Mostly in winter time, you may have experienced a stomach flu which causes a sudden onset of vomiting or diarrhea. Stomach flu is a highly contagious illness which can spread rapidly to children, adults and the elderly once it makes the rounds. Patients will suffer from symptoms including nausea, vomiting and/or diarrhea, and it may affect their daily activities such as work or study. It probably is one of the illnesses where many people feel miserable when they have repeated bouts of symptoms.
I usually see patients with a common cold or flu without wearing a mask. However, I always gargle and wash my hands thoroughly after I examine patients with stomach flu in order to prevent contagion. In this article, general practitioner Dr. Yoshiya Hasegawa gives us useful information about causes, treatments and prevention for the stomach flu.
Contents
1. What is stomach flu?
Stomach flu commonly causes vomiting, diarrhea and/or stomachache. I usually diagnose children with “stomach flu” and older people with “gastroenteritis” which are basically the same illness. Viral or bacterial infection causes inflammation in the gastrointestinal system and prevents the stomach and the intestine from functioning. Hence, the patient may experience bloating in the stomach, nausea, vomiting and/or diarrhea.
You will be diagnosed with rotavirus infection or norovirus infection, once the type of viruses that cause the onset is identified.
In the beginning of November, there tends to be a gradual increase in the number of patients with stomach flu or infectious gastroenteritis, and this decreases after reaching a peak in December. It then increases again during the period between January and March, and then gradually goes down. Norovirus reaches its peak in December while rotavirus spreads the most in spring. Foodborne illness, or food poisoning caused by bacteria such as vibrio parahaemolyticus is the most common cause of gastroenteritis in summertime.
2.Causes of stomach flu
Following are common causes of stomach flu.
2-1. Rotavirus infection
Infants between 6 months and two years old are more likely to be infected with rotavirus, and most children under 5 years old get infected at least once. Adults may also be infected, however they either show mild symptoms or do not have any onset. Children who come across the second infection develop very mild symptoms.
Patients who are infected with rotavirus may show the following symptoms after an incubation period which lasts for two to four days.
- Nausea, vomiting
- Diarrhea
- High fever
High fever and diarrhea are especially common for patients with rotavirus infection lasts for three to four days.
rotavirus causes inflammation of the intestines.
2-2. Norovirus infection
When norovirus enter a human body, the virus is replicated on the epithelial cells in the small intestine and causes “stomachache, diarrhea, nausea or vomiting” due to stomach paralysis or reduced gastric motility. It usually develops in 12 to 48 hours after being exposed. The principal symptom includes acute onset of vomiting or nausea. Some may experience a mild fever between 37 to 38 degrees, and nausea or stomach bloating are the most common symptoms among adult patients. It usually takes within one to two days for a full recovery.
2-3. Adenovirus infection
Adenovirus infection is very common among small children and causes various symptoms: cold-like symptoms such as cough or runny nose; gastroenteritis, conjunctivitis; or cystitis. There are more than 50 types of adenovirus, and each can cause a different symptom.
Gastroenteritis caused by an adenovirus infection can happen anytime throughout the year while norovirus and rotavirus have its seasonal outbreak. Some patients may experience a mild fever or vomiting, while others may develop a sore throat or pink eyes.
2-4. Stomach flu without particular causes
When patients are diagnosed with stomach flu, doctors will treat the symptoms and let it run its course without the need to dive into the cause.
In Japan, use of the rapid diagnostic kit of norovirus is covered by health insurance for children under 3 and the elderly over 65 while the diagnostic tests for rotavirus and adenovirus infection are covered for all ages. However, these kits may not be available at some medical institutions –– in fact, so does mine.
3. Treatments of stomach flu
Treatment is administered as follows.
3-1. When you have a fever over 38 degrees.
A fever higher than 38 degrees rarely occurs in the common stomach flu. Rotavirus infection or bacterial gastroenteritis is suspected if the patient experiences a high fever over 38 degrees. Immediate blood test will be ordered to check for white blood cell (WBC) count and C reactive protein (CRP). If the test shows normal on either count, rotavirus is suspected. However, there are no specific medication to cure the virus and only remedy for the symptoms are administered.
When bacterial gastroenteritis is suspected and the test indicates an increase in WBC and CRP, an antibiotic is orally administered. Dehydration is likely to occur when patients suffer from diarrhea and vomiting along with a fever more than 38 degrees. Therefore, intravenous rehydration will be administered.
3-2. Fasting works
If the patient experiences nausea, vomiting and diarrhea without a high fever over 38 degrees, they may want to try fasting. In fact, doctors will only prescribe antiemetics or probiotics for these patients. The efficacy of those medication is not proven, and it is given to offer relief. If the patient is able to hydrate themselves, they even may not need to visit a doctor.
3-3. When you cannot hydrate yourself
If the patient is unable to obtain water by themselves, anti-emetic suppositories is administered. They can try taking some water after 30 to 60 minutes have passed. When vomiting occurs too often to keep down fluids, intravenous rehydration will be required at a medical institution.
4. How to avoid a stomach flu
There’s no effective treatment for a stomach flu, so prevention is key.
4-1. Hand wash
Stomach flu is triggered when germs or viruses from the hands enter the body. You can prevent germs entering your mouth by washing your hands thoroughly before eating. A disposable paper towel is better than a cloth towel which is more likely to spread infection through its use.
4-2. Hand disinfection
The most popular hand disinfection is a rubbing alcohol. Alcohol is very effective in killing germs, but it does not work against norovirus. The only way to “disinfect” norovirus is with chlorine-based disinfectants. However, you cannot rub chlorine on your hands so a prevention is to wash your hands thoroughly.
4-3. Keep bathroom clean
Stomach flu may spread when an infected person touches something in a room or foods with their hands where germs present after defecation. It happens because some germs are not washed away even after one has washed their hands. Some healthy adults do not notice they are infected because their symptoms are not so severe and unknowingly, they discharge germs. It is important to keep the bathroom clean and disinfect the toilet seat, door lever and/or faucet handle as necessary.
Remember bacteria and viruses are always present on your hands.
5. Preventive methods when your family experience bouts of diarrhea or vomiting
Stomach flu is so contagious that some people who clean up patients’ vomits can get infected.
5-1. When using toilet or washing hands
Do not share soaps and towels with an infected person. Washing hands thoroughly with soap before leaving a bathroom is effective in avoiding the spread of germs. When there are more than two bathrooms in a house, it is better that the sick person uses a separate bathroom from the rest of the family.
5-2. Clean-up procedures for vomit
When someone vomits, it is necessary to clean up the vomit and disinfect the surrounding area. The person cleaning up should put on a mask and gloves and wipe away the vomit starting from the outside, in a circular motion. Remember to decontaminate the surrounding infected area because vomit can reach as far as 2 meters away. Norovirus can spread through the air when it is dry, and norovirus particles may enter others’ mouths and cause an infection. Wipe the area with chlorine-based disinfectants and then clean up again with a wet towel after 30 minutes. Make sure to dispose of all towels or paper towels into a plastic trash bag.
5-3. Disinfect clothing
Do not touch clothing and linens contaminated with vomit or stool without protection. Make sure to put on gloves and a mask and wash them in a bucket to remove particles. Then it should be soaked in disinfectant for more than 30 minutes. Do not forget to decontaminate the bucket and the surrounding laundry area. A person who cleans up need to change their clothes and decontaminate themselves because virus is present on the clothes. In addition to chlorine, high heat clothes dryer is effective. Make sure it is set to over 85 Celsius.
6. Summery
- Stomach flu is a highly contagious disease so it is important to avoid infection.
- Diagnosis test is not necessary since symptomatic treatment is only available for stomach flu.
- Avoid eating if a patient can hydrate by themselves. In the case where a patient cannot hydrate by themselves, intravenous drip may be necessary.