Isothermal Detection of Influenza D Virus using Reverse Transcription Loop-Mediated Isothermal Amplification

Influenza D virus (IDV) belongs to the Orthomyxoviridae family and was first identified in pigs in Oklahoma, USA, in 2011. Cattle are currently considered its primary reservoir, where it causes bovine respiratory disease, although antibodies have also been detected in sheep, goats, horses, and camelids. Active human infections have not yet been confirmed, but seroprevalence in the general population in Italy rose from 5% in 2005 to 46% in 2014. In workers occupationally exposed to cattle, the prevalence of IDV antibodies reached as high as 97%. Researchers developed and validated a rapid, field-deployable RT-LAMP assay for detecting IDV. The assay demonstrated a specificity of 99.2% and a sensitivity ranging from 81.8% to 95.6% depending on cycle quantification values. This method provides a cost-effective and accessible alternative to quantitative RT-PCR, improving surveillance and preparedness for emerging influenza threats.