These were the conditions in Greece in 2010, when in several areas the outbreak of West Nile fever coincided with local outbreaks of malaria. Deferral created a roadblock to testing, as well as imposing additional strains on the already strapped public health infrastructure. A blood shortage ensued.
Screening each sample for several pathogens is possible, but it can get expensive. "The problem with testing," Semenza said, "is really several questions, each with its own cost. For instance, when do we test and how long do we test for? A year after someone was exposed? Two years?
"And how many organisms do we need to test for? One? Two? There is a limit to the cost-effectiveness," he added. For some blood-borne diseases, it can take months if not years for blood to show a positive reaction for the disease in question.
Because it is hardly feasible to test each blood donor and each donation for every possible pathogen, pre-emptive treatment and new technology may hold some promise. One pre-emptive technique, pathogen reduction, involves treating donated blood to eliminate the possibility of infection from a range of microorganisms, rather than targeting each and every known disease individually.
Currently used in France, Poland, Spain, Switzerland and the United Kingdom, various compounds, among these riboflavin (vitamin B2) and methylene blue in combination with light, are used to inactivate known pathogens in platelets or blood plasma.
The development of artificial blood and blood components may further reduce risk of infection through tainted blood. Two types of synthetic coagulation factors -- the main therapeutic components of fresh frozen plasma -- have been in use for several years.
Artificial red blood cells with synthetic membranes are under development. In Russia and South Africa, a simple polyhemoglobin -- an oxygen-carrying blood substitute -- is already in limited clinical use.
Reprinted from Climatewire with permission from Environment & Energy Publishing, LLC. www.eenews.net, 202-628-6500