Ten viruses can cause disease, so far there is no vaccine and specific drugs, but fortunately it only causes gastroenteritis

Everyone will encounter once a year vomiting, diarrhea, headache and head heat, which is called acute gastroenteritis. It is painful and even affects work and study.

Diarrhea and vomiting, perhaps one of the most common symptoms of illness, make us wonder what we’ve been eating lately.

In most people’s common knowledge, gastroenteritis is caused by food poisoning, such as eating spoilage food, eating food that is not cooked, etc.

If a family member or relative develops gastroenteritis at the same time, we are used to looking for the “culprit”. However, sometimes the result is not satisfactory. It may be that we can not find the food we ate together and we can not find the suspicious food, which becomes an “unsolved case”.

In fact, not all gastroenteritis is caused by food poisoning (a toxic illness caused by bacteria or bacterial toxins), and it’s possible that viruses are behind it.

In 1968, an outbreak of acute gastroenteritis occurred at an elementary school in Norwalk, Ohio. Many children threw up, and the children didn’t develop good hygiene habits, so gastroenteritis quickly spread.

Just over a week later, acute gastroenteritis hit the entire city of Norwalk, and scientists are interested in it.
After research, Kapikian et al. in 1972 found a virus particle in the feces of those patients, and named it Norwalk virus.

Bronson Novak Elementary School in Norwalk, Ohio

As research progressed, the full genome of the norovirus was sequenced, and its family was named norovirus as we now know it, with disease records going back at least to 1929.

I’ve heard a lot about norovirus, but I don’t see much of it in my life. It’s both familiar and strange.
That’s because only in the case of a large outbreak is it publicized by name, and more often it causes gastroenteritis that can be mistaken for something else.

Globally, the Centers for Disease Control and Prevention (CDC) estimates that norovirus causes 685 million illnesses and 200,000 deaths a year, a number that may seem implausible.

However, acute gastroenteritis caused by norovirus is not low in our lives.

From 2011 to 2015, 200 of the 714 diarrhea cases tested positive for the virus, including rotavirus (10.08%) and norovirus (18.63%), according to the statistics of two third-class A hospitals collected by the Xicheng District Center for Disease Control and Prevention in Beijing.

Of course, this is just a count of diarrhoea cases, and vomiting is more common in children infected with norovirus (the younger they are, the more likely they are to vomit), so there may be more cases.

If there are any differences between the symptoms of acute gastroenteritis caused by norovirus and those of normal food poisoning, there are some.

First of all, norovirus infection has a certain incubation period, usually between 12 hours and 48 hours, with a median of about a day and a half. Based on the incubation period of 4-6 hours for common food poisoning, there is no “real culprit”.

Then there are the specific symptoms. Vomiting, diarrhea, headache, fever, similar to food poisoning, but people with norovirus are more likely to have watery diarrhea.

The so-called watery diarrhea is a powerful version of diarrhea, if diarrhea is a long way, then watery diarrhea is a sprout, yellow, fishy and less solid, if in a public toilet blowout, the next door will be amazed at your flow of (false).

In addition to diarrhea and vomiting, there may also be chills, muscle aches and other symptoms, in general is quite uncomfortable.

On top of that, norovirus infection has no drugs to treat it. In children, symptoms are usually severe vomiting, which can be triggered again if a parent gives a stomach stimulant such as ibuprofen to reduce a fever.

If you do catch norovirus, the best thing you can do is replenish fluids and electrolytes, because vomiting and watery diarrhea can drain your body of fluids and lead to severe illness.

Fortunately, though, norovirus infection is thought to be self-limited, meaning that, like a cold, it clears itself within a certain period of time, even without intervention or treatment.
Symptoms of norovirus usually only last about three days.

The rare cases of severe illness or death usually occur in very old people and very young children.
In England and Wales between 2001 and 2006, norovirus infection accounted for 20% of all deaths from infectious bowel disease among people aged over 65, but it is still a risk.

However, the real strength of norovirus is not in its lethality, but in its infectiousness, and it has even earned the industry the nickname of “the perfect virus”.

Generally, gastrointestinal diseases caused by food poisoning, although there is a certain degree of aggregation, are mostly due to the common consumption of spoiled or contaminated food, and there is almost no human-to-human transmission.

But norovirus is a different story. Norovirus is spread by foodborne, waterborne, and the first unlucky infected person is followed by human-to-human transmission, mainly fecal-oral transmission and aerosol transmission of vomit.

Medical workers enter a German cruise ship after an outbreak of norovirus

So it’s very common for one person to have an acute bout of gastroenteritis, and then for other relatives and friends who live together to have gastroenteritis soon after, and you may not have overlapping dietary records.

Not only does it spread from person to person, but it is so rapid and persistent that it can be hard to prevent a single person from infecting a whole family, and the consequences would be even worse in a denser public space.

George H.W. Bush vomited in public after eating sushi in Japan in 1992

In June 1998, 126 people attended a dinner party at a large British hotel, which was divided into six tables. A woman suddenly vomited during the dinner, which caused a bit of trouble but was quickly cleaned up by staff.

Three days after the dinner, 52 people reported vomiting, diarrhea, fever and other symptoms. Statistically, the probability of getting sick was positively correlated with the distance between them and the vomiting woman, and norovirus was the culprit.

In 2014, the Mount Harple Health and Safety Laboratory in the United Kingdom built the Vomit Larry, a ruthless vomiting machine, to study how norovirus can spread through vomit.

Experiments using fluorescently added water as vomit showed that vomit could be sprayed up to three meters and cover an area of eight square meters, which is far from enough to clean up in a visible area.

Of course, these are just the basics. What’s more frightening is that norovirus is extremely contagious. It is generally believed that less than 100 virus particles are needed to cause infection, and some studies suggest that less than 20 particles are needed.

In the way of human-to-human transmission, the most impossible to prevent is faecal-oral transmission, with the infection of norovirus, the toilet used by the infected person will be a high-risk place, 3 days after the onset of the disease, the amount of virus in the patient’s stool is very large, up to 10^11 (100 billion) virus particles per gram of stool.

After two to five days of initial symptoms, patients can continue to expel the virus for up to two to three weeks, and the virus can survive on surfaces for several weeks.
If hygiene is not good, you get the virus everywhere you go, and the rest is your imagination.

Does anyone out there already have a clean freak and want to wipe their hands with alcohol?
Unfortunately, it doesn’t work. Alcohol or hand wash is very ineffective at inactivating norovirus. It takes a few minutes of disinfection with a chlorine-based disinfectant at an effective concentration to kill it.

However, don’t worry too much, because you can still wash off norovirus if you can’t kill it. Using hand sanitizer and soap correctly will remove the virus particles from your hands, reducing your risk of infection.

Is there any way to avoid food-borne infections?

Shellfish are considered to be a high risk food and have been linked to many outbreaks of norovirus.
The reason is that the filter feeding mode of shellfish can enrich the norovirus in the body of water, and the enrichment ability is also affected by seasonal and spatial factors.

In general, shellfish are at higher risk from November to March. Avoid eating raw or undercooked oysters in cold weather.
As for other food should also be raw and cooked classification, to avoid pollution, fully cooked before eating.

Of course, don’t assume that just because you have been infected with norovirus recently and recovered from it, norovirus is an RNA virus that mutates very quickly, with new variants appearing every 1 to 3 years.

A study on human volunteers showed that resistance to the same norovirus only lasts for six to 24 months and can be reinfected with the same strain.
This is one of the reasons there is no vaccine for norovirus on the market.

There is no vaccine, no magic bullet, strong infectiousness, we can only be glad that this virus will only cause not too serious symptoms, even so it also rely on their own strength in the news frequently brush the sense of existence, so that many ordinary people for the first time to experience a blast of fun.

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