Successful Medical Treatment of Prosthetic Mitral Valve Endocarditis Caused by Brucella abortus

Brucella infection presenting as infective endocarditis complicated by embolic stroke

Brucellosis (undulant fever) is a zoonotic infection caused by Brucella species. It typically presents with fever, malaise, night sweats, and arthralgia. One of its rare complications is infective endocarditis, which occurs in approximately 1.3% of patients and can be further complicated by embolic stroke. This report describes a rare occurrence of Brucella endocarditis presenting as an embolic stroke. A 34-year-old male presented with sudden left-sided weakness and fever. He reported headaches, fever, and generalized weakness in the preceding week. The patient worked on a farm and hence had animal contact. A neurological exam showed left-sided facial weakness, and power of 0/5 and 1/5 in the left upper and lower extremities, respectively. CT scan of the head revealed a right middle cerebral artery (MCA) territory infarct with penumbra and a right MCA occlusion. He underwent a cerebral artery thrombectomy with successful recanalization. However, he continued to have fever and high inflammatory markers. Echocardiography showed aortic valve vegetation and blood cultures grew Brucella melitensis. A multidisciplinary meeting was held to determine the optimal management, which included a course of rifampicin and doxycycline.

Four decades of experience of prosthetic valve endocarditis reflect a high variety of diverse pathogens

Prosthetic valve endocarditis (PVE) remains a serious condition with a high mortality rate. Precise identification of the PVE-associated pathogen/s and their virulence is essential for successful therapy, and patient survival. The commonly described PVE-associated pathogens are staphylococci, streptococci and enterococci, with Staphylococcus aureus being the most frequently diagnosed species. Furthermore, multi-drug resistance pathogens are increasing in prevalence, and continue to pose new challenges mandating a personalized approach. Blood cultures in combination with echocardiography are the most common methods to diagnose PVE, often being the only indication, it exists. In many cases, the diagnostic strategy recommended in the clinical guidelines does not identify the precise microbial agent and to frequently, false negative blood cultures are reported. Despite the fact that blood culture findings are not always a good indicator of the actual PVE agent in the valve tissue, only a minority of re-operated prostheses are subjected to microbiological diagnostic evaluation. In this review, we focus on the diversity and the complete spectrum of PVE-associated bacterial, fungal and viral pathogens in blood, and prosthetic heart valve, their possible virulence potential, and their challenges in making a microbial diagnosis. We are curious to understand if the unacceptable high mortality of PVE is associated with the high number of negative microbial findings in connection with a possible PVE. Herein, we discuss the possibilities and limits of the diagnostic methods conventionally used and make recommendations for enhanced pathogen identification. We also show possible virulence factors of the most common PVE-associated pathogens and their clinical effects. Based on blood culture, molecular biological diagnostics, and specific valve examination, better derivations for the antibiotic therapy as well as possible preventive intervention can be established in the future.

Brucella Prosthetic Valve Endocarditis: A Systematic Review

Objective

Brucella prosthetic valve endocarditis is a rare but a life-threatening complication of brucellosis. It remains a diagnostic challenge. Optimal treatment of Brucella prosthetic valve endocarditis is debated. Available data is limited to case reports or small case series. The purpose of this study was to systematically review all published cases of Brucella prosthetic valve endocarditis in the literature.

Method

A systematic review of PubMed database, Google, Google Scholar, and Scopus (From January 1974 to the present) for studies providing epidemiological, clinical and microbiological data as well as data on treatment and outcomes of Brucella prosthetic valve endocarditis was performed.

Results

A total of 51 reported cases were reviewed. Brucella melitensis (45%) and Brucella abortus (11.7%) were the most frequently isolated species. Most common type of prosthesis valve was mechanical prothesis (84.3%) and ten patients had double valve prosthesis (19.6%). Fever and dyspnea were present in 100% and 37.2% of the cases, respectively. The diagnosis was set with echocardiographic finding in 30 cases (93.7%), which revealed vegetation in 27 cases (84.3%). Most used antibiotics were rifampicin, doxycycline and aminoglycoside or cotrimoxazole. No deaths were noted in patients treated by combined medical and surgical treatment, but mortality was noted in 27.7% of the cases treated by antibiotics alone (p = 0.006).

Conclusion

This systematic review highlights diagnostic challenges and demonstrates that surgery improved outcome by reducing mortality in patients treated with the combined surgical and medical treatment option. Brucellosis should be considered in the differential diagnosis of prosthetic valve endocarditis in patients residing in or traveling to areas of endemicity.

Brucella Endocarditis of the Native Mitral Valve Treated With Antibiotics

Brucellosis is a rare zoonotic infection with a low annual incidence in the United States. Infective endocarditis secondary to brucellosis involving native or prosthetic valves is contemplated to be an extremely rare entity. As Brucella can present with non-specific sign and symptoms, clinicians need to have a higher degree of suspicion of Brucella endocarditis in culture-negative endocarditis patients, particularly those who have a history of exposure to farm animals. Timely diagnosis with appropriate management using antibiotics can prevent valvular damage and restore the valve's structural integrity. In this case report, we present a case of culture-negative, serology-proven Brucella endocarditis of native mitral valve, with an initial presentation of stroke that was successfully treated with combination antibiotic therapy.

Successful Management of Prosthetic Valve Brucella Endocarditis with Antibiotherapy Alone

Objectives

To report a case of mechanical aortic prosthesis Brucella endocarditis successfully treated with antibiotics alone.Materials and methods: We describe a clinical case and present a review of the literature.

Results

A 60-year-old female farmer with a mechanical aortic prosthetic valve presented with low back pain and fever. She was diagnosed with prosthetic valve Brucella mellitensis endocarditis and was cured with antibiotic therapy alone. Few cases of successfully treated prosthetic valve Brucella endocarditis without surgery have been reported.

Conclusion

Prosthetic valve Brucella endocarditis usually requires surgical valve replacement. However, selected patients may be successfully treated with antibiotic therapy alone.

LEARNING POINTS

Brucella endocarditis is responsible for most fatal cases of brucellosis.Brucellosis relapse after treatment in patients with a cardiac valve prosthesis should arouse suspicion for endocarditis.Long-term medical treatment alone can be successful in selected patients with Brucella endocarditis, even in those with prosthetic valve endocarditis..