Unintentional puncture of the skin by a contaminated hypodermic needle. Hospital and medical staff are most expected to be at risk of this. Needlestick injuries hold a risk of grave infections, such as hepatitis and HIV, and require immediate medical attention and care. The wound should be cleaned thoroughly. If there is a risk of infection, preventive medication will be administered. Blood tests are then carried out to determine whether or not an infection has been transmitted.