Infection with Increases the Replication and Dissemination of Coinfecting Powassan Virus in Ticks.

Powassan virus (POWV) is a tick-borne neuroinvasive flavivirus endemic to North America. It is generally transmitted by the tick, . This species also transmits , the causative agent of Lyme disease. Infection with can result in arthritis, carditis, and neuroborreliosis. These pathogens experience sylvatic overlap. To determine the risk of human exposure to coinfected ticks, the interactions between POWV and are assessed in laboratory-infected . Adult male and female ticks are orally inoculated with either both pathogens, POWV only, only, or uninfected media. After twenty-one days, the ticks are dissected, and RNA is extracted from their midguts and salivary glands. In infected midguts, the quantity of POWV in coinfected ticks was elevated compared to those with only POWV. In addition, the salivary glands of ticks with infected midguts had increased POWV dissemination to those with only POWV. RNA sequencing is performed to identify the potential mechanism for this pattern, which varies between the organs. ticks are found to be capable of harboring both POWV and with a benefit to POWV replication and dissemination.