Human-Pathogenic Kasokero Virus in Field-Collected Ticks

Area of Science:

• Virology
• Arthropod-borne diseases
• Zoonotic infections

Background:

• Kasokero virus (KASV), an Orthonairovirus, was first isolated in 1977 from bats in Uganda.
• Laboratory infections indicate KASV poses a human health risk.
• A specific tick vector for KASV has not been previously identified.

Purpose of the Study:

• To investigate the potential tick vector of Kasokero virus.
• To determine the enzootic transmission cycle of KASV.
• To assess the risk of KASV spillover to humans.

Main Methods:

• Testing of 786 Ornithodoros (Reticulinasus) faini tick pools for KASV RNA.
• Collection of ticks from a Rousettus aegyptiacus bat roosting site in western Uganda.
• Isolation of infectious KASV from positive tick samples.

Main Results:

• Kasokero virus RNA detected in 43 of 786 tick pools.
• Two infectious KASV isolates were recovered from ticks.
• One isolate was obtained from ticks that had been depleted of host blood.

Conclusions:

• Ornithodoros (Reticulinasus) faini ticks are likely vectors for Kasokero virus.
• KASV is maintained in an enzootic cycle involving these ticks and Rousettus aegyptiacus bats.
• The findings suggest a potential for incidental virus spillover to humans.