Chikungunya virus – named from a word in the Kimakonde language meaning “to become contorted,” describing the stooped over appearance of its victims crippled with joint pain. This acute mosquito-borne infection of African origin has caused titanic epidemics in the Indian Ocean and South Asia during the past decade. Since early December 2013, more than 20,000 cases have been detected in the Caribbean and northern South America. There is no reason not to expect it to land on the US mainland, where competent vectors are common. The AABB Transfusion Transmitted Disease (TTD) Committee’s Emerging Infections subgroup and FDA’s Division of Emerging and Transfusion Transmitted Diseases (http://bit.ly/1lLKfth) have all been following the Caribbean outbreak closely.
Are we looking at the next West Nile virus (WNV), something more benign, or worse? The rate of asymptomatic infections, those posing risk to blood recipients, is about 20 percent, compared to around 80 percent for WNV. Devastating infection is very unusual compared to WNV, but debilitating symptoms can persist for months. Despite millions of cases in the Eastern Hemisphere, there have been none attributed to transfusion. That said, the virus is present in the blood during the incubation period, and parenteral transmission to monkeys has been demonstrated. How should we be responding?
Our options are:
- Do nothing and watch, as we did before the emergence of WNV in summer 2002, responding if and when transfusion-transmission risk is demonstrated.
- Enhance our ability to identify the approximately 80 percent of donors who would be expected to have symptoms, by effectively eliciting call-backs by donors who get sick after a donation, so that we can recall their products. This strategy is in progress through the TTD committee.
- Understand donor travel and temporal donation patterns following travel, allowing us to model the impacts of a short-term deferral for travel to affected areas. While operationally challenging, this may mitigate many acute tropical virus “sins.” Discussions on this option are underway.
- Engage our test builders to have “on-the-shelf” nucleic acid assays to detect Chikungunya using available test platforms. These conversations are occurring, but testing companies want to know the return on investment – currently hard to know.
So what should we do? I am not sure, but preparedness is a lesson we should have learned over the past 30 years. I am sure you will follow this unfolding issue with me as we try to engage in risk-based decision making (http://bit.ly/1joffMv).
Louis Katz, MD, Executive Vice President, Scientific, Medical, Technical, Quality, and Regulatory; LKatz@americasblood.org