Endocarditis is also called infective endocarditis (IE), bacterial endocarditis (BE) or subacute bacterial endocarditis. Endocarditis presents itself as an inflammation of the lining of the heart valves caused by bacteria, rarely fungi or some other organisms through blood stream. These bacteria cause plaques and injury or scarring to heart valves leading to leaky valves. Endocarditis will produce symptoms of fever, chills, sweats, weakness, muscle/joint pain, chest pain, and shortness of breath and swelling of legs/hands.
Diagnosis of Endocarditis
Endocarditis is diagnosed with the help of medical history, blood test and electrocardiogram, on occasion’s echocardiogram can also be done. The spread of infection to other organs is detected with the aid of chest x-ray, MRI and CT scan. The definitive diagnostic for endocarditis is positive blood culture and positive echocardiogram. Blood cultures should be taken for suspected endocarditis patients before starting antibiotic treatment. Blood cultures not only help in confirming the diagnosis of endocarditis, but it also helps in detecting the causative agent for endocarditis and its susceptibility and sensitivity to different antibiotics. Some cultures are negative for causative microorganism in endocarditis and this might be due to slow-growing microorganisms or due to prior administration of antimicrobials before taking blood culture. In these cases, systemic approach should be adopted for serological investigation.
How Long Do You Need To Take Antibiotics for Endocarditis?
The first line of treatment for endocarditis is antibiotic therapy for infection caused by bacteria and if it is caused by fungus then anti-fungals are used. There are different types of antibiotics used for different strains of bacteria as each strain is susceptible to different antibiotic. A patient is infected with which strain will be determined by lab culture and the particular strain is sensitive for which antibiotic will also be determined in the susceptibility test in the laboratory itself. The most common species of bacteria that cause endocarditis are staphylococcus, streptococcus and enterococcal.
Other species that can cause endocarditis are HACEK (Haemophilus, Actinobacillus actinomycetemcomitans, Cardiobacterium hominis, Eikenella and Kingella), Bartonella, Brucella, Chlamydia, Coxiella, Legionella, mycobacteria and various fungi (Candida, Aspergillus, Trichosporon and Mucorales). The course of antibiotic treatment will depend totally on the type and severity of infection. Usually, the minimum course of antibiotic treatment that is suggested is 4 weeks that can be extended to up to 6 weeks if the signs of infection persist after 4 week therapy.
The different antibiotics that are used are gentamicin in the dosage of 1mg/kg body weight every 8 hourly IV/IM; streptomycin 7.5mg/kg body weight every 12 hourly; vancomycin 1 g IV every 12 hourly; teicoplanin 10 mg/kg body weight every 12 hourly followed by 10 mg/kg daily and/or amoxicillin/ampicillin 2 g IV every 4-6 hourly.
Empirical therapy is used in cases of penicillin resistant species, i.e., a combination of flucloxacillin 8-12 g in 4-6 daily divided doses along with gentamicin 1mg/kg body weight every 8 hourly; ampicillin/amoxicillin along with gentamicin. In MRSA resistant patients vancomycin 1 g 12 hourly along with rifampicin 300-600 mg 12 hourly orally and gentamicin 1 mg/kg 8 hourly IV is used.
Fungal infection is treated with amphotericin B 1 mg/kg daily and flucytosine 100 mg/kg in 4 divided doses; fluconazole 400 mg 12 hourly; caspofungin 70 mg initially followed by 50 mg daily; voriconazole 6 mg/kg 12 hourly on the first day followed by 4 mg/kg 12 hourly IV. The minimum course for fungal infection is 6 weeks that can also be extended to more depending on recovery of the patient. Unfortunately, fungal infection requires surgical intervention most of the times. In all the cases of therapy renal function should be monitored closely whether it is antibiotic treatment or anti-fungal treatment.
Apparently, there is high mortality and morbidity rate around 20% in patients suffering from endocarditis. Although, most of the times antibiotic therapy will be sufficient in endocarditis cases, but approximately 20 to 25% cases might require surgery. Therefore, it is best to limit exposure to any infection that might be a trigger to it and to visit doctor at the first sign and symptom of the disease without any delay.