Q fever: a rare cause of endocarditis

Coxiella Burnetii endocarditis is very rare. It is the main complication of the chronic form of Q fever. Blood cultures are negative and clinical presentation very variable and diagnosis is essentially based on indirect immunofluorescence serum analysis. The authors report the case of a 19 year old patient with a history of rheumatic aortic regurgitation admitted for an episode of left ventricular failure in a context of long-term pyrexia without valvular vegetations or mutilation. The antiphase I Ig G antibody levels were significant. Treatment with doxycycline and fluoroquinolone was initiated. The clinical improvement was spectacular. Three months later, the patient underwent aortic valve replacement and histological examination of the valve showed subacute endocarditis on chronically fibrotic valvular disease. This is an interesting case by its rarity and its diagnostic and therapeutic problems.     

Q fever endocarditis: over 14 years of surgical experience in a referral center for rickettsioses

BACKGROUND AND AIM OF THE STUDY: Q fever endocarditis caused by Coxiella burnetii is the most important etiology of negative blood culture endocarditis. Without specific clinical findings, diagnosis is difficult and prevalence of this life-threatening disease is underestimated. METHODS: Q fever endocarditis was assessed in 19 patients (15 men, four women; age range: 36-79 years) by evaluating clinical and echocardiographic criteria and specific serology. All patients had evidence of pre-existing valvular disease, and 10 had a valvular prosthesis. Diagnosis was assessed in: the presence of unexplained fever (n = 5), heart failure with valvular dysfunction (n = 10), hemolysis (n = 1), glomerulonephritis (n = 1) and stroke (n = 2). A late diagnosis was made in eight patients, either during or after surgery. RESULTS: In all cases, usual blood cultures remained negative, despite specific serology being positive. Transthoracic and transesophageal echocardiography were conclusive in only six cases (four vegetations, two periannular abscesses). Surgery was indicated in 15 patients for heart failure or valvular dysfunction (n = 12), hemolysis (n = 1) and periannular abscess (n = 2). Intraoperative findings were suggestive of endocarditis in seven cases; valvular cultures were positive in 92% of cases. All patients were treated with combined doxycycline/ hydrochloroquine or quinolone, for a mean of 24 months (range: 6-60 months). Mean follow up was 40 months (range: 6-144 months). Two patients died from heart failure, one patient was lost to follow up, and 16 patients had no late relapses. CONCLUSION: Q fever is an underestimated cause of endocardititis, and early diagnosis is the key to good prognosis. The need for systematic serologic examination in case of valvular dysfunction, with or without endocarditis symptoms, is emphasized.     

Serologic evidence of acute murine typhus infection in a patient with culture-negative endocarditis

A patient with culture-negative infective endocarditis is presented in whom detailed serological studies were indicative of acute infection with murine typhus. The patient had aortic and mitral regurgitation with congestive heart failure and typical peripheral manifestations of subacute endocarditis, but no documented fever. Aortic and mitral valve replacement surgery and a 6-week course of doxycycline therapy produced a clinical cure in this patient, as well as a diagnostic fall in markedly elevated preoperative typhus indirect fluorescent antibody (IFA) and complement fixation (CF) titers. Serological studies were consistently negative for Q fever.     

Q fever infectious endocarditis. Apropos of a new case

We report a case of Coxiella burnetii endocarditis in a 42-year old man presenting with a long-known cardiac murmur and an infectious syndrome of several months duration. The aetiological diagnosis, delayed by the lack of knowledge of a primary Q fever, was established by serology. The infection responded to tetracycline combined with cotrimoxazole, but a valve replacement performed for haemodynamic reasons was followed by serious complications. We remind the readers that Q fever endocarditis must be considered as a possible diagnosis in all cases of endocarditis with negative blood cultures and that specific serological examinations in search of anti-phase I antibodies of the IgA type should be performed as soon as possible, using the indirect immunofluorescence technique. Attention is drawn to the different serological responses of the three clinical types of Q fever infection and to the cellular immunity associated with that disease.     

Serological diagnosis of Q fever endocarditis

The diagnosis of Q fever endocarditis cannot be made by bacterialcultures and necessitates serological identification of specificantibodies to Coxiella burnetii which stimulates mainly theproduction of anti-phase II antibodies during the acute diséase,but primarily anti-phase I antibodies in endocarditis. Indirectmicro-immunofluorescence allows rapid detection of specificIgA, IgG and IgM. The results of serological analyses of 191acute cases of Q fever were compared with those of 8 cases ofCoxiella burnetii endocarditis. All sera were evaluated by complementfixation and microimmunofluorescence tests. The highest titredifferences between primary Q fever and Q fever endocarditiswere observed with anti-phase IIgA and IgG antibodies measuredby microimmunofluorescence followed by anti-phase I antibodiesmeasured by complement fixation tests. Anti-phase IIgG and IgMtitres were consistently higher than anti-phase II titres inendocarditis. The reverse is true in acute Q fever. In addition,anti-phase I Ig A appeared to be diagnostic for Coxiella burnetiiendocarditis. Accordingly we recommend the testing of thesespecific IgA, IgG, and IgM by microimmunofluorescence in casesof culture-negative endocarditis. These tests could also proveuseful for following the development of Coxiella burnetii endocarditisin patients under treatment.     

Q fever bioprosthetic aortic valve endocarditis (PVE) successfully treated with doxycycline monotherapy

Q fever is a zoonotic infection caused by Coxiella burnetii. The most common clinical manifestation of acute Q fever infection is as an atypical community-acquired pneumonia. The pulmonary findings are accompanied by extrapulmonary findings, most typically an increase in serum transaminases and splenomegaly. Because C. burnetii is difficult to culture, the diagnosis of Q fever is usually made serologically. The diagnosis of acute Q fever atypical community-acquired pneumonia is made by demonstrating a fourfold or greater increase in titer between acute and convalescent specimens or by demonstrating elevated immunoglobulin (IgM) (phase II) titers. Chronic Q fever is manifested as granulomatous hepatitis or more commonly as culture-negative endocarditis (CNE). Chronic Q fever (CNE) is a difficult diagnosis because of difficulty in culturing the organism from the blood and the vegetations with Q fever CNE are small or absent. The diagnosis of chronic Q fever CNE is based on serology. Such patients commonly have highly elevated IgM and IgG titers (phase I/II) titers. Chronic Q fever CNE may involve native or prosthetic heart valves. Q fever prosthetic valve endocarditis is rare compared with native valve Q fever endocarditis. Q fever prosthetic valve endocarditis usually requires valve replacement for cure. We present a case of chronic Q fever bioprosthetic aortic valve endocarditis that was successfully treated with doxycycline monotherapy that did not require aortic valve replacement.     

Spontaneous splenic rupture complicating acute Q fever.

Q fever is usually a self-limited febrile illness that involves the lungs and the liver. Acute complications are rare. We present the case of a 30-yr-old patient with spontaneous splenic rupture during the course of acute Q fever infection. He was admitted to the hospital with high temperature and the radiological signs of an atypical pneumonia. Forty-eight hours after admission, he developed shock. Because of free intraabdominal liquid, a laparatomy was performed that revealed a tear in the enlarged spleen. A splenectomy was performed. The diagnosis of Q fever was established by a significant titer increase in complement fixation test and IgM-ELISA. Serological investigations into the patient's surroundings revealed evidence of Q fever infection in 10 additional persons. Q fever should be taken into account as a possible differential diagnosis in patients with unexplained febrile illness and symptoms of pneumonia. The acute course of Q fever infection can be complicated by splenic rupture. The diagnosis of an acute infection with Coxiella burnetii often requires serologic testing of a second serum sample obtained at least 10 days after the onset of symptoms. Q fever should be ruled out in cases of unexplained splenic rupture particularly in Q fever endemic areas.     

Risks factors and prevention of Q fever endocarditis.

Coxiella burnetii causes acute and chronic Q fever. To evaluate the risk factors of development of chronic endocarditis following Q fever and to assess the best preventive therapy, a retrospective study of patients diagnosed as having Q fever during 1985-2000 was conducted. Twelve patients with acute Q fever who developed endocarditis and 102 patients with Q fever endocarditis were included in the study. When compared to 200 control patients with acute Q fever, preexisting valvular disease (P<10(-7)), especially a prosthetic valve (P=.01), were encountered more often among patients with endocarditis. Among patients with valvular defects, we estimate the risk of developing endocarditis to be 39%. A combination of doxycycline plus hydroxychloroquine was better at preventing the development of endocarditis than doxycycline alone (P=.009). Our results should encourage physicians to detect valvular lesions in patients with acute Q fever and to search for acute Q fever in patients with a valvulopathy and unexplained fever. A proper treatment for such patients and a scheduled follow-up should reduce the risk of developing endocarditis.     

Q fever endocarditis: the Mayo Clinic experience

OBJECTIVES: To report the Mayo Clinic experience of Q fever endocarditis. BACKGROUND: Q fever endocarditis is rare in North America with few case reports in the literature. The Centers for Disease Control lists Q fever as a reportable illness but does not differentiate endocarditis as a syndrome in its database. METHODS: A search of the database for elevated Q fever IgG serology at our institution was conducted from December 1980 to December 2005. Patients with elevated serologies were retrospectively identified and their medical records were reviewed to determine which cases met criteria for a diagnosis of endocarditis. RESULTS: Eight patients with elevated serology were identified. One case failed to meet criteria and was therefore excluded. All patients presented with fever and had previously diagnosed valvular disease. Only 3 patients had valvular vegetations on transesophageal echocardiography. All 7 patients were treated with antimicrobial therapy, which was not uniform. Six required surgical intervention on the affected valves, and 2 required multiple valve surgeries. Follow-up ranged from 1 to 17 years. CONCLUSIONS: Q fever endocarditis is a rare disease in the United States, where no reliable reporting exists. Q fever endocarditis involves underlying abnormal native valves or prosthetic valves. Vegetations are small or absent. Relapses are common. Surgeries are common adding to morbidity and cost. The chronicity of the syndrome and its high morbidity mandate an increased awareness of the condition in patients with culture-negative endocarditis or unexplained perivalvular leaks detected by echocardiography. Appropriate diagnosis and tailored treatment are likely to reduce the need for repeat surgeries.     

Acalculous cholecystitis: an unusual presentation of acute Q fever masquerading as infectious endocarditis

We report here a patient with acute Q fever-related acalculous cholecystitis, who presented with prolonged fever, valvular abnormalities, and positive serology for Q fever phase 1 antigens, features suggesting chronic Q fever endocarditis. The pathogenesis of this rare presentation of Q fever is discussed.     

Prosthetic valve endocarditis due to Coxiella burnetii: six cases]

PURPOSE: Prosthetic valve endocarditis is a dangerous complication of valvular surgery (3-6%). Among involved pathogens, Coxiella burnetii is an occasional agent, though isolated with increasing frequency. We report our experience with this peculiar endocarditis and lay stress on specific diagnostic and therapeutic difficulties. METHODS: Between 1990 and 1995, six patients retrospectively met the diagnosis criteria for definite endocarditis due to Coxiella burnetii. RESULTS: Five Algerian men and one French woman presented with prosthetic valve endocarditis with negative blood cultures (on bioprosthesis: four cases, on mechanical valve: two cases). The main clinical and biological feature was febrile congestive heart failure with hepatomegaly, splenomegaly, hepatic and renal abnormalities, inflammatory syndrome, hypergammaglobulinemia, anemia and lymphopenia. Serological testing for Coxiella burnetii provided diagnosis in all cases. Echocardiography displayed vegetations in all cases. Valvular replacement was performed in four patients. With antibiotic therapy including doxycycline or/and hydroxychloroquine, quinolones or rifampicine, all patients experienced complete clinical, biological and echographic remission. CONCLUSION: Q fever prosthetic valve endocarditis presents as a systemic disorder occurring in patients with valvular heart disease. From now on, early diagnosis and efficient medical treatment may provide permanent prosthetic sterilization.     

Q fever endocarditis: a case report and review of the literature

The case of a 31-year-old man from Alberta diagnosed with Q fever endocarditis is presented. To the authors' knowledge, this is the first case of Q fever endocarditis diagnosed in the province of Alberta. The patient had undergone open valvulotomy for congenital aortic stenosis as an infant. He presented with congestive heart failure secondary to severe aortic regurgitation and underwent mechanical aortic valve replacement. Early failure of the mechanical prosthesis and numerous laboratory abnormalities prompted an investigation for endocarditis, which was initially negative. Markedly positive serology eventually established the diagnosis of chronic Q fever. The patient subsequently underwent a second aortic valve replacement following initiation of appropriate antimicrobials directed against Coxiella burnetii. The present report reviews the clinical presentation and diagnosis of Q fever endocarditis. It highlights the insidious and nonspecific nature of the presenting symptoms, and emphasizes the use of serology for diagnosis. Increased awareness and earlier diagnosis can significantly decrease the morbidity and mortality associated with this disease.     

Acute and chronic Q fever in patients with cancer.

Q fever is caused by Coxiella burnetii, a strictly intracellular bacterium that lives within the phagolysosome of infected cells. We report here five cases of Q fever in patients with cancer. Three of them had a solid tumor, one had a B cell lymphoma, and one had chronic myeloid leukemia. One patient had acute Q fever, and the four others had chronic Q fever endocarditis. Two patients with endocarditis had no previous history of valvulopathy. C. burnetii was isolated from the valves of two patients. One of the patients with endocarditis died. Patients with cancer who have unexplained fever and live in areas in which C. burnetii is endemic should undergo serological testing for infection with this microorganism.     

Acute heart failure due to Q fever endocarditis

We report a case of Q fever endocarditis in a patient who presentedwith a slight pyrexia and acute cardiac failure due to aorticincompetence. The diagnosis was made by detecting high titresof serum IgG and IgA antibody against Coxiella burnetii phaseI antigens and confirmed by demonstrating C. burnetii on theexcised aortic valve using immunofluorescene and electron microscopy.Aortic valve replacement was followed by initially successfulantibiotic treatment for 15 months. Reappearance of Ig A anti-phaseI antibodies 5 months later suggested continued presence ofbacteria, although the patient's condition remained satisfactory.In endemic areas, such as rural southern France, Q fever endocarditisshould be considered when there is evidence of acute heart valvedamage but are few other features of infection.     

Endocarditis due to Coxiella burnetti despite the absence of obvious exposure

Q?fever is an ubiquitous zoonotic disease caused by Coxiella burnetti, an intracellular Gram negative bacteria. It may present as an acute or a chronic disease course. Endocarditis due to Coxiella burnetti represents 1 to 5% of all infectious endocarditis. We report a 41-year-old man without obvious exposure history, who presented with a Q fever endocarditis.     

Hemangioma of the mitral valve: Following the murmur

Cardiac hemangiomas are an exceedingly rare condition, with about 100 cases described in the literature, of which only 13 were valvular.We report the case of a 66-year-old woman, with no prior cardiovascular disease, who presented with an abdominal infection caused by Enterococcus faecalis, complicated by recrudescent fever and new-onset systolic mitral murmur. The transesophageal echocardiogram revealed a large vegetation on the posterior leaflet of the mitral valve, with a high embolic risk, leading to a diagnosis of acute endocarditis. The patient began antibiotics, with no clinical improvement, developing severe heart failure and coronary and cerebrovascular embolic phenomena, and underwent excision of the mass and placement of a biological mitral prosthesis. The histopathologic analysis revealed a cavernous hemangioma.Eight months later, the patient presented with recurrence of acute bacterial endocarditis and septic shock, and underwent replacement of the prosthetic valve. The histologic exam showed no signs of hemangioma.The rarity of this case and its complications make its presentation relevant.     

Chronic sternal wound infection and endocarditis with Coxiella burnetii.

Chronic Q fever is most commonly associated with culture-negative endocarditis and less frequently with infection of vascular grafts, infection of aneurysms, hepatitis, pulmonary disease, osteomyelitis, and neurological abnormalities. We report a case of chronic sternal wound infection, polyclonal gammopathy, and mixed cryoglobulinemia in which Q fever endocarditis was subsequently diagnosed. Polymerase chain reaction analysis of the wound tissue was positive for Coxiella burnetii DNA, and treatment of the endocarditis resulted in prompt healing of the wound. Chronic Q fever can occur without epidemiological risk factors for C. burnetii exposure and can produce multisystem inflammatory dysfunction, aberrations of the immune system, and persistent wound infections.     

Dysregulation of cytokines in acute Q fever: role of interleukin-10 and tumor necrosis factor in chronic evolution of Q fever

Q fever manifests as primary infection or acute Q fever and may become chronic in patients with underlying valvulopathy. Because Coxiella burnetii infection depends on host response, we measured tumor necrosis factor (TNF), interleukin (IL)-6, IL-12, and IL-10 in patients with different clinical presentations of acute Q fever. Compared with control subjects, patients with uncomplicated acute Q fever exhibited increased release of the 4 cytokines. Their amounts were higher in patients with hepatitis than in patients with fever or pneumonia. In patients with valvulopathy, who exhibited the highest risk of chronic evolution, the amounts of TNF and IL-10 were higher than in patients without valvulopathy. TNF production was specifically enhanced in patients who developed Q fever endocarditis. These results show that acute Q fever is associated with cytokine overproduction. Persistent TNF amounts were associated with the occurrence of endocarditis in patients with valvulopathy, and that may be a marker of chronic evolution of Q fever.     

Whipple's endocarditis: review of the literature and comparisons with Q fever, Bartonella infection, and blood culture-positive endocarditis.

Whipple's disease is a systemic infection sometimes associated with cardiac manifestations. Recently, there has been an increase in the number of reported cases of Whipple's endocarditis. The purpose of our study was to describe this entity. Data from 35 well-described cases of Whipple's endocarditis were collected and compared with those of blood culture-positive endocarditis, Q fever endocarditis, and Bartonella endocarditis. Some patients with generalized Whipple's disease presented with cardiac involvement, among other symptoms. Others presented with a nonspecific, blood culture-negative endocarditis with no associated symptoms. In comparison with cases of endocarditis due to other causes, congestive heart failure, fever, and previous valvular disease were less frequently observed in the cases of Whipple's endocarditis. Without examination of the excised valves, the diagnosis of infective endocarditis could not have been confirmed in most cases. Treatment is not well established. Whipple's endocarditis is a specific entity involving minor inflammatory reactions and negative blood cultures, and its incidence is probably underestimated.     

Doxycycline and chloroquine as treatment for chronic Q fever endocarditis

Endocarditis is a rare but severe complication of Q fever, an infectious disease caused by the intracellular pathogen Coxiella burnetii. Heart involvement is the most common clinical presentation of chronic Q fever, and it occurs almost invariably in patients with previous valvular disease or artificial valves, and in the immunocompromised host. The optimal treatment of Q fever endocarditis is still today debated, and recommended duration of treatment varies from one year to one's lifespan. A case of chronic Q fever endocarditis is described in a patient with biological prosthetic aortic valve and aortic homograft, successfully treated with doxycycline and chloroquine for 2 years.