“ Q ” FEVER : CLINICAL FEATURES IN 72 CASES

Summary In 72 consecutive cases of “ Q ” fever, with no death, the commonest symptoms were headache and anorexia. Myalgia, sore eyes, cough, chills and sweats were also frequent. The commonest signs were a relative bradycardia, hepatomegaly and splenomegaly. Minor chest signs were frequently found. The total duration of fever was 10 days or less in the majority of cases. The longest duration of continuous fever was 24 days, and of intermittent fever 34 days. Common laboratory findings included an increased erythrocyte sedimentation rate, the presence of atypical mononuclear cells during the acute illness and an absolute lymphocytosis during convalescence. Only three patients had radiologically demonstrable pneumonic changes. However, respiratory infection of a lower severity was frequent, and this suggests that local strains of Coxiella burneti may be less virulent than overseas strains. Subclinical involvement of the liver was common, and in seven cases there was electrocardiographic evidence of transient myocardopathy. About 70% of patients returned to work within six weeks from the onset, but the convalescence of the remainder was protracted. The duration of convalescence was prolonged with increasing age. Infection with C. burneti may become chronic. Cases are described in which “ Q ” fever was complicated by pneumonia, pleural effusion, thrombocytopenia, encephalitis and endocarditis, and in which the problem of chronicity is illustrated.