Co-Infection Dynamics of <i>Baculovirus penaei</i> (BP–PvSNPV) in <i>Penaeus vannamei</i> Across Latin America

Baculovirus penaei (BP) is an exclusively enteric virus that targets the mucosal epithelial cells of the hepatopancreatic (HP) tubules and the anterior midgut. Its impacts are most pronounced during early developmental stages, including zoea, mysis, and early post-larvae (PL), where infections often lead to significant hatchery losses. Traditionally, BP's significance as a pathogen has been tied to its high pathogenicity in these early larval stages. When outbreaks occur at this critical point, the affected tanks are typically discarded, limiting opportunities for further research.In later developmental stages, BP infections are not directly associated with substantial mortality. This has likely contributed to the pathogen being undervalued, at least as a potential marker for co-infections. Nevertheless, BP's role as part of complex co-infection scenarios highlights its broader relevance.Various molecular diagnostic methods have been developed to detect BP. However, these methods frequently fail to amplify PCR products, likely due to the high genetic diversity among BP strains. Such variability contributes to inconsistencies between molecular diagnostics and histological findings, where distinct polyhedral occlusion bodies are consistently observed in HP tissues.The present study reports the presence of BP across all cultivation stages of Penaeus vannamei farmed in Latin America, from post-larvae to broodstock in maturation. BP is consistently observed in association with co-infections, often alongside bacterial lesions in the hepatopancreas. Additionally, the findings underscore significant deficiencies in current molecular detection methods, which appear to lack the specificity required to reliably identify BP. These limitations emphasize the need for improved diagnostic approaches to better account for BP's genetic diversity and its role in shrimp health and disease dynamics.