surgical site infection（SSI）是術後常見的合併症，對於傷口的分類及其SSI的發生率敘述，下列何者錯誤？
clean wound: no hollow viscus entered, primary wound closure; SSI發生率：0.1～0.3%
clean-contaminated wound: hollow viscus entered but controlled; SSI發生率：5～8%
contaminated wound: uncontrolled spillage from viscus; SSI發生率：20～25%
dirty wound: untreated, uncontrolled spillage from viscus; SSI發生率：30～40%
