A total of 548 food handlers from 14 catering establishments located throughout Hong Kong were nasally swabbed by a trained researcher using a moistened transport swab on 2 occasions, 3-6 months apart, to define nasal carriage status
Swabs were transferred
to the laboratory for culture within 2 hours of collection.
Persistent carriers were defined as individuals with both specimens
positive with the same spa type, whereas those positive on 1
occasion were classified as transient carriers