Eleven patients received injections ofmethylprednisolone and lidocaine to relieve the pain andinflammation os arthritis at the same orthopedic surgery clinic.All of them develop septic arthritis caused by Serratia marcescens.Unopened bottles of methylprednisolone from the same lot numberstested sterile, the said medicine was preserved with a quat. Cottonballs were used to wipe multiple used injection vials before thethe medication was drawn in a disposable syringe. The site ofinjection in each patient was also wiped with cotton ball. Thecotton balls were soaked in benzalkonium chloride, and fresh cottonballs were added as the jar was emptied. Opened methylprednisolonecontainers and the jar of cotton balls contained S. marcescens. Howwas the infection transmitted? What part of the routine procedurecaused the contamination?
