Researchers collect fecal samples to study norovirus

Sunday, March 6, 2016 - 12:53pm

A University of Michigan research team is collecting stool samples from people with norovirus symptoms or those who have recovered within the past three days in order to study the virus and seek a potential cure. Each year, 19 to 21 million people in the United States suffer from gastroenteritis — inflammation and irritation of the stomach and intestines — caused by norovirus.

Norovirus is the most common cause of gastroenteritis. It is spread through fecally contaminated food or water, person-to-person contact and touching contaminated surfaces followed by placing fingers near or in the mouth. The virus can spread quickly and cause an outbreak in settings where large groups of people gather, like schools and hospitals.

Last month, the University experienced an outbreak of the virus in which hundreds of students sought medical attention.

Though for most people the disease is not fatal, the infection can cause symptoms such as vomiting, nausea and diarrhea, and it has the potential to cause severe symptoms and death in infants and the elderly. It is estimated that 570 to 800 deaths occur each year in the United States due to norovirus infections. Worldwide, norovirus is responsible for about 200,000 deaths each year, 70,000 of them being children in developing countries.

Currently there is no cure for the norovirus because the viral strains that infect people are difficult to study in a laboratory setting. Many labs study a virus that infects mice — murine norovirus — instead. Though murine norovirus and human norovirus are related, they are not exactly the same, which researchers say is a setback for finding a treatment.

Study leader Christiane Wobus, associate professor of Microbiology and Immunology, said noroviruses infect their hosts in a species-specific manner, and researchers ultimately aim to study the human norovirus, not the murine norovirus. 

“You can learn a lot from studying murine norovirus, but you want to know what you learn from it also applies and translates to human norovirus,” Wobus said. “So ultimately we want to directly study the human norovirus.”

So far, the team has collected three stool samples for the study. The stool samples may contain the norovirus that infected the patients.

Wobus said her team is building off of another recent study that describes how to grow a human norovirus in the lab. She said using that method and the human norovirus from the collected stool samples could help with identifying and developing drugs to treat the viral infection.

“You can infect cells in a dish (with the human norovirus) and test whether the compound of interest blocks the infection,” Wobus said.

However, the previous study only grew one strain of human norovirus in the lab, so Wobus said her team’s first step would be to confirm that the norovirus strain from the stool samples is capable of growing in a dish.

“There are many different strains,” Wobus said. “The study focuses on one strain that is the most commonly seen, but we don’t know whether other strains can work in the same system."

LSA sophomore Kaitlin McKernan, a student recently affected by norovirus, said she thought collecting samples from the norovirus patients and studying them is a good idea because the University has the capability to learn about the virus and its characteristics.  

“(The University) can try to prevent another outbreak like this one, and the hospital and local doctors might know how to treat it better or use better sanitation to prevent it from spreading,” McKernan said.