Course # DL-996: Norovirus: Traveler's Diarrhea and Much More
by Lucy Treagan, Ph.D. - Prof. Biol. Emerita - University of San Francisco
Approved for 2.0 CE
Level of Difficulty: Intermediate
An epidemic of gastroenteritis took place in an elementary school in Norwalk, Ohio in 1968. Clinical samples that originated from this epidemic were eventually demonstrated to contain virus-like particles (the Norwalk agent). In the 1990s the genome of Norwalk agent was sequenced and the agent assigned to a new genus, Norovirus, in the Caliciviridae family.
Noroviruses are small, icosahedral, single-stranded RNA viruses. They are easily transmitted by the oral–fecal route through food, water, fomites, and person-to person. These viruses are highly infectious and cause outbreaks of gastroenteritis on cruise ships, in nursing homes, schools, camps, and in many additional settings. The illness is generally mild and self-limited but may be severe in immunocompromised persons and in the elderly. The outbreaks are difficult to control due to high infectivity and ease of transmission of noroviruses.
Noroviruses are also important causative agents of sporadic gastroenteritis within communities, as well as playing an important causative role in diarrheal diseases that are common among travelers to developing countries (travelers’ diarrhea).
Norovirus infections are diagnosed by molecular methods, such as real-time reverse transcriptase polymerase chain reaction (RT-PCR). ELISA assays for specific antibody may also be useful in establishing diagnosis.
At the present time no specific treatment for norovirus gastroenteritis is available.
After completing this course the participant will be able to:
- Describe principal characteristics and classification of noroviruses.
- Discuss noroviruses and their role in human disease.
- Compare outbreaks of gastroenteritis with sporadic cases caused by noroviruses.
- Outline epidemiology of norovirus infection.
- Discuss clinical symptoms of norovirus gastroenteritis.
- Explain the nature of susceptibility to norovirus infection.
- Summarize methods used in laboratory diagnosis of norovirus gastroenteritis.
- Discuss the role of the immune response in norovirus infections.