Tag Archives: norovirus

Over 100 schools hit by the winter vomiting bug

It’s that time of the year again: Black Friday, Thanksgiving, influenza, and norovirus. The winter cold months are the perfect environment for some pathogens to spread.

Norovirus, also called the “winter vomiting bug”, is a very contagious virus that causes vomiting and diarrhea. Norovirus is spread by coughing, sneezing and close contact, or touching the same surfaces. People infected with norovirus can shed billions of norovirus particles and only a few virus particles can make other people sick.

About 60 schools in north-east England have been hit by a suspected outbreak of norovirus. Some schools in the region had to close down last week and undergo a ‘deep clean’, after hundreds of staff and pupils were hit with vomiting, diarrhea and flu-like symptoms.

Public Health England (PHE) said it was not able to give an exact figure of the number of schools that have been affected, nor their location. However, figures published by PHE suggested norovirus rates are 26 percent higher than they usually are at this time of year.

Between October 28 and November 10, a total of 332 people were infected by the highly contagious bug. A total of 18 outbreaks caused hospital wards to close or to restrict admissions across England and Wales. PHE said it expects these types of bugs to go around schools and workplaces during this time of year, as norovirus is predominantly a ‘winter pathogen’.

On the other side of the Atlantic, Mesa County Valley School District 51 – a school district in Colorado, United States – announced the closing of the entire school district through the end of this school week. All 46 schools in the district reported several students and teachers have gotten sick with vomiting and diarrhea. Although the cause has not yet been clearly identified yet, experts believe this is most likely norovirus.

Noroviruses are thought to be the most common cause of acute gastroenteritis (diarrhea and vomiting). On average, noroviruses cause 19 to 21 million cases of acute gastroenteritis, 1.7–1.9 million outpatient visits and 400,000 emergency department visits in the U.S. per year, according to the CDC.

Young children, the elderly, and people who have a weakened immune system are particularly susceptible to catching noroviruses. The spread of the virus can be hard to control because it’s contagious before symptoms appear.

The Think Noro public health campaign advises:

N“No visits to hospitals, care homes and GP surgeries if you are suffering from symptoms of Norovirus – send someone else to visit loved ones until you are better.”

O“Once you’ve been symptom-free for at least 48 hours, you’re safe to return to work, school or visit hospitals and care home.”

R“Regularly wash your hands with soap and warm water, especially after using the toilet, and before eating or preparing food.”

O“Only hand-washing will prevent the spread of Norovirus – alcohol hand gels DON’T kill the virus.” Hand sanitizers are not effective against norovirus; soap is your best weapon.

There is still no licensed vaccine against norovirus, but there are promising candidates in the pipeline.

Credit: Wikimedia Commons.

Norovirus spread in a Thanksgiving feast


Credit: Wikimedia Commons.

Credit: Wikimedia Commons.

Thanksgiving, or Thanksgiving Day, is a public holiday celebrated on the fourth Thursday of November in the United States. The holiday is the perfect opportunity to catch up with friends and family, eat some turkey and indulge in some pumpkin pie before the Christmas season. But Thanksgiving does not always go as planned especially if you get sick with the flu or gastroenteritis (sometimes called “stomach flu”) or food poisoning. Any of these common illnesses can put a quick end to Thanksgiving festivities.

A study looking into 18 gastrointestinal illness complaints in people who ate Thanksgiving Day dinner at a restaurant in Tennessee in 2017 found that contamination happened after one customer vomited in a private dining room and an employee used disinfectant spray (labeled as effective against norovirus) to clean the area. The employee then, after washing hands, served family-style platters of food and cut pecan pie. The investigation by the US Centers for Disease Control and Prevention (CDC), Vanderbilt University Medical Center, and Tennessee Department of Health was published in the latest issue of Morbidity and Mortality Weekly Report (MMWR).

The restaurant served 676 people that day but health officials were provided with contact, seating time and location information for over 100 customers who had reservations. Subsequently, health officials were able to enroll 137 (20% of the 676) in a case-control study. Stool specimens confirmed norovirus in two patients as well as in an environmental sample collected from the underside of a table leg near where the customer vomited. Of the foods that customers ate, only pecan pie was significantly associated with illnesses, but only 16 of 34 patients had eaten it.

The investigators concluded that norovirus probably spread through the restaurant by multiple routes and that inadequate employee hand washing probably facilitated foodborne transmission through servings of pecan pie. The point-source norovirus outbreak occurred after the infected customer vomited, transmission near the vomiting event likely occurred by aerosol or fomite. Norovirus spread throughout the restaurant could have occurred by aerosol, person-to-person, fomite, or foodborne routes.

According to the CDC, norovirus is responsible for 58% of foodborne illnesses in the US. In recent years, the majority of foodborne norovirus outbreaks occurred in restaurants, often related to an infected employee practicing poor hand hygiene and subsequently serving food. Norovirus cannot be completely inactivated by many common sanitizers and disinfectants used at manufacturer recommended concentrations or contact times. Norovirus infection can recur even after thorough cleaning and disinfection. Every year, foodborne norovirus illness costs about $2 billion, mainly due to lost productivity and healthcare expenses in the United States.


Norovirus outbreak strikes in Maine, but it’s likely under control

Roughly a hundred people have been infected by a highly contagious norovirus in Maine, the CDC reports.


Image credits CDC.

On Friday, the Maine Center for Disease Control and Prevention reported identifying 97 cases associated with a norovirus outbreak. The source seems to be the Woods Pond Beach, according to Bridgton Town Manager Bob Peabody, as all infectees either swam there or came into contact with someone who did.

These individuals reported experiencing symptoms such as vomiting, diarrhea, fever, and cramps over several days. The symptoms generally lasted a few days. Authorities in the town of Bridgeton closed down the beach on July 6th, following the first reported infections, to identify and deal with the source of the infections.

Norovirus causes gastrointestinal disease and can spread in a multitude of ways. You can contract the virus by eating contaminated food, touching an infected surface and then touching your mouth, or by having contact with someone who is infected. It’s especially virulent in areas where large numbers of people share limited space — such as hospitals, schools, or more famously, at the Winter Olympics in Korea. In the Maine outbreak, beachgoers who put their heads under water or swallowed water while swimming were at greater risk of infection, but several people who were not at the beach also caught got sick after caring for someone who was ill.

“It’s highly contagious, so it would appear that there’s a human element there, that somebody had it and was at the beach,” Peabody told the Portland Press Herald. “I think the message is, if you’re sick or your children are sick, don’t go to the beach.”

Water samples taken on July 9th from the pond and the sinks in a public bathroom on the beach were tested for E. coli — the results showing that the swimming water contained safe levels of the bacteria. However, water from the taps was found to be above the safe limit. The sinks themselves were removed and hand sanitizers were installed as an extra precaution before the beach was re-opened for public access on July 10th.

Hot weather generally makes dipping spots much more prone to contamination, as a large number of people hit the beaches to cool off. A single carrier can infest the water (bacteria such as norovirus can be spread by infected individuals vomiting in the water, for example), and bacteria have a much easier time thriving in hot waters.

“We’re seeing the effects of climate change and temperature on lakes,” said Colin Holme, executive director of the Lakes Environmental Association, explained for the Portland Press Herald. “These problems could be more frequent in the future because the temperature is going to rise and people are going to seek the water in relief.”

Authorities recommend that beachgoers wash their hands and practice good hygiene both before and after taking a dip. If you’re going to the beach with an infant, you should change their swim diapers frequently, preferably in a bathroom away from the water, and dispose of them in a trash container. Swimmers, in general, should also avoid swallowing water.

Oysters, Olympics, Ocean liners and Outbreaks


Credit: Pixabay

The US Food and Drug Administration (FDA), federal and state health authorities, along with Canadian public health officials, are investigating multi-province and multi-state norovirus outbreaks linked to raw oysters from British Columbia. Currently, there is no word on how many illnesses and states are involved in the US part of the outbreak; however, potentially contaminated raw oysters harvested in the south and central parts of Baynes Sound, British Columbia, Canada, were distributed to California, Illinois, Massachusetts, New York, and Washington. It is possible that additional states received these oysters either directly from Canada or through further distribution within the U.S.

According to the Public Health Agency of Canada (PHAC), 172 cases so far have been reported in three provinces — British Columbia, Alberta, and Ontario. The US Centers for Disease Control and Prevention (CDC) said contaminated oysters and other shellfish are common causes of norovirus outbreaks and therefore, it recommends cooking oysters and other shellfish thoroughly (to 145°F or higher) before eating.

Norovirus is the most common cause of acute gastroenteritis (AGE), resulting in roughly 1 in 5 cases worldwide, across all settings and age groups — it’s well-known for causing outbreaks where people share close quarters, such as during conventions, at the Olympics, and on cruise ships.

The virus was a prominent headliner at the recently concluded Winter Olympics in Pyeong Chang, South Korea. Last year at the World Athletics Championships in London, the virus rapidly spread through one hotel, and several athletes withdrew from events after suffering symptoms including vomiting. Norovirus is the same bug that caused hundreds of illnesses at Chipotle restaurants in 2015 and 2017. In 2017, the CDC recorded nine norovirus outbreaks on cruise ships that affected hundreds of people.

Norovirus causes 19 to 21 million illnesses, 400,000 emergency room visits, and 570 to 800 deaths, mostly in young children and the elderly, each year in the United States alone. Norovirus kills over 200,000 annually and can be a significant economic drain to societies where outbreaks of the virus are frequent. Globally, it is estimated to cost approximately $4.2 billion in health care costs and over $60 billion in societal costs. According to the US Department of Agriculture, which monitors foodborne illnesses, norovirus is five times as deadly and eight times as costly as the E. coli virus. These cost estimates are conservative as many norovirus cases go unreported. In contrast, rotavirus, a diarrheal disease that kills babies but rarely endangers patients over the age of five, was estimated to cost $2 billion annually before a vaccine was made.

Norovirus sheds from the feces of infected people and animals, and just 10 viral particles are enough to cause an infection. Norovirus can cling to hard surfaces and people can become sick from eating contaminated food or drinking contaminated water. The virus affects members from all age groups and is usually characterized by inflammation of the stomach, diarrhea, and vomiting. There are different methods to treat the infection and correct diagnosis will, in most cases, lead to a full recovery. However, despite the majority of people recovering after a few days of discomfort, the virus has the potential to be highly fatal, especially to young children and the elderly.

There is currently no specific medication or vaccine for norovirus infection, although several vaccine strategies, mostly using virus-like particle antigens (VLPs), are in development and have shown proof of efficacy, the most advanced being the adjuvanted bivalent intramuscular norovirus virus-like particle (VLP) vaccine. Without a vaccine, the single best way to avoid infection is to practice good handwashing habits, especially after using the restroom and before eating. Rigorous handwashing before eating or touching the face could theoretically reduce the size of the outbreak by 100 percent

Scientists create vomiting machine to study viral infections

Inventions are at the very core of human development, and quite often, the scope of the invention is not easy to grasp. Such is the case with a new “vomiting machine” which will be used to study noroviruses – fast spreading viruses that cause acute gastroenteritis.

Image credits: Grace Tung-Thompson.

Somewhere in the North Carolina State campus, a machine has been throwing up vanilla pudding. We don’t know exactly where… because we weren’t particularly curious. But the machine is serving a noble purpose. Norovirus causes 20 million cases of food poisoning in the US every year and the virus is highly contagious through airborne particulates – something especially convenient for a virus that makes you puke.

Researchers from North Carolina State University in Raleigh and Wake Forest University in Winston-Salem created a batch of fake vomit that they infected with the MS2 bacteriophage virus, a type of norovirus that isn’t harmful to humans (typical norovirus is too dangerous to work with). They sprayed the vomit through the machine to see how much of the virus actually becomes airborne.

They found that only 0.02% of the virus becomes airborne, but that’s more than enough to infect other people directly, or indirectly. That translates into as many as 13,000 virus particles. And it only takes 20 to 1,300 virus particles to get someone sick.

“But those airborne particles could also land on nearby surfaces like tables and door handles, causing environmental contamination,” Jaykus said. “And norovirus can hang around for weeks, so anyone that touches that table and then puts their hand to their mouth could be at risk for infection.”

Constructing the machine wasn’t easy. It took them two years to create a replica of the upper body tract, but the results are definitely valuable. Vomit-borne viral transmission is not something we’ve studied in detail, and like it or not, someone has to do it.

Norovirus is the most common cause of viral gastroenteritis in humans. It affects people of all ages, causing nausea, projectile vomiting, watery diarrhea, abdominal pain, and in some cases, loss of taste. General lethargy, weakness, muscle aches, headache, and low-grade fever may occur.