New primer sets to detect recent human adenovirus F41 variants in wastewater: Is it linked to the new acute hepatitis?

Human adenovirus type F-41 has been pursued as one of the potential reasons for the new acute hepatitis cases of unknown cause in young children. Tracking the spread of this virus in the population using wastewater-based epidemiology tools can help clinical investigations to determine its relation to this new hepatitis outbreak. In this study, methods to detect human adenovirus type F (40 and 41) and specifically type F41 were designed and implemented to quantify the amount of these pathogens in wastewater samples from Stockholm, Sweden. An assay based on reverse transcriptase quantitative polymerase chain reaction using TaqMan technology and primers targeting the three main capsid genes of adenoviruses: hexon, penton and fiber, was designed. The hexon primers were specific to adenovirus F41, while fiber primers could quantify both adenoviruses, F40 and F41. Wastewater samples from Stockholm were used to validate the designed assay and, in addition, pepper mild mottle virus (PMMoV) levels were quantified to study the data normalization. Our results can help link the occurrence of the virus variant with new cases of acute hepatitis and contribute to a better understanding of the possible causes. It can also provide valuable information that can be used in future investigations on the monitoring of human adenovirus type F in wastewater.