In the Jones criteria for rheumatic fever, how many major criteria are required for diagnosis?

The Jones criteria for diagnosing rheumatic fever includes a set of major and minor manifestations. For a diagnosis of rheumatic fever to be made, at least two major criteria must be present, alongside either supportive minor criteria or evidence of a preceding streptococcal infection. The major criteria include carditis, polyarthritis, chorea, erythema marginatum, and subcutaneous nodules. Meeting just one major criterion does not fulfill the diagnostic requirement, and therefore, a minimum of two major criteria is essential to support the diagnosis of rheumatic fever. This approach helps ensure that the diagnosis is made accurately, as rheumatic fever can lead to significant long-term complications if not recognized and treated appropriately.