What can be done to help prevent group a streptococcal infections?

Strep pyogenes. Treatment of infected individuals, hand washing, minimizing exposure to infected persons may all assist in limiting spread.
Watch that Saliva! The best way to avoid getting a strep throat infection is to avoid close contact with someone who is already infected with strep. Respiratory drops, sneezing, kissing, shaking hands, sharing contaminated drinks etc are all common modes of transfer. Good hygiene and hand washing are modes to decrease transmission.