Bartonella and Afipia

Bartonella

Classification. The genus Bartonella includes, among others, the species

B. bacilliformis, B. quintana, B. henselae, and B. clarridgeia.

Morphology and culture. Bartonella bacteria are small (0.6-1 µm), Gram- negative, frequently pleomorphic rods. Bartonellae can be grown on culture mediums enriched with blood or serum.

Diagnosis. Special staining techniques are used to render bartonellae visible under the microscope in tissue specimens. Growth in cultures more than seven days. Amplification of specific DNA in tissue samples or blood, followed by sequencing. Antibody assay with IF or EIA.

Therapy. tetracyclines, macrolides.

Epidemiology and prevention. Oroya  fever (also known as Carrion disease) is observed only in humans and is restricted to mountain valleys with elevations above 800 m in the western and central Cordilleras in South America because an essential vector, the sand fly, lives only there. Cat scratch disease, on the other hand, is known all over the world. It is transmitted directly from cats to humans or indirectly by cat fleas. The cats involved are usually not sick. Table 4.14 lists the pathogens and clinical pictures for the various bartonel- loses.

Afipia felis

The bacterial species Afipia (Armed Forces Institute of Pathology) felis was discovered several years ago. At first, it appeared that most cases of cat scratch disease were caused by this pathogen. Then it turned out that the culprit in those cases was usually either B. henselae or B. clarridgeia and that Afipia felis was responsible for only a small number. Afipia felis and B. henselae cat scratch infections present with the same clinical symptoms. Most cases of A. felis infections clear up spontaneously without antibiotic therapy. Should use of an antibiotic be clinically indicated, a tetracycline (or in severe cases a carbapenem or aminoglycoside) would be appropriate.