Yes, BRUCELLOSIS is a Scrabble word!

Letter values in Scrabble US: B 3, R 1, U 1, C 3, E 1, L 1, L 1, O 1, S 1, I 1, S 1.

Is it a valid word?

BRUCELLOSIS is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

infectious bacterial disease of human beings transmitted by contact with infected animals or infected meat or milk products; characterized by fever and headache
an infectious disease of domestic animals often resulting in spontaneous abortion; transmittable to human beings

Also: undulant fever, malta fever, gibraltar fever, rock fever, mediterranean fever, contagious abortion, bang's disease.