Yes, INFECTIONS is a Scrabble word!

Letter values in Scrabble US: I 1, N 1, F 4, E 1, C 3, T 1, I 1, O 1, N 1, S 1.

Is it a valid word?

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

the pathological state resulting from the invasion of the body by pathogenic microorganisms
(phonetics) the alteration of a speech sound under the influence of a neighboring sound
(medicine) the invasion of the body by pathogenic microorganisms and their multiplication which can lead to tissue damage and disease
an incident in which an infectious disease is transmitted
the communication of an attitude or emotional state among a number of people
moral corruption or contamination
(international law) illegality that taints or contaminates a ship or cargo rendering it liable to seizure