WASHINGTON - Blood banks look at the nation's Hispanic population boom and see an unexpected potential to save thousands of lives: the possibility of more so-called universal blood donors.
It turns out that Latinos are more likely than the average American to have Type O blood, the type blood banks value most because it can be used by so many patients.
That potential so far is mostly untapped. Now blood banks are beginning major efforts to boost Latino donations, amid concern that the blood supply could face a serious imbalance if population shifts bring more demand for Type O transfusions without a parallel increase in giving.
'It's a great opportunity we have,' says Dr. Alexander Indrikovs, blood bank director at the University of Texas Medical Branch in Galveston, who outlined the issue at a recent meeting of leading blood bankers.
On the other hand, 'It's obvious that if we continue to target only the traditional blood donation group, which has been mostly Caucasian, the imbalance is going to grow larger,' he adds.
Faced with a tight supply and an aging donor pool, banks have long struggled to increase the nation's overall blood stocks. While 60 percent of the U.S. population is eligible to donate blood, just 5 percent does.
Yet more than 34,000 pints of blood are needed every day, and demand is rising annually. Spot shortages that force hospitals to postpone elective surgeries occur in various cities every year, usually around holidays.
There are four major blood groups: A, B, AB and O. A and B are antigens, essentially markers on blood cells that the immune system can target. Blood labeled 'O' lacks those antigens. Blood also is designated as either Rh-positive or Rh-negative.
While blood banks want donors of all types, Type O-positive blood is especially valuable. It is the most common blood type, which means it's most in demand - and if you have Type O blood, only a Type O transfusion will work for you. If you're accidentally given another type, your immune system would spot the antigens and attack.
However, people with other blood types can receive Type O blood in an emergency. That's why Type O donors are called universal donors, and why blood banks make a concerted effort to recruit them, both O-positives and the fairly rare O-negatives.
About 45 percent of the general U.S. population has Type O blood, a proportion that varies by race and ethnicity. Estimates suggest roughly 37 percent of whites and 47 percent of blacks are O-positive.
Blood banks have long thought Hispanics had even higher Type O rates. Indrikovs surveyed major blood banks in parts of Latin America to try to nail that down - and found O-positive donors ranging from 54 percent in Venezuela to 62 percent in Guatemala and 71 percent in Mexico.
But at Indrikovs' own University of Texas hospital, 53 percent of donations last year were Type O - but 58 percent of transfusions were. That's the imbalance that has him worried.
Increasing diversity in the blood supply is crucial, because sometimes patients require a closer match than standard blood typing provides. Blood banks have long sought to increase donations by black Americans, who make up about 13 percent of the population but just under 8 percent of blood donors.
The newest focus is on Hispanics, who make up nearly 15 percent of the population but an even smaller fraction of blood donors - roughly 3 percent to 4 percent, according to the American Red Cross, which supplies about half the nation's blood, and America's Blood Centers, which provides the other half.
Why so few?
The chief reason is that a pre-stocked volunteer blood supply is a rarity in Latin America, making the U.S. system a mystery to recent immigrants, says Dr. Celso Bianco of America's Blood Centers. Instead, Latin America relies largely on 'replacement' donations, where friends or relatives give blood to replace supplies used for a loved one's transfusion.
Language barriers and immigration issues play a role, too. Blood donors must show a valid ID so banks can track them down if testing uncovers an illness; that system discourages illegal immigrants.
'We have legally millions of people from Latin America living in the U.S. We need to get them on board to be regular blood donors,' cautions Indrikovs, himself a native of the Dominican Republic.
To target them, blood banks are turning to Spanish-language media and linking blood drives to soccer clubs. The Red Cross has translated its blood donation Web site at www.cruzrojaamericana.org.
Tell new donors they're essentially getting a free checkup, advises Millie Irizarry of Florida's Blood Centers, which has boosted Hispanic donations more than 10 percent in two years. Donating blood can let people learn their cholesterol levels, blood pressure and other potential signs of illness.
Next up: A Spanish soap opera, or novella, broadcast through much of Florida is about to feature a main character in need of repeated transfusions - and Irizarry has lined up lots of give-blood advertising.