Molecular and Serological Prevalences of Vector-Borne Diseases in Cats from Madrid, Spain
T. Ayllón1; P.P.V.P. Diniz2; A. Sainz1; A. Villaescusa1; E.B. Breitschwerdt2
Anaplasma phagocytophilum (Aph), Bartonella henselae (Bh) and Ehrlichia canis (Ec) are considered emerging or re-emerging diseases in human and veterinary medicine worldwide. In Spain, human bartonellosis, ehrlichiosis and, recently, anaplasmosis have been reported. Classically, non-specific clinical and laboratory abnormalities are induced by infection with these organisms in animals and human patients, which leads to misdiagnosis and artificially low estimates of disease prevalence. Furthermore, limited epidemiological data is available for these organisms in cats from Spain.
The aim of this study was to determine the molecular and serological prevalences of Aph, Bh and Ec in 155 cats examined at the Veterinary Teaching Hospital in Madrid, Spain. Between September, 2005 and May, 2006, blood samples obtained from cats for any diagnostic purpose were entered into the study. Epidemiological data recorded for each cat included: breed, gender, age, access to outdoor environment, contact with other animals, arthropod-exposure history, endoparasite treatments, previous anti-rickettsial treatments and travel history. Antibody reactivity against Aph, Bh and Ec antigens, was determined using an indirect immunofluorescence antibody (IFA) test with cut-off titers of 1:40 for Aph and Ec, and 1:64 for Bh. Using PCR, Aph and Ec DNA was amplified targeting the 16S rRNA and groESL genes. Bh DNA was amplified targeting the intergenic transcribed spacer (ITS) region.
Seroprevalences were: Aph: 13.5% (21 cats), and Bh: 5.2% (8 cats) and Ec: 11% (17 cats). Two cats were Aph and Ec seroreactive, two cats were Aph and Bh seroreactive and one cat was Bh and Ec seroreactive. Neither Anaplasma spp. nor Ehrlichia spp. DNA was amplified from any sample. Bartonella spp. DNA was amplified, cloned and sequenced from one sample. When consensual sequences were compared with other GenBank sequences (Nov/2007), the Spanish cat ITS sequence was 100% homologous to B. henselae Houston-1 (BX897699). With the exception of an association between the Aph seroreactivity and pure breed cats (p=0.024), there were no statistical associations between Aph, Bh, or Ec seroreactivity and epidemiological parameters. These results indicate that a portion of the cat population examined at a Veterinary Teaching Hospital in Madrid, Spain, has been exposed to the vector-borne organisms evaluated in this study. Although seroreactivity to Anaplasma spp. and Ehrlichia spp. was detected in some cats, there was no molecular evidence of active infection with either genus. Surprisingly, the B. henselae serological and molecular prevalence was comparatively low in this cat population. Demographics of the study population, including the majority of subjects being client-owned cats, and changes in vector distribution may justify disagreement with prevalences encountered in other locations in Spain. Since this hospital population does not represent the regional or national feline population, these data cannot be extrapolated to other cat populations or other regions of Spain.