Systemic Cat Scratch Disease in Immunocompetent Adults: A Retrospective Case Series

BACKGROUND: Cat-scratch disease (CSD) has worldwide distribution and is the most frequent presentation of Bartonella henselae infection. Systemic CSD has mainly been reported in immunocompetent children and immunosuppressed adults. The aim of this study was to assess the clinical and laboratory findings of systemic CSD in immunocompetent adults. METHODS: A retrospective, cohort study of all consecutive, immunocompetent adult patients diagnosed with systemic CSD in 10-year period (2007–2016), was conducted at the University Hospital for Infectious Diseases Zagreb. Diagnosis was established by serology (IgM > 1:20, IgG > 1:256 or the fourfold rise in IgG titer in the convalescent phase) or polymerase chain reaction (PCR). RESULTS: In total, 32 cases were identified, 23 males, mean age of 35 ± 16 years, and majority of them (96.9%) recalled cat exposure. Twenty-one patients (65.6%) presented as fever of unknown origin, nine (28.1%) with hepatosplenic form, one patient with oculoglandular with prolonged fever and one with parotitis. Thirty-one (96.9%) patients were febrile for the 8.4 ± 5.6 days before hospitalization. Only 18.8% had concomitant lymphadenitis, 59.4% had headache, 28.1% abdominal pain and respiratory symptoms, 37.5% hepatomegaly and 31.3% splenomegaly on clinical examination. All except one patient had elevated CRP (70.8 ± 46.9), 12 patients (37.5%) had elevated WBC, 7 patients (21.8%) had elevated aminotranspherases, and 4 patients (12.5%) had multiple spleen abscesses. The diagnosis was established after 5.2 ± 5.3 days of hospitalization. Thirty (93.7%) received antibiotic treatment for the mean duration of 11.4 ± 5.2 days (18 (56.2%) macrolides (3 in monotherapy), 16 (50%) β-lactams (in combination), three (9.37%) doxycycline monotherapy, five (15.6%) fluoroquinolones (2 in monotherapy), four (12.5%) rifampicin, and five (15.6%) gentamicin always in combination). The mean duration of fever on antibiotic therapy was 7.3 ± 5.8 days. All patients were cured without sequelae regardless of treatment. CONCLUSION: Systemic CSD is not rare in healthy individuals. Since the diversity of the clinical manifestations in adults may be misleading, the infection should be suspected in patients with recent contact with a cat even despite the presence of lymphadenopathy. DISCLOSURES: All authors: No reported disclosures.