Rotavirus Infection

What is rotavirus infection?

Rotavirus infection is a contagious illness of the stomach and intestines caused by a virus called rotavirus. Doctors often call this type of illness gastroenteritis, which simply means inflammation of the stomach and bowel. The infection usually leads to watery diarrhea, vomiting, fever, and stomach pain. Its main danger is dehydration, which is the loss of more fluid and salts from the body than a person takes in.

Rotavirus most commonly affects infants and young children, especially those younger than five years old. Before vaccines became widely available, nearly every child had at least one rotavirus infection by school age. Older children and adults can also become infected, but their symptoms are often milder because they have built up some immunity from earlier exposures. In many hospitals, including the Pediatrics department at Acibadem, care for children with rotavirus infection focuses mainly on preventing and correcting dehydration.

The illness typically runs its course in a few days to about a week. Most children recover fully, but very young infants, children with weakened immune systems, and children who cannot keep fluids down may become dehydrated quickly and sometimes need care in a hospital.

Rotavirus infection symptoms

Rotavirus infection symptoms usually appear about two days after a person is exposed to the virus. This waiting period is called the incubation period. The illness often begins suddenly with vomiting and fever, followed by frequent watery diarrhea.

• Watery diarrhea, often several times a day and sometimes lasting three to eight days
• Vomiting, which is often the first symptom and usually lasts one to three days
• Fever, which may be mild or moderate
• Stomach pain or cramping
• Loss of appetite and reduced interest in drinking
• Tiredness or irritability
• Signs of dehydration, such as a dry mouth, fewer wet diapers, no tears when crying, sunken eyes, or unusual sleepiness

Symptoms can vary by age and by how many times a person has been infected before. A first infection in a young child is often the most severe. Later infections tend to be milder or may cause no symptoms at all. Adults who catch rotavirus from a sick child may have only mild diarrhea or an upset stomach, although some adults become quite ill.

The course of the illness usually follows a pattern. In the early stage, vomiting and fever are most noticeable. Over the next day or two, diarrhea becomes the main problem. The risk of dehydration is highest during this middle stage, when fluid is being lost through both vomiting and diarrhea. In the recovery stage, stools slowly become less watery and appetite returns. Some children have loose stools for a short time after the other symptoms improve.

Dehydration deserves special attention because it can develop quickly in small children. Warning signs include a dry mouth and tongue, decreased urination, crying without tears, a sunken soft spot on an infant’s head, cool or blotchy hands and feet, and unusual drowsiness or fussiness. These signs mean a child should be checked by a doctor without delay.

Causes and risk factors

The cause of rotavirus infection is the rotavirus itself, a small virus that infects the lining of the small intestine. When the virus damages the cells that normally absorb water and nutrients, the intestine cannot take in fluid properly, and watery diarrhea results.

Rotavirus spreads mainly through what doctors call the fecal-oral route. This means that tiny amounts of stool from an infected person reach another person’s mouth, usually by way of hands, surfaces, food, or water. Common ways this happens include:

• Not washing hands well after changing a diaper or using the toilet
• Touching contaminated toys, doorknobs, countertops, or other surfaces and then touching the mouth
• Eating food or drinking water that has been contaminated with the virus
• Close contact with a sick child, especially in group settings

Rotavirus is very hardy. It can survive on hands and surfaces for a long time, and ordinary cleaning does not always remove it. A person with rotavirus infection sheds large amounts of the virus in their stool, both before symptoms begin and for several days after they stop. This is why the infection spreads so easily within families, child care centers, and hospitals.

Several factors raise the risk of catching rotavirus or of becoming seriously ill from it:

• Young age, particularly between about 3 months and 3 years, when the body has little or no immunity
• Not being vaccinated against rotavirus
• Attending child care or living with other young children
• Weakened immune system, for example from certain medical conditions or treatments
• Premature birth or low birth weight
• Underlying conditions that make it harder to tolerate fluid loss
• Limited access to clean water and sanitation, which makes spread more likely

Rotavirus infections tend to be more common in cooler months in temperate climates, although they can occur at any time of year. Because immunity builds up with each infection, older children and adults usually have milder illness, but they can still pass the virus to others.

Rotavirus infection diagnosis

In many cases, a rotavirus infection diagnosis is based on the pattern of symptoms alone. When a young child develops sudden vomiting followed by watery diarrhea and fever, especially during rotavirus season or when other children nearby are sick, a doctor may recognize the illness without special testing. Because the treatment for most viral stomach infections is the same, identifying the exact virus does not always change care.

When testing is helpful, doctors have several options:

• Stool antigen test: A small sample of stool is checked in the laboratory for rotavirus proteins. This is the most commonly used test and can often give results within a day.
• Molecular stool test (PCR): This test looks for the genetic material of the virus. It is very sensitive and may be used in hospitals, during outbreaks, or when a panel of several gut infections is being checked at once.
• Physical examination: The doctor checks for signs of dehydration, such as a dry mouth, sunken eyes, poor skin elasticity, rapid heartbeat, and low energy. This assessment is often the most important part of the visit because it guides treatment.
• Blood tests: In a child who appears significantly dehydrated or unusually ill, blood tests may be ordered to check salt levels, kidney function, and acid balance.

Imaging tests such as X-rays or ultrasound are not needed to diagnose rotavirus. A doctor may order them only if the symptoms are unusual and another problem, such as a bowel blockage or appendicitis, needs to be ruled out.

Testing is more likely in certain situations: when a child is admitted to a hospital, when there is an outbreak in a child care center, when the diarrhea is prolonged or contains blood, or when the child has a weakened immune system. In these cases, confirming the diagnosis helps with infection control and with deciding whether other causes should be investigated.

Rotavirus infection treatment options

There is no medicine that kills rotavirus. Rotavirus infection treatment is therefore supportive, which means it aims to keep the body’s fluids and salts in balance while the immune system clears the virus on its own. Antibiotics do not work against viruses and are not used for rotavirus.

Oral rehydration. The most important treatment is replacing lost fluids by mouth. Doctors often recommend an oral rehydration solution, which is a drink that contains a carefully balanced mix of water, salts, and sugar so the intestine can absorb it even during diarrhea. These solutions are available at pharmacies. Giving small amounts frequently, such as a spoonful or a few sips every few minutes, often works better than large drinks, which may trigger more vomiting. Plain water alone, sports drinks, fruit juice, and soda are generally not recommended as the main fluid for infants and young children because they do not have the right balance of salts and sugar.

Continued feeding. Breastfed infants should usually continue to breastfeed, often more frequently than usual. Formula-fed infants can typically continue their normal formula once vomiting has settled. Older children may return to an ordinary, easily digested diet as soon as they are able to eat. Prolonged fasting is not recommended, because food helps the intestine recover.

Medications. Medicines to stop diarrhea are generally not recommended for young children with rotavirus, as they can have side effects and may hide signs of worsening illness. In some situations a doctor may prescribe a medicine to reduce vomiting so that a child can keep fluids down. A doctor may also recommend a fever reducer such as acetaminophen for comfort. Aspirin should not be given to children. Zinc supplements are recommended in some regions for children with diarrhea, particularly where malnutrition is common; your doctor can advise whether this applies. Probiotics, which are supplements of helpful bacteria, have been studied for childhood diarrhea with mixed results, and their use varies among doctors.

Hospital care. A child who cannot keep fluids down, who shows signs of moderate or severe dehydration, or who is very young or has another serious health condition may need hospital care. In the hospital, fluids may be given through a thin tube passed through the nose into the stomach, or directly into a vein through an intravenous line. Doctors monitor weight, urine output, and blood salt levels while the child recovers. Most children who need hospital care improve within a few days.

Procedures and surgery. Surgery is not a treatment for rotavirus infection. Rarely, a very young infant with severe symptoms may need to be evaluated for other problems that can look similar, but this is the exception rather than the rule.

Preventing spread. Careful hand washing with soap and water after diaper changes and before preparing food is important, because alcohol-based hand sanitizers do not remove rotavirus reliably. Disinfecting surfaces and keeping a sick child home from child care until diarrhea has stopped can help protect others.

Vaccination. Although a vaccine does not treat an existing infection, rotavirus vaccines given to infants in the first months of life are the most effective way to prevent severe illness. The vaccine is given by mouth in two or three doses, depending on the product, starting at around two months of age. There is an age limit for starting and completing the series, so timing matters. Your child’s doctor can explain the schedule that applies in your area.

Living with rotavirus infection and outlook

For most children, rotavirus infection is an unpleasant but short illness. Vomiting usually settles within a day or two, and diarrhea generally improves within about a week. Appetite and energy return gradually. With adequate fluid replacement, the large majority of children recover completely without lasting effects.

The main complication is dehydration, and in rare cases severe dehydration can be life-threatening if it is not treated. This is why watching fluid intake and urine output at home is so important, and why medical care should be sought early when a child is not drinking or is showing warning signs.

During the illness, parents and caregivers may find the following helpful:

• Offer small amounts of oral rehydration solution often, and keep a rough count of wet diapers or trips to the toilet.
• Continue breastfeeding or usual feeds as tolerated, and do not force large meals.
• Expect that stools may stay loose for a few days after the child seems better.
• Wash hands thoroughly after every diaper change, and clean changing areas, toys, and bathroom surfaces.
• Keep the child home from child care or school until at least 24 hours after the last episode of vomiting or diarrhea, or as advised locally.

Having rotavirus once does not give complete protection, but each infection generally makes the next one milder. Vaccinated children can still catch rotavirus, but their illness is usually much less severe. If a child has repeated or unusually long-lasting diarrhea, a doctor may look for other causes, since rotavirus itself does not usually cause chronic problems.

Frequently asked questions

How long does a rotavirus infection last?

Rotavirus infection symptoms usually begin about two days after exposure. Vomiting often lasts one to three days, and diarrhea commonly lasts three to eight days. Some children have loose stools for a short time afterward. If diarrhea continues for more than about a week, or if symptoms worsen instead of improving, a doctor should reassess the child.

What are the first rotavirus infection symptoms in babies?

In infants, the illness often begins suddenly with vomiting and fever, followed within a day or so by frequent watery diarrhea. Babies may also be fussier than usual and less interested in feeding. Because infants can become dehydrated quickly, caregivers should watch for fewer wet diapers, a dry mouth, no tears when crying, or unusual sleepiness, and seek medical advice if these appear.

What are the main rotavirus infection causes and how does it spread?

Rotavirus infection is caused by the rotavirus, which spreads when tiny amounts of stool from an infected person reach another person’s mouth. This usually happens through unwashed hands, contaminated surfaces, toys, food, or water. The virus is very hardy, survives well on surfaces, and is shed in stool before symptoms start and for days afterward, which is why it spreads so easily among young children.

How is a rotavirus infection diagnosis confirmed?

Doctors often diagnose rotavirus based on the typical symptoms, especially in a young child during rotavirus season. When confirmation is needed, a stool sample can be tested for rotavirus proteins or genetic material. Blood tests may be used to check for dehydration and salt imbalance in a child who appears unwell. Imaging is not usually needed.

Is there a specific rotavirus infection treatment or antibiotic?

There is no antiviral medicine for rotavirus, and antibiotics do not help because the illness is caused by a virus, not bacteria. Treatment focuses on replacing lost fluids with an oral rehydration solution and continuing to feed the child. In more serious cases, fluids may be given in a hospital through a tube or a vein. Anti-diarrheal medicines are generally not recommended for young children.

Can adults get rotavirus infection?

Yes. Adults can be infected, often after caring for a sick child. Because most adults have had rotavirus before, their symptoms are usually milder and may include only brief diarrhea or an upset stomach. Older adults and people with weakened immune systems can become more seriously ill and should also pay attention to fluid intake.

Can the rotavirus vaccine prevent rotavirus infection?

Rotavirus vaccines are given by mouth to infants in the first months of life and are very effective at preventing severe illness, hospitalization, and dehydration. Vaccinated children may still catch the virus, but the illness is usually mild. The vaccine must be started and finished within specific age limits, so it is worth discussing the schedule with your child’s doctor early.

When to see a doctor

Most children with rotavirus infection can be cared for at home with fluids and rest. However, dehydration can develop quickly in small children, and some warning signs need prompt medical attention. Contact a doctor or seek urgent care if a child has any of the following:

• Signs of dehydration: very little or no urine for six to eight hours, a dry mouth and tongue, no tears when crying, sunken eyes, or a sunken soft spot on an infant’s head
• Unable to keep fluids down because of repeated vomiting
• Unusual drowsiness, limpness, or difficulty waking, or extreme irritability that cannot be soothed
• Blood or black color in the stool, or green or bloody vomit
• High fever, especially in an infant younger than three months, or any fever that lasts more than a few days
• Severe or worsening stomach pain, or a swollen, hard belly
• Diarrhea lasting more than about a week or frequent large watery stools that do not slow down
• Cold, pale, or blotchy hands and feet, rapid breathing, or a fast heartbeat
• A child with a weakened immune system or a serious long-term illness who develops vomiting and diarrhea

Infants under six months, children who were born prematurely, and children who have not been vaccinated deserve a lower threshold for medical review. If you are unsure whether a child is drinking enough or whether symptoms are improving, it is reasonable to have them examined. Early assessment and rehydration are the key to a safe recovery from rotavirus infection.