the pfeiffer reaction was first studied , and then the animals were allowed to live until the controls , inoculated with the same emulsion or culture of leptospira icteroides but without the serum , or with serum from patients suffering from other diseases than yellow fever , had died of the experimental infection with typical symptoms a positive pfeiffer phenomenon was observed in fifteen of the eighteen convalescent cases studied , or approximately 83 per cent .
C0012634
diseases
C0009450
infection