Diagnostic categories for acute rheumatic fever
In 2022, of all 505 acute rheumatic fever (ARF) diagnoses (Box 2.2; Supplementary Table 2.7) among First Nations people:
- 213 (42%) diagnoses were definite diagnoses
- 151 (30%) diagnoses were probable diagnoses
- 141 (28%) were possible diagnoses.
Box 2.2: ARF diagnostic categories
There is no one specific diagnostic test for ARF. Instead, it is diagnosed based on medical history and a pattern of clinical features (‘manifestations’) as follows:
Definite ARF, first episode: 2 major or one major and 2 minor manifestations plus evidence of preceding Strep A infection.
Definite ARF, recurrent episode: 2 major or one major and 2 minor manifestations or 3 minor manifestations plus evidence of preceding Strep A infection. (Prior to the 2020 RHDAustralia guidelines, the manifestation requirement was one major and one minor manifestation plus preceding Strep A to confirm diagnosis.)
Probable ARF: clinical presentation falls short by either one major or one minor manifestation, or the absence of streptococcal serology results, but where ARF is the most likely diagnosis.
Possible ARF: Strong clinical suspicion of ARF, but insufficient signs and symptoms for diagnosis of definite or probable ARF.
The new guidelines were released in 2020 and may have been implemented at different times in different jurisdictions. The definitions prior to 2020 have been added in parentheses where they differ.
For more information on types of manifestations, see Technical notes.
Source: RHDAustralia 2020.
RHDAustralia (ARF/RHD writing group) (2020) 'The 2020 Australian guideline for the prevention, diagnosis and management of acute rheumatic fever and rheumatic heart disease', 3.2 edn (2022), RHDAustralia, Menzies School of Health Research, Darwin.