Acute Rheumatic Fever Flashcards
Is ARF nationally notifiable?
No.
Notifiable in all S/T except ACT/Tas.
What organism causes ARF?
GAS
How does ARF develop?
Abnormal autoimmune response to GAS infection (classically pharyngitis) with cross-reactivity with cardiac antigens in inherently susceptible people (3-5%).
Recurrent episodes common (10X greater risk in people with past ARF)
What is RHD?
Repeated episodes of ARF causing cumulative cardiac valve damage.
How is GAS transmitted?
Person-to-person: direct contact, droplets, fomites.
What are clinical features of ARF?
JONES Criteria: Fever, arthralgia
* J - joints (arthrtis - poly/migratory)
* O = heart - carditis (mainly valvulitus)
* N - nodes (subcutaneous)
* E - erythema marginatum
* S - Sydenham’s corea
What are the clinical features of RHD?
- Atrial fibrillation
- CHF
- Endocarditis
- Thromboembolic complications (e.g. stroke)
Which groups are at higher risk for ARF?
- Aboriginal and Torres Strait Islander
- Maori/Pasifika
- Immigrants from developing countries
- Children 5-14 years (peak 8yrs)
- People from high-prevalence communities
- Increased GAS exposure:
1. Overcrowded living
2. Socioeconomic disadvantage
3. Low health literacy
What is the case definition of ARF?
Confirmed = clinical + lab suggestive
Probable and possible = clinical features + clinician confidence
RHD = echo criteria (World Heart Federation)
How is ARF diagnosed?
Australian guidelines - combinations of major/minor manifestations + evidence of preceding GAS (ASOT / anti-DNAse B / swab)
RHD = echo, diagnosed by cardiologist.
What is the incubation period for ARF?
2-3 weeks after GAS
(6-9 weeks for chorea)
What is the infectious period for GAS?
10 - 21 days for untreated, uncomplicated GAS
What is the outbreak definition for ARF?
Greater than the expected number of confirmed / probable ARF cases occurring during an approximately 4 week period within a defined region.
What are some prevention measures for ARF and RHD?
Primordial: SDoH (health hardware, reduce overcrowding); Health Living Practices F/W
Primary: early Dx & Tx of skin/throat infxn (especially high-risk groups)
Secondary: current cornerstone. Commencement of regular ABx PPx (BPG)
Tertiary: heart failure medication, heart surgery, anticoagulation, echo screening in selected populations
What is secondary prophylaxis for ARF?
Consistent and regular ABx for people who have had ARF or RHD to prevent further Strep A infection, recurrence of ARF and further heart damage.
Uses long-acting benzathine benzylpenicillin G (BPG) rather than short-acting benzylpenicillin.
BPG should be given no later than 28 days after last infection (or 21 days for those on 21-day regimen)
How is secondary prevention different from secondary prophylaxis?
Secondary prevention includes ABx + activities to limit Strep A infection.
Includes organisational-level factors, environmental, and socio-political actions.
Culturally appropriate education, support for patient / family / community, coordination/collaboration between health services and schools, advocacy for necessary resources for people at risk of or living with ARF/RHD.
What are some resources for public health management of ARF and RHD?
SoNG, Australian guideline for prevention, diagnosis and management of ARF, RHD.
https://www.rhdaustralia.org.au/resources/2020-australian-guideline-prevention-diagnosis-and-management-acute-rheumatic-fever-and
How are cases of ARF managed?
- Collect info: HH crowding, Dx, Sx, contacts
- Hospital management
- Education: patient, carers, family (culturally appropriate, disease and prevention)
- Secondary PPx: BPG q 21-28 days
How are contacts of ARF managed?
Nil routine.
Do exclusion criteria apply to case of GAS?
Yes - strep pharyngitis/impetigo requires exclusion from school/CC/work (esp healthcare and institutions) until 24hr after appropriate ABx.
What environmental managemnt is required for ARF?
EH assessment may be useful: social/environmental issues where appropriate/reasonable e.g. crowding, toilets, running water, waste removal.
Refer concerns re: health hardware to housing provider.
Which Healthy Living Practices have strong evidence for reducing Strep A infection?
Strong:
* Washing people (hands, bodies)
* Reducing overcrowding
Medium:
* Washing clothes and bedding
* Reducing negative effects of animals, insects, vermin (indirect)
* Reducing hazards that cause trauma - clean and tidy houses
Weak:
* Removing wastewater safely
* Improving nutrition, ability to store,prepare and cook food
* Reducing health impacts of dust
* Controlling living environment temp
How are outbreaks of ARF managed?
- Lack of evidence to provide clear guidance on ARF outbreak/response strategies
- Case definition
- Outbreak definition - O>E within 4 weeks in a defined region
- Information to community/clinicians
- Control/prevention
* ensure people with ARF/RHD receiving PPx
* Find and examine HH/family contacts for impetigo/pharyngitis; test and treat
* Examine at-risk contacts for ARF
* Community education re: prevention
Cont…
1. Active case finding - at-risk contacts, cardiac auscultation, echo
2. Collect samples from cases for culture; throat and skin
3. Community education
Which S/Ts have a RHD registry?
NSW, QLD, NT, SA, WA
Essentially all S/Ts except VIC, ACT, Tas
What is involved in screening for RHD?
Echocardiographic screening can accurately detect previously undiagnosed RHD but does not meet all criteria for a screening program.
There is insufficient evidence to support routine, population-level screening for EHD in Australia. Targetted screening of high-risk groups more appropriate.
