Survival of waterborne enteric viruses in the Msunduzi River in Pietermaritzburg

Abstract

Waterborne enteric viruses are ubiquitous in a riverine environment. However, there has been no direct correlation between bacterial faecal indicators and viral contamination in water. Therefore, a viral indicator or combination of bacterial and viral indicators may be necessary to determine contamination in environmental waters and their sources. Enteric viruses are detected in water using various methods including qPCR, RT-PCR, cell culture and sequencing. In this study, adenovirus, norovirus GI and GII, rotavirus A and hepatitis A were detected in all samples collected from the Msunduzi River in Pietermaritzburg using a digital PCR method. Results obtained indicated that environmental factors, including ammonia, temperature, pH, phosphates, rainfall, suspended solids, turbidity and TOC, were found to affect enteric virus survival in a riverine environment. It was further observed that anthropogenic activities such as the Dusi Canoe Marathon impacted the distribution of enteric viruses throughout the Msunduzi River. Adenovirus 40 and 41 and all serotypes were detected together with other enteric viruses and bacterial indicators proving to be a possible indicator for viral pathogens. Little to no correlation was found between enteric viral pathogens and enteric microbial loads in this river. Future work should include the investigation of other possible viral indicators and forming an indicator complex that includes both bacterial and viral indicators for water quality based microbial risk assessment framework.