Norovirus – Symptoms and Causes

Overview

Norovirus is a highly contagious illness that causes sudden, severe vomiting and diarrhea. People typically develop symptoms 12 to 48 hours after exposure, with illness usually lasting 1 to 3 days.

The virus spreads easily through contaminated food and water, as well as touching infected surfaces and close contact with infected people.

Most people recover without medical treatment, but dehydration can be a serious concern, especially for young children, older adults, and people with existing medical conditions.

Norovirus outbreaks happen most often in enclosed spaces where many people gather, such as hospitals, nursing homes, schools, child care centers, and cruise ships.

These settings create ideal conditions for the virus to spread quickly from person to person through shared spaces and surfaces.

Symptoms

Norovirus infection typically causes sudden symptoms that include:

• Nausea
• Vomiting
• Stomach pain or cramps
• Watery or loose diarrhea
• General feeling of illness
• Mild fever
• Muscle aches

These symptoms usually start 12 to 48 hours after exposure to the virus and last for 1 to 3 days.

After recovery, a person can still spread the virus through their stool for several weeks. For people with other medical conditions, this virus shedding might continue for months.

Some infected people show no symptoms at all. Even without symptoms, these people can still pass the virus to others. The virus is highly contagious, making it easy to spread in crowded settings.

When to Visit a Healthcare Provider

If you have diarrhea that continues for several days, it’s important to contact your doctor. You should also seek medical help if you experience severe vomiting, blood in your stool, stomach pain, or signs of dehydration.

These symptoms may indicate a more serious condition that requires professional medical treatment.

Causes

Noroviruses spread very easily from person to person. The virus passes through stool and vomit. Someone with norovirus can spread it while sick and for several days after feeling better.

These viruses can live on surfaces for days or even weeks.

You can get norovirus by eating food that has the virus on it, drinking water that contains the virus, touching your mouth after touching contaminated surfaces, or being close to someone who has norovirus.

These viruses are tough to eliminate because they can survive in both hot and cold temperatures. Many common cleaning products don’t kill noroviruses effectively.

People in crowded places like schools, cruise ships, and nursing homes have higher risks of getting norovirus. The virus spreads quickly in these settings where many people share spaces and food.

Risk Factors

Several factors can increase your chance of getting norovirus:

• Eating food prepared by someone with the virus or food touched by contaminated water or surfaces
• Children in daycare or preschools
• Living in crowded spaces like nursing homes
• Staying in places where many people gather, such as hotels or cruise ships
• Direct contact with an infected person

The virus spreads easily in environments where people live or eat close together.

Possible Health Issues

For most people, norovirus goes away within a few days without serious problems. However, some groups face higher risks. These include young children, older adults, pregnant people, and those with weak immune systems or other health conditions.

In these high-risk groups, norovirus can lead to severe dehydration and, in rare cases, death.

Watch for these warning signs of dehydration:

• Feeling very tired
• Dry mouth and throat
• Less energy than normal
• Feeling dizzy
• Not urinating as often

Children suffering from dehydration may cry without tears. They might also seem unusually sleepy or irritable.

If you notice these symptoms, seek medical help right away. Proper treatment can prevent serious complications.

Preventing Norovirus Infection

Norovirus spreads easily from person to person. Since many types exist, you can get infected multiple times during your life. Following good hygiene practices is key to staying healthy.

Hand Hygiene

Proper handwashing is your first defense against norovirus. Wash hands with soap and water for at least 20 seconds, especially after using the bathroom, before preparing food, before eating, and after changing diapers.

Remember that hand sanitizers don’t work well against norovirus. Always choose soap and water when possible.

Food Safety Measures

To avoid foodborne transmission, make sure to:

• Wash all fruits and vegetables thoroughly before eating
• Cook seafood completely
• Avoid food prepared by someone who appears sick
• Drink only bottled, boiled, or carbonated beverages when traveling
• Be cautious with street food in high-risk areas

Cleaning and Disinfection

When someone has been sick, you should:

• Wear gloves while cleaning
• Use chlorine bleach solutions on contaminated surfaces
• Disinfect commonly touched areas like doorknobs and light switches

When Someone Is Sick

If you or a family member has norovirus, make sure to:

1. Stay home from work or school
2. Avoid preparing food for others
3. Limit contact with household members
4. Continue these precautions for 2-3 days after symptoms stop

Handling Body Fluids Safely

When cleaning up vomit or diarrhea, remember to:

• Use disposable gloves and towels
• Move contaminated material as little as possible
• Seal waste in plastic bags before trashing
• Wash contaminated clothing and linens separately

Travel Precautions

Wait until you’ve been symptom-free for 2-3 days before traveling. When in areas with high norovirus risk, eat only well-cooked foods. Avoid potentially contaminated water sources.