EPIDEMIOLOGY OF REUMATIC FEVER Dr Faris Al Lami

Definition A non supportive complication of Group A , B Hemolytic Streptococcal (GABHS) Upper Respiratory Tract Infection (URTI). A systemic disease, more frequently involving : joints and the heart less frequently Involving: CNS, skin and subcutaneous tissue.

Risk factors : 1.Over weight 2.Low socioeconomic status 3.High latitude 4.Positive family history 5.Age 5-15 years

Clinical Manifestations Major criteria 1.Polyarithritis It occurred in 75% of cases migratory in nature affecting two and more joints lasts 3-4 weeks

Carditis Occurs in 40-50% of cases Most serious Occur within 1-2 weeks of onset Lasts for 6 weeks- 6 months Presented with significant murmer pericardits CHF Sometimes silent

Subcutaneous nodules Occurs in 1% of cases Presented with rounded, mobile, non –tender, over the joints, scalp, vertebra column Seen in severe cases only

Erythema marginatum: Seen in 5% of cases

Sydenham Chorea: Seen in 10-15% of cases

Minor criteria Clinical: Polyarithralgia Fever Polyarithralgia Past history of Acute Rheumatic Fever (ARF) or Chronic Rheumatic Cardiopathy (CRC)

Minor criteria Laboratory: Prolonged PR interval on ECG Acute Phase Reaction ( high ESR, high CRP, high WBC)

PLUS Evidence of preceding streptococcal URTI (positive culture, high ASOT, Scarlet fever)

Other manifestations: Erythema multiforme Abdominal pain Backache Precordial pain Epistaxis Vomiting Malaise Weight loss Anemia

Diagnosis: Two major or one major and two minor plus evidence of recent streptococcal infection

Epidemiological characteristics About 20% of URTI ( especially sore throat) that occurred in school age children are caused by GABHS Only 20% of streptococcal URTI produce symptoms ( for every symptomatic streptococcal URTI there are four asymptomatic cases ) 3. The attack rate of ARF varies from 0.3% ( under endemic condition) to 3% ( during epidemics of untreated severe exudative pharyngitis)

4.Positive association between severity of pharyngitis and risk of ARF 5.For every two cases of ARF with history of streptococcal URTI , there is one case without such history 6.For every three cases of ARF , one will develop CRC

7.For every case of CRC with history of ARF , there is another case of CRC without such history 8.Symptomatic streptococcal pharyngitis can infect 8-50% of household contacts 9.Healthy carriers form 20-50% of school children , but they are not important source of infection or of cases of ARF

PRIMARY PREVENTION Aim: Definite diagnosis and eradication of streptococcal URTI

Definite diagnosis of Streptococcal URTI: Scarlet fever Positive culture Increasing ASOT

Characteristic Symptoms of streptococcal URTI: Exudates on throat Temperature of > 38 C Enlarged tender anterior cervical lymph nodes Erosion of the edges of the nostril with scabbing

Non characteristic symptoms: Cold Cough Trachitis Conjunctivitis

Eradication of streptococcal URTI achieved by: Achieving bactericidal level of antibiotic within 9 days of onset of symptoms for 10 days Benzathin Penicillin 600,000 (< 6 years) 1,200,000 (> 6 years) If sensitive: Erythromycin 20 mg / kg / day (< 12 years in four divided doses 250 mg x 4 (12 years and over) Treatment should continue for 10 days

SECONDARY PREVENTION Indicated for patients with CRC, and ARF Aim: to interrupt reinfection – recurrence cycle

A bacteriostatic level of antibiotic against GABHS for 5 consecutive years or till age of 16 years Benzathin Penicillin 600, 000 (< 6 years) 1,200,000(6+ years) every month If sensitive: Sulfadiazine 0.5 gm/ day (< 6 years) 1 gm/day (6+ years)

Patients with CRC and those with CV surgery should be kept on this regimen for life The risk of recurrence of ARF following subsequent GABHS infection is 50% for the next 5 years A child with ARF has 150 times risk for further attacks as a child without such history