Starry Heart Valve: A Story Behind CAT Scratch

Abstract

SESSION TITLE: Bacterial Infections 1 SESSION TYPE: Affiliate Case Report Poster PRESENTED ON: Tuesday, October 31, 2017 at 01:30 PM - 02:30 PM INTRODUCTION: Bartonella species are zoonotic bacterial pathogens in humans. B.quintana and B.henselae are the most common agents causing human infections. B.henselae infection is associated with exposure to cats and their fleas; endocarditis may occur in patients with known valvular disease. CASE PRESENTATION: A 62-year-old female, with no prior history of heart disease, presented with 10 days of bilateral leg swelling, malaise and exertional dyspnea. She lived with her 4 cats. Examination was notable for bilateral pitting edema extending to her waist with visible scratch marks on her abdomen and lower extremities. Laboratory data revealed new pancytopenia and an elevated serum creatinine (2.1 mg/dl). She was started on clindamycin for cellulitis. Blood cultures were negative. Transthoracic echocardiogram, obtained to evaluate the severe edema, showed an aortic valve vegetation measuring 2.7 cm x 1.3 cm with aortic insufficiency. The lesion was confirmed with a transesophageal study. The patient was deemed to have culture negative endocarditis; antibiotics were changed to vancomycin, ceftriaxone and doxycycline. B.henselae and B.quintana IgG titers were positive with the titer of > 1:1024. She underwent an aortic valve replacement. PCR of the heart valve tissue was positive for Bartonella. The bacterial colonies were strongly positive by Warthin Starry stain and demonstrated strong reactivity with a Bartonella immunostain. Vancomycin and ceftriaxone were discontinued; she was transitioned to doxycycline 100 mg twice daily with rifampin 300 mg twice daily for six weeks followed by doxycycline monotherapy for 6 months. DISCUSSION: Patients with Bartonella endocarditis generally present with subacute, nonspecific symptoms including fever, fatigue, weakness, and weight loss, like our patient. Our patient’s exposure to her four cats, with frequent scratches on her thighs and lower abdomen, and a culture-negative valuvular vegetation, raised the suspicion of Bartonella endocarditis. There are several methods to confirm the presence of Bartonella infection including tissue cell culture, Warthin-Starry staining of the resected valve, immuno histologic methods, serologic testing, and PCR amplification using valve specimens. If Bartonella is proven, treatment with 6 weeks of doxycycline along with 2 weeks of gentamycin and rifampin is recommended. However, there are no set guidelines defining optimal duration of therapy. Anecdotal evidences support extended doxycycline therapy for 3-6 months to prevent potential dissemination. CONCLUSIONS: Clinicians should suspect Bartonella endocarditis in patients with culture-negative endocarditis who have had extensive contact to cats. Reference #1: Chomel B et al: Fatal Case of Endocarditis Associated with Bartonella henselae Type I Infection in a Domestic Cat. Journal Of Clinical Microbiology; Nov. 2003, p. 5337-5339 Reference #2: Drancourt M et al: Bartonella (rochalimaea) quintana endocarditis in three homeless men. N Engl J Med 1995;332: 419-23 DISCLOSURE: The following authors have nothing to disclose: Thushara Paul, Siddhant Datta No Product/Research Disclosure Information