Coxiella burnetii vascular graft infection.
ABSTRACT Coxiella burnetii, the causative agent of Q fever, may cause culture-negative vascular graft infections. Very few cases of C. burnetii infection of a vascular graft have been reported. All were diagnosed by serology.
We report the first case of Coxiella burnetii vascular graft infection diagnosed by broad-range PCR and discuss the diagnostic approaches and treatment strategies of chronic C. burnetii infection.
C. burnetii should be considered as etiological agent in patients with a vascular graft and fever, abdominal pain, and laboratory signs of inflammation, with or without exposure history. Broad-range PCR should be performed on culture-negative surgical samples in patients with suspected infection of vascular graft.
[show abstract] [hide abstract]
ABSTRACT: Histologic examination of valve samples is considered as the gold standard for the diagnosis of infectious endocarditis. Molecular tools are also very promising for patients with negative-culture endocarditis. Thus, we studied the contribution of valvular histology, culture, and 16S rRNA PCR amplification plus sequencing to the diagnosis of infectious endocarditis in patients undergoing valve surgery. We performed culture, histological examination, and broad-range PCR amplification plus sequencing on valve samples taken from 127 patients with infectious endocarditis and from 118 patients without endocarditis. The sensitivity and specificity of these tests for the diagnosis of endocarditis in patients undergoing valve surgery were studied. The sensitivity of PCR was of 61% (64/105) whereas that of histological examination was of 63% (62/98) and that of valve culture was of only 13% (14/105). All 68 positive PCR results considered reliable according to an interpretation scheme were from patients with infectious endocarditis, resulting in a 100% (118/118) specificity of the interpreted molecular approach. The specificity of histology was also of 100% (118/118) when using stringent criteria (ie, presence of vegetation, microorganisms, and/or valvular inflammation with mainly polymorphonuclear cells). PCR identified an etiological agent in 38% (5/13) of definite blood culture-negative infectious endocarditis. We show that valvular histology with stringent criteria is the gold standard for the diagnosis of infectious endocarditis. Broad-range amplification of 16S rRNA gene is indicated for infectious endocarditis of unknown etiology, whereas valve culture is of limited sensitivity.The American Journal of Medicine 04/2005; 118(3):230-8. · 5.43 Impact Factor
Article: Immunohistologic demonstration of Coxiella burnetii in the valves of patients with Q fever endocarditis.[show abstract] [hide abstract]
ABSTRACT: Cardiac valves that were resected from patients with Q fever endocarditis were examined by immunohistologic methods to correlate the presence of Coxiella burnetii in the valves with the histopathologic, serologic, microbiologic, and clinical findings. Seventeen patients with serologic and microbiologic or clinical evidence of Q fever endocarditis who presented with cardiac failure secondary to valvular dysfunction and required valve replacement surgery were selected from the clinical records of the Unité des Rickettsies, Marseille, France. Clinical data were collected by questionnaire. Serologic characterization was performed by indirect immunofluorescent antibody testing; shell vial cultivation of C burnetii was performed from resected valves and blood when available; and pathologic and immunohistologic testing for localization of C burnetti in resected valves were performed by standard methods using both polyclonal and monoclonal C burnetti antibodies. Demographic and clinical findings were typical of patients with Q fever endocarditis. Pure chronic inflammation or mixtures of acute and chronic inflammation were the most frequent inflammatory patterns present and were associated with fibrin deposition, necrosis, and fibrosis. Well-formed granulomas were not present, but the granulomatous inflammation observed in 6 of these 17 patients was associated with foreign body reactions or with valvular calcifications secondary to preexisting valvular damage and could not be directly attributed to infection. C burnetii were present nearly exclusively in macrophages in sites of inflammation and valvular injury and only in the vegetations. Immunohistologic results confirmed the valve culture results in 10 of 14 cases. The pathologic findings in the valves of patients with Q fever endocarditis are nonspecific. The presence of empty or foamy macrophages is suggestive of infection by C burnetii; however, definitive identification rests upon the demonstration of the organism in the tissue by immunohistology. Q fever endocarditis probably results from infection of previously damaged heart valves. The finding of the absence of granulomas in these cases contrasts with the pathologic findings in patients with acute, self-limited Q fever and suggests an aberrant host immune response that permits persistence of the bacterium and chronic, prolonged valvular infection and injury. The pathologic findings and distribution of C burnetii in the damaged valve tissues explain the clinical findings of valve failure and occasional embolic episodes, as well as the frequent ability to isolate C burnetii from the peripheral blood of infected patients. Immunohistology may be a valuable diagnostic tool in places where serology and culture are not available.The American Journal of Medicine 12/1994; 97(5):451-8. · 5.43 Impact Factor
Article: Cardiac valves in patients with Q fever endocarditis: microbiological, molecular, and histologic studies.[show abstract] [hide abstract]
ABSTRACT: The pathologic features of Q fever endocarditis, which is caused by Coxiella burnetii, were histologically evaluated in cardiac valves from 28 patients. We used quantitative image analysis to compare valvular fibrosis, calcifications, vegetations, inflammation, and vascularization due to Q fever endocarditis with that due to non-Q fever endocarditis and valvular degeneration. We also studied the presence of C. burnetii in valves by immunohistochemical analysis, culture, and polymerase chain reaction (PCR). Histologically, Q fever endocarditis was characterized by significant fibrosis and calcifications, slight inflammation and vascularization, and small or absent vegetations. Despite antibiotic treatment, non-statistically significant variations at the histologic level were observed. These pathologic features could be confused with noninfectious valvular degenerative damage. We found that the detection of C. burnetii in cardiac valves by immunohistochemical analysis, culture, and PCR decreased significantly only after 1 year of antibiotic treatment, which emphasizes the long persistence of this organism in valve tissues. Pathologic and immunohistochemical analyses may contribute to the diagnosis of Q fever endocarditis.The Journal of Infectious Diseases 05/2003; 187(7):1097-106. · 6.41 Impact Factor
Page 1 of 4
(page number not for citation purposes)
BMC Infectious Diseases
Coxiella burnetii vascular graft infection
Laurence Senn1, Mario Franciolli2, Didier Raoult3, Alexandre Moulin4,
Ludwig Von Segesser5, Thierry Calandra1 and Gilbert Greub*1,6
Address: 1Infectious Diseases Service, Department of Internal Medicine, University Hospital, Lausanne, Switzerland, 2Bellinzona Hospital,
Switzerland, 3Unité des Rickettsies, Université de la Méditerranée, Marseille, France, 4University Institute of Pathology, Lausanne, Switzerland,
5Department of Cardio-vascular Surgery, University Hospital, Lausanne, Switzerland and 6Institute of Microbiology, University of Lausanne,
Bugnon 48, 1011 Lausanne, Switzerland
Email: Laurence Senn - Laurence.Senn@chuv.ch; Mario Franciolli - firstname.lastname@example.org; Didier Raoult - Didier.Raoult@gmail.com;
Alexandre Moulin - Alexandre.Moulin@chuv.ch; Ludwig Von Segesser - Ludwig.Von-Segesser@chuv.ch;
Thierry Calandra - Thierry.Calandra@chuv.ch; Gilbert Greub* - Gilbert.Greub@chuv.ch
* Corresponding author
Background: Coxiella burnetii, the causative agent of Q fever, may cause culture-negative vascular
graft infections. Very few cases of C. burnetii infection of a vascular graft have been reported. All
were diagnosed by serology.
Case presentation: We report the first case of Coxiella burnetii vascular graft infection diagnosed
by broad-range PCR and discuss the diagnostic approaches and treatment strategies of chronic C.
Conclusion: C. burnetii should be considered as etiological agent in patients with a vascular graft
and fever, abdominal pain, and laboratory signs of inflammation, with or without exposure history.
Broad-range PCR should be performed on culture-negative surgical samples in patients with
suspected infection of vascular graft.
Infection of synthetic abdominal aortic grafts occurs in
≤1% of patients, with a higher risk (1.5–2%) for grafts that
extend to the femoral location. Vascular graft infection
may result from intra-operative contamination, local
extension from infected adjacent tissue or by hematoge-
nous seeding. The most commonly involved pathogens
are Staphylococcus aureus (30%), Enterobacteriaceae (25%),
coagulase-negative Staphylococci (12%), Enterococci (9%),
Pseudomonas aeruginosa (7%) and Streptococci (5%).
Cultures remain negative in approximately 5% of cases
. C. burnetii account for some of these culture-negative
vascular graft infections. Very few cases of C. burnetii infec-
tion of a vascular graft have been reported [2-5]. All previ-
ously reported cases were diagnosed by serology. The
confirmation of the vascular localization of C. burnetii
infection was obtained after the serological diagnosis of
chronic Q fever by culture  and/or DNA amplification
of C. burnetii from vascular graft samples [3-5]. Here, we
report a case of C. burnetii vascular graft infection diag-
nosed by broad-range PCR from a surgical sample of a
para-prosthetic abscess which was confirmed by serology.
To our knowledge, ours is the first case where the diagno-
sis was made by broad-range PCR and suggests that broad-
range PCR should be considered in all cases of culture-
negative vascular graft infections.
Published: 07 December 2005
BMC Infectious Diseases 2005, 5:109doi:10.1186/1471-2334-5-109
Received: 07 September 2005
Accepted: 07 December 2005
This article is available from: http://www.biomedcentral.com/1471-2334/5/109
© 2005 Senn et al; licensee BioMed Central Ltd.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0),
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
BMC Infectious Diseases 2005, 5:109http://www.biomedcentral.com/1471-2334/5/109
Page 2 of 4
(page number not for citation purposes)
A 63-year-old man presented to a regional hospital on
September 8, 2003 with a 2-week history of diffuse
abdominal pain and mild diarrhea, without fever. In
1988, he had received a Dacron aorto-bifemoral graft for
an infra-renal aortic aneurysm. A computerized tomogra-
phy (CT) of the abdomen revealed a para-prosthetic fluid
collection. Blood cultures were sterile in the absence of
any recent antibiotic therapy. Laboratory results showed a
white blood cell count of 5.8 G/l, a CRP of 48 mg/l, no
increase of liver enzymes and a normal serum creatinine
level. Empirical ciprofloxacin and metronidazole therapy
was initiated and abdominal pain improved.
After two months of antibiotic therapy, the patient was
admitted to the University Hospital in Lausanne for
removal of the vascular prosthesis because of presumed
persistent infection, despite two months of antibiotic
treatment. On admission, the patient was afebrile. Clini-
cal examination was normal except for mild periumbilical
tenderness on deep palpation. Laboratory results showed
a normal WBC count (4.9 G/l), a normal CRP (<2 mg/l),
and normal renal and liver functions. At laparotomy,
extensive adhesions and a right para-iliac purulent mass
were found. The prosthetic graft was partially removed,
and replaced by a homograft. Multiple intra-operative
specimens did not grow any microorganisms in culture.
Histopathology showed a chronic inflammatory infiltrate,
ill-formed non-necrotizing granulomas, and degenerative
changes such as calcifications and fibrosis (Figure 1A
&1B). No microorganisms could be identified using Peri-
odic acid-Schiff, Gram, Grocott methenamine silver and
16S rRNA PCR amplification plus sequencing performed
on a fragment of the para-iliac mass was positive for Cox-
iella burnetii, using the BAK11w forward and the PC3mod
reverse primers . The diagnosis of C. burnetii chronic
infection was confirmed by a positive serology performed
at Unité des Rickettsies, Marseille, France: phase I anti-
body titer (IgG): 1600, phase II antibody titer (IgG): 3200.
Antibiotic therapy with doxycycline (100 mg bid orally)
and chloroquine (200 mg tid orally) was started. The dose
of doxycycline was increased to 300 mg daily to reach a
concentration of at least 5 µg/mL . Eighteen months
later (May 2005), the patient was asymptomatic and
serology showed persistence of high levels of phase I IgG
(1600) and phase II IgG (3200).
C. burnetii is a strict intracellular bacterium. It is the caus-
ative agent of Q fever, a worldwide zoonosis mainly trans-
mitted by inhalation of infected particles. There is a wide
animal reservoir, and sheep and cattle are probably the
main source of human infections. Our patient had no
environmental exposure to C. burnetii. Chronic Q fever is
mainly seen in patients with underlying risk factors such
as valvulopathy, pregnancy, and immunosuppression.
Endocarditis accounts for 73% of chronic Q fever cases,
followed by vascular infection (8%), including infections
of aneurysms and vascular grafts [4,8]. Given the signifi-
cant morbidity and mortality of vascular infection, and
given the importance of targeted and prolonged antibiotic
therapy, the diagnosis of C. burnetii infection is crucial to
a successful therapeutic outcome. We report here a rare
case of C. burnetii vascular graft infection. This unexpected
diagnosis was based on broad-range PCR. Q fever is prob-
ably underdiagnosed since the diagnosis will be missed if
it is not systematically looked for in patients with vascular
graft infections of unknown etiology.
Histology of the aortic lesion
Histology of the aortic lesion: A. Chronic inflammatory
infiltrate (yellow arrowhead), fibrosis (black arrowhead), and
ill-formed granuloma (arrow). Hematoxylin-eosin, 100× mag-
nification. B. Closer view of the ill-formed granuloma
(arrow). Hematoxylin-eosin, 400× magnification.
BMC Infectious Diseases 2005, 5:109http://www.biomedcentral.com/1471-2334/5/109
Page 3 of 4
(page number not for citation purposes)
The diagnosis of Q fever is most frequently made by serol-
ogy. C. burnetii presents a variation of phase (phases I and
II). Antiphase I IgG at titers of ≥1:800 by microimmun-
ofluorescence are indicative of chronic Q fever [9,10]. The
diagnosis has also be made using molecular methods
including 16S rRNA PCR amplification plus sequencing
or a specific C. burnetii PCR. To shorten the diagnostic
delay, Fenollar et al. developed a nested-PCR assay with
serum as a template which showed a sensitivity of 64%
and a specificity of 100% . In the present case, 16s
rRNA PCR amplification plus sequencing was critical for
diagnosis, since Q fever had not been suspected clinically.
Broad-range PCR was also recently shown to be useful for
the diagnosis of blood culture-negative infectious endo-
carditis, identifying an etiological agent in 35.5% of cases
(11/31), including 3 cases due to C. burnetii . The his-
tology of Q fever endocarditis is non-specific and is char-
acterized by fibrosis and
inflammation, and small or absent vegetations. Brouqui et
al. observed a granulomatous inflammation in one third
of cases with Q fever endocarditis, but well formed granu-
loma were not identified. In these cases, degenerative
changes such as valvular calcifications or foreign body
reaction prevented the establishment of a specific associa-
tion between C. burnetii infection and granulomatous
inflammation . The presence of foamy macrophages,
also observed in our case, may suggest a Coxiella infection.
Definite histological diagnosis relies upon immunohistol-
ogy, that may demonstrate the presence of C. burnetii
within the cytoplasm of macrophages . However, this
diagnostic method is less sensitive than PCR . Thus,
immunohistology is unlikely to be a useful tool for the
diagnosis of C. burnetii vascular graft infection. Cell cul-
ture is not widely available as a diagnostic technique as it
requires trained technicians and a biosafety level 3 labora-
Tetracyclines are the antibiotics of choice for acute Q fever
. The bactericidal activity of doxycycline is maximal at
pH 6.6. However, the Coxiella-containing vacuole is
acidic. Therefore, addition of chloroquine that acts as an
alkalinizing agent of the vacuole is essential to improve
the efficacy of doxycycline therapy . Combination of
doxycycline and hydroxychloroquine for at least 18
months is the recommended therapy for Q fever endocar-
ditis . This combined treatment is probably also indi-
cated in case of C. burnetii vascular graft infection. Since
serum doxycycline concentration is correlated with
decrease in levels of phase I antibodies, it is recommended
to adjust the dosage of doxycycline . Patients are con-
sidered cured when phase I IgG antibodies decrease below
1:800, and IgA and IgM antibodies below 1:50 . In
this case, after 18 months of therapy, antiphase I serology
remains strongly positive suggesting persistent infection
most likely due to the fact that the infected prosthesis
could only be partially removed. It also shows how diffi-
cult it is to eradicate C. burnetii and emphasizes the need
for prolonged antibiotic treatment course. Serological fol-
low-up will guide our decision regarding the treatment
C. burnetii infection should be considered in patients with
a vascular graft and unexplained low-grade fever, abdom-
inal discomfort, laboratory signs of inflammation, and/or
a history of environmental exposure. Broad-range PCR
should be performed on surgical samples in patients with
suspected infection of aneurysm or vascular graft. C. bur-
netii serology and/or specific C. burnetii PCR should also
systematically be performed in cases of culture-negative
vascular graft infection.
The author(s) declare that they have no competing inter-
LS, MF, DR, LVS, TC and GG were involved in patient care.
LS wrote the first draft of the manuscript. AM did the his-
tology and provided the images. All authors improved the
manuscript and approved its final version.
We thank Dr Philip E. Tarr for critical reading of the manuscript.
1.Goëau-Brissonnière OA, Coggia M: Arterial prosthetic infec-
tions. In: Waldvogel FA, Bisno AL, eds Infections Associated with Indwell-
ing medical Devices 3rd ed Washington, DC: ASM Press 2000:127-144.
2. Ellis ME, Smith CC, Moffat MA: Chronic or fatal Q-fever infec-
tion: a review of 16 patients seen in North-East Scotland
(1967-80). Q J Med 1983, 52:54-66.
3.Fournier PE, Casalta JP, Piquet P, Tournigand P, Branchereau A,
Raoult D: Coxiella burnetii infection of aneurysms or vascular
grafts: report of seven cases and review. Clin Infect Dis 1998,
4.Raoult D, Tissot-Dupont H, Foucault C, Gouvernet J, Fournier PE,
Bernit E, Stein A, Nesri M, Harle JR, Weiller PJ: Q fever 1985-1998.
Clinical and epidemiologic features of 1,383 infections. Med-
icine (Baltimore) 2000, 79:109-123.
5.Georghiou GP, Hirsch R, Vidne BA, Raanani E: Coxiella burnetii
infection of an aortic graft: surgical view and a word of cau-
tion. Interactive Cardiovascular and Thoracic Surgery 2004, 3:333-335.
6. Goldenberger D, Kunzli A, Vogt P, Zbinden R, Altwegg M: Molecular
diagnosis of bacterial endocarditis by broad-range PCR
amplification and direct sequencing. J Clin Microbiol 1997,
7.Rolain JM, Mallet MN, Raoult D: Correlation between serum
doxycycline concentrations and serologic evolution in
patients with Coxiella burnetii endocarditis. J Infect Dis 2003,
8. Sessa C, Vokrri L, Porcu P, Maurin M, Stahl JP, Magne JL: Abdominal
aortic aneurysm and Coxiella burnetii infection: report of
three cases and review of the literature. J Vasc Surg 2005,
9.Rolain JM, Lecam C, Raoult D: Simplified serological diagnosis of
endocarditis due to Coxiella burnetii and Bartonella. Clin
Diagn Lab Immunol 2003, 10:1147-1148.
10.Maurin M, Raoult D: Q fever. Clin Microbiol Rev 1999, 12:518-553.
Publish with BioMed Central and every
scientist can read your work free of charge
"BioMed Central will be the most significant development for
disseminating the results of biomedical research in our lifetime."
Sir Paul Nurse, Cancer Research UK
Your research papers will be:
available free of charge to the entire biomedical community
peer reviewed and published immediately upon acceptance
cited in PubMed and archived on PubMed Central
yours — you keep the copyright
Submit your manuscript here:
BMC Infectious Diseases 2005, 5:109 http://www.biomedcentral.com/1471-2334/5/109
Page 4 of 4
(page number not for citation purposes)
11. Fenollar F, Fournier PE, Raoult D: Molecular detection of Cox-
iella burnetii in the sera of patients with Q fever endocarditis
or vascular infection. J Clin Microbiol 2004, 42:4919-4924.
Greub G, Lepidi H, Rovery C, Casalta JP, Habib G, Collard F, Fournier
PE, Raoult D: Diagnosis of infectious endocarditis in patients
undergoing valve surgery. Am J Med 2005, 118:230-238.
Brouqui P, Dumler JS, Raoult D: Immunohistologic demonstra-
tion of Coxiella burnetii in the valves of patients with Q fever
endocarditis. Am J Med 1994, 97:451-458.
Lepidi H, Houpikian P, Liang Z, Raoult D: Cardiac valves in
patients with Q fever endocarditis: microbiological, molecu-
lar, and histologic studies. J Infect Dis 2003, 187:1097-1106.
Raoult D, Houpikian P, Tissot DH, Riss JM, rditi-Djiane J, Brouqui P:
Treatment of Q fever endocarditis: comparison of 2 regi-
mens containing doxycycline and ofloxacin or hydroxychlo-
roquine. Arch Intern Med 1999, 159:167-173.
Dupont HT, Thirion X, Raoult D: Q fever serology: cutoff deter-
mination for microimmunofluorescence. Clin Diagn Lab Immu-
nol 1994, 1:189-196.
The pre-publication history for this paper can be accessed