research, the prevalence of this pathogen was 3% in cat and 7% in dog fleas. According to our knowledge, fleas may take part in natural transmission of R. typhi and R. felis (see Eremeeva et al 2008, Teoh et al 2017, as well as R. rickettsii in experimental conditions (Dobler andPfeffer 2011, Blanton andWalker 2017). A study from the Netherlands showed occurrence of Rickettsia helvetica DNA in two unknown species of fleas collected from rodents (Sprong et al 2009).…”

ConcomitantPlasmodium vivaxmalaria and murine typhus infection with pulmonary involvement

“…The positive IFA to Rickettsia typhi should be caution with cross reactivity among R. prowazekii , R. felis and R. rickettsii. 11 However, R. prowazekii , R. felis and R. rickettsii are not endemic in Thailand. Both malaria and murine typhus are endemic in Southeast Asia, especially in Thailand.…”