Högskolan i Skövde

Avian influenza, known as bird flu, is a highly contagious acute respiratory infection that infects many avian species, humans and other animals. Birds infected with Influenza A virus can shed large amounts of virus in feces, which can be detected in the lakes. Similarly, people infected with enteric viruses also shed high amounts of virus in their feces, which can end up in lake water. In this study, the presence of influenza A and seven enteric viruses (norovirus GII, astrovirus, enterovirus, adenovirus, sapovirus, hepatitis E virus, and pepper mild mottle virus) were investigated in recreational lakes to explore whether their identification could be used as an early warning of outbreaks. Lake water samples were collected from Axlemossen, Delsjön, Slottsskogen, and Torpadammen. The samples were taken monthly from November 2023 until April 2024 and analyzed for detection of viruses by concentration through ultrafiltration and quantitative polymerase chain reaction. Influenza A virus was selectively detected in the urban lakes of Slottsskogen and Torpadammen, where favorable pH, temperature, and high bird populations likely supported the virus's stability in the lakes. In contrast, enteric viruses showed a broader distribution across all lakes, likely driven by human fecal contamination from recreational activities or possibly from untreated wastewater discharges from unknown sources. The method used in this study aids in studying the presence and behavior of circulating strains in birds. Additionally, it can help understand the potential public health risks of waterborne viruses, especially those transmitted through avian or human fecal matter in the local environment.