When most scientists hear the word astrovirus, they think of viruses that cause mild diarrhea in humans or animals. Historically, this is because astroviruses were primarily known as enteric or gut pathogens. However, this is changing as more and more astroviruses are now increasingly recognized to be associated with neurologic and respiratory disease.
In a new open-access Letter to the Editor published in the Journal of Influenza and Other Respiratory Viruses, our UTMB One Health team, led by Dr. Judith Oguzie, reports the first detection and genomic characterization of a bovine astrovirus (BoAstV) in the nasal swabs from cows with respiratory illness in Mexico (1). This suggests that this virus may be part of the broader landscape of pathogens involved in bovine respiratory illness.
Astroviruses are divided into two genera: Mamastrovirus, and Avastrovirus which infect mammalian and avian species, respectively. In mammals, astroviruses are more diverse than many people realize, as mamastroviruses are a common cause of human infection, and one of the most important causes of pediatric acute gastroenteritis, thus, raising questions about the zoonotic potential in the broader One Health context. In cattle specifically, BoAstV is considered as an emerging and under-characterized virus group. Even though astroviruses are still often framed, as enteric pathogens evidence has been accumulating that certain bovine astrovirus strains may also be a cause of respiratory disease.
As a surveillance project focused on understanding the respiratory viruses associated with cattle, researchers from UTMB One Health and the Universidad Autόnoma de Nuevo Leόn (UANL) in Mexico collected nasal swabs from 40 sick cattle during the period February 2024 to May 2025 on Mexican farms. After initial molecular screening for common respiratory viruses, 14 specimens were selected for metagenomic next-generation sequencing, a powerful approach that can identify both known and unexpected viruses in a single sample. These 14 were chosen because they showed molecular evidence of influenza D virus and/or coronaviruses. Among these sequenced specimens, BoAstV nucleic acid was identified in three nasal swabs collected from cattle with respiratory illness (including fever and nasal discharge). Phylogenetic analysis placed them within a respiratory-associated bovine astrovirus lineage rather than in the classic enteric astrovirus groupings.
While the contents of the above letter does not prove that BoAstV caused cattle illnesses, it supports the hypotheses that such viruses may be unrecognized respiratory disease problem in cattle.
Additionally, this study expands regional surveillance knowledge, as these observations are the first reported detection of BoAstV among cattle in Mexico. Also, the observations in Mexico are consistent with the reported detection of Astroviruses in the upper and lower respiratory tracts of calves with acute signs of bronchopneumonia in France (2). These findings provide growing evidence that that some BoAstV lineages may be respiratory-associated, meaning they could be part of the bovine respiratory disease complex and therefore warrants tracking more systematically.
In a world where livestock health, agricultural stability, and emerging infections intersect, this study is a reminder that the next important discovery may not always be the headline virus, it may be the one we weren’t routinely testing for at all.
References
- Oguzie JU, Hernandez-Vidal G, Moreno-Degollado G, Marushchak LV, Rodriguez J, Gray GC. Novel Astrovirus Detected in Nasal Swabs of Sick Cattle, Mexico. Influenza Other Respir Viruses. 2026;20(1):e70226. doi: 10.1111/irv.70226.
- Gaudino M, Salem E, Ducatez MF, Meyer G. 2023. Identification of Astrovirus in the virome of the upper and lower respiratory tracts of calves with acute signs of bronchopneumonia. Microbiol Spectr 11:e03026-23. https://doi.org/10.1128/spectrum.03026-23