Diagnostic criteria of rheumatic fever in a New Zealand community.

The diagnostic criteria of acute rheumatic fever are reviewed from experience in a New Zealand community. Two-hundred-and-sixty-one first attacks labelled rheumatic fever and 209 other episodes occurred in a defined geographic population during 1962--76. The major importance of heart, joint and brain manifestations is confirmed. Criterior levels for fever, P-R interval prolongation, erythrocyte sedimentation rate, white cell count and antistreptolysin-O titre are suggested. Nodules and evidence of established rheumatic heart disease were not found to be of diagnostic significance because they tended to be equally common among patients with rheumatic fever and patients considered to have another disease. Separate criteria for cases with and without pre-existent rheumatic heart disease are given, to enable assignment of episodes to probable rheumatic fever status.