Using advanced surveillance tools to understand norovirus evolution, public health impacts, and to enhance outbreak response

Abstract

Noroviruses are the most common cause of sporadic gastroenteritis and causative agent for 90% of all gastrointestinal outbreaks in developed countries. Norovirus illness is characterized by abrupt onset of nausea, vomiting, diarrhea, abdominal pain, and occasionally fever. Symptoms typically resolve within 2-3 days, but are often severe enough to prevent affected cases from attending school or work. Noroviruses are highly contagious, and are easily transmitted person to person within households, health care facilities, as well as schools and daycares.

Occasionally, noroviruses are responsible for foodborne outbreaks. Robust epidemiological and laboratory surveillance systems are critical for timely detection of outbreaks. Outbreak response protocols serve to coordinate the activities of various public health partners with the goal of identifying specific foods and risk factors associated with illness as well as actions necessary to control disease transmission.  

Several laboratory tools are at available to the BCCDC Public Health Laboratory for norovirus surveillance and outbreak investigations. First, norovirus outbreak samples that are submitted are sequenced to assess genotype that enables an understanding of genetic relatedness within and between outbreak, and to determine if strain replacement is occurring, contributing to epidemic severity. Secondly, recognizing the limitation of passive surveillance for norovirus, wastewater-based surveillance is used to understand norovirus activity at the community level. Lastly, several research-based tools are used to better understand norovirus transmission and mitigation, which include whole-genome sequences and microbial-source tracking in marine environments (GEMSTONE project).

Speakers

Dr. Mayank Singal MD MPH CCFP FRCPC is the medical lead for enteric, vector-borne, and zoonotic diseases at BCCDC and Assistant Clinical Professor at UBC. Mayank leads a multidisciplinary team to assess public health risks, design surveillance systems and develop evidence-informed provincial guidelines for control and prevention of communicable diseases. His most recent work includes the areas of rabies, COVID-19, avian influenza, Mpox, and numerous enteric outbreaks.

Dr. Natalie Prystajecky PhD SCCM is the Program Head for Environmental Microbiology and co-Program Head for Molecular and Microbial Genomics at BCCDC Public Health Laboratory. She is also a Clinical Associate Professor at UBC. In her clinical roles and research endeavours, she uses emerging technologies such as genomics to improve routine surveillance and outbreak investigations for a wide range of pathogens. In recent years, she played a pivotal role in developing sequencing capacity at the BCCDC, launching BC’s wastewater surveillance program and conducting collaborative research to respond to H5N1 in birds.