Adenovirus Infection

Adenoviruses are a group of common viruses that can cause infections ranging from mild cold-like symptoms to more serious illnesses, particularly in young children and people with weakened immune systems.

Table of contents

• What are adenoviruses?
• Who gets infected?
• Symptoms and affected body systems
• How the infection spreads
• How long symptoms last
• Diagnosis
• Treatment
• Prevention

What are adenoviruses?

Adenoviruses are a group of common viruses that can cause a range of cold- or flu-like infections throughout your body. Researchers have identified about 50 types of adenoviruses that can infect humans^[1]. These viruses are very tough and can survive for long periods on surfaces like doorknobs, towels, and toys, making them highly resistant to many common disinfectants^[2].

Adenovirus infections occur throughout the year, but they tend to peak in the winter and early spring^[1]. These viruses don’t have a specific “season” like the flu, so infections can happen at any time^[4].

Who gets infected?

Adenoviruses can affect people of all ages, but they’re most common in children younger than 5 years old^[1]. The spread of adenoviruses in babies and young children occurs often in daycares. Babies and children in this setting come into close contact with one another. They’re also more likely to put objects in their mouths and less likely to wash their hands frequently^[1].

Most children will have had at least one adenovirus infection by the age of 10^[3]. Children ages 6 months to 2 years who are in childcare are more likely to become ill with these viruses^[7].

In adults, the spread of adenoviruses can occur in crowded environments. If you spend time in a dormitory or military quarters, you may be at a higher risk of contracting the virus. The virus also commonly spreads in hospitals and nursing homes^[1].

People with weakened immune systems are more likely to get seriously ill from an adenovirus infection. This includes people who’ve had stem cell transplants or organ transplants (medical procedures where cells or organs are transferred into a patient’s body). It also includes people who have cancer or HIV/AIDS. If you have cardiac or respiratory disease, your chances of severe infection increase as well^[1].

Symptoms and affected body systems

The symptoms of adenovirus infections you experience depend on which part of your body the virus infects^[1]. Most adenovirus infections are mild with few symptoms^[2].

Respiratory system infections

The virus most commonly infects your respiratory system. An adenovirus infection in your respiratory tract can cause symptoms similar to the common cold or flu. Symptoms or conditions you may experience include cough, fever, runny nose, sore throat, pink eye (also called conjunctivitis, which is redness and inflammation of the eye), ear infection, swollen lymph nodes, chest cold, and pneumonia (infection of the lungs)^[1].

Symptoms of respiratory infections may start 2 to 14 days after exposure^[3]. Children will commonly have a high fever, which may last for several days. Children may have a runny nose or congestion, and some children may develop an ear infection^[7].

Gastrointestinal infections

Adenoviruses can also affect your gastrointestinal tract. An infection in your gastrointestinal tract may cause diarrhea. You may also experience gastroenteritis, which is inflammation of your stomach or intestines. It can cause stomach pain, diarrhea, nausea and vomiting^[1].

Symptoms of a digestive tract infection may start 3 to 10 days after exposure. Symptoms usually occur in children younger than 5 years and may last 1 to 2 weeks. They can include watery diarrhea that starts suddenly, fever, belly pain, and vomiting^[7].

Other infections

More rarely, adenoviruses can affect your bladder or nervous system. Viruses in your bladder can cause urinary tract infections (infections in the organs that produce and carry urine). Viruses in your nervous system can cause conditions that can affect your brain. These conditions include encephalitis (inflammation of the brain) and meningitis (inflammation of the membranes surrounding the brain and spinal cord)^[1].

How the infection spreads

Adenoviruses are very contagious. They can easily spread through several routes^[1]:

• Close contact: The virus can spread from person to person through shaking hands, kissing or hugging.
• The air: The virus can spread through sneezing and coughing. Respiratory droplets released in sneezes and coughs can transfer to other people through the air.
• Surfaces and objects: After touching a contaminated surface, you can get the virus by touching your eyes, nose or mouth before washing your hands. The virus can live for many hours on things such as doorknobs, counters, and toys^[3].
• Stool (poop): The virus can spread through fecal-oral transmission, often because of poor hand washing or from eating or drinking contaminated food or water^[3].
• Water: Transmission can occur through water in swimming pools, but this is less common^[2].

Adenoviruses can survive on surfaces for up to 30 days^[9]. Sometimes the virus can be shed (released from the body) for a long time after a person recovers from an adenovirus infection, especially among people who have weakened immune systems. This “virus shedding” usually occurs without any symptoms, even though the person can still spread adenovirus to other people^[2].

How long symptoms last

Most adenovirus symptoms last from a few days to up to two weeks. Severe infections may last longer. You may have symptoms that continue to linger for a while, such as a cough^[1]. The symptoms usually start 2 days to 2 weeks after contact with adenovirus^[4].

Diagnosis

Adenovirus infection symptoms are a lot like those caused by other infections. Usually, tests aren’t needed if someone has mild symptoms^[4]. The healthcare provider will ask about your symptoms and health history. They will give you a physical exam^[7].

Tests for adenovirus are only needed for very ill children or those with another serious health problem^[7]. But if a person has a serious infection, doctors can test respiratory or eye secretions, a stool sample, or a blood or urine sample to confirm the diagnosis^[4]. A PCR test (a laboratory method that detects genetic material from the virus) on blood or respiratory secretions may detect adenovirus DNA^[4].

Treatment

There are no approved antiviral medicines and no specific treatment for people with adenovirus infection. Most adenovirus infections are mild and may be managed with rest and over-the-counter pain medicines or fever reducers to help relieve symptoms^[2].

Treatment for adenovirus infections is done to help ease symptoms and includes^[7]:

• Getting plenty of rest
• Drinking enough liquids to prevent dehydration
• Giving acetaminophen if fevers are making you uncomfortable
• Using a humidifier or saltwater nose drops to help with congestion

Most adenovirus infections get better on their own in a few days^[2]. Always read the label and use medications as directed. If you have concerns, you should speak with your healthcare provider^[2].

In immunocompromised patients, several drugs, such as cidofovir, have been used to treat severe adenovirus infections, although these agents have significant risks of toxicities^[12]. Fortunately, most infections are self-limited in the setting of a normal immune response and do not warrant specific therapy^[12].

Prevention

You can take important steps to reduce your risk of getting or spreading adenovirus infections^[2]:

• Practice good hygiene: Wash your hands frequently and thoroughly. Hand washing is especially important in childcare settings and healthcare facilities.
• Avoid touching your eyes, nose or mouth with unwashed hands.
• Avoid close contact with people who are ill.
• Cover your mouth and nose with a tissue when coughing or sneezing.
• Stay home when you’re sick to avoid spreading the infection.
• Clean and disinfect frequently touched surfaces using EPA-registered disinfectants that are effective at killing adenovirus.
• Avoid sharing towels and utensils with an infected person.

It is important to keep adequate levels of chlorine in swimming pools to prevent outbreaks of conjunctivitis caused by adenoviruses^[2].

There is a vaccine for adenovirus types 4 and 7 that is used in military personnel who may be at higher risk for infection from these two adenovirus types. This vaccine contains live virus and is not approved for use outside of the military. There is currently no adenovirus vaccine available to the general public^[2].