Acute Rheumatic Fever – The Basics Dr Peter Murray Public Health Registrar May 24, 2016

What this lecture will cover about acute rheumatic fever (ARF) Pathogenesis Epidemiology Clinical features Treatment

Pathogenesis

Pathogenesis of ARF

Pathogenesis of ARF cont

Pathogenesis of rheumatic heart disease

Epidemiology

National Epidemiology of ARF Annually: –102 cases in 2015 –Downward trend Peak age 5-14 years In New Zealand there are significant inequalities –Ethnicity Maori have a x 23 greater risk Pacific have a x 50 greater risk –Socio-economic position –Place

Local notifications since notified cases – 81 new and 5 recurrences Gender –55% male Age –82% aged 19 years or less Ethnicity –53% Pacific –44% Māori

Local notifications since 2010 cont

Clinical features

Jones Criteria Major criteria Arthritis - occurs in 75% of first episodes Carditis - occurs in 40-50% of first episodes, may be asymptomatic Chorea - occurs in 10% of first episodes Erythema marginatum - occurs in 10% of first episodes Subcutaneous nodules – 2% Minor criteria Polyarthralgia Fever raised ESR or CRP Prolonged PR interval PLUS Evidence of preceding group A streptococcal infection - eg elevated or rising streptococcal antibody titre. 2 major criteria, or 1 major and 2 minor (with evidence of preceding strep. infection) indicates acute rheumatic fever. However chorea can be diagnostic features without any other criteria being present.

ARF – Major Criteria Arthritis Classically migratory polyarthritis As one joint starts to recover another flares Usually large joints, but not always Dramatic response to aspirin/NSAIDs Occasionally monoarthritis – particularly if treated early

ARF – Major Criteria Carditis Cardiac inflammation usually affects the valves especially mitral and aortic valve. –Usually mild in first attack (unless delay) Can cause ECG changes: prolonged P-R interval (minor criteria) Can cause scarring of cardiac valves leading to rheumatic heart disease

ARF – Major Criteria Chorea (Sydenham 1686) May be sudden or gradual in onset Usually symmetrical R=L Deterioration at school (writing) Stops during sleep Increased by anxiety/stress Often emotional, weepy Antibodies to caudate nucleus/basal ganglia Latency 3 months post strep infection

ARF – Major Criteria Erythema marginatum Erythematous, blanches with pressure Not itchy Mainly on trunk and on the proximal limbs Completely asymptomatic

ARF – Major Criteria Subcutaneous nodules Painless, small ( cm) Over bony prominences Elbows, hands, feet, scapulae Rare (2%) Associated with carditis

Treatment and outcomes

Treatment Eradicate streptococcus (including screen family) Symptomatic treatment Commence secondary prophylaxis with penicillin to prevent disease recurrences –ARF recurrence is usually in non-compliant patients

Why are we interested in preventing ARF? Only long-term outcome from ARF is rheumatic heart disease Results from carditis which causes scarring of cardiac valves Can give rise to complications e.g. cardiac failure or heart infection. Treatment is with penicillin –Severe cases may require valve surgery

Future directions in treatment ? Vaccine –Key issue is that GAS is a diverse species –Some positive developments in literature –Key positive of a GAS vaccine is that it would help reduce all GAS disease –Probably sometime off

Key Messages ARF is triggered by GAS infection –Disproportionately impacts Māori and Pacific children Can lead to permanent heart damage – RHD Rates are dropping across the country and the region Diagnosed by meeting the Jones criteria Treatment is penicillin –Prevents disease recurrence –Aim is to prevent RHD

Questions?