Concerns over the Zika virus in recent months have driven a decline in blood donations in border cities like Yuma, where travel restrictions rule out some potential donors. The loss of winter visitors is also a factor.
Blood donations are down 36 percent in southwestern Arizona. The Food and Drug Administration implemented rules in February that eliminate donors who have traveled to Mexico up to 28 days prior to donating.
Sue Thew of United Blood Services said that affects a sizable number of potential donors.
"In southern Arizona a lot of people may live in one area and actually travel freely across the border to live in Mexico, or work and go to school in the San Luis area," said Thew.
Proximity concerns over Zika aren’t the only reason for reduced donations. Southwestern Arizona is home to tens of thousands of winter visitors who donate blood. As summer approaches, that population is leaving.
"Winter visitors are very dedicated blood donors and participate very heavily in the Yuma area blood dives. So once that population leaves Arizona so do a lot of regular blood donors," Thew said.
Demand for blood increases over the summer, particularly during holidays like the upcoming Memorial Day weekend.