Whole-Genome Characterization of Rodent Coronaviruses (RCoVs) in Thailand, 2024-2025

Area of Science:

• Veterinary Virology
• Zoonotic Disease Research
• One Health Surveillance

Background:

• Rodents are significant reservoirs for diverse coronaviruses with zoonotic potential.
• Limited data exists on rodent coronaviruses (RCoVs) circulating in Thailand.
• Understanding RCoV prevalence and genetics is crucial for public health.

Purpose of the Study:

• To determine the prevalence and genetic characteristics of RCoVs in Thai rodent populations.
• To analyze the phylogenetic relationships of detected RCoVs.
• To assess potential host adaptation and zoonotic implications.

Main Methods:

• Sampling of 435 rodents across Thailand (Jan 2024 - Apr 2025).
• Screening of oral and rectal swabs using RT-PCR targeting the RdRp gene.
• Whole-genome and RdRp gene sequencing for positive samples, followed by phylogenetic analysis.

Main Results:

• RCoVs detected in 2.07% of rodents, exclusively in Bandicota indica.
• All Thai RCoVs belonged to Betacoronavirus muris, clustering with Asian RCoVs.
• High nucleotide identity (~97%) with RCoVs from China, Thailand, and Vietnam; variable spike proteins noted.

Conclusions:

• This study identified genetically diverse RCoVs in Thai rodents, indicating regional circulation.
• Variability in spike proteins suggests adaptive evolution and warrants further investigation.
• Ongoing One Health surveillance is essential for early detection of emerging coronavirus threats.