The Revised Jones Criteria for Acute Rheumatic Fever (ARF) calculator evaluates clinical inputs from a patient to determine if the diagnostic criteria for initial or recurrent ARF are met. The computation relies on a series of inputs concerning population risk, patient history, evidence of preceding infection, and specific clinical criteria. Here is how the computation is structured:

1. Population Risk and History Assessment:
   - The population risk can be either "Low risk" or "Moderate or high risk".
   - The patient’s history is assessed to determine if they have a history of acute rheumatic fever or rheumatic heart disease (YES/NO).

2. Evidence of Preceding Group A Streptococcus Infection:
   - The calculator checks for evidence of previous group A Streptococcus infection through one of the following:
     - Increased or rising anti-streptolysin O titer or other streptococcal antibodies.
     - Positive rapid group A streptococcal carbohydrate antigen test in a pediatric patient.
     - Positive throat culture for group A beta-hemolytic streptococci.

3. Major Criteria:
   - The major criteria include:
     - Clinical or subclinical carditis.
     - Arthritis, which is dependent on population risk.
     - Chorea, erythema marginatum, or subcutaneous nodules.

4. Minor Criteria:
   - The minor criteria are:
     - Prolonged PR interval.
     - Arthralgia.
     - Fever, dependent on population risk.
     - Increased erythrocyte sedimentation rate or C-reactive protein.

5. Diagnostic Computation:
   - If the patient has no history of ARF or rheumatic heart disease, and there is evidence of preceding streptococcal infection along with two major criteria or one major and two minor criteria, the result is "Diagnostic criteria for initial ARF are met".
   - If the patient has a history of ARF or rheumatic heart disease, and there is evidence of preceding streptococcal infection along with two major criteria or one major and two minor criteria, the result is "Diagnostic criteria for recurrent ARF are met".
   - If these conditions are not met, the diagnosis criteria for ARF are not met.

6. Output:
   - Depending on the results of the above conditions, the output is determined as one of the following:
     - Diagnostic criteria for initial ARF are met.
     - Diagnostic criteria for recurrent ARF are met.
     - Diagnostic criteria for ARF are not met.

The Revised Jones Criteria is a clinical calculator used for the diagnosis of acute rheumatic fever (ARF). This scoring system is primarily applicable to pediatric patients, as ARF most commonly affects children between the ages of 5 and 15 years. 

The Revised Jones Criteria is used to stratify the likelihood of ARF based on the presence of major and minor clinical manifestations, along with evidence of a preceding group A streptococcal infection. Major criteria include carditis, polyarthritis, chorea, erythema marginatum, and subcutaneous nodules, while minor criteria include fever, arthralgia, elevated acute phase reactants, and prolonged PR interval on EKG. 

The clinical utility of this calculator is to aid in the diagnosis of ARF, which can be challenging due to its nonspecific symptoms and the lack of a definitive diagnostic test. It helps clinicians to make a more accurate diagnosis and initiate appropriate treatment promptly, thereby preventing the progression to rheumatic heart disease.

Exclusion criteria for the use of the Revised Jones Criteria include patients with a clear alternative diagnosis for their symptoms, and those without evidence of a preceding group A streptococcal infection. It's also important to note that the criteria may not be as applicable in low

Revised Jones criteria for acute rheumatic fever

Guidelines for the diagnosis of rheumatic fever. Jones Criteria, 1992 update. Special Writing Group of the Committee on Rheumatic Fever, Endocarditis, and Kawasaki Disease of the Council on Cardiovascular Disease in the Young of the American Heart Association.