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Recorded zika virus webinar is available

Latest updates

The FDA (https://www.fda.gov/) posted an update to its website with advice to blood collection establishments on non-travel related cases of Zika virus in Florida.

The CDC (https://www.cdc.gov/) also updated its website to include areas at risk for locally acquired vector-borne Zika cases.

Questions and answers

Selected references

To learn more about how the Zika virus spreads, risk factors for transmission and how to keep informed on emerging information and strategies, view a recording of an April 28 webinar, From A to Zika, on UNOS Connect.

After viewing the webinar, you will be able to:

  • Recognize risk factors for Zika transmission
  • Describe guidelines related to the potential for Zika transmission in transplantation
  • Locate resources for up to date information and strategies for the Zika virus

Webinar Summary:
This webinar explores the unique challenges that the Zika virus presents as an emerging disease. Transmission primarily occurs through a mosquito bite, but there are reported cases of sexual transmission, and it is possible that solid organ donation could lead to transmission as well.

It is important for the transplant community to understand that Zika transmission to recipients may be possible if they are transplanted with an infected organ. The Zika virus may pass from donor to recipient, or recipients may become infected after international travel. It is unknown how immunosuppression affects transplant recipients’ health and what role Zika may play in retaining or eroding their healthy status.

Continuing Education Information
ABTC will award 1 CEPTC credit for participation. In order to receive a certificate, you must view the Zika webinar and complete an evaluation and assessment.

There is no cost to view the webinar. After registration you will receive a confirmation e-mail. Please make sure your email settings allow for communications from Citrix. Contact your IT department for assistance.

The session will be recorded for those unable to attend the live event. Contact education@unos.org with any questions.

Questions and answers

Background/Epidemiology

How is Zika transmitted?
The most common mode of transmission is via the bite of an infected mosquito. Other modes of transmission include from pregnant mother to fetus, sexual transmission, blood transfusion, and laboratory exposure. Transmission by organ or tissue transplantation may be possible, but has not been observed to date.

What is Zika’s incubation period?  Are antibodies formed after infection?  How long are they detectable?
The incubation period (the time from exposure to symptoms) for Zika virus disease is not known, but is likely to be a few days to a week.  Antibodies are typically detectable by the end of the first week following illness onset.  Once a person has been infected, he or she is likely to be protected from future infections.

How does the incubation period affect selection of living liver donor candidates? Or does it?
Since most people infected with Zika virus are asymptomatic, the absence of symptoms does not mean that the potential donor may not be infected and capable of transmitting virus to a recipient. Thus, the incubation period (time from infection to development of symptoms) is not that helpful in excluding the possibility of donor infection.

How should a positive Zika test affect donation?
With regard to organ donation, we don’t know how long Zika persists in tissue. The appropriate amount of time to defer a donor with a positive NAT test for Zika is uncertain. For living HCT/P donors (largely of reproductive age) the FDA requires a 6 month deferral for those with active Zika in the past 6 months and the same period for HCT/P cadaveric donors.

For deceased donors, no automatic deferral is recommended at this time. If the donor has an active viral infection at the time of death, then a clinical judgment must be made taking into account individual donor and candidate urgency. The risk of serious infection is unknown.

The FDA or AATB can offer further guidance on eyes, tissue, blood and other non-solid organ donation.

Is there any data on duration of viremia in blood, GU tract, or other organs?
During the first week after onset of symptoms, Zika virus disease can often be diagnosed by performing reverse transcriptase-polymerase chain reaction (RT-PCR) on serum.  Two case reports have indicated prolonged present of virus in semen of symptomatic males following symptomatic Zika virus infection.  Zika virus RNA has been detected in urine and in some cases, for longer periods than serum.

How long is a female at risk for transmission to fetus after exposure to Zika?
Zika virus can be passed from a pregnant woman to her fetus at any time during pregnancy or at delivery.

Once infected, do people build immunity from further infection? 
Once a person has been infected, he or she is likely to be protected from future infections.

What drug therapies can be used?
No antivirals with proven activity against ZIKV are currently available.

Are there long term deficits in adults who test positive for Zika? What complications might they encounter? At what rate do these complications arise?
Clinical illness is usually mild with symptoms lasting for several days to a week. Severe disease requiring hospitalization is uncommon and case fatality is low. However, there have been cases of Guillain-Barre syndrome reported in patients following suspected Zika virus infection. No other long term sequelae of infection have been reported.

Screening, Guidelines and Testing

What tests are used to diagnose the disease?
Preliminary diagnosis is based on the patient’s clinical features, places and dates of travel, and activities. Laboratory diagnosis is generally accomplished by testing serum or plasma to detect virus, viral nucleic acid, or virus-specific immunoglobulin M and neutralizing antibodies.

What definitive guidelines are there for screening donors? Are there differences in screening living versus deceased donors?
The OPTN has created guidelines for donor screening.  These quidelines continue to evolve as new information becomes available.  Current OPTN guidelines suggest the following practices. In general, either deceased or living donors with exposure to ZIKV and compatible symptoms should be used with caution. Living donors with symptoms could be tested for ZIKV with the assistance of state health departments. Testing for dengue and chikungunya would be appropriate as well. No testing is currently available in a time frame likely to assist in the decision of whether or not to procure organs from a potential deceased donor, but an active viral infection will most likely rule out a donor as a viable option.

The FDA or AATB can offer guidance on eyes, tissue, blood and other non-solid organ donation.

What are appropriate screening question for living donors? What countries of travel should we be concerned about and within what time frame that donor visited them?
Living donors could be asked about exposures to ZIKV. Exposures include recent travel to areas endemic for ZIKV (refer to CDC website) and, for woman, sexual contact with a man with ZIKV exposure in the past 3 months.  For those with exposures, it is reasonable to ask about symptoms such as fever, rash, conjunctivitis, and joint pains.

Who is responsible for testing and screening of donors?
The living donor recovery center would be responsible for any screening and testing for living donors. There is no specific testing available for deceased donors that can be done in a useful time frame for organ procurement. As is true of other potential transmissible risks, assessment for ZIKV is a joint responsibility of the OPO and the accepting transplant hospital for deceased donors.

What will transplant hospitals request from OPOs in regard to testing?
No laboratory testing is available in a time period useful for procurement decisions. In general, for recipients with a cause of death clinically compatible with an arborvirus infection, donations should be used with great caution.

What is the waiting period for living donors?
The OPTN has not created policy defining a waiting period from exposure to procurement.  The FDA, however, has defined a four week deferral period for blood donation after travel to a ZIKV endemic area. For potential living donors with documented ZIKV infection, a longer period (six months?) may be reasonable.

Will a question about Zika exposure be added to the Increased Risk Questionnaire?
Additional questions are being added to the DRAI.

Zika and Transplant Donors and Recipients

How might this impact our donation population?
We currently do not pursue pregnant donors at any stage of pregnancy.

In some regions, many potential donors may be exposed. This is currently the case in Puerto Rico. Areas of active ZIKV transmission may increase during the warmer months in the southern regions of the United States. Because of this, it is important to be thoughtful in assessing the true risk of donor-derived infection and balancing that against the benefit of a new organ.

Why is there a six month wait?  It seems excessive.
There is no policy requiring a six month wait for organ donation.  In the case of living donors with known ZIKV infection, a longer waiting period might be safer.

How does this disease impact donors and recipients? How does this impact living donation?
Whether or not immunosuppressed individuals will develop more severe disease is not known but certainly possible.

What do we know about Zika in the immunosuppressed patient? What risks might they incur?
Whether or not immunosuppressed individuals will develop more severe disease is not known but certainly possible.

Are there any studies on solid organ transmission? What is the actual chance of donor transmitted infection through transplantation?
There is almost no information on whether immunosuppressed individuals will develop more severe disease and no information on the true risk of donor derived disease.

Are there documented cases of Zika in post-transplant patients?  Or other immunocompromised people (comparison data)?
At this time, there is no information regarding such cases.

Are there special considerations for heart transplant recipients?
Not compared to recipients of other organs.

What treatments are there for post-transplant patients who’ve contracted Zika?
Provide supportive care. There is no antiviral treatment.

We have patients who live in Puerto Rico. What should we tell them about precautions to take?
They should get general recommendations regarding mosquito avoidance.

How long do living donors from endemic areas need to wait before donating a kidney?
There is no hard and fast policy; 28 days seems reasonable if practical.

Selected references

National

OPTN guidance on zika virus: deceased and living donor guidelines

Centers for Disease Control Zika page
See information on several topics:

  • Zika and pregnancy
  • Zika and blood transfusion
  • Information for clinicians
  • Travel notices
  • Information for travelers and travel health providers
  • Nationally notifiable list
  • Mosquito avoidance

World

World Health Organization Zika fact sheet

Dr. Rabe’s References

Besnard M, et al. Evidence of perinatal transmission of Zika virus, French Polynesia, December 2013 and February 2014. Euro Surveill 2014; 19(13):20751.

Duffy MR, et al. Zika virus outbreak on Yap Island, Federated States of Micronesia. N Engl J Med 2009; 360:2536–2543.

Foy BD, et al. Probable non-vector-borne transmission of Zika virus, Colorado, USA. Emerg Infect Dis 2011; 17(5):880–882.

Hayes EB. Zika virus outside Africa. Emerg Infect Dis 2009; 15(9)1347–1350.

Kusana S, et al. Two cases of Zika fever imported from French Polynesia to Japan, December to January 2013. Euro Surveill 2014; 19(4):20683.

Kwong JC, et al. Case report: Zika virus infection acquired during brief travel to Indonesia. Am J Trop Med Hyg 2013; 89(3):516‒517.

Lanciotti RS, et al. Genetic and serologic properties of Zika virus associated with an epidemic, Yap State, Micronesia, 2007. Emerg Infect Dis 2008; 14(8):1232‒1239.

Musso D, et al. Potential for Zika virus transmission through blood transfusion demonstrated during an outbreak in French Polynesia, November 2013 to February 2014. Euro Surveill 2014; 19(14):20761.

Oehler E, et al. Zika virus infection complicated by Guillain-Barre syndrome – case report, French Polynesia, December 2013. Euro Surveill 2014; 19(9):20720.

Tappe D, et al. First case of laboratory-confirmed Zika virus infection imported into Europe, November 2013. Euro Surveill 2014; 19(4):20685.