What is the primary purpose of screening donor blood for infectious diseases?

• A. To ensure irradiated blood only
• B. To determine the donor's blood type
• C. To check for nutritional status
• D. To ensure safety by detecting infections such as HIV, HBV, HCV, and syphilis

Answer: (D)

Screening donor blood for infectious diseases centers on protecting the recipient by ensuring the blood does not carry pathogens that could be transmitted through transfusion. Many infections, such as HIV, hepatitis B, hepatitis C, and syphilis, can be present in blood without causing symptoms in the donor, so tests are used to detect them before the blood is used. By identifying and discarding infected units, blood banks markedly reduce the risk of transfusion-transmitted infections. Other steps like irradiating blood or determining blood type are separate safety or compatibility measures and not the purpose of infectious-disease screening. There’s still a small residual risk due to window periods and test limitations, but screening significantly improves safety.