Natcher Auditorium, NIH Bethesda, Maryland Natcher Auditorium, NIH Bethesda, Maryland NHLBI National Institutes of Health Centers for Disease Control and Prevention Evaluating the Threat to Transfusion and Transplantation Safety Evaluating the Threat to Transfusion and Transplantation Safety Department of Health & Human Services America’s Blood Centers December 14-15, 2009 Emerging Arboviruses: Maria Rios & Deborah Taylor, Organizers

Centers for Disease Control and Prevention Department of Health & Human Services America’s Blood Centers NHLBI National Institutes of Health Division of Emerging and Transfusion Transmitted Diseases Office of Blood Research and Review, CBER, FDA Workshop Co-Sponsors

Arbovirus Associated Emerging Diseases Arboviruses (Arthropod-borne virus) are found around the world: – most commonly spread by blood-sucking insects – circulation depends on the presence of the transmitting vector and vertebrate host amplifiers. Arthropod-borne diseases are becoming increasingly widespread. Global concern: DENV, JEV, CHIKV, TBEV and WNV.

Arthropod-borne virus: Arbovirus For most arboviruses humans are not the amplifying host and human infections are rare. Arboviral infections occur mostly during warmer and wetter months. In mild climates cases occur year round. Sylvatic cycle

Arbovirus and Public Health Human infections have an asymptomatic viremic phase posing a threat to transfusion and transplantation Arbovirus transmitting vectors are present and expanding their distribution in the U.S. Aedes albopictus

Arbovirus and Public Health Large gaps in knowledge The potential for another arbovirus, like WNV, to reach and establish epidemic status in the U.S. is of concern and requires: preparedness risk assessment strategic action plans

Scope of the Workshop To facilitate dissemination of scientific knowledge among Government, Academia, Blood Establishments and other industry such as test kit manufacturers. –Biology, epidemiology and pathogenesis of vector-borne viruses of public health relevance –Potential risk for transmission by transfusion of blood –Strategies for prevention of vector-borne virus transmission To promote discussion on strategies to address public health needs: –Potential emergence of these pathogens –Impact on transfusion and transplantation safety

Highlights of the Workshop Relevant risks for arbovirus emergence are: –travel, trade, demographics, poor sanitation, urbanization (populations moving from rural to urban areas & deforestation) –climate change The transmitting vectors for several arboviruses are present in the U.S. and expanding their range. Hosts in the sylvatic cycle may be important but not always necessary. Urban cycles can support epidemics.

Highlights of the Workshop Dengue and Chikungunya viruses have been reported mostly among travelers in the U.S. Dengue is an immediate problem since epidemics are occurring in the US (namely PR and Key West). JEV has been reported among travelers; its life cycle is similar to WNV. A licensed vaccine available.

DENV & CHIKV in the U.S. - Autochthonous transmission of DENV has occurred in Puerto Rico, Hawaii, Texas and Florida (CDC) - Can be transmitted by blood transfusion - The transmitting vector is abundant in parts of the U.S. Highlights of the Workshop

The pros and cons of availability of a safe blood supply during an outbreak was discussed. Many dengue patients need transfusions and are at risk of receiving blood containing a different serotype, which may worsen the clinical picture. The recent outbreaks in PR had multiple co- circulating serotypes. Arbovirus detection & prevention Blood Safety

-There is a need for DENV NAT assay. - ARC is planning to screen blood in PR using Bio-Rad NS1 antigen assay under IND. Highlights of the Workshop Arbovirus detection & prevention Blood screening

Highlights of the Workshop Test kit manufacturers indicated that they have prototype assays for DENV1-4 and CHIKV. It was firmly stated that there are no plans for development of these assays in the near future, even for research purposes. Pathogen reduction / inactivation technologies, if successful, may help ensure the safety of blood in the absence of tests for known and unknown viruses. Recommended that resources be dedicated to realize this goal. Arbovirus detection & prevention

Highlights of the Workshop Arbovirus detection & prevention Vaccines Although DENV vaccine may affect outcome of infection, it may not prevent infection. Natural immunity is life-long, however neutralizing titers tend to wane. A DENV vaccine must be tetravalent; several are in clinical trials.

“Vector control was argued to be the most appropriate and efficacious measure for prevention of arbovirus infections. Vector control will help to ensure public health and will impact the safety of the blood supply.” Highlights of the Workshop Arbovirus detection & prevention Vector Control

Highlights of the Workshop CDC staff stated that there are effective mechanisms for arbovirus surveillance and reporting through ArboNet. –Zika virus, CHIKV and JEV have been found as result of the surveillance. CDC mentioned that ArboNet, has been recently affected by the reduction of funding of state health departments and CDC. Surveillance

Highlights of the Workshop The tolerance threshold for risk in the blood supply was also discussed. There is a low tolerance threshold for risk associated with blood. Risk

Highlights of the Workshop Risk DENV is the most common arbovirus throughout the world. It affects children preferentially and the outcome in children is worse than in adults.

Workshop Take-home Message The successful measures adopted to mitigate WNV transmission by blood should be used as a model for future needs. The cooperation and communication among stakeholders was critical for WNV and will be critical for success in dealing with other potential epidemics.

Acknowledgements Speakers and Discussants Steering Committee Celso Bianco William Bower Cristina Cassetti Roger Dodd Joel Gaydos Melissa Greenwald Diane Gubernot Simone Glynn Sally A. Hojvat Jerry Holmberg Robert S. Lanciotti Catherine Laughlin Hira Nakhasi George Nemo Patricia Repik Jennifer Scharpf Peter L. Summers Mark Walderhaug