adenovirus
Meaning of adenovirus: Named for the tonsil like tissue it was first pulled from, this virus family now doubles as a delivery vehicle for engineered genes.
Definition of adenovirus
Adenovirus is a family of common viruses that infect the lining of the airways, the eyes and the gut. Most infections produce a mild, self limited illness resembling a cold, pink eye or a short bout of diarrhea, and they settle without specific treatment. The same viruses, stripped of their ability to reproduce, are widely used to carry genetic material into cells.
What illnesses does it cause?
| Site | Typical illness |
|---|---|
| Nose and throat | Sore throat, fever and cough much like a cold, sometimes with swollen neck glands |
| Eyes | Conjunctivitis, ranging from mild pink eye to a painful outbreak that spreads easily |
| Gut | Watery diarrhea and vomiting, mainly in young children |
| Bladder | Burning and visible blood in the urine, without bacteria on culture |
Adenoviruses are unusually hardy for viruses. They resist drying and many common disinfectants, survive on surfaces and in water, and spread by hand contact, droplets and the fecal to oral route. That durability explains the clusters that appear in nurseries, swimming pools, eye clinics and crowded residential settings, and why an outbreak can persist after the first cases have recovered.
Who becomes seriously ill from it?
In a person with a working immune system the illness is usually a nuisance rather than a threat. The picture changes for someone whose immunity is suppressed, particularly after a bone marrow or organ transplant. There the virus can reactivate from tissue where it has lain quiet and spread through the bloodstream, inflaming the liver, the lungs or the brain at the same time. Newborns and infants form the other vulnerable group, in whom adenovirus is a recognized cause of pneumonia that can leave lasting damage to the airways.
Why is it used to carry genes?
Because it is good at getting inside cells and can be made harmless. Genes essential for reproduction are deleted, leaving a shell that still docks with a cell and delivers its cargo but cannot make copies of itself. The delivered material stays separate from the cell's own chromosomes, so the effect fades as those cells are replaced, which limits gene therapy uses but suits a vaccine, where a short lived display of one foreign protein is all that is wanted. Modified adenoviruses are also engineered to reproduce inside tumor cells and destroy them, the approach behind oncolytic virus therapy. The main obstacle is the immune system itself, which recognizes the carrier and may blunt a repeat dose.
Used in a sentence
Testing identified adenovirus as the cause of the child's conjunctivitis and upper respiratory symptoms.
Good to know
Adenovirus infection is usually mild in people with normal immune function, so a severe or widespread infection more often reflects suppressed immunity, such as after a transplant, than an unusually aggressive virus.
Word origin
Where “adenovirus” comes from
Named for the adenoid tissue from which the virus family was first isolated, from Greek aden, meaning gland.