Viral Gastroenteritis: Symptoms, Causes & Treatment

Viral gastroenteritis is an acute inflammation of the stomach and intestines caused by a virus. It can lead to symptoms such as diarrhea, nausea, vomiting, and abdominal pain that may last up to 8 days if left untreated.

Viral gastroenteritis is mainly spread through food or water contaminated with viruses such as rotavirus, norovirus, astrovirus, and adenovirus. Because of this, properly washing and handling food is important to help prevent this type of infection.

Treatment for viral gastroenteritis is usually guided by a primary care provider or pediatrician. It generally includes rest, drinking plenty of fluids to prevent dehydration, eating light and easy-to-digest foods, or hospitalization in more severe cases.

Common symptoms

The main symptoms of viral gastroenteritis are:

• Nausea and vomiting

• Watery diarrhea three or more times a day

• Abdominal pain or cramping

• Low-grade fever or chills

• Headache

• Loss of appetite

• Muscle aches

• General malaise

Gastroenteritis can also cause dehydration, especially in children, older adults, or people with a weakened immune system. In these cases, symptoms may include dizziness, dry lips, cold sweats or reduced sweating, and changes in heart rate.

Symptoms of viral gastroenteritis may start 1 to 2 hours or up to 1 day after eating food or drinking water contaminated with the virus.

How long does viral gastroenteritis last?

When it is caused by norovirus, astrovirus, or rotavirus, viral gastroenteritis can last from 1 to 8 days.

However, when it is caused by adenovirus, it may last from 1 to 2 weeks.

Confirming a diagnosis

The diagnosis of viral gastroenteritis is confirmed by a primary care provider, pediatrician, or gastroenterologist based on symptoms, medical and diet history, and a physical exam.

In some cases, the provider may also order a complete blood count (CBC), electrolyte testing, a stool test, or a CT scan to rule out conditions with similar symptoms, such as food poisoning, appendicitis, or inflammatory bowel disease.

Possible causes

Viral gastroenteritis is caused by viruses that infect and damage cells in the gastrointestinal tract, which interferes with nutrient absorption and leads to symptoms.

The main viruses that cause viral gastroenteritis include:

• Rotavirus: one of the main causes of severe acute diarrheal illness, especially in babies and children under 5, although it can also infect adults

• Astrovirus: less common and mainly affects babies and young children, but it can also affect adults

• Norovirus: the most common cause of viral gastroenteritis worldwide, is highly contagious, usually causes outbreaks in daycares, schools, nursing homes, and cruise ships, and affects people of all ages

• Adenovirus: less common, tends to infect mainly babies and young children, but it can also infect adults

These viruses can contaminate food and water and then be passed to people, causing signs and symptoms of intestinal infection.

Transmission and spread

Viral gastroenteritis can be spread by eating or drinking something prepared by a sick person who did not wash their hands, by consuming food grown or prepared with contaminated water, or by swimming in water contaminated with feces, according to the CDC.

These viruses can also be spread by touching contaminated surfaces or objects.

Outbreaks are also very common in closed settings, such as daycares, hospitals, schools, and cruise trips, because people are in close contact and often share meals.

Is viral gastroenteritis contagious?

Viral gastroenteritis is highly contagious. The viruses that cause this infection can spread through touch, shaking hands with an infected person, or using objects or surfaces handled by other people.

Transmission can also happen through saliva droplets or aerosols. For example, when a person vomits, virus particles can spread through the air and land on surfaces or other people.

It is important to note that infected people can spread the virus even when they do not have symptoms of viral gastroenteritis.

Treatment options

Treatment for viral gastroenteritis depends on severity and may include:

1. Rest

Rest is very important because it helps the body recover and supports the immune system in fighting the virus.

2. Increased fluid intake

Drinking more fluids, such as water, tea, soup, or coconut water, helps prevent dehydration caused by fluid loss from diarrhea or vomiting.

It is also important to drink homemade oral rehydration solution or oral rehydration salts recommended by a healthcare provider to replace fluids and minerals, based on recommendations from the World Health Organization (WHO).

3. Light, easy-to-digest diet

It is important to eat light, easy-to-digest foods to provide the body with nutrients without making vomiting or diarrhea worse.

Good options include rice, cooked fruit, lean meats such as chicken breast, and toast.

On the other hand, milk and dairy products, coffee, high-fat foods, high-sugar foods, and alcoholic beverages should be avoided.

4. Medications

In some cases, a healthcare provider may prescribe antiemetic medicines such as metoclopramide (Reglan) or ondansetron (Zofran) to help control nausea and vomiting.

5. Hospitalization

Hospitalization is recommended in cases of severe dehydration caused by viral gastroenteritis. In these cases, fluids and electrolytes are given through an IV.

Antiemetic medicines may also be used to treat severe vomiting or vomiting that does not improve with oral medicines.

Prevention measures

To help prevent viral gastroenteritis, it is recommended to:

• Wash fruits and vegetables well before eating them

• Protect food and the kitchen from insects, pets, and other animals

• Do not use water from streams, rivers, or contaminated wells

• Store cooked foods between 32°F and 41°F (0°C and 5°C) for as few days as possible

• Keep raw foods separate from cooked foods and use different utensils for each

• Cook foods thoroughly

• Keep utensils and silverware clean and avoid sharing them

• Avoid touching surfaces and then putting your hands in your mouth

• Continue breastfeeding and avoid early weaning to help increase children’s resistance to diarrhea

• Clean surfaces that may be contaminated with bleach if someone in the home has viral gastroenteritis

• Wash hands with water and mild soap, especially before and after using the bathroom, changing diapers, handling or preparing food, breastfeeding, and touching animals

There is also a vaccine used to prevent rotavirus infection, which is given to children to stimulate the immune system to produce antibodies against the most common types of rotavirus.