NAME: Adenovirus (excluding serotypes 40 and 41)
SYNONYM OR CROSS REFERENCE: Acute respiratory disease (ARD), childhood febrile illness, adenovirus species A, B, C, D, E, F, G, pharyngoconjunctival fever.
CHARACTERISTICS: Human adenoviruses are members of the family Adenoviridae and genus Mastadenovirus. Within the almost 100 different serotypes of human adenovirus, 51 are known to be pathogenic in humans Footnote 1Footnote 2. The virus is nonenveloped with an icosahedral capsid at 70-90 nm in diameter and each contains a single linear, double-stranded DNA genome of approximately 36 kb Footnote 2.
PATHOGENICITY/TOXICITY: Adenovirus cause generally mild respiratory tract infections which are self-limiting and generally asymptomatic despite virologic and serologic proof of infection Footnote 3, and only around 45% of infections are manifested by disease Footnote 1. It is a major agent of acute respiratory disease, mainly caused by serotypes 4 and 7, and is characterized by fever, rhinitis, pharyngitis, cough, and conjunctivitis Footnote 1. Other common illnesses can be observed in the respiratory tract, gastrointestinal tract, and eyes (acute follicular conjunctivitis) Footnote 2. Common diseases caused by various adenovirus serotypes are:
General infections are commonly observed in young children, particularly by serotypes 1, 2, and 5 Footnote 1. Symptoms of infection may include fever, nasal congestion, coryza, and pharyngitis. Other more serious illnesses such as nephritis, neutropenia, myocarditis, hepatitis, disseminated intravascular coagulation and meningoencephalitis can occur Footnote 2Footnote 5. Eye infections such as acute follicular conjunctivitis, often accompanied by significant periauricular lymphadenopathy, are often mild and complete recovery is common Footnote 6. Neonatal disease, meningoencephalitis, myocarditis, and venereal diseases are uncommon Footnote 2.
EPIDEMIOLOGY: Adenovirus is of worldwide prevalence, and is ubiquitous throughout the year, especially during later winter and early spring Footnote 5. Serotype 5 is the most common, with serotypes 1 and 2 being highly endemic Footnote 1. Children are especially susceptible to infection Footnote 2Footnote 5Footnote 7. Adenovirus serotypes 3, 4, 7, and 21 have been associated with outbreaks of acute respiratory disease among military recruits Footnote 3Footnote 8. These outbreaks have resulted in hospitalization and some mortality Footnote 8. Smaller outbreaks of serotypes 3, 4, and 7 occur in the summertime due to contaminated swimming pool water, which commonly resulted in conjunctivitis Footnote 1Footnote 2. Serious adenovirus infections occur more frequently in immunocompromised individuals Footnote 2Footnote 7.
HOST RANGE: Humans.
INFECTIOUS DOSE: Inhalation of as few as 5 adenovirus particles can cause disease in susceptible individuals Footnote 3. The National Institutes of Health lists the infectious dose for adenovirus serotype 7 as >150 viral units, administered as nasal drops Footnote 9.
INCUBATION PERIOD: Approximately 2 to 14 days Footnote 2.
COMMUNICABILITY: Children shed non enteric adenovirus in throat and stool samples for 3 to 6 weeks following lower respiratory infection or generalized illness. Chance of transmission is high in crowded and closed settings such as day cares, boarding schools and long-term care facilities. Transmission between family members is common. In rare cases, virus shedding may last for 18 months or longer Footnote 2.
DRUG SUSCEPTIBILITY: None. Many reports indicate cidofovir to be effective against adenoviruses; however, no controlled trials have been performed so far, and the drug is not currently licensed for use Footnote 5.
SUSCEPTIBILITY TO DISINFECTANTS: Adenoviruses are resistant to lipid disinfectants, but are inactivated by formaldehyde and chlorine Footnote 5. They can be inactivated by contact with 1:5 dilution of bleach for 1 minute or 2 minutes contact with alcohol-based hand gels Footnote 2.
SURVIVAL OUTSIDE HOST: Most serotypes are stable at 36 °C for a week, for several weeks at room temperature, and for several months at 4 °C Footnote 2Footnote 10. Adenoviruses are very stable in the environment and persist for 7 days to 3 months on dry inanimate surfaces Footnote 10. They can also survive for weeks in tap water, sewage effluent and sea water Footnote 11. Adenovirus type 2 can survive on common environmental surfaces for up to 8 weeks at room temperature Footnote 12.
SURVEILLANCE: Monitor for symptoms. Infected cells can be observed by microscopy, and adenoviruses can be detected using immunofluorescence, enzyme-linked immunoassay, or PCR for antigen detection Footnote 2.
Note: All diagnostic methods are not necessarily available in all countries.
FIRST AID/TREATMENT: No formally approved effective antiviral agents exist for treatment of adenoviral infections Footnote 7. Illness is generally self-limiting and treatment is supportive Footnote 5. It has been suggested that immunocompromised patients may require drug treatment with cidofovir or other antiviral drugs Footnote 7.
LABORATORY-ACQUIRED INFECTIONS: At least 10 cases of laboratory-acquired adenovirus infections have occurred up to 2006; however, the serotypes involved were not reported Footnote 13.
SOURCES/SPECIMENS: Generally, fecal samples, and respiratory secretions from an infected individual contain infectious virus. Other tissues may contain virus depending on symptoms Footnote 2.
SPECIAL HAZARDS: None.
RISK GROUP CLASSIFICATION: Risk Group 2 Footnote 15. This risk group applies to the species as a whole, and may not apply to every serotype within the species.
CONTAINMENT REQUIREMENTS: Containment Level 2 facilities, equipment, and operational practices for work involving infectious or potentially infectious materials. These containment requirements apply to the species as a whole, and may not apply to each serotype within the species.
PROTECTIVE CLOTHING: Lab coat. Gloves when direct skin contact with infected materials or animals is unavoidable. Eye protection must be used where there is a known or potential risk of exposure to splashes Footnote 16.
OTHER PRECAUTIONS: All procedures that may produce aerosols, or involve high concentrations or large volumes should be conducted in a biological safety cabinet (BSC). The use of needles, syringes, and other sharp objects should be strictly limited. Additional precautions should be considered with work involving animals or large scale activities Footnote 16.
SPILLS: Allow aerosols to settle and, wearing protective clothing, gently cover spill with paper towels and apply an appropriate disinfectant, starting at the perimeter and working towards the centre. Allow sufficient contact time before clean up Footnote 16.
DISPOSAL: Decontaminate all wastes that contain or have come in contact with the infectious organism before disposing by autoclave, chemical disinfection, gamma irradiation, or incineration Footnote 16.
STORAGE: The infectious agent should be stored in leak-proof containers that are appropriately labelled Footnote 16.
REGULATORY INFORMATION: The import, transport, and use of pathogens in Canada is regulated under many regulatory bodies, including the Public Health Agency of Canada, Health Canada, Canadian Food Inspection Agency, Environment Canada, and Transport Canada. Users are responsible for ensuring they are compliant with all relevant acts, regulations, guidelines, and standards.
UPDATED: November 2011
PREPARED BY: Pathogen Regulation Directorate, Public Health Agency of Canada.
Although the information, opinions and recommendations contained in this Pathogen Safety Data Sheet are compiled from sources believed to be reliable, we accept no responsibility for the accuracy, sufficiency, or reliability or for any loss or injury resulting from the use of the information. Newly discovered hazards are frequent and this information may not be completely up to date.
Copyright © Public Health Agency of Canada, 2011 Canada