Zika Virus. Report to the Standing Committee on Health. Dr. Graham Sher Chief Executive Officer, Canadian Blood Services

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1 Dr. Graham Sher Chief Executive Officer, Services Dr. Dana Devine Chief Medical and Scientific Officer, Services Services Services is an arm s-length organization within the larger health-care system of transfusion and transplantation medicine. It is regulated by Health Canada and funded by the provincial and territorial ministers of health, who serve as corporate members and who appoint the Services board of directors. Services manages the national supply of blood, blood products and stem cells and related services, for all provinces and territories (excluding Quebec, whose blood supply is managed by Héma- Québec). Our role includes development and management of the national public cord blood bank, and stewardship as the sole procurer, contract manufacturer and distributor of plasma protein products in Canada (excluding Quebec). These products are used to treat patients with diseases such as hemophilia and immune disorders. On behalf of provincial and territorial health systems, Services bulk-purchases approximately 35 brands of plasma protein products from Canadian and international suppliers, including products available for patients under the Health Canada Special Access Program. We also lead an integrated, interprovincial system for organ donation and transplantation for all of Canada. We operate the ground-breaking Canadian Transplant Registry and related programs, which are improving and saving the lives of Canadians waiting for transplants. Next steps in organ donation and transplantation include developing an appropriate clinical governance model for Canada, and compiling progress reports that present timely and meaningful data to help inform government decision-making in organ donation and transplantation. Services is dedicated to providing value through improving patient outcomes, enhancing health-system performance and optimizing cost efficiency. We operate an integrated, pan-canadian service delivery model; our national scope, infrastructure and governance make our organization unique in the Canadian health-care landscape. 1

2 Zika virus and infection The Zika virus is a member of the flavivirus family. Like its cousins, dengue virus and chikungunya virus, the Zika virus is normally transmitted by mosquitoes. Although the virus was first discovered in the Zika forest of Uganda in 1947, we know relatively little about its biology or about the course of Zika-related disease in humans. The Zika virus is estimated to cause clinical disease in only one in five infected people. It is believed the symptoms of infection are mild in most people. Symptoms of Zika virus infection are similar to many other diseases; the most common symptoms are fever, rash, joint pain and conjunctivitis. People who do become symptomatic with the Zika virus recover within approximately two weeks. In a small group of Zika-infected adults, the immune response to the virus infection produces antibodies that attack the patient s own nervous system, causing a form of transient paralysis called Guillain-Barré Syndrome. Guillain-Barré Syndrome appears to be a rare complication of Zika virus infection. It is also a rare occurrence following other viral infections, such as influenza and other respiratory viruses. In recent months, however, an unexpected consequence of Zika virus infection has been identified. In some pregnant women, the virus has been associated with malformation of the fetus such that the brain fails to develop normally (microcephaly, or small brain). It is hypothesized there may be other factors that put one woman infected with the Zika virus at risk of having an affected fetus while another with Zika infection has a normal pregnancy. It is also unclear why this association was not commonly recognized before the recent outbreak of the Zika virus in Brazil. Research is underway to understand this phenomenon. Zika transmission and risk to the blood supply Transmission of the Zika virus is a concern for Services. Although there is no irrefutable evidence the Zika virus can be transmitted by blood transfusion, two cases reported from Brazil strongly suggest this. This correlation is consistent with the observation made during the recent large outbreak of the Zika virus in French Polynesia ( ). During that outbreak, 2.8 per cent of asymptomatic blood donors had measurable Zika virus ribonucleic acid in their blood. As a result, blood operators around the world have watched with concern as the Zika virus spread rapidly. There is currently no licensed test for screening blood for the Zika virus. Accordingly, blood operators in countries without the Zika virus have deferred donors who have travelled to risk areas. It also appears that males who are ill with Zika virus infection can transmit it to their sexual partners, although it is not yet known whether this is a common or rare occurence. The virus may be found in semen for a longer period than the usual recovery period of two weeks. It is not yet determined whether the virus can also be spread from female to male sexual partners. 2

3 Zika progression and the Canadian response Services has watched the Zika virus in the Western Hemisphere rapidly spread from a cluster of cases reported in Brazil in May 2015, to Columbia in October 2015, and then to Mexico, Guatemala, El Salvador, Venezuela and Paraguay by November 2015, with cases appearing in Puerto Rico in December By January 2016, it was clear all of the Caribbean would soon be part of the Zika outbreak. The estimated number of cases in other countries, which had been reporting their cases earlier in 2015, continued to climb. In light of this spread, Services took immediate action. With utmost consideration for the safety of patients and donors, and after consultation with its international Scientific and Research Advisory Committee, Services worked closely with Héma-Québec to determine an appropriate strategy to mitigate any risk to the Canadian blood supply. We recognized that such a risk was relatively small. Even if we did not change our blood donation eligibility criteria, the risk would be present only in the small number of Canadian blood donors who had travelled to an area with the Zika virus, and who then donated blood within a few days of their return to Canada. On Jan. 28, 2016, in a prudent application of the precautionary principle, we announced a formal change to our blood donation eligibility criteria would be in place no later than Feb. 5. In the interim and effective immediately, donors who had recently travelled to Zika-risk areas were asked to postpone their appointments to donate blood for one month after their return to Canada. This step was implemented as a temporary measure while we undertook a formal risk assessment process to determine the final deferral period. Risk assessment Services applies a rigorous risk-based decision-making process that is primarily focused on ensuring the blood supply is safe from transmissible diseases. We use all available scientific information to understand the nature of the risk, and data on the travel behaviour of blood donors to understand the impact on the sufficiency of the blood supply. We develop sophisticated risk models based on certain key assumptions. These key assumptions derive from a reasonable set of assumptions and predictions based on experience with the pathogen of interest, or where such information is not available, on related pathogens. Our Zika modelling was based on the following assumptions: The risk to a travelling blood donor of contracting the Zika virus is the same as the risk of acquiring dengue virus as estimated in Singapore during a large outbreak in The incidence of the Zika virus is based on the number of suspected positive cases in Mexico, Central and South America and the Caribbean, and adjusted to include asymptomatic cases. The accuracy of the data is uncertain at this time. 3

4 The rate of transmission of the Zika virus to a patient if an infected unit was transfused was assumed to be 100 per cent. In some areas, our risk modelling purposely overestimated risk. While the number of suspected cases of Zika infection was used, this figure includes cases of other infections also present in those countries that have similar symptoms to those associated with the Zika virus (e.g., dengue). Also, most cases of the Zika virus have occurred in South America, whereas most travel by Canadian blood donors is to Mexico and the Caribbean. The risk model, however, assumes the distribution of donor travel is equally spread over the Americas. The model also does not account for the fact that most Canadian travellers visit resorts with insect control. Deferral period Since Feb. 5, 2016, a 21-day deferral period has been in place. Blood donors who have travelled outside of Canada, the continental U.S. and Europe are ineligible to donate blood for 21 days from the date of their return to Canada. Héma-Québec also implemented a 21-day deferral period. The 21-day deferral period, and all other measures to mitigate the risk to the blood supply, was discussed with Health Canada, as regulator of the blood system in Canada, before implementation. The 21-day deferral period was determined based on the following considerations: Estimated risk of an infectious unit of blood entering the Canadian blood supply. Available information on the duration of illness and residency time of the virus in the bloodstream. Pragmatic need for a time period that already aligned with Services computer system options to enable rapid implementation. Need for a simple approach that did not require changing every time a new country reported presence of the Zika virus. Calculated impact on the sufficiency of the blood supply, based on data from a 2014 survey of blood donor travel. Most importantly, the proportionate risk, so as to have a minimum effect on the security of the blood supply in Canada. It was known at that time the United States Food and Drug Administration was contemplating a 28-day deferral period for blood donors. Most other countries that do not currently have the Zika virus have since implemented a 28-day deferral period. The selection of the 28-day deferral period is based on two risk calculations done by the Transfusion- Transmissible Diseases Committee of the U.S.-based AABB (formerly known as the American Association of Blood Banks). The AABB provides formal guidance to blood operators around the globe. This committee assessed risk mitigation based on a 14-day travel deferral and a 28-day travel deferral. No calculations were done for a 21-day deferral. 4

5 These two timeframes were selected in part because they had been used for other types of blood donor deferrals in other jurisdictions, especially Europe. Because it is possible that a 14-day deferral is too short, the AABB recommended a 28-day deferral for blood donors who had travelled to areas in the Americas with reported outbreaks of the Zika virus. The FDA deferral follows this recommendation. The Services risk model includes a calculation for a 21-day deferral. It demonstrates the risk of a unit of blood infected with the Zika virus entering the Canadian blood supply with a 21-day deferral period in place is one in 38 million. Using this model, the risk with a 28-day deferral is one in 380 million. For comparative purposes, the calculated residual risk of transmission of HIV, hepatitis B and hepatitis C combined is one in 3.8 million, which has been deemed to be an acceptable level of blood safety. Region of travel As a further precaution, the region of travel for which donors may be deferred is intentionally wide, as it is not yet known where or how rapidly the Zika virus will spread. The deferral region covers those areas where the mosquito vector is found and where other transfusion-transmissible viruses have been reported. Sexual partners Some jurisdictions have also implemented a deferral, or a self-deferral, for the sexual partners of anyone who has travelled to a Zika-risk area. Using similar risk modelling as that applied by the Australian blood operator, Services has determined the risk of a unit of blood infected with the Zika virus entering the Canadian blood system through blood donation by a sexual partner of anyone who has travelled to a Zika-risk area is approximately one in eight million. The estimated risk is higher than for travel alone because the model assumes the travelling male sex partner would have the Zika virus in his semen for six months after travel. The risk, however, is very small. As a result, Services, like the Australian blood operator, is not planning to introduce a deferral period associated with sexual contact with travellers. Such a deferral period would significantly reduce the number of eligible donors with no meaningful increase in blood safety. Cells, tissues and organs Services is also responsible for aspects of the provision of stem cells in Canada. We operate the OneMatch Stem Cell and Marrow Network for unrelated stem cell donors and the national public cord blood bank. With respect to transmission of the Zika virus, current thinking is the risk calculations for adult stem cell donors are similar to those for blood. This thinking will be reassessed as more information becomes available. Services ensures individuals who are on the path to become stem cell donors are aware of the deferral period for travellers to Zika-risk areas. Because the Zika virus appears to be found in higher concentrations in the fetal circulatory system, stem cells from cord blood could pose a greater risk to transplant recipients than stem cells from adult donors. We are collecting information from donating mothers about their travel during pregnancy and revising the 5

6 donation eligibility criteria for the cord blood program. As stem cells from cord blood have not yet been issued from Canada s bank, there is no real risk to recipients at this time. Because stem cells from cord blood are provided to both Canadian and international patients, it is necessary to consider a more international approach to eligibility criteria for cord blood donors. Health Canada has also provided guidance for cells, tissues and organs, which aligns with the 21-day deferral Services and Héma-Québec have implemented for blood donors. While Services does not screen organ donors (this screening is conducted by organ procurement programs), we believe the advice related to organ donor management provided by both Health Canada and the Canadian Transplant Society is an appropriate first step to mitigate risk. As more knowledge becomes available, this deferral period may be modified. Ongoing surveillance Services continues to actively monitor the evolving situation with the Zika virus. We are in regular contact with other blood operators, and with international epidemiology and surveillance groups, to keep abreast of the developments with the Zika virus. Services has activated established networks with provincial public health units to stay vigilant. Although there are fewer than two dozen known cases of the Zika virus infecting Canadian travellers, we know, through this network, that none are blood donors. In addition to continually monitoring the Zika virus, Services remains keenly sensitive to any threat to the safety of the blood system in Canada. We are considering pathogen inactivation technologies to improve our state of readiness, not only for the Zika virus, but for other bloodborne pathogens that may threaten the blood supply. These pathogen inactivation technologies are used in many countries around the globe but are not yet available in Canada. We anticipate they will be approved for use in Canada in the coming months. Services has long been on record as stating the necessity of using pathogen inactivation technologies to protect the Canadian blood supply from emerging and known pathogens. Commercial technologies can only be applied to platelets and plasma at the moment, and so would only protect part of the blood supply. However, encouraging clinical trials are almost complete for two red blood cell or whole blood technologies that would fully protect all blood products. Impacts on the security of the blood supply The new deferral period for travellers to Zika-risk areas is expected to reduce the number of eligible donors. Current deferral rates since the 21-day requirement was implemented indicate the number of eligible donors has been reduced by just over one per cent. It can be reasonably assumed the actual number is higher due to the number of donors who will self-defer. We are encouraging Canadians to donate before they travel to help make up for the shortfall, and urging new and returning donors who have not recently travelled outside of Canada, the United States and Europe, to book an appointment. New 6

7 donors are critical to maintaining a healthy blood supply and ensuring patients continue to receive the safe and effective blood and blood products they need. Commitment to safety and security of supply Canadian patients depend on us to manage a safe and secure blood system. Our rigorous decision-making process ensures the blood supply is safe from transmissible diseases. We can assure Canadians that the swift, decisive actions we have taken are the best solution for Canada and have effectively mitigated the risk of the Zika virus entering the Canadian blood supply. 7