Infective Endocarditis & Acute Rheumatic Fever PDF

Infective endocarditis is a major public health challenge. In 2019, the estimated incidence of IE was 13.8 cases per 100 000 subjects per year, and IE accounted for 66300 deaths worldwide. The population at risk of IE has increased and new data on IE in different clinical scenarios have arisen....

Infective endocarditis is a major public health challenge. In 2019, the estimated incidence of IE was 13.8 cases per 100 000 subjects per year, and IE accounted for 66300 deaths worldwide. The population at risk of IE has increased and new data on IE in different clinical scenarios have arisen. Furthermore, the emerging and increasing antibiotic resistance among oral streptococci is of concern  Clinical Features IE remains a diagnostic challenge due to its variable clinical presentation. A diagnosis of IE should be considered in all patients with sepsis or fever of unknown origin in the presence of risk factors. IE may present as an acute, rapidly progressive infection, but also as a subacute or chronic disease with low-grade, or even no fever, and non-specific symptoms that may mislead or confuse initial assessment. It can also present with a complication mimicking a wide range of medical conditions, such as rheumatological, neurological, and autoimmune disorders, or even malignancy, before reaching a diagnosis of IE. Therefore, high suspicion for IE is generally driven by fever and positive blood cultures in the absence of an alternative focus of infection, especially in patients with one or more risk factors Risk Factors Granular positivity for C3 in a case of post-infectious GN. This pattern is described as "bumps and humps" or "lumpy-bumpy", traditionally associated with postinfectious GN (Immunofluorescence for C3, anti- humn-C3 antibodies marked with fluorescein, fluorescence microscopy, x400). https://www.kidneypathology.com/English_version/Histologic_patterns.html  Acute rheumatic fever (ARF) is a sequela of streptococcal infection—typically following 2 to 3 weeks after group A streptococcal pharyngitis—that occurs most commonly in children and has rheumatologic, cardiac, and neurologic manifestations. The incidence of ARF has declined in most developed countries, and many physicians have little or no practical experience with the diagnosis and management of this condition.  History Usually, a latent period of approximately 18 days occurs between the onset of streptococcal pharyngitis and the onset of ARF. This latent period is rarely shorter than 1 week or longer than 5 weeks. Approximately 70% of older children and young adults recollect the pharyngitis. However, only approximately 20% of young children recollect pharyngitis. Therefore, younger children who present with signs or symptoms consistent with ARF merit a higher index of suspicion. Typically, the first manifestation of ARF is a very painful migratory polyarthritis. Large joints such as knees, ankles, elbows, or shoulders are typically affected. Often, associated fever and constitutional toxicity develop. Sydenham chorea (ie, rapid, irregular, aimless involuntary movements of the arms and legs, trunk, and facial muscles) was once a common late-onset clinical manifestation but is now rare. Acute attacks usually resolve within 12 weeks.  Physical Examination Physical findings can be nonspecific and misleading. Therefore, a high index of suspicion is required for diagnosis. Suspicious signs for carditis include new or changing valvular murmurs, cardiomegaly, congestive heart failure, and/or pericarditis. Nearly 60% of patients with carditis develop isolated mitral valve involvement, followed in prevalence by combined mitral and aortic valve involvement.  Physical Examination Arthritis, which occurs in 80% of patients, usually involves multiple large joints, particularly the knees, ankles, elbows, and wrists. Hips and smaller joints of hands and feet are less commonly involved. Migratory polyarthritis is usually associated with a febrile illness. It involves a series of painful joints, followed by another series of painful joints. This form of arthritis rarely causes permanent joint deformity.  Diagnostic Considerations Other problems to be considered include the following: Bacterial endocarditis Still disease - Systemic-onset juvenile rheumatoid arthritis or adult Still disease Vasculitis Jones criteria for the diagnosis of initial ARF are the presence of two major manifestations or one major and two minor manifestations. Major manifestations comprise the following: Carditis, clinical and/or subclinical (ie, detected by echocardiography) Arthritis Chorea Erythema marginatum Subcutaneous nodules Minor manifestations in low-risk populations comprise the following: Polyarthralgia Fever ≥38.5°C Acute phase reactions: Erythrocyte sedimentation rate (ESR) ≥60 mm in the first hour and/or C-reactive protein (CRP) level ≥3.0 mg/dL Prolonged PR interval, after accounting for age variability (unless carditis is a major criterion) Minor manifestations in moderate- and high-risk populations comprise the following: Monoarthralgia Fever ≥38°C ESR ≥30 mm/h and/or CRP ≥3.0 mg/dL Prolonged PR interval, after accounting for age variability (unless carditis is a major criterion)  Laboratory studies According to the AHA, any one of the following can serve as evidence of preceding group A streptococcal infection: Elevated or rising streptococcal antibody titer; a rise in titer is better evidence than a single titer result A positive throat culture for group A β-hemolytic streptococci A positive rapid group A streptococcal carbohydrate antigen test in a child whose clinical presentation suggests a high pretest probability of streptococcal pharyngitis Antistreptococcal antibodies usually reach a peak titer (in Todd units) at the time of onset of ARF and are more useful for diagnosis. Specific antibodies to streptococcal antigens also indicate true infection rather than mere carriage of the organism. These antibodies target extracellular products produced by streptococci. They include the following: Antistreptolysin O (ASO) Antideoxyribonuclease B (anti-DNAse B) Antistreptokinase Antihyaluronidase Anti-DNAase (anti-DNPase)  Chest Radiography A chest radiograph may reveal cardiomegaly. See the image below.  Echocardiography with Doppler Echocardiography is the gold standard for diagnosis of rheumatic heart disease  Medical Care Treatment strategies for acute rheumatic fever (ARF) can be divided into the following: Management of the acute attack Management of the current infection Prevention of further infection and attacks Surgical Care The primary goal of treating an ARF attack is to eradicate streptococcal organisms and bacterial antigens from the pharyngeal region. Penicillin is the drug of choice in persons who are not at risk of allergic reaction. A single parenteral injection of benzathine benzylpenicillin can ensure compliance. Oral cephalosporins, rather than erythromycin, are recommended as an alternative in patients who are allergic to penicillin. Corticosteroids should be reserved for the treatment of severe carditis. After 2-3 weeks, the dosage may be tapered, reduced by 25% each week.