From cat scratch disease to endocarditis, the possible natural history of Bartonella henselae infection

Abstract

Background: Most patients with infectious endocarditis (IE) due to Bartonella henselae have a history of exposure to cats and pre-existing heart valve lesions. To date, none of the reported patients have had a history of typical cat scratch disease (CSD) which is also a manifestation of infection with B. henselae.

Case presentation: Here we report the case of a patient who had CSD and six months later developed IE of the mitral valve caused by B. henselae.

Conclusion: Based on this unique case, we speculate that CSD represents the primary-infection of B. henselae and that IE follows in patients with heart valve lesions.

Figure 1

Valve of our patient with B. henselae endocarditis. Resected valve with B. henselae infection showing large and non-inflammatory vegetation on the valvular surface (A, hematoxylin-eosin, original magnification × 100). The diagnosis of vegetation was made by the presence of fibrinous material with numerous darkly stained bacilli (arrows in Figure 1B) consistent with Bartonella, organized in numerous clusters (B, Warthin-Starry silver staining, original magnification × 400). The bacteria (arrows in Figure 1C) are detected by immunohistochemical analysis in an extracellular location inside the valvular vegetation (C, polyclonal antibody anti-B. henselae with hematoxylin counterstain, original magnification × 200). Resected lymph node showed a necrotizing lymphadenitis. Numerous microabscesses composed of fragmented neutrophils were observed in homogenous necrotic areas. Necrotic regions were surrounded by a ring of macrophages and epithelioid histiocytes to form stellate inflammatory granulomas consistent with cat-scratch disease (D, hematoxylin-eosin, original magnification × 100).

Figure 2

Western blotting using Bartonella antigen of a patient with IE. Western blotting was performed with the first serum sample from May 2005 at a 1:200 dilution. Molecular masses (in kilodaltons) are given on the left. A through C: Serum was analyzed by using B. quintana (lane 1), B. henselae (lane 2), B. elizabethae (lane 3), B. vinsonii subsp. Berkhoffii (lane 4) and B. alsatica (lane 5) antigens. (A) Untreated serum. (B) B. quintana-adsorbed serum. Antibodies to the B. henselae remained. (C) B. henselae-adsorbed serum. All antibodies were removed.

Figure 3

Natural history of B. henselae endocarditis. 1: Cycle of B. henselae between cat and Ctenocephalides felis. 2: Contamination of human being. 3: Clinical presentation in non immunocompromised patient with contact with cat. 4: Clinical presentation contact in immunocompromised with contact with cat. 5: Predisposing vavular lesion. 6: Endocarditis.