Introduction

• Most common cause of acquired heart disease in children and young adults worldwide
• The incidence has declined remarkably in the industrialized countries
• In many developing countries, rheumatic fever, and rheumatic heart disease remain a very significant public health problem

EPIDEMIOLOGY

• Identical to that of group A streptococcal upper respiratory tract infections
• Most often occurs in children - 5 and 15 years
• Most initial attacks in adults take place at the end of the second and beginning of the third decades

EPIDEMIOLOGY

• Risk factors classically associated with individual attacks or outbreaks of acute rheumatic fever - lower standards of living, overcrowding, socially and economically disadvantaged populations

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EPIDEMIOLOGY

• 3% of individuals with untreated group A streptococcal pharyngitis will develop rheumatic fever
• The epidemiology of rheumatic fever is also influenced by the serotypes of group A streptococci (e.g., serotypes 1, 3, 5, 6, 18, etc.)
• Mucoid isolates are frequently associated with virulence and with rheumatic fever

PATHOGENESIS

• Grouped into three major categories

(1) Direct infection by the group A

Streptococcus

(2) Toxic effect of streptococcal extracellular products on the host tissues

(3) Abnormal or dysfunctional immune response to one or more as yet unidentified somatic or extracellular antigens produced by all (or perhaps only by some) group A streptococci

PATHOGENESIS

• Hypothesis of “Antigenic mimicry" between human and group A streptococcal antigens has been studied extensively
• Similarity between the group-specific carbohydrate of the group A streptococcus and the glycoprotein of heart valves
• Molecular similarity among the streptococcal cell membrane, streptococcal M protein sarcolemma, and other moieties of the human myocardial cell

Diagnosis

• Mainly clinical
• Requires supporting evidence from clinical microbiology and clinical immunology laboratories.
• Jones(1944) proposed criteria to assist in standardizing the diagnosis of RF
• Modified in 1992 by the American Heart Association

The Jones Criteria for Rheumatic Fever, Updated 1992

• Major Criteria
• Carditis
• Migratory polyarthritis
• Sydenham's chorea
• Subcutaneous nodules
• Erythema marginatum

• Minor Criteria
• Clinical
• fever
• Arthralgia
• Laboratory
• Elevated acute phase reactants
• Prolonged PR interval

plus

• Supporting evidence of a recent group A streptococcal infection
• positive throat culture or
• rapid antigen detection test; and/ or elevated or
• increasing streptococcal antibody test

Carditis of ARF

• Pan carditis - pericardium, myocardium, and endocardium
• 40 and 60% - have evidence of carditis
• Features of Pan Carditis
• sinus tachycardia
• murmur of mitral regurgitation
• S3 gallop
• pericardial friction rub
• cardiomegaly
• prolonged PR interval and evidence of heart failure may be present – nonspecific

Carditis of ARF

• Healing of the rheumatic valvulitis

Causes fibrous thickening and adhesion - resulting in valvular stenosis and/or regurgitation

• Mitral valve is involved most frequently, followed by the aortic valve
• Isolated aortic valve disease - rare
• Rheumatic pericarditis - serous effusion, fibrin deposits, and even pericardial calcification

Migratory polyarthritis

• Present in as many as 75% of cases
• Affects the ankles, wrists, knees, and elbows over a period of days
• Does not affect the small joints of the hands or feet and seldom involves the hip joints
• Arthralgia should not be used as a major criterion

Sydenham's chorea

• Occurs in fewer than 10% of patients with rheumatic fever.
• Latent period between the onset of the initiating streptococcal infection and the onset of Sydenham's chorea may be as long as several months

Subcutaneous nodules

• Present in fewer than 10% of cases.
• Subcutaneous nodules are found over extensor surfaces of joints, are seen most often in patients with long-standing rheumatic heart disease
• Extremely rare in initial attack

Erythema marginatum

• Erythema marginatum is an uncommon manifestation - evanescent macular eruption with rounded borders usually concentrated on the trunk

Diagnosis with Jones criteria

• Either two major criteria or
• One major criterion and two minor criteria

plus

• Evidence of an antecedent streptococcal infection are required
• recovery of the organism on culture

or

• by evidence of an immune response to one of the commonly measured group A streptococcal antibodies (e.g., anti-streptolysin O, anti-deoxyribonuclease B, anti-hyaluronidase)

Diagnosis

• Group A streptococci can be recovered from the URT of only 25 to 40% of patients at the time of diagnosis
• Two or three throat cultures should be obtained before antibiotic therapy
• 80% of patients with ARF have an elevated ASO titer at presentation

Diagnosis

• Sensitivity increases to 95% with anti- deoxyribonuclease B, anti-hyaluronidase
• Demonstration of a rising titer from the acute to the convalescent phase
• More reliable means of documenting the recent infection
• Diagnosis should be reconsidered if three antibody tests are negative and there is no evidence of a preceding infection

Differential Diagnosis

• Arthritis : RA, SLE, Reactive arthritis, Serum sickness, Sickle cell disease, Malignancies, Lyme disease, Gonococcal infection
• Carditis : Viral myocarditis, Viral pericarditis, IE, Kawasaki disease
• Chorea : Huntington chorea, Wilson disease, SLE, Cerebral palsy, Tics

Treatment

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• Anti-streptococcal antibiotic therapy

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• Therapy for the clinical manifestations of the disease

Treatment

• Patients should be treated as if they have GAS– irrespective of culture status

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• 10-day course in adults of oral penicillin V (500 mg BD)
• Erythromycin (250 mg QID) - in penicillin allergy
• Benzathine penicillin G - a single intramuscular injection of 1.2 million units

Medical therapy for the manifestations of ARF

• With arthritis
• Salicylates up to 2 g four times daily are very effective
• May be given for 4 to 6 weeks and gradually tapered to prevent a rebound
• The ESR is used to determine the rate of tapering for salicylates

Medical therapy for the manifestations of ARF

• With significant carditis
• Steroid therapy is particularly effective and may be lifesaving in very ill patients
• Prednisone 30mg QID
• No evidence that steroid therapy affects the course of carditis or diminishes the incidence of residual heart disease
• Conventional medical measures for heart failure if CHF

Medical therapy for the manifestations of ARF

• Previously patients with Acute Rheumatic fever were kept at complete bed rest for months
• Now, indication for complete bed rest include
• Persistent active carditis
• Severe heart failure

Medical therapy for the manifestations of ARF

• Patients with arthritis will begin to feel better very soon after anti-inflammatory therapy with salicylates is begun
• Released from bed rest then, but
• Should not resume full activity
• Until signs of inflammatory process have abated
• Acute-phase reactants -- returned to normal

Secondary prophylaxis

• Initiated to prevent subsequent colonisation of the upper respiratory tract with group A streptococci
• Recommendations of the AHA & WHO
• Intramuscular injection of 1.2 million units of Benzathine penicillin G every 3-4 weeks

OR

• Oral penicillin V (250 mg twice daily)

OR

• Oral sulfadiazine (1.0 g daily)

Prognosis

• Depends on

1. Manifestation at initial episode

2. Severity of initial episode

3. Presence of recurrences