Q fever endocarditis

Q fever endocarditis, which is seen most often in Great Britain and Australia, has been rarely observed in the United States. A patient with an eight month febrile illness who had signs and symptoms of endocarditis and serologic studies diagnostic of Q fever endocarditis is reported. A history of extensive travel makes it unclear where he originally contracted the disease. Q fever endocarditis is probably underdiagnosed and should be looked for in any case of culture negative endocarditis or chronic fever of unknown origin.     

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.     

Chronic Q fever endocarditis.

Eight patients with chronic Q fever endocarditis were treated with tetracycline for up to 40 months. In addition, five of these patients received co-trimoxazole. Six patients had prosthetic valves. Two patients who had Q fever endocarditis on their native valves required valve replacement because of haemodynamic difficulties: in only one did the Q fever endocarditis contribute to the haemodynamic difficulty. One patient died. It is suggested that medical treatment is continued until clinically and haematologically there is no evidence of endocarditis and the Q fever phase 1 antibody titre is less than 200. No recurrence of Q fever endocarditis has been detected in three of our patients who have now stopped treatment.     

Cellular immunity in Q fever: specific lymphocyte unresponsiveness in Q fever endocarditis

Human infection with the rickettsia Coxiella burnetii presents as acute influenza-like primary Q fever, subacute granulomatous hepatitis, or chronic endocarditis with hepatitis. To investigate whether persistent infection is associated with a possible immunologic defect, we tested lymphocyte proliferation specific for Coxiella in vitro in peripheral blood mononuclear cells from patients and controls. All four patients with endocarditis had profound lymphocyte unresponsiveness to Coxiella antigens with normal proliferation to control antigens. Hepatitis and primary Q fever were associated with vigorous responses in vitro to Coxiella antigens. Suppression of lymphocyte unresponsiveness was in part mediated by an antigen-nonspecific, glass-adherent cell. We hypothesize that specific T cell unresponsiveness is an important factor in persistent infection with C. burnetii and offer in vitro lymphocyte stimulation as a more specific diagnostic test to distinguish cases of endocarditis among those with chronic hepatitis due to Q fever.     

Proteus mirabilis: a rare cause of infectious endocarditis

Native valve endocarditis resulting from Proteus mirabilis is an exceptionally rare entity. To date, 10 cases have been reported. We present a case of a 58-y-old female with fevers, bacteremia, and embolic phenomenon. Unlike previous cases, early antibiotic treatment precluded valvular repair or death, leading to a favorable outcome.     

Moraxella lacunata: a rare cause of infective endocarditis

We describe the first case of Moraxella lacunata definite native valve endocarditis in a patient with previously normal mitral valves. The disease was complicated with embolizations of the brain and spleen. After 6 weeks of antimicrobial treatment, valvular replacement was performed. The clinical course and diagnostic findings suggest that Moraxella lacunata possesses high aggressiveness leading to progressive valvular destruction and embolizations.     

Abiotrophia defectiva: a rare cause of infective endocarditis

A case of Abiotrophia defectiva-caused infective endocarditis is described. The patient was successfully treated with penicillin combined with gentamicin. Due to the fastidious nature of the agent, there is a need for special media for isolation and moreover, there is a need for a future development of susceptibility assays applicable to the organism.     

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 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.     

Q fever endocarditis in Queensland.

Thirteen patients with proven Q fever endocarditis and three additional patients with probable endocarditis are reviewed. The most helpful diagnostic test is the demonstration of a high complement fixing antibody titre to Phase 1 antigen of Coxiella burneti. The macroscopic pathology of the aortic valve is described and includes aneurysmal pockets in the aortic wall and valve annulus which are demonstrable angiographically. Evidence is presented that the infection may be controlled by prolonged tetracycline therapy and that this is accompanied by a falling antibody titre to Phase 1 antigen. Valve replacement is undertaken only for symptomatic and hemodynamic indications. The combined tetracycline therapy and valve replacement have produced a fall in titres with eradication of infection and palliation of the cardiac disability in all patients followed for long periods.     

Body piercing: a rare cause of mitral valve endocarditis

Body piercing has become a way of life for many individuals. It represents freedom, as well as rebellion, and can provide shock value to the public. Often, it is used as a rite of passage from adolescence into adulthood, and can also provide a boost in self-esteem. However, body piercing may lead to non-infectious complications such as prolonged bleeding and keloid formation, while infectious complications include the transmission of blood-borne infections (e.g. human immunodeficiency virus, hepatitis B, C and D), as well as bacteremia through the site of piercing. Infective endocarditis in individuals with congenital heart defects has been identified after body piercing. Here, the first documented case is reported of mitral valve endocarditis in a previously fit and healthy young female following navel piercing.