Rickettsia felis, Bartonella henselae, and B. clarridgeiae, New Zealand.

To the Editor: The cat flea (Ctenocephalides fells fells Bouche, 1935) is a ubiquitous parasite of domestic and wild animals that also feeds readily on people. Recent studies have implicated the cat flea as a vector of new and emerging infectious diseases (1). To determine the pathogens in C.felis in New Zealand, we collected 3 cat fleas from each of 11 dogs and 21 cats at the Massey University Veterinary Teaching Hospital from May to June 2003. The fleas were stored in 95% alcohol until they were identified by using morphologic criteria and washed in sterile phosphate-buffered saline. The DNA from each flea was extracted individually by using the QiaAmp Tissue Kit (QIAGEN Ltd., Hilden, Germany), according to the manufacturer's instructions. When polymerase chain reaction (PCR) was performed with primers for gltA and rOmpA as described (2), products were obtained with DNA from 15 (15%) of the fleas. The sequences of the products were identical to those of Rickettsia felis (GenBank AF191026) with infected fleas taken from both dogs (3/11; 27%) and cats (7/21; 33%). When PCR was performed with primers for the 16S-23S rDNA interspacer region as described (3), products were obtained with DNA of four fleas. The sequences of the products from three fleas (from two cats) were identical to that of Bartonella henselae (GenBank AF312495), and the sequence of the product of one flea (from a cat) was identical to that of B. clarridgeiae (GenBank AF 167989).

Our study is the first to identify R. felis in Oceania. The organism is a recently described human pathogen, and infections with this spotted fever group rickettsia have already been reported in 11 persons: 4 persons in the United States, 2 persons in Brazil, 4 persons in Europe, and 1 person in Thailand. The symptoms of the patients were nonspecific and included fever, headache, and rash. Diagnoses were made by sequencing products obtained by PCR with primers for the 17-kDa protein (4), citrate synthase (4), and PS 120 protein (5) genes. R. fells has been established in tissue culture (XTC-2 and Vero cells) (6), and serologic testing has been used to diagnose infections (5). Reports indicate that patients respond rapidly to doxycycline therapy (5), and in vitro studies have shown the organism is susceptible to rifampin, thiamphenicol, and fluoroquinolones.

B. henselae is an agent of catscratch disease, bacillary angiomatosis, bacillary peliosis, endocarditis, bacteremia, and various neurologic and ocular conditions. Cats are the reservoir hosts, and contact with cats and their fleas is an established risk factor for most infections. Although B. henselae has been isolated from 17% of domestic cats in New Zealand (7), only two human infections have been reported in the country; neuroretinitis was diagnosed in both patients (8). In neighboring Australia, however, cat-scratch disease, bacillary angiomatosis, and endocarditis have been diagnosed in numerous patients. Cats are also the reservoir hosts of B. clarridgeiae which has been implicated as an agent of cat-scratch disease in humans and aortic valve endocarditis and hepatic disease in dogs (9). The organism has been found in cat fleas (as great as 17%) in Europe (1), and although we found only one flea infected with B. clarridgeiae in New Zealand, this description is the first of the organism in Oceania. However, B. clarridgeiae has been found in domestic cats in nearby Indonesia and the Philippines (10).

Our findings add to the accumulating data on R. felis, B. henselae, and B. clarridgeiae and should alert medical workers in New Zealand, a common tourist destination, to the possibility that their patients may be infected with these organisms.

References

(1.) Rolain JM, Franc M, Davoust B, Raoult D. Molecular detection of Bartonella quintana, B. koehlerae, B. henselae, B. clarridgeiae, Rickettsia felis, and Wolbachia pipientis in cat fleas, France. Emerg Infect Dis 2003;9:338-42.

(2.) Roux V, Ranult D. Inter-and intraspecies identification of Bartonella (Rochalimaea) species. J Clin Microbiol 1995;33:15734.

(3.) Fournier PE, Roux V, Raoult D. Phylogenetic analysis of spotted fever group rickettsiae by study of the outer surface protein rOmpA, int J Syst Bacteriol 1998;48:83949.

(4.) Schriefer ME, Sacci JB Jr., Dumler JS, Bullen MG, Azad AF. identification of a novel rickettsial infection in a patient diagnosed with murine typhus. J Clin Microbiol 1994;32:949-54.

(5.) Richter J, Fournier PE, Petridou J. Haussinger D, Raoult D. Rickettsia fees infection acquired in Europe and documented by polymerase chain reaction. Emerg Infect Dis 2002;8:207-8.

(6.) Raoult D, La Scola B, Enea M, Fournier PE, Roux V, Fenollar F, et al. A flea-associated Rickettsia pathogenic for humans. Emerg Infect Dis 2001;7:73-81.

(7.) Joseph AK, Wood CW, Robson JM, Paul SL, Morris AJ. Bartonella henselae baeteremia in domestic cats from Auckland. N Z Vet J 1997;45:185-7.

(8.) Dai S, Best S, St John M. Bartonella henselae neuroretinitis in cat scratch disease. N Z Med J 2001;114:360-1.

(9.) Gillespie TN, Washabau RJ, Goldschmidt MH, Cullen JM, Rogala AR, Breitschwerdt EB. Detection of Bartonella henselae and Bartonella clarridgeiae DNA in hepatic specimens from two dogs with hepatic disease. J Am Vet Med Assoc 2003;222:47-51.

(10.) Chomel BB, Carlos ET, Kasten RW, Yamamoto K, Chang CC, Carlos RS, et al. Bartonella henselae and Bartonella clarridgeiae infection in domestic cats from the Philippines. Am J Trop Med Hyg 1999;60:593-7.

Address for correspondence: Patrick Kelly, Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Private Bag 11 222, Palmerston North, New Zealand; fax: [phone]; email: [e-mail]

Patrick J. Kelly, * Natalie Meads, * Anita Theobald, * Pierre-Edouard Fournier, ([dagger]) and Didier Raoult ([dagger])

* Massey University, Palmerston North, New Zealand; and ([dagger]) Faculte de Medecine, Marseille, France