Detection of Rickettsia and Bartonella in Fleas and Ticks Collected from Pets at Veterinary Clinics in Georgia, United States

Many human infections are transmitted through contact with household pets. The purpose of this cross-sectional study was to determine the occurrence of ticks and fleas on pets (dogs and cats) in local veterinary clinics in Statesboro, Georgia. We screened ectoparasites for Rickettsia and Bartonella and assessed owner knowledge and practices related to tick- and flea-borne diseases. Ectoparasites were collected and identified using standard taxonomic keys, and their genomic DNA was extracted. Three TaqMan assays were used to test ectoparasites for flea-borne Rickettsia DNA. Nested PCR targeting riboflavin synthase encoding gene (ribC) was used to detect Bartonella species DNA. Restriction fragment length polymorphism analysis and sequencing were used to identify the microorganisms detected. Upon providing written consent, owners completed a self-administered questionnaire to provide information concerning their knowledge and practices about vector-borne diseases. Data from 27 pets were collected from 2 veterinary clinics during September to December 2014. A total of 58 ectoparasites including fleas (n = 51) and ticks (n = 7) were collected from 19 cats and dogs. The cat flea, Ctenocephalides felis (n = 44), was the predominant flea species followed by Pulex sp. (n = 7). All ticks were Ixodes scapularis. Using PCR, RFLP, and sequencing, it was determined that the majority of cat fleas contained DNA of known human pathogens, including Rickettsia asembonensis (72.5%), Rickettsia felis (5.9%), Bartonella henselae (2%), and Bartonella quintana (7.8%). DNA of B. quintana was also detected in 2 Pulex sp. fleas and 2 ticks. Two animals had ectoparasites co-infected with Rickettsia and Bartonella. Most owners (95.7%) knew that fleas can transmit animal disease agents, but they were less aware that fleas can spread diseases to humans, and only 12.5% of owners knew about cat scratch disease. Our data indicate that there is a risk of flea- and tick-borne zoonotic infections in households owning cats and dogs. Educational materials, vector-control preventive measures, and appropriate personal attitudes and practices are needed to ensure public health safety and wholesome interactions with pets.