We will examine and compare acute infection dynamics (14 days) with the ZIKV strain PRVABC59 between four Indian rhesus macaques infected via mosquito bite (Aedes aegypti, black-eyed Liverpool strain) and animals we previously infected with ZIKV strain PRVABC59 by subcutaneous inoculation (ZIKV-022). Animals will be euthanized after 14 dpi and 20+ tissues will be collected and processed for RNA isolation and viral load. These experiments will examine whether subcutaneous inoculation accurately represents mosquito infection in rhesus macaques and whether infection by mosquito bite results in increased plasma viral loads and more extensive tissue burden similar to that observed for other flaviviruses such as West Nile virus.
The total number of blood fed mosquitoes per animal and the amount of infectious ZIKV in the saliva of those mosquitoes will be used to estimate the dose of inoculum each animal receives. Blood fed mosquitoes will be examined for infection (detection of ZIKV in the midgut), dissemination (detection of ZIKV in the extremities), and transmission by capillary feeding (detection of ZIKV in the saliva).
Four Indian-origin rhesus macaques (3 males, 1 female) will be infected by mosquito bite with ZIKV Puerto Rico (PRVABC59). Blood plasma, urine, and saliva will be collected from each animal at -4, and 0-14 dpi, and serum will be collect at 0 and 14 dpi. Viral RNA will be measured using qRT-PCR for all sample types and will be compared between these animals and animals infected subcutaneously with 104 PFU WT PRVABC59 in a previous study (ZIKV-022). In addition, we will be collecting tissues from these animals at necropsy including lymph nodes, CNS tissues, and reproductive tissues.
- 268283 will be challenged by mosquito feeding
- 328696 will be challenged by mosquito feeding
- 349332 will be challenged by mosquito feeding
- 458001 will be challenged by mosquito feeding
Clinical and Assay Data
Viral RNA quantification
- January 30, 2017: This study is scheduled to begin on January 30, 2017. All animals were successfully fed on by mosquitoes on January 30, 2017; 328696 received 18 bites, 349332 received 8 bites, 268283 received 5 bites, 458001 received 5 bites.
- January 31, 2017: As of 1 day post challenge, 328696, 349332, and 458001 all had positive plasma viral loads.
- February 2, 2017: 268283 finally had a positive plasma viral load 2 days post challenge.