Thesis Format
Monograph
Degree
Master of Science
Program
Microbiology and Immunology
Supervisor
Troyer, Ryan
Abstract
Rotaviruses are waterborne pathogens that cause severe gastroenteritis and are highly UV-resistant. Ultraviolet light at 254 nm has been shown to cause the inactivation of rotavirus; little research on the capabilities of other UV wavelengths has been conducted. In this project, multiple wavelengths across the UVC spectrum were tested for their ability to inactivate the Wa and SA11 rotavirus strains. Action spectra generated show that SA11 is more susceptible to UV light than Wa, especially at lower wavelengths. Rotavirus was also quantified in wastewater samples from London, Ontario across months with varying levels of stringency from the COVID-19 pandemic. Using a qPCR detection assay, it was determined rotavirus concentrations fluctuate throughout time, although it is unclear if societal restrictions had an impact on this. These results provide important data for development of water treatment processes that use UV light to eliminate pathogens, as well as monitor the prevalence of rotavirus.
Summary for Lay Audience
Rotavirus is a waterborne virus that is the most common cause of gastroenteritis, or stomach flu, in humans worldwide. It is of high concern for young children below the age of 5 years old, with approximately 2 million hospitalizations annually. Ultraviolet (UV) light is a common method of water purification used to disinfect drinking water, wastewater, and industrial water, by causing a virus to be unable to replicate. UV light at 254 nanometers (nm) has been the standard industry practice due to its availability commercially and economically and is effective in inactivating rotavirus. The production of LED lamps that emit UV light at wavelengths other than 254 nm has opened the door to test if rotavirus is susceptible at other conditions. To understand rotavirus’ inactivation due to UV light, this project was conducted to see how susceptible rotavirus is at wavelengths across the UVC spectrum. Two rotavirus strains were tested, the human Wa and simian SA11, and were inactivated under 9 different wavelengths of UV light to see what conditions were the most effective. The results showed that SA11 is more susceptible to inactivation than Wa, especially at lower wavelengths, and their susceptibilities differ from one another at each wavelength.
Rotavirus is often found in wastewater due to its transmission through fecal matter. Quantifying its concentration is important in identifying outbreaks and determining measures necessary to combat its spread. During the COVID-19 pandemic, societal restrictions were implemented that restricted mobility. This project utilized a qPCR detection assay to quantify rotavirus in London, Ontario by using wastewater samples from 5 months during the pandemic to see if societal restrictions had an impact. The highest concentration of rotavirus occurred in June 2021, and decreased as time passed. Interestingly, this timepoint had the most restrictions. This work showed that rotavirus concentrations do fluctuate throughout time, however it is unclear if societal restrictions had an impact on this. Understanding rotavirus prevalence in wastewater, as well as its susceptibility to UV light, will aid in the development of more efficient water treatment equipment and help provide insight into rotavirus outbreaks and measures to prevent it.
Recommended Citation
Kamal, Samuel, "The Detection, Quantification, and UV Inactivation of Waterborne Rotavirus" (2024). Electronic Thesis and Dissertation Repository. 10546.
https://ir.lib.uwo.ca/etd/10546
