Standardized Diagnostic Assays for Omsk Hemorrhagic Fever Virus

Area of Science:

• Virology
• Infectious Diseases
• Molecular Diagnostics

Background:

• Omsk hemorrhagic fever (OHFV) is a zoonotic disease caused by a Flavivirus with a significant fatality rate.
• Ecological shifts may increase the risk of OHFV spread to new regions, including South Korea.
• A reliable diagnostic method is crucial for surveillance and control, especially in non-endemic areas.

Purpose of the Study:

• To develop and validate a sensitive and specific diagnostic protocol for Omsk hemorrhagic fever virus (OHFV).
• To establish a real-time RT-PCR assay for detecting OHFV in potential surveillance settings.
• To ensure broad strain coverage and high accuracy in diagnostic testing.

Main Methods:

• Developed a real-time reverse transcription polymerase chain reaction (RT-PCR) assay targeting the NS2A and C genes of OHFV.
• Designed primers and probes from available OHFV genomes for comprehensive strain coverage.
• Validated assay performance using synthetic DNA/RNA and tested specificity against related flaviviruses and an alphavirus.

Main Results:

• The assay demonstrated high analytical sensitivity with limits of detection of 74.50 copies/µL (NS2A) and 70.41 copies/µL (C).
• No cross-reactivity was observed with tested flaviviruses (West Nile, Yellow Fever, Zika, St. Louis encephalitis, Tick-borne encephalitis) and an alphavirus.
• The developed protocol showed high sensitivity, specificity, and reproducibility.

Conclusions:

• The validated real-time RT-PCR assay is a reliable tool for OHFV detection.
• This diagnostic protocol can support national and international surveillance systems for Omsk hemorrhagic fever.
• Early and accurate diagnosis is essential for managing the potential spread of OHFV.