What potential issues arise from using directed donations more than voluntary donations?

The focus on using directed donations, where blood is donated for a specific patient, can lead to increased risks associated with familial blood transmission. This is primarily due to a higher likelihood of genetic similarities among family members, which may increase the risk of transmitting genetic conditions or infectious diseases that could be dormant in the donor but pose a risk to recipients. Family members often share similar health backgrounds and may carry similar pathogens or genetic traits. This reality contrasts with voluntary donations, which typically encompass a more diverse donor pool, thereby reducing the risk of transmitting certain inherited issues or infections.

In contrast, the other options present nuances that do not align as closely with the core concern of directed donations. For instance, while higher reliability in testing is a positive aspect of both directed and voluntary donations, it doesn't directly address the primary risks associated with familial ties in directed donations. Similarly, the notion of having more control over the supply chain with directed donations lacks direct relevance to the risk factors tied to familial transmission. Therefore, increased risk from families proves to be the most significant potential issue when considering the differences between directed and voluntary blood donations.