Gabus et al. Journal of Medical Case Reports 2010, 4:245 http://www.jmedicalcasereports.com/content/4/1/245 retroperitoneal hematoma. After blood, urine and pleural fluid had been collected for culture, he was empirically treated intravenously with amoxicillin/clavulanate 2.2 g four times a day and ciprofloxacin 200 mg twice a day for presumed septic shock. A transthoracic echocardio- graphy, that was performed because of the systolic mur- mur and the hemodynamic instability, showed evidence of tricuspid valvular involvement with several large vege- tations of approximately 2.5 cm in diameter, severe valvu- lar regurgitation, and a reduced ejection fraction (45%) (Figure 1). As no pathogen could be isolated from blood cultures after 60 hours of incubation, we considered all agents of culture-negative endocarditis as possible etiol- ogy. Investigations for HACEK microorganisms, and sero- logic studies for Bartonella spp., Brucella spp. and Coxiella burnetti were negative; PCR of the blood and pleural fluid for Tropheryma whipplei was positive. The PCR technique described by Meibach et al. in 2003 was used [11]. Having diagnosed Tropheryma whipplei right heart endocarditis, we switched the antibiotic regimen to ceftriaxone 2 g once daily. Favorable clinical changes kept him from requiring surgery, and he returned home after 25 days with a combined treatment of doxycycline 100 mg twice a day, hydroxychloroquine 200 mg and sulfa- methoxazole-trimethoprim 160/800 mg three times a day for a minimum of one year. The blood levels of doxycy- cline and hydroxychloroquine were measured every other month and doses adapted to therapeutic levels (doxycy- cline: > 5 μg/ml, hydroxychloroquine 1 +/- 0.2 mg/l). At a one-year follow-up he had completely recovered, gained weight and all his laboratory values were back to normal. A control echography performed after one year (Figure 2) confirmed the treatment success. Figure 1 Transthoracic echocardiography at time of diagnosis showing large vegetations on the tricuspid valve caused by Tropheryma whipplei. The tricuspid valve is indicated by an arrow. VD; right ventricle: OD; right atrium. Page 2 of 4 Figure 2 Transthoracic echocardiography after one year of treatment. No vegetation was found. The tricuspid valve is indicated by an arrow. VD; right ventricle: OD; right atrium: VG; left ventricle: OG; left atrium. Discussion Right-sided endocarditis, which usually involves the tri- cuspid valve, occurs predominantly in intravenous drug users or is related to congenital defects, intracardiac catheters, pacemakers or cardiac anomalies [12]. Physi- cians often use the Duke criteria to diagnose endocardi- tis, but in patients with blood culture-negative endocarditis due to Tropheryma whipplei, two of the criteria (fever and a history of valvulopathy) are gener- ally absent, making them difficult to diagnose [4]. In 2001, Fenollar et al. reviewed the literature of Whipple’s endocarditis based on valve histology [5]. According to that study, patients with Whipple’s endocarditis have no previous heart disease and are most often afebrile, their blood cultures are negative, and vegetation is observed on an echocardiograph in 75% of cases. Fenollar et al described 35 cases which came from a pathology series without detailed clinical history. A tricuspid endocarditis associated with involvement of other valves (mostly aor- tic) is reported in 6% of cases [4]. To the best of our knowledge, only one case of a patient diagnosed with Tropheryma whipplei tricuspid endocarditis without any other valve involved has been completely reported [13]. It describes the case of a young female presenting with migratory arthralgia, abdominal pain, diarrhea, and weight loss of two years duration. Physical examination revealed a systolic murmur on the left sternal margin. The diagnosis of Whipple’s disease was made on jejunal biopsy by electron microscopy and transoesophageal echocardiogram revealed a fixed vegetation on the tri- cuspid valve. The patient was successfully treated with penicillin G and streptomycin for 14 days, followed by sulfamethoxazole-trimethoprim for one year [13]. No surgery involving the valve was carried out.