A parainfluenza virus type 3 outbreak at a residential aged care facility: The role of microbiologic testing in early identification and antimicrobial stewardship.

We report an outbreak of parainfluenza 3, which had an attack rate of 30%, in a residential care facility in Melbourne, Australia. One-fifth of affected residents required hospitalization, but there were no deaths. The outbreak demonstrated the value of active surveillance and early microbiologic testing and the urgent need for antimicrobial stewardship programs in the aged care setting.