The second major way HIV is transmitted is through parenteral exposure, where there is a break in skin integrity and direct exposure to infected blood or blood products. HIV is very efficiently transmitted with transfusion of infected blood; there is a 95% chance of infection when a single unit of whole blood that is HIV-positive is transfused. Contaminated transmissions remain a significant problem in areas where the blood supply is not routinely screened for HIV. Injection drug use carries a risk of 0.67% per exposure and is responsible for the recent dramatic increases in HIV infections in Eastern Europe. Healthcare workers have an approximately 0.4% risk of contracting HIV per needlestick exposure from an infected patient.