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a light microscope. Many hundreds of species of viruses live and replicate inside plants and animals.
Fortunately, most human viral pathogens cause acute, self-limited illnesses for which symptomatic treatment
is sufficient. A few of them however are sources of plagues including influenza, measles, smallpox, and
human immunodeficiency virus (HIV). It is difficult to diagnose viral pathogens with certainty at the time of
illness. Confirmation often requires a specialized viral culture, or recognition of the viral antigen or genome.
There are few antiviral drugs and these are often reserved for use in immunocompromised individuals who
are most at risk for severe or chronic disease.
ID: Adenoviruses
LTC Niranjan Kanesa-thasan, MC, USAIntroduction: Many adenoviruses cause febrile syndromes commonly associated with upper and lower
airway diseases such as pharyngitis, bronchitis, and pneumonia (see these topics). Over 49 adenoviruses
have been described as etiologic agents of acute respiratory distress syndrome (ARDS) but only a few
(types 1-5, 7, 14, and 21) are major respiratory pathogens. These agents are extremely contagious, resulting
in epidemic outbreaks worldwide in crowded quarters such as recruit training sites. Seasonal Variation:
In temperate regions, adenoviruses appear more frequently in fall or winter months. In tropical areas,
adenovirus infections occur during wet or cooler weather. Risk Factors: Age is a particular factor— infants
and children are typically more susceptible than adults. Residing in close environments (training camps,
institutions, shipboard) frequently gives rise to outbreaks of adenoviral ARDS because there is frequent
exchange of respiratory secretions.
Subjective: Symptoms
Fever, headache, prostration, coryza (nasal mucous membrane inflammation and discharge), sore throat and
cough after short (1-5 days) incubation period; usually occurs with constitutional symptoms of malaise, chills,
anorexia; persists for 2-5 days then spontaneously resolves.
Focused History: Do you have a productive cough? (usually presents with dry, nonproductive cough) When
did you first feel sick? (usually within past few days – if more prolonged consider bacterial causes of ARD)
Has any close contact been ill with similar illness in past few weeks? (contagious illness that moves rapidly
through closed communities)
Objective: Signs
Using Basic Tools: Vitals: fever up to 102°F
Inspection: Follicular, erythematous, or exudative pharynx/tonsils; swollen, tender cervical lymph nodes;
conjunctivitis.
Auscultation: Possible rales
Using Advanced Tools: Lab: Monospot to rule out mononucleosis
Assessment:
Differential Diagnosis
Pneumonia - may be indistinguishable from viral ARD or ARDS (see Respiratory: Pneumonia).
Pharyngitis - ulcerative pharyngitis is associated with the enteroviruses; palatal petechiae, red beefy uvula,
and scarlatiniform rashes are often associated with Group A streptococcal pharyngitis.
Influenza - typically results in more systemic disease, including sustained fever, malaise, and myalgia
accompanying respiratory manifestations in adults
Infectious Mononucleosis - persistent illness for several weeks suggests IM (see ID chapter).
Plan:
Treatment
There is no specific therapy. Treat symptomatically with fluids and antipyretics until disease resolves.