Cat scratch disease (CSD) is an important zoonotic disease caused by Bartonella henselae. Cats become infected from exposure to infected fleas, and humans become infected when wounds, scratches, or other injuries are exposed to contaminated flea feces. Veterinarians are considered an at-risk population. The first human case of CSD was diagnosed in Taiwan in 1998, and a reference laboratory was established in 2001. In 2002, 295 blood or serum samples were collected from veterinarians, veterinary students, or veterinary technicians from Taiwan to determine the seropositivity of this population. In addition, 131 cats (30 pet cats, 37 breeding cats, 64 stray cats) were also screened. Human and cat blood was screened for Bartonella by using polymerase chain reaction. Isolation of Bartonella species from cat blood was attempted on chocolate agar plates. In the veterinary-associated samples, only 1.7% were seropositive. The prevalence rates of seropositivity and bacteremia in cats were 23.7% and 19.1%, respectively. In addition, 9.2% of cats were infected with 2 genotypes of Bartonella. Stray cats had the highest seropositivity, followed by pet cats. None of the cats from the breeding facility were seropositive; strict flea control was practiced.

COMMENTARY: The absence of seropositivity in breeding cats receiving strict ectoparasite control is interesting. The finding that stray cats had the highest seropositivity is not surprising and is yet another argument for control of free-ranging cats. CSD is a zoonotic disease; children are one of the most commonly affected populations. It is also important to note that seroprevalence of Bartonella species is associated with climatic factors; studies consistently show that it is most common in warm, humid climates. Given the warmer winters occurring in many regions of the United States, a strong argument can be made for year-round flea control for all pets.

Cat-scratch disease in veterinary-associated populations and in its cat reservoir in Taiwan. Chang C, Lee C, Maruyama S, et al. VET RES 37:565-577, 2006.