All Zika, All the Time
There is a scary aspect to protecting blood safety being brought into bright relief by expanding Zika epidemics in the Americas. We have generally considered sustainability of the blood supply over the medium- and long-terms in the context of the commoditization of blood, unrestrained competition, and declining margins, but Zika raises more acute concerns. The recent Food and Drug Administration guidance and its impact on the blood community in Puerto Rico are instructive, esp. after talking to colleagues there. A quick read of the guidance tells us that the agency expects cessation of collections on the island by March 1 unless certain conditions are met; conditions that likely cannot be on that timeline. The expectation then, absent enforcement discretion, is that the island will import components from the mainland to cover need. I have no doubt the blood community will respond in the short run, regardless of financial considerations, because that is our mission. However, if Puerto Rico stands down for several weeks or months, where will the people now employed to collect, process, and distribute blood get their paychecks? After they have moved on to other jobs to support their families, how will their capacity be reconstituted when the crisis passes?
When local transmission of Zika lands in Florida, the Gulf Coast, or California, under what circumstances will we face the same issues here? Also, recall that a potentially competent Zika vector (Aedes albopictus) is present in fully the Southeastern third of the continental U.S. "Local transmission" seems like a straightforward concept-Aedesmosquitos on the mainland transmit Zika to people, which I fully expect will happen. But what constitutes "local transmission" in the context of the blood community? It is undefined in the guidance, and inquiries to public health have not yet been productive. It seems abundantly clear (to me at least) that we cannot shut down collections in Florida or Texas for one or a few cases of vector transmission of Zika virus-but how many are too many? What is missing in the guidance and the public discussion to date is an estimate of "acceptable risk" from Zika in blood that can be used to calibrate our response. The parameters used to calculate that threshold must include protecting not just the safety of the current blood supply, but also adequacy and sustaining our infrastructure in potentially affected areas into the future.
There is informative experience at our ABC member OneBlood that clinical surveillance at the level of zip code and county can be used "on the fly" to mitigate blood risks from chikungunya and dengue. I suspect a similar geographic approach is appropriate for Zika, but that it will not be perfect. As I have asked before where trade-offs are considered, "how safe is safe enough"?
Louis Katz, MD; Chief Medical Officer; email@example.com