Adenovirus infection
Encyclopedia
Adenovirus infections most commonly cause illness
of the respiratory system
; however, depending on the infecting serotype, they may also cause various other illnesses and presentations.
, conjunctivitis
, cystitis
, and rash illness. Symptoms of respiratory illness caused by adenovirus infection range from the common cold
syndrome to pneumonia
, croup
, and bronchitis
. Patients with compromised immune systems are especially susceptible to severe complications of adenovirus infection. Acute respiratory disease (ARD), first recognized among military recruits during World War II, can be caused by adenovirus infections during conditions of crowding and stress.
It usually occurs in the age group 5-18. It is often found in summer camps and during the spring and fall in schools. In Japan, the illness is commonly referred to as "pool fever" as it is often spread via public swimming pools.
characteristics of the adenoviruses vary by type, all are transmitted by direct contact, fecal-oral transmission, and occasionally waterborne transmission. Some types are capable of establishing persistent asymptomatic infections in tonsils, adenoids, and intestines of infected hosts, and shedding can occur for months or years. Some adenoviruses (e.g., serotypes 1, 2, 5, and 6) have been shown to be endemic in parts of the world where they have been studied, and infection is usually acquired during childhood. Other types cause sporadic infection and occasional outbreaks; for example, epidemic keratoconjunctivitis
is associated with adenovirus serotypes 8, 19, and 37. Epidemics of febrile disease with conjunctivitis are associated with waterborne transmission of some adenovirus types, often centering around inadequately chlorinated swimming pools and small lakes. ARD is most often associated with adenovirus types 4 and 7 in the United States. Enteric adenoviruses 40 and 41 cause gastroenteritis, usually in children. For some adenovirus serotypes, the clinical spectrum of disease associated with infection varies depending on the site of infection; for example, infection with adenovirus 7 acquired by inhalation is associated with severe lower respiratory tract disease, whereas oral transmission of the virus typically causes no or mild disease. Outbreaks of adenovirus-associated respiratory disease have been more common in the late winter, spring, and early summer; however, adenovirus infections can occur throughout the year.
"Ad14 (for adenovirus serotype 14
), has caused at least 140 illnesses in New York, Oregon, Texas and Washington, according to a report from the Centers for Disease Control and Prevention. The illness made headlines in Texas in September, when a so-called "boot camp flu" sickened hundreds at Lackland Air Force Base in San Antonio. A 19-year-old trainee died."
Several adenoviruses, especially adenovirus serotype 36 (Adv36), have been shown to cause obesity
in animals, and are associated with human obesity.
detection, polymerase chain reaction
assay, virus isolation, and serology
can be used to identify adenovirus infections. Adenovirus typing is usually accomplished by hemagglutination-inhibition
and/or neutralization with type-specific antisera. Since adenovirus can be excreted for prolonged periods, the presence of virus does not necessarily mean it is associated with disease.
s were developed for adenovirus serotypes 4 and 7, but were available only for preventing ARD among US military recruits, and production stopped in 1996. Strict attention to good infection-control practices is effective for stopping nosocomial outbreaks of adenovirus-associated disease, such as epidemic keratoconjunctivitis. Maintaining adequate levels of chlorination is necessary for preventing swimming pool-associated outbreaks of adenovirus conjunctivitis.
in which all or part of a lung has increased translucency
radiographically, which is called Swyer-James Syndrome
. Severe adenovirus pneumonia also may result in bronchiolitis obliterans
, a subacute inflammatory process in which the small airways are replaced by scar tissue
, resulting in a reduction in lung volume and lung compliance.
Illness
Illness is a state of poor health. Illness is sometimes considered another word for disease. Others maintain that fine distinctions exist...
of the respiratory system
Respiratory system
The respiratory system is the anatomical system of an organism that introduces respiratory gases to the interior and performs gas exchange. In humans and other mammals, the anatomical features of the respiratory system include airways, lungs, and the respiratory muscles...
; however, depending on the infecting serotype, they may also cause various other illnesses and presentations.
Resultant illnesses and presentations
Besides from respiratory involvement, illnesses and presentations of adenovirus include gastroenteritisGastroenteritis
Gastroenteritis is marked by severe inflammation of the gastrointestinal tract involving both the stomach and small intestine resulting in acute diarrhea and vomiting. It can be transferred by contact with contaminated food and water...
, conjunctivitis
Conjunctivitis
Conjunctivitis refers to inflammation of the conjunctiva...
, cystitis
Cystitis
Cystitis is a term that refers to urinary bladder inflammation that results from any one of a number of distinct syndromes. It is most commonly caused by a bacterial infection in which case it is referred to as a urinary tract infection.-Signs and symptoms:...
, and rash illness. Symptoms of respiratory illness caused by adenovirus infection range from the common cold
Common cold
The common cold is a viral infectious disease of the upper respiratory system, caused primarily by rhinoviruses and coronaviruses. Common symptoms include a cough, sore throat, runny nose, and fever...
syndrome to pneumonia
Pneumonia
Pneumonia is an inflammatory condition of the lung—especially affecting the microscopic air sacs —associated with fever, chest symptoms, and a lack of air space on a chest X-ray. Pneumonia is typically caused by an infection but there are a number of other causes...
, croup
Croup
Croup is a respiratory condition that is usually triggered by an acute viral infection of the upper airway. The infection leads to swelling inside the throat, which interferes with normal breathing and produces the classical symptoms of a "barking" cough, stridor, and hoarseness...
, and bronchitis
Bronchitis
Acute bronchitis is an inflammation of the large bronchi in the lungs that is usually caused by viruses or bacteria and may last several days or weeks. Characteristic symptoms include cough, sputum production, and shortness of breath and wheezing related to the obstruction of the inflamed airways...
. Patients with compromised immune systems are especially susceptible to severe complications of adenovirus infection. Acute respiratory disease (ARD), first recognized among military recruits during World War II, can be caused by adenovirus infections during conditions of crowding and stress.
Pharyngoconjunctival fever
Pharyngoconjunctival fever is a specific presentation of adenovirus infection, manifested as:- high fever that lasts 4-5 days
- pharyngitisPharyngitisPharyngitis is an inflammation of the throat or pharynx. In most cases it is quite painful, and is the most common cause of a sore throat.Like many types of inflammation, pharyngitis can be acute – characterized by a rapid onset and typically a relatively short course – or chronic....
(sore throat) - conjunctivitisConjunctivitisConjunctivitis refers to inflammation of the conjunctiva...
(inflamed eyes, usually without pus formation like pink eye) - enlargement of the lymph nodeLymph nodeA lymph node is a small ball or an oval-shaped organ of the immune system, distributed widely throughout the body including the armpit and stomach/gut and linked by lymphatic vessels. Lymph nodes are garrisons of B, T, and other immune cells. Lymph nodes are found all through the body, and act as...
s of the neck - headache, malaise, and weakness
- Incubation period of 5-9 days
It usually occurs in the age group 5-18. It is often found in summer camps and during the spring and fall in schools. In Japan, the illness is commonly referred to as "pool fever" as it is often spread via public swimming pools.
Serotype-specific features
Although epidemiologicEpidemiology
Epidemiology is the study of health-event, health-characteristic, or health-determinant patterns in a population. It is the cornerstone method of public health research, and helps inform policy decisions and evidence-based medicine by identifying risk factors for disease and targets for preventive...
characteristics of the adenoviruses vary by type, all are transmitted by direct contact, fecal-oral transmission, and occasionally waterborne transmission. Some types are capable of establishing persistent asymptomatic infections in tonsils, adenoids, and intestines of infected hosts, and shedding can occur for months or years. Some adenoviruses (e.g., serotypes 1, 2, 5, and 6) have been shown to be endemic in parts of the world where they have been studied, and infection is usually acquired during childhood. Other types cause sporadic infection and occasional outbreaks; for example, epidemic keratoconjunctivitis
Keratoconjunctivitis
Keratoconjunctivitis is inflammation of the cornea and conjunctiva.When only the cornea is inflamed, it is called keratitis; when only the conjunctiva is inflamed, it is called conjunctivitis....
is associated with adenovirus serotypes 8, 19, and 37. Epidemics of febrile disease with conjunctivitis are associated with waterborne transmission of some adenovirus types, often centering around inadequately chlorinated swimming pools and small lakes. ARD is most often associated with adenovirus types 4 and 7 in the United States. Enteric adenoviruses 40 and 41 cause gastroenteritis, usually in children. For some adenovirus serotypes, the clinical spectrum of disease associated with infection varies depending on the site of infection; for example, infection with adenovirus 7 acquired by inhalation is associated with severe lower respiratory tract disease, whereas oral transmission of the virus typically causes no or mild disease. Outbreaks of adenovirus-associated respiratory disease have been more common in the late winter, spring, and early summer; however, adenovirus infections can occur throughout the year.
"Ad14 (for adenovirus serotype 14
Adenovirus serotype 14
Adenovirus serotype 14 is a serovar of adenovirus which, unlike other adenovirus serovars, is known to cause potentially fatal adenovirus infections...
), has caused at least 140 illnesses in New York, Oregon, Texas and Washington, according to a report from the Centers for Disease Control and Prevention. The illness made headlines in Texas in September, when a so-called "boot camp flu" sickened hundreds at Lackland Air Force Base in San Antonio. A 19-year-old trainee died."
Several adenoviruses, especially adenovirus serotype 36 (Adv36), have been shown to cause obesity
Obesity
Obesity is a medical condition in which excess body fat has accumulated to the extent that it may have an adverse effect on health, leading to reduced life expectancy and/or increased health problems...
in animals, and are associated with human obesity.
Diagnosis
AntigenAntigen
An antigen is a foreign molecule that, when introduced into the body, triggers the production of an antibody by the immune system. The immune system will then kill or neutralize the antigen that is recognized as a foreign and potentially harmful invader. These invaders can be molecules such as...
detection, polymerase chain reaction
Polymerase chain reaction
The polymerase chain reaction is a scientific technique in molecular biology to amplify a single or a few copies of a piece of DNA across several orders of magnitude, generating thousands to millions of copies of a particular DNA sequence....
assay, virus isolation, and serology
Serology
Serology is the scientific study of blood serum and other bodily fluids. In practice, the term usually refers to the diagnostic identification of antibodies in the serum...
can be used to identify adenovirus infections. Adenovirus typing is usually accomplished by hemagglutination-inhibition
Hemagglutination assay
The hemagglutination assay is a method of quantification for viruses or bacteria by hemagglutination...
and/or neutralization with type-specific antisera. Since adenovirus can be excreted for prolonged periods, the presence of virus does not necessarily mean it is associated with disease.
Treatment
Most infections are mild and require no therapy or only symptomatic treatment. Because there is no virus-specific therapy, serious adenovirus illness can be managed only by treating symptoms and complications of the infection. Deaths are exceedingly rare but have been reported.Prevention
Safe and effective adenovirus vaccineAdenovirus vaccine
An adenovirus vaccine is a vaccine against Adenovirus.It was used by the United States military from 1971 to 1999, but was discontinued when the only manufacturer stopped production. This vaccine elicited immunity to serotypes 4 and 7. On March 16, 2011, the U.S. Food and Drug Administration...
s were developed for adenovirus serotypes 4 and 7, but were available only for preventing ARD among US military recruits, and production stopped in 1996. Strict attention to good infection-control practices is effective for stopping nosocomial outbreaks of adenovirus-associated disease, such as epidemic keratoconjunctivitis. Maintaining adequate levels of chlorination is necessary for preventing swimming pool-associated outbreaks of adenovirus conjunctivitis.
Prognosis
Adenovirus can cause severe necrotizing pneumoniaPneumonia
Pneumonia is an inflammatory condition of the lung—especially affecting the microscopic air sacs —associated with fever, chest symptoms, and a lack of air space on a chest X-ray. Pneumonia is typically caused by an infection but there are a number of other causes...
in which all or part of a lung has increased translucency
Swyer-James syndrome
Swyer James syndrome is a rare lung disorder found by Physicians Paul Robert Swyer, William Mathiseon Macleod and Radiologist George James in the 1950's in Canada. At the same time J...
radiographically, which is called Swyer-James Syndrome
Swyer-James syndrome
Swyer James syndrome is a rare lung disorder found by Physicians Paul Robert Swyer, William Mathiseon Macleod and Radiologist George James in the 1950's in Canada. At the same time J...
. Severe adenovirus pneumonia also may result in bronchiolitis obliterans
Bronchiolitis obliterans
Bronchiolitis obliterans , also called obliterative bronchiolitis and constrictive bronchiolitis , is a rare and life-threatening form of non-reversible obstructive lung disease in which the bronchioles are compressed and narrowed by fibrosis and/or inflammation...
, a subacute inflammatory process in which the small airways are replaced by scar tissue
Fibrosis
Fibrosis is the formation of excess fibrous connective tissue in an organ or tissue in a reparative or reactive process. This is as opposed to formation of fibrous tissue as a normal constituent of an organ or tissue...
, resulting in a reduction in lung volume and lung compliance.
External links
- Centers for Disease Control and Prevention--National Center for Infectious Dieseases--Division of Viral and Rickettsial Diseases, Respiratory and Enteric Viruses Branch