Norovirus "strikes" suddenly, read this article to learn how to protect the health of your family

As the Spring Festival holiday comes to an end, people are returning home one after another, and major transportation hubs are crowded with people. However, during this peak period of return, the Norovirus may quietly "lurk" and pose a threat to people's health. Norovirus, an intestinal infection virus that prefers winter and spring, is highly contagious and can be infected if you are not careful. Therefore, while enjoying the afterglow of the Spring Festival, we must always remain vigilant and take preventive measures.

So what is Norovirus? Is it scary? How to prevent it? How to treat it? Let's learn about it together!

Image source: Pixabay

First, let us understand what Norovirus is?

Norovirus is an intestinal infection virus, also known as Norwalk virus. Although it is small in size, it has huge "energy". It is the "culprit" of acute gastroenteritis and has a strong ability to spread. Almost everyone has no resistance to it, whether adults or innocent and cute children, they may be targeted by it. Norovirus is available all year round, but from October to March of the following year, it enters its active period, just like "punching in for work". At this time, the number of cases of diarrhea caused by infection with it increases significantly, so people also gave it a vivid nickname-"winter vomiting disease". my country has always listed it as a Class C infectious disease for reporting and management.

The reason why the Norovirus can "make waves" among the crowd is mainly because it has several "powerful abilities":

First, it has strong environmental resistance. It can survive in a temperature range of 0 to 60 degrees Celsius. Ordinary hot water cannot kill the norovirus, and 75% alcohol and hand sanitizer cannot inactivate the norovirus. The norovirus can survive on the surface of objects for 2 weeks and survive in water for more than 2 months.

Second, the infection dose is low. To be infected with the Norovirus, you don’t need a large number of viruses to invade the body. Just 18-2800 virus particles can make you infected. Once someone is infected, billions of virus particles can be excreted at a time.

Third, the detoxification period is long. Since the incubation period, the patient has been excreting the norovirus silently. The peak period of detoxification is 2-5 days after the onset of the disease, and this detoxification state will last for 2-3 weeks. Even in some special immunosuppressed patients, the detoxification period will exceed 56 days.

Fourth, the immune protection is short-lived. Even if you have been infected with norovirus before, the immune protection produced by your body can only last for 6-24 months, and you may still be infected again with the same or a different strain of norovirus.

Fifth, the incubation period is relatively short, usually 24-48 hours, with a minimum of 12 hours and a maximum of 72 hours.

These characteristics of norovirus also make it easy for clustered outbreaks to occur in places where people gather, such as schools, childcare facilities, and nursing homes. [1]

Image source: Pixabay

Norovirus can be transmitted in a variety of ways, mainly through the fecal-oral route. Specifically, it can be transmitted in the following ways:

Human-to-human transmission: This is one of the main ways that norovirus spreads. When an infected person vomits or has diarrhea, a large amount of aerosols or droplets carrying the virus are produced. Once people around inhale these aerosols, they may be infected. In addition, direct contact with the vomit or feces of an infected person, or touching the surface of contaminated objects and then touching the mouth and nose with hands can also allow the virus to enter. In places where there are dense crowds and frequent contact, such as schools, kindergartens, and nursing homes, this mode of transmission is very likely to lead to an outbreak.

Transmission through water: If the drinking water source is contaminated with norovirus and is not effectively purified and disinfected, drinking such water will cause infection with the virus.

Transmission through food: Oysters and other shellfish are natural filter feeders. If the water is contaminated by norovirus, it may lead to the contamination of shellfish. Eating these shellfish raw or not thoroughly cooked may cause the virus to be eaten. In addition, cold foods such as salads and fruit platters contaminated by norovirus are also common transmission routes.

Main symptoms of norovirus[2]

Norovirus infection is mainly mild, with diarrhea and vomiting being the most common symptoms, followed by nausea, abdominal pain, fever, chills, headache and muscle aches. Interestingly, children are more likely to experience vomiting, while adults are more likely to experience diarrhea. Sometimes, these symptoms are mistaken for "food poisoning" or "gastrointestinal colds." In addition, some people are infected with norovirus but do not have any symptoms. They are like "invisible spreaders" who do not know they are infected, but may inadvertently spread the virus to others.

What should I do if I am infected with Norovirus?

If you are infected with norovirus, don't panic. Gastroenteritis caused by norovirus is a self-limiting disease that usually lasts 12 to 72 hours, which means that even without the use of antiviral drugs, the body has a certain ability to heal itself.

First, isolate and rest. Once you suspect you have been infected with the norovirus, you should immediately isolate yourself and avoid crowded places to prevent the virus from spreading to others. At the same time, you should get enough rest so that your body has enough energy to fight the virus.

Second, replenish water and electrolytes. Frequent vomiting and diarrhea can cause a large amount of water loss and electrolyte imbalance. Therefore, it is necessary to replenish water and electrolytes in time. You can take oral rehydration salts and drink them after mixing them according to the proportion in the instructions; you can also drink light salt water, rice soup, etc. in moderation, but avoid drinking beverages with high sugar content to avoid aggravating diarrhea.

The third is a light diet. During the illness, the diet should be light and easy to digest. You can choose rice porridge, noodles, steamed bread and other foods, and avoid eating greasy, spicy and irritating foods to avoid increasing the burden on the gastrointestinal tract. After the symptoms are relieved, gradually resume a normal diet.

Fourth, seek medical treatment. Most people have mild symptoms after the onset of the disease and do not need treatment, but for infants, young children, the elderly, especially those who already have underlying diseases, if they experience frequent vomiting or diarrhea, leading to dehydration and other more serious symptoms, they must seek medical treatment in time.

Currently, there is no vaccine that can prevent norovirus infection, so we can only start with the details in our daily lives and do a good job of prevention:

First, wash your hands frequently. This is the simplest and most effective way to prevent norovirus infection. Wash your hands correctly with soap or hand sanitizer according to the 6-step hand washing method before meals, after defecation, before processing food, and after touching public items. Scrub your hands under running water for at least 20 seconds. Pay attention to washing the palms, backs of hands, between fingers, between nails, etc. to ensure that your hands are clean. Here we would like to remind everyone that alcohol-containing disinfectant wipes and hand-free disinfectants are ineffective against norovirus and must not be used instead of hand washing.

Second, pay attention to food and water hygiene. Do not drink raw water, drink boiled water or purified drinking water. Wash vegetables and fruits thoroughly, preferably rinse with running water and soak for a while. When cooking food, make sure it is thoroughly cooked, especially shellfish and seafood that are easy to carry viruses, which must be cooked at high temperatures. Norovirus is not resistant to high temperatures and will die if it is exposed to a high temperature of more than 80°C for 30 seconds.

The third is to maintain a healthy lifestyle. Regular work and rest, a reasonable diet and moderate exercise, these healthy lifestyles can enhance our body's immunity and make our body more capable of resisting the invasion of viruses.

Fourth, do a good job of environmental cleaning and disinfection. Keep the indoor temperature appropriate, open windows frequently for ventilation, and let fresh air circulate indoors. If the patient's vomit or feces contaminates the environment and objects, use chlorine-containing preparations (such as 84 disinfectant, chlorine-containing disinfectant tablets, etc.) for disinfection. The disinfection targets mainly include the patient's excrement, vomit and its used containers, tableware, toilets, environmental surfaces that the patient frequently contacts, indoor floors, walls, furniture surfaces, clothes, objects, etc. The disinfection time should be up to 30 minutes.

Disinfectant preparation

Taking chlorine-containing disinfectant tablets (effective chlorine content 500mg±50mg/tablet) as an example, to prepare 1L of chlorine-containing disinfectant containing 500mg/L of effective chlorine, use a measuring cup to measure 1L of clean water and pour it into the tool bucket, take 1 chlorine-containing disinfectant tablet and place it in the tool bucket to wait for it to be fully dissolved. If necessary, use a stirring tool to accelerate the dissolution.

Common disinfection methods[3]

1. Patients’ vomit and excrement. Patients should use special toilets or urinals as much as possible, and chlorine-containing disinfectants with effective chlorine content of 10,000 mg/L to 20,000 mg/L can be used for one hour before being discharged into the sewage treatment system.

If vomitus or excrement is on the surface of an object, you can use disposable absorbent materials (such as gauze, rags, etc.) to dip in chlorine-containing disinfectant with an effective chlorine content of 5000mg/L to 10000mg/L, cover it completely, and let it sit for more than 30 minutes before carefully cleaning it. Avoid contact with pollutants during the cleaning process. After removing the pollutants, spray or wipe the surface and surrounding areas with chlorine-containing disinfectant with an effective chlorine content of 1000mg/L or other high-level disinfectants for 30 minutes.

Mops, rags and other tools used in cleaning, and containers containing pollutants should be soaked and disinfected in a chlorine-containing disinfectant solution with an effective chlorine content of 5000 mg/L for 30 minutes and then rinsed thoroughly before reuse. Mops for toilets and restrooms should be dedicated.

2. Floor, wall and object surfaces. If there are visible contaminants, they should be removed before disinfection. If there are no visible contaminants, chlorine-containing disinfectants with an effective chlorine content of 1000 mg/L can be used for 30 minutes, or other high-level disinfectants can be used for spraying, wiping or soaking.

3. Clothing, bedding and other fabrics. Avoid generating aerosols when collecting contaminated clothing, bedding and other fabrics. Disinfect and remove the contaminants first, then soak and disinfect them with a chlorine-containing disinfectant with an effective chlorine content of 500 mg/L for 30 minutes; you can also use circulating steam disinfection or boiling disinfection for 30 minutes. If immediate disinfection is not possible, place them in a sealed bag and dispose of them as soon as possible.

4. Food utensils. After removing food residues from tableware (drinking utensils) and food processing tools, boil them for 30 minutes for disinfection, or soak them in a chlorine-containing disinfectant with an effective chlorine content of 500 mg/L for 30 minutes, then wash them with clean water.

5. Skin and mucous membranes. When the skin is contaminated, the contaminants should be removed immediately, and then wiped and disinfected with 0.5% iodine tincture disinfectant for more than 3 minutes; mucous membranes should be rinsed and disinfected with 0.1% iodine tincture.

Special reminder: Cleaning staff must wear protective equipment such as plastic gloves and medical surgical masks throughout the process to avoid direct contact with pollutants, and wash their hands carefully after cleaning.

The warm atmosphere of the Spring Festival is gradually fading, but we should not relax our awareness of health protection. On the way back, pay special attention to personal hygiene and food safety, and don't let the Norovirus take advantage of the opportunity to attack and disrupt the strong New Year atmosphere. Remember to wash your hands frequently, don't drink raw water, and keep raw and cooked food separate to avoid cross infection. If unfortunately infected, isolate and treat in time, handle and disinfect vomit and excrement, and don't spread the virus to relatives and friends.

Let us take these health knowledge with us and safely get through the peak of the return journey after the Spring Festival, hold health and happiness tightly in our hands, and welcome the new year!

References:

[1] Liao Qiaohong, Ran Lu, Jin Miao, et al. Technical Guidelines for Investigation and Prevention and Control of Norovirus Infection Outbreaks (2015 Edition)[J]. Chinese Journal of Viral Diseases, 2015, 5(06): 448-458. DOI: 10.16505/j.2095-0136.2015.06.003.

[2] Yin Jia, Wang Di, Huang Cheng. Epidemiological study of norovirus in patients with acute gastroenteritis in primary and secondary schools and childcare institutions[J]. Journal of Practical Clinical Medicine, 2023, 27(19): 75-79.

[3] Technical Guidelines for the Prevention and Control of Norovirus Infection in Key Places such as Schools and Other Places: Disinfection and Prevention[J]. Chinese Journal of Viral Diseases, 2024, 14(06): 521-522. DOI: 10.16505/j.2095-0136.2024.0105.

Source: Zhongxian Center for Disease Control and Prevention

Author: Xiong Xiaoshi, Chief Physician of Zhongxian Center for Disease Control and Prevention

Review expert: Yan Qiong, deputy chief physician of Zhongxian Center for Disease Control and Prevention

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