Aircraft wastewater virome surveillance from domestic and international flights reveals viral diversity among travellers: A proof-of-concept study from Gujarat, India

Background Aircraft wastewater surveillance (AWS) at airports is an emerging method for detecting pathogens shed by international and domestic travellers. Global spread of infectious diseases occurs rapidly through air travel, and implementing surveillance systems at airports can help identify emerging viruses and track pathogens at scale. We aimed to characterize the viral diversity shed by travellers, which may represent routine viral circulation or active infection, at Ahmedabad airport in Gujarat.Methods We collected wastewater samples from domestic and international terminals where domestic flights connect to 18 states and 3 Union Territories, while international flights operate across 16 destinations in 11 countries. Samples were collected from June 2024 to November 2025. We used a capture probe-based enrichment approach for virome surveillance and detected multiple viruses of public health importance.Results We identified a total of 40 viral families and 315 viral species, with a median of 71 genomes/segments detected per sample in domestic wastewater and 48.5 genomes/segments per sample in international wastewater. We detected several respiratory and enteric viruses, including Influenza A virus, SARS-CoV-2, Human mastadenovirus A, Human mastadenovirus B, Noroviruses, Rotavirus A, Hepatitis A virus, Astrovirus MLB1, Human mastadenovirus F. Among these, certain viruses showed relatively higher mean RPKMF abundance in either domestic or international wastewater samples such as Bovine rotavirus A, Human rotavirus ID45/2, and BK polyomavirus observed in international wastewater samples, whereas Aichivirus A1, Norovirus GII.2, and Human immunodeficiency virus 1 showed higher abundance in domestic wastewater samples. We also detected multiple Influenza virus subtypes, including Influenza A subtypes H1N1, H3N2, H5N1, H7N1, and H9N2, along with Influenza B and Influenza C viruses.Conclusions Continuous surveillance can provide early warning signals to public health authorities, timely decision-making and coordinated responses can reduce the spread of disease which also requires collaboration with national and international health authorities.