Q fever endocarditis

Despite a worldwide distribution of Coxiella burnetii, only single cases of Q fever endocarditis have been reported outside Great Britain and Australia. We present 10 patients; five were female, only four had a history of environmental exposure, and the mitral valve was involved as commonly as the aortic valve. One patient had congenital aortic stenosis, and three patients had a prosthetic valve. We confirm the importance of hepatic involvement, thrombocytopenia and hypergammaglobulinemia as diagnostic features. Diagnosis was established by finding an elevated complement-fixing antibody to Phase I C. burnetii antigen. Tetracycline, with or without lincomycin or cotrimoxazole, was used in nine patients, and one patient received cotrimoxazole as the sole antibiotic agent. Optimal duration of therapy is unknown. In one patient, relapse followed when treatment was stopped after 18 months. Valve replacement was necessary in five patients, because of hemodynamic problems. Five patients died, and the mean survival is 36 months with a range of five to 66 months. We suggest that Q fever endocarditis is frequently missed, and we recommend clinicians to consider the diagnosis in all cases of culture-negative endocarditis.     

Q Fever Presenting As Recurrent, Culture-negative Endocarditis with Aortic Prosthetic Valve Failure: A Case Report and Review of the Literature.

The present report describes a case of recurrent, culture-negative endocarditis presenting with aortic prosthetic valve dysfunction in a 62-year-old man who required four valve replacement surgeries. On each occasion, he presented with valve failure. Fever was only documented during his first presentation. Furthermore, no vegetations were detectable on his aortic valve at transesophageal echocardiography. On the occasion of his most recent presentation, a detailed history of animal exposure - including hunting and skinning deer, moose and other large animals with his bare hands - was the only clue to his diagnosis. Serum antibodies against Coxiella burnetii were strongly positive, and C burnetii DNA was detected by polymerase chain reaction from his resected aortic valve tissue. Q fever is a worldwide zoonotic infection with diverse reservoirs. This diagnosis should be considered when evaluating unexplained prosthetic valve dysfunction, particularly in the setting of animal exposure.     

Q fever endocarditis in the United States.

A patient with Q fever endocarditis, which is almost unknown in the United States, was followed for a total of 32 months; the study was begun 3 1/2 months before aortic valve replacement. Diagnosis was confirmed by serology, visualization of Coxiella burnetii in excised aortic valve tissue by direct and immunofluorescence staining, and isolation of C. burnetii from aortic valve tissue. Serum antibodies against phase I and phase II antigens of C. burnetii were identified. Almost all phase I and phase II antibodies were IgG. These findings are compared with those in an uncomplicated case of acute Q fever. New findings on the immune response to chronic Q fever are presented.     

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.     

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.     

Coxiella burnetii endocarditis: long-term clinical course in 20 patients

INTRODUCTION AND OBJECTIVES: Coxiella burnetii is a causative agent of increasingly frequent subacute infective endocarditis, and is associated with elevated morbimortality. Our aim in the present study was to assess the clinical, serological and therapeutic long-term evolution of 20 patients with Coxiella burnetii endocarditis. METHODS: Twenty patients (13 male and 7 female, age 42 +/- 10 years) admitted between 1982 and 1996 were retrospectively studied. All of them fulfilled the Duke criteria modified by Raoult for Q fever endocarditis. RESULTS: Endocarditis involved prosthetic and native valves in 14 and 6 patients, respectively. All patients except one received antibiotic treatment. Patients treated with doxycycline in monotherapy showed worse evolution than those treated with doxycycline in combination with other antibiotics. Valve replacement was performed in 15 patients, due to prosthetic dysfunction in most of them. The overall mortality was 40% (8 patients). At follow-up of 74 months (range 19-156) (mean 74 +/- 47) all patients showed persistent high levels of phase I antibodies. At follow-up of 15 to 65 months (32 +/- 30) antibiotic treatment was suspended in five patients because they were asymptomatic and without microbiologic findings of valvular endocarditis. CONCLUSIONS: Q fever endocarditis was associated with severe complications, which often required valve replacement. All patients showed persistent high serological titers of Coxiella burnetii endocarditis without other signs of active infection. This finding raises the issue of suspending antibiotic treatment in patients with negative microbiologic findings and questions the persistence of abnormal serology as a monitor of treatment efficacy.     

Influence of etiology on the functional result of aortic valve replacement

The functional result of aortic valve replacement has been assessed in patients treated for isolated aortic incompetence. Using maximal oxygen uptake as an index of myocardial function, a significant difference (p less than .05) exists between the patients who had Q fever endocarditis on the one hand and those who had bacterial endocarditis or rheumatic fever on the other hand. We believe that permanent myocardial damage occurs as a result of bacterial endocarditis and rheumatic fever but because of the biological properties of Coxiella burnetii the myocardium is spared in Q fever endocarditis.     

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.     

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.     

Quiescent Q fever endocarditis exacerbated by cardiac surgery and corticosteroid therapy

Q fever endocarditis occurs in up to 11% of patients infected by Coxiella burnetti. Major clues for the diagnosis are culture-negative endocarditis, hepatic involvement, rash, and thrombocytopenia. Characteristically, the diagnosis is delayed. In our patient, Q fever endocarditis occurred without previously recorded signs of infection. Fever, rash, and hepatic involvement all occurred following aortic valve replacement. The histologic picture of the excised valve was consistent with endocarditis, and serologic tests disclosed elevated IgA and IgG antiphase 1 antibody titers against C burnetti, compatible with Q fever endocarditis. It is assumed that the exacerbation of quiescent Q fever endocarditis was caused by cardiac surgery and steroid therapy.     

Q fever: current concepts

Persons with Q fever usually present with severe retrobulbar headache, a fever to 104 degrees F or higher with shaking chills, general malaise, myalgia, chest pain, and sometimes pneumonia and hepatitis. Cattle, sheep, goats, and ticks are the primary reservoirs of the etiologic agent, Coxiella burnetii. Humans are usually infected by inhaling infectious aerosols. Because C. burnetii can survive for long periods in the environment, it poses a continuing health hazard once it is disseminated. Q fever usually occurs sporadically, but large outbreaks are frequently observed throughout the world, particularly among abattoir workers and personnel working in research centers. Q fever endocarditis follows a chronic course and is frequently fatal. Tests for antibodies to C. burnetii are required for confirmation of the diagnosis. Tetracyclines remain the mainstay of treatment for acute Q fever, and tetracyclines in combination with other antibiotics have been advocated for patients with Q fever endocarditis. Vaccines for Q fever have been proven effective in clinical trials.     

Endocarditis caused by Coxiella burnetii in aortic prosthesis. Presentation of a case with a fatal course

A case of endocarditis caused by Coxiella burnetii in a patient with an aortic Starr-Edwards prosthesis is described. The diagnosis was made by detecting high titres of antibody against Coxiella burnetii phase I antigens. After 15 weeks of chemotherapy with tetracycline and cotrimoxazole, aortic prosthetic valve replacement was carried out because of haemodynamic deterioration and he died 4 days later. The histologic picture of the excised valve was consistent with endocarditis. Coxiella burnetii should be considered in the differential diagnosis of culture-negative endocarditis in our country, especially when the patient has not receiving antibiotic treatment in the last 2 weeks.     

Q Fever Endocarditis Presenting with Superior Mesenteric Artery Embolism and Renal Infarction

Q fever is a zoonotic disease with a reservoir in mammals, birds, and ticks. Acute cases in human beings can be asymptomatic, or they can present with a flu-like illness, pneumonia, or hepatitis. Approximately 5% of cases progress to chronic Q fever. Endocarditis, the most typical manifestation of chronic Q fever, is usually associated with small vegetations that occur in patients who have had prior valvular damage or who are immunocompromised. We present what we think is the first reported case of superior mesenteric artery embolism from Q fever endocarditis of the aortic valve, in a 39-year-old woman who needed surgical embolectomy and subsequent aortic valve replacement.     

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.     

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.     

1例Q热肺炎诊治报告北大核心CSCD

Q热是一种重要的人兽共患病,病原体为贝氏柯克斯体(Coxiella burnetii),其经呼吸道吸入进入体内,引起急性Q热,严重急性Q热可出现肺炎、肝炎或心肌炎并发症。部分患者治疗不彻底转为慢性Q热。慢性Q热为贝氏柯克斯体在机体局部持续感染,常需要外科手术及数年抗感染治疗,其严重危害患者身体健康及加重家庭经济负担;。追其原因是临床医生对该病认识不足,导致延误治疗所致。本文旨在报告1例Q热肺炎的诊治和体会,以提高临床医生对该病认识。     

Silent Q fever endocarditis. Report of a case]

A murmur of aortic regurgitation was discovered in an asymptomatic patient who had suffered from an acute Coxiella Burnetti infection several months before hand. Transoesophageal echocardiography, serology and direct immunofluorescence of the aortic valve confirmed the diagnosis of Q fever endocarditis. Treatment with Vibramycin and Plaquenil was instituted after aortic valve replacement. Cardiac complications of Q fever should be recognised as they may remain asymptomatic for long periods of time. Transthoracic and transoesophageal echocardiography should be widely used in acute forms of Q fever and systematic in chronic infections with Coxiella Burnetti.     

Q fever 1985-1998. Clinical and epidemiologic features of 1,383 infections

In order to describe the clinical features and the epidemiologic findings of 1,383 patients hospitalized in France for acute or chronic Q fever, we conducted a retrospective analysis based on 74,702 sera tested in our diagnostic center, National Reference Center and World Health Organization Collaborative Center for Rickettsial Diseases. The physicians in charge of all patients with evidence of acute Q fever (seroconversion and/or presence of IgM) or chronic Q fever (prolonged disease and/or IgG antibody titer to phase I of Coxiella burnetii > or = 800) were asked to complete a questionnaire, which was computerized. A total of 1,070 cases of acute Q fever was recorded. Males were more frequently diagnosed, and most cases were identified in the spring. Cases were observed more frequently in patients between the ages of 30 and 69 years. We classified patients according to the different clinical forms of acute Q fever, hepatitis (40%), pneumonia and hepatitis (20%), pneumonia (17%), isolated fever (17%), meningoencephalitis (1%), myocarditis (1%), pericarditis (1%), and meningitis (0.7%). We showed for the first time, to our knowledge, that different clinical forms of acute Q fever are associated with significantly different patient status. Hepatitis occurred in younger patients, pneumonia in older and more immunocompromised patients, and isolated fever was more common in female patients. Risk factors were not specifically associated with a clinical form except meningoencephalitis and contact with animals. The prognosis was usually good except for those with myocarditis or meningoencephalitis as 13 patients died who were significantly older than others. For chronic Q fever, antibody titers to C. burnetii phase I above 800 and IgA above 50 were predictive in 94% of cases. Among 313 patients with chronic Q fever, 259 had endocarditis, mainly patients with previous valvulopathy; 25 had an infection of vascular aneurysm or prosthesis. Patients with endocarditis or vascular infection were more frequently immunocompromised and older than those with acute Q fever. Fifteen women were infected during pregnancy; they were significantly more exposed to animals and gave birth to only 5 babies, only 2 with a normal birth weight. More rare manifestations observed were chronic hepatitis (8 cases), osteoarticular infection (7 cases), and chronic pericarditis (3 cases). Nineteen patients were observed who experienced first a documented acute infection, then, due to underlying conditions, a chronic infection. To our knowledge, we report the largest series of Q fever to date. Our results indicate that Q fever is a protean disease, grossly underestimated, with some of the clinical manifestations being only recently reported, such as Q fever during pregnancy, chronic vascular infection, osteomyelitis, pericarditis, and myocarditis. Our data confirm that chronic Q fever is mainly determined by host factors and demonstrate for the first time that host factors may also play a role in the clinical expression of acute Q fever.     

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.     

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.