Adenovirus Classification in Respiratory Panels
Adenovirus is classified as a typical viral respiratory pathogen, not an atypical pathogen, on respiratory panels. 1, 2
Understanding the Terminology
The term "atypical" in respiratory diagnostics specifically refers to bacterial pathogens including Legionella species, Mycoplasma pneumoniae, and Chlamydophila pneumoniae—not viruses. 1
Adenovirus is a viral pathogen that is routinely included alongside other respiratory viruses such as influenza, RSV, rhinovirus, parainfluenza, human metapneumovirus, and coronaviruses on standard respiratory panels. 1, 2
The American Thoracic Society guidelines clearly distinguish between viral pathogens (including adenovirus) and atypical bacterial pathogens when describing multiplex respiratory panel composition. 1
Clinical Significance of Adenovirus
Adenovirus causes significant respiratory disease and is appropriately included in comprehensive respiratory pathogen testing:
Serotypes 40 and 41 primarily affect the gastrointestinal tract, but other serotypes commonly cause respiratory infections affecting both upper and lower respiratory tract epithelia. 1
Adenovirus can cause severe pneumonia, particularly in immunocompromised patients (transplant recipients, HIV-positive individuals), with fatality rates exceeding 50% in untreated severe cases. 3, 4, 5, 6
In immunocompromised adults, adenovirus shows 100% discordance between upper and lower respiratory tract specimens, meaning lower respiratory tract testing may be necessary when clinical suspicion is high despite negative upper tract samples. 1
Practical Testing Considerations
Key clinical scenarios where adenovirus detection matters:
Immunocompromised hosts at high risk for progression to disseminated disease requiring antiviral therapy (cidofovir or brincidofovir, though neither is FDA-approved for this indication). 1, 3, 4
Pediatric populations where adenovirus accounts for 5-20% of hospitalizations for childhood diarrhea and can cause severe lower respiratory tract infections even in immunocompetent children. 1, 7
Outbreak settings in closed or crowded environments (military recruits, institutional settings) where epidemics can occur. 5, 6
Important caveat: Prolonged viral shedding in immunocompromised patients may lead to positive PCR results without active disease, potentially causing overdiagnosis and overtreatment. 1