What are the Jones criteria for diagnosing acute rheumatic fever and the recommended treatment and secondary prophylaxis?

Jones Criteria for Acute Rheumatic Fever

Diagnostic Framework

The 2015 revised Jones Criteria require documented evidence of recent group A streptococcal (GAS) infection PLUS either 2 major manifestations OR 1 major and 2 minor manifestations, with different thresholds based on population risk. 1

Evidence of Preceding GAS Infection (Required)

• Positive throat culture or rapid antigen detection test 2
• Elevated or rising anti-streptolysin O (ASO) titer 3
• Elevated anti-DNase B titer 3
• Combined ASO and anti-DNase B testing detects up to 98% of proven streptococcal cases 3

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Population Risk Stratification (Critical First Step)

Low-Risk Populations

• ARF incidence ≤ 2 per 100,000 school-aged children per year 2, 3
• OR rheumatic heart disease (RHD) prevalence ≤ 1 per 1,000 population per year 2, 3

Moderate-to-High-Risk Populations

• Exceed the above thresholds 2, 3
• Require more sensitive (but less specific) diagnostic criteria 2, 3

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Major Criteria

For Low-Risk Populations

• Carditis – clinical signs OR subclinical involvement detected by Doppler echocardiography 2
• Polyarthritis – involvement of ≥ 2 joints (monoarthritis does NOT qualify) 2
• Sydenham's chorea 2
• Erythema marginatum – evanescent pink rash with pale centers and serpiginous margins on trunk and proximal extremities; never facial, blanches with pressure 1, 2
• Subcutaneous nodules – firm, painless nodules over bony prominences (knees, elbows, wrists, occiput, spinous processes) 1, 2

For Moderate-to-High-Risk Populations (Expanded Criteria)

• All of the above low-risk major criteria 2
• Monoarthritis – single joint involvement now counts as major 2
• Polyarthralgia – joint pain without swelling (after exclusion of other causes) now counts as major 2

Critical pitfall: Erythema marginatum and subcutaneous nodules almost never occur as isolated findings; they are nearly always accompanied by carditis. 2

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Minor Criteria

For Low-Risk Populations

• Polyarthralgia (joint pain without swelling) 2
• Fever ≥ 38.5°C 2
• Elevated inflammatory markers – ESR ≥ 60 mm/h OR CRP ≥ 3.0 mg/dL 2
• Prolonged PR interval on ECG (unless carditis is already counted as major) 2

For Moderate-to-High-Risk Populations (Lower Thresholds)

• Monoarthralgia (lower threshold than polyarthralgia) 2
• Fever ≥ 38°C (lower threshold) 1, 2
• Elevated inflammatory markers – ESR ≥ 30 mm/h OR CRP ≥ 3.0 mg/dL (lower ESR threshold) 2
• Prolonged PR interval (unless carditis is already major) 2

Critical pitfall: A joint manifestation can be counted EITHER as a major OR a minor criterion, never both in the same patient. 2

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Echocardiographic Criteria for Subclinical Carditis

Subclinical carditis detected by Doppler echocardiography now counts as a major manifestation—this represents the most significant change from the 1992 criteria. 1, 2

Pathological Mitral Regurgitation (ALL criteria required)

• Jet visible in ≥ 2 echocardiographic planes 2
• Jet length > 1 cm 2
• Holosystolic timing 2
• Peak velocity > 2.5 m/s 2

Pathological Aortic Regurgitation (ALL criteria required)

• Jet visible in ≥ 2 echocardiographic planes 2
• Holodiastolic timing 2
• Peak velocity > 2.5 m/s 2

Echocardiography Pitfalls

• Blood pressure must be measured at the time of echocardiography because systemic pressure influences jet characteristics 2
• Peak velocity < 3.0 m/s is more likely physiological regurgitation 2
• Must differentiate rheumatic valvulitis from physiological regurgitation, mitral valve prolapse, congenital valve anomalies (bicuspid aortic valve, cleft mitral valve), and infective endocarditis 2
• Standard echocardiography with Doppler should be performed in all suspected cases regardless of auscultation findings 4

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Special Diagnostic Scenarios

Recurrent ARF (Prior ARF or Established RHD)

In patients with documented prior ARF/RHD and recent GAS infection, the diagnostic threshold is lowered to ANY of the following: 1, 2

• 2 major manifestations 1, 2

• OR 1 major + 2 minor manifestations 1, 2

• OR 3 minor manifestations 1, 2

• When only minor manifestations are present, exclude other causes before diagnosing recurrent ARF 1

"Possible" Rheumatic Fever

• When clinical suspicion remains high despite incomplete Jones criteria, offer 12 months of secondary prophylaxis followed by repeat detailed history, physical examination, and echocardiography 1, 2
• If recurrent joint symptoms occur in a patient adherent to prophylaxis WITHOUT serologic evidence of GAS infection AND WITHOUT echocardiographic valvulitis, the symptoms are likely unrelated to ARF and discontinuation of prophylaxis may be appropriate 1, 2

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Differential Diagnoses to Exclude

• Infective endocarditis – must be ruled out in any patient with valvular abnormalities 2
• Post-streptococcal reactive arthritis 5
• Lyme disease 5
• Serum sickness and drug reactions 5
• Systemic lupus erythematosus 2
• Congenital valve abnormalities (bicuspid aortic valve, cleft mitral valve) 2
• Viral myocarditis 2

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Key Diagnostic Pitfalls

• Normal ESR and CRP levels should prompt serious reconsideration of the ARF diagnosis, except in patients with isolated chorea where inflammatory markers may be normal 1
• Cardiac auscultation alone has very low sensitivity for diagnosing carditis and should never be relied upon as the sole method for excluding cardiac involvement 4
• Fever associated with ARF usually exceeds 38.5°C orally in most settings; the widespread availability of antipyretic agents requires detailed history to contextualize fever presentation 1
• Worsening of choreiform movements in a child with previous low-grade residual chorea may be difficult to distinguish from a new attack 1