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ZIKV-002
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Prolonged shedding in urine
david h oconnor 2016-03-17
As in ZIKV-001, we are detecting virus in urine after it is no longer detectable in plasma. In ZIKV-001, this only lasted for a few days. We should know early next week how long the ZIKV-002 animal with viruria (virus in urine) continues to shed.



-dave
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Lower viral laods
david h oconnor 2016-03-15
With a little more data, it is now clear that the animals challenged with African lineage Zika virus have consistently lower plasma viremia than animals infected with Asian lineage Zika virus. Moreover, only one of the three animals in this study have any detectable virus in urine, while all three animals given Asian lineage virus had detectable virus in urine. If experience with HIV is any guide, higher concentrations of virus in various fluids can be proportional to transmission risk.



-dave
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ZIKV-002 challenge virus sequence information
david h oconnor 2016-03-11
I just posted our initial analysis of the ZIKV-002 challenge sequence. Of interest to others who are using this African lineage virus, we noted a four amino-acid deletion in the majority of sequences in a region of envelope. It is possible this occurred during in vitro expansion of the source virus, but it is also possible this deletion is present in the source virus. At this time, we have no way to assess when the deletion arose or what, if any, impact it will have on virus replication. We would urge others using their viruses to sequence them. If you have a challenge stock that will be used in an animal study, Dr. Shelby O'Connor (soconnor@primate.wisc.edu) will sequence it free of charge as a service provided by the Wisconsin National Primate Research Center's Genetics Services Unit.



-dave
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Infected
david h oconnor 2016-03-09
All three animals challenged with African lineage Zika virus are now infected. As before, the amount of virus in the blood one day after infection is proportional to the challenge dose. Also similar to our first study, virus is not detected in the urine early during infection even when it is present in blood.



Andrea notes that viral loads at day 1 and 2 are slightly lower than what we observed in ZIKV-001.



[UPDATE] - after looking more closely, this difference is more striking than I initially noticed. All three of the animals challenged with African ZIKV have lower viral loads than any of the three animals challenged with Asian ZIKV. If this trend holds, and it is still very, very preliminary, it could provide a reason why the consequences of Asian/American ZIKV infections are more severe than what was previously observed in Africa.



Information about the challenge virus should be available later tonight.



-dave
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First viral loads later today or tomorrow morning
david h oconnor 2016-03-08
Plasma viral loads will be determined on samples collected for each of the next ten days. The first question we will answer with today's data is whether animals were successfully infected.



-dave
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ZIKV-002 begins Monday
david h oconnor 2016-03-03
We will be starting ZIKV-002 on Monday March 7, 2016.
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