Gabus et al. Journal of Medical Case Reports 2010, 4:245 http://www.jmedicalcasereports.com/content/4/1/245 Contrary to the patient described by Ferrari et al. who presented symptoms (arthralgia and digestive involve- ment) suggestive of Whipple’s disease [13], our patient presented a Tropheryma whipplei endocarditis manifest- ing as severe shock. Apart from weight loss, he didn’t exhibit any of the typical symptoms of Whipple’s dis- ease. He also did not have any risk factors for right- sided endocarditis. Diagnosis of Whipple’s disease is suspected most of the time on the basis of gastrointestinal symptoms and is generally confirmed by intestinal biopsies. According to recently published data it seems that the occurrence of endocarditis due to Tropheryma whipplei, without any of the classical features of Whipple’s disease, is not as rare as was previously thought [14]. As we did not suspect Whipple’s disease at the beginning, we did not perform intestinal biopsies. No serology is yet available. PCR is especially useful for the diagnosis of Whipple endocarditis and may be directly performed on blood samples and pleural fluid, as we did, or on valvular sam- ples [15]. PCR performed on blood allows a non-inva- sive diagnosis and rapid results. However, cautious interpretation of PCR results is needed since PCRs have been positive in healthy patients, most likely as a result of contamination [16]. Conversely, sensitivity of PCR on blood samples may be impaired by the presence of PCR inhibitors and by the relatively low amount of circulat- ing DNA. For patients with concomitant gastrointestinal involvement, diagnosis may also be made more easily from a small bowel biopsy that will be positive on PAS- staining. In the present case, the obvious vegetation on cardiac ultrasound, the positive PCR on two different samples (blood and pleural fluid), and the favorable change in the condition with antibiotics makes the etio- logical role of Tropheryma whipplei in this right-sided endocarditis absolutely clear. Concerning treatment, our patient was initially treated by ceftriaxone then with a combination of sulfamethoxa- zole/trimethoprim, hydroxychloroquine and doxycycline for one year. By analogy with what is known about Cox- iella burnetii, the association of a lysotropic agent (hydroxychloroquine) to doxycycline tends to reduce the acidity of the vacuole in which Tropheryma whipplei is located and thus improves the efficacy of doxycycline inactive at lower pH [17,18]. Interestingly, between sul- famethoxazole and trimethoprim, only sulfamethoxazole is active and trimethoprim is absolutely not effective against Tropheryma whipplei; thus, the association of sulfamethoxazole and trimethoprim represents a monotherapy. Conclusion In summary, Tropheryma whipplei infectious endocardi- tis is a rare disease and tricuspid involvement is found Page 3 of 4 even less often. This diagnosis should always be consid- ered when facing a blood-culture negative endocarditis particularly in right-sided endocarditis without risk fac- tors. Although not standardized yet, treatment of Tropheryma whipplei endocarditis should probably include a bactericidal antibiotic (such as doxycycline) and should be given for a prolonged period of time (a minimum of one year). Competing interests The authors declare that they have no competing interests. Consent Written informed consent was obtained from the patient for publication of this case report and any accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal. Authors’ contributions VG was responsible for writing the manuscript and reviewing the literature. ZG, SJ and RR had significant roles in data gathering and were major contributors to the content of the manuscript. VG, ZG, RR, GG and DG were involved in patient management. GG and DG had a significant role in data interpretation and provided significant revisions to the manuscript. All authors read and approved the final manuscript. Acknowledgements We are indebted to Hans H. Siegrist and Thompson Kinge for their helpful review of the manuscript and for their assistance with the preparation of the manuscript. We are also indebted to Dr G. Bloemberg and to the Institute of Medical Microbiology of the University of Zurich who performed the PCR of Tropheryma whipplei. The authors had no financial support. Author details 1Department of Internal Medicine, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Switzerland. 2Department of Internal Medicine, Community Hospital, 2300 La Chaux-de-Fonds, Switzerland. 3Infectious disease service, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Switzerland. 4Institute of Microbiology, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Switzerland. Received: 19 September 2009 Accepted: 4 August 2010 Published: 4 August 2010 References 1. Relman DA, Schmidt TM, MacDermott RP, Falkow S: Identification of the uncultured bacillus of Whipple’s disease. N Engl J Med 1992, 327:293-301. 2. La Scola B, Fenollar F, Fournier PE, Altwegg M, Mallet MN, Raoult D: Description of Tropheryma whipplei gen. nov., sp. nov., the Whipple’s disease bacillus. Int J Syst Evol Microbiol 2001, 51:1471-1479. 3. Dutly F, Altweg M: Whipple’s disease and “Tropheryma whippelii”. Clin Microbiol Rev 2001, 14:561-583. 4. 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