Fever of Unknown Origin is caused by the following organisms in a farmer, who raised goats

(A) Brucella melitensis # BRUCELLOSIS is a zoonosis, primarily affecting goats, sheep, cattle, buffaloes, pigs and other animals and transmitted to humans by contact with infected animals or through their products. Acute brucellosis is mostly due to Br. melitensis. (It is usually known as undulant fever, but this is misleading as only some cases show the undulant pattern). It is associated with prolonged bacteremia and irregular fever. The symptomatology is varied, consisting of muscular and articular pains, asthmatic attacks, nocturnal drenching sweats, exhaustion, anorexia, constipation, nervous irritability and chills. The usual complications are articular, osseous, visceral or neurological.# Pathogenicity of Brucellosis: All three major species of brucellae are pathogenic to human beings. Br. melitensis is the most pathogenic, Br. abortus and Br. suis of intermediate pathogenicity. The incubation period is usually about 10--30 days, but may sometimes be very prolonged. Human infection may be of three types: Latent infection with only serological but no clinical evidence; Acute or subacute brucellosis; and Chronic brucellosis. Acute brucellosis is mostly due to Br. melitensis. (It is usually known as undulant fever, but this is misleading as only some cases show the undulant pattern). It is associated with prolonged bacteremia and irregular fever (Pyrexi of unknown origin). The symptomatology is varied, consisting of muscular and articular pains, asthmatic attacks, nocturnal drenching sweats, exhaustion, anorexia, constipation, nervous irritability and chills.