AUTHOR=Tanabe Lyndsey Kiana , Espinosa Aaron Gabriel , Tiong Regine Hui Yi , Kim Hie Lim 
  
TITLE=Host whole-genome sequencing reveals Scutavirus chelonidalpha5 infection in sea turtles from Singapore
  
JOURNAL=Frontiers in Amphibian and Reptile Science
  
VOLUME=Volume 4 - 2026
  
YEAR=2026
  
URL=https://www.frontiersin.org/journals/amphibian-and-reptile-science/articles/10.3389/famrs.2026.1814588
  
DOI=10.3389/famrs.2026.1814588
  
ISSN=2813-6780
  
ABSTRACT=Fibropapillomatosis (FP) is a tumor-forming disease affecting sea turtles worldwide, linked to Scutavirus chelonidalpha5 (formerly known as chelonid alphaherpesvirus 5, ChHV5) and influenced by environmental stressors. Despite extensive studies elsewhere, FP has not been confirmed in wild sea turtles in Singapore, a highly urbanized city-state with heavily modified coastlines. Here, we report the occurrence of lesions suggestive of FP in Singapore observed in two stranded green turtles (Chelonia mydas) with external and internal tumors. To assess viral presence, we analyzed whole genome sequencing datasets generated from blood and tissue samples of four green turtles and four hawksbill turtles (Eretmochelys imbricata), including individuals with and without visible tumors. Two complementary approaches were used: reference-based analysis (BWA-MEM) and metagenomic analysis (Kraken2). Scutavirus chelonidalpha5-associated reads were detected in all eight genome datasets, with both approaches providing consistent and cross-validated detection of viral sequences. Viral sequences were detected in all genome datasets, with no significant difference between turtles with and without tumors, suggesting that additional host and environmental cofactors such as immune status, microbiome composition, and anthropogenic stressors likely modulate disease expression. This study illustrates the value of genomic surveillance for detecting latent viral infections in both clinically affected and apparently healthy turtles and supports the need for integrated genomic and ecological surveillance of sea turtle health which can inform conservation strategies, improve ecosystem management, and support the resilience of sea turtle populations in Southeast Asia.