Laboratory technologists (22%) developed infections with Shigella sonn
ei, The isolates had the same antibiogram and pulse-held gel electroph
oresis pattern as an unknown isolate handled by a laboratory student.
Covering faucet handles with paper towels during hand washing in the l
aboratory was protective, No further cases occurred after the laborato
ry was cleaned with a phenolic agent and a handle-free faucet was inst
alled.