ADENOVIRUS INFECTIONS

ADENOVIRUS INFECTIONS - Ronald L. Malm, DO
BASICS
DESCRIPTION
Usually self-limited febrile illnesses characterized by inflammation of conjunctivae and the respiratory tract. Adenovirus infections occur in epidemic and endemic situations.
• Common types
- Acute febrile respiratory illness, affecting primarily children
- Acute respiratory disease, affecting adults
- Viral pneumonia, affecting children and adults
- Acute pharyngoconjunctival fever, affecting children, particularly after summer swimming
- Acute follicular conjunctivitis, affecting all ages
- Epidemic keratoconjunctivitis, affecting adults
- Intestinal infections leading to enteritis, mesenteric adenitis, and intussusception
• Conjunctivitis, sometimes called pink eye
• System(s) Affected: Cardiovascular; Gastrointestinal; Hemic/Lymphatic/Immunologic; Musculoskeletal; Nervous; Pulmonary; Renal/Urologic
ALERT
Geriatric Considerations
Complications more likely
Pediatric Considerations
Viral pneumonia in infants may be fatal.
GENERAL PREVENTION
• Live types 4 and 7 adenovirus vaccine orally in enteric-coated capsules reduces incidence of acute respiratory disease.
• Frequent hand washing among office personnel and family members
EPIDEMIOLOGY
• Predominant age: All ages
• Predominant sex: Male = Female
Incidence
• Very common infection, estimated at 2-5% of all respiratory infections
• More common in infants and children
RISK FACTORS
• Large number of people gathered in a small area (e.g., military recruits, college students at the beginning of the school year, day care centers, community swimming pools, etc.)
• Immunocompromised at risk for severe disease
ETIOLOGY
• Adenovirus (DNA viruses 60-90 nm in size with 47 known serotypes; three types cause gastroenteritis); difficult to eliminate from skin and environmental surfaces
• Different serotypes have different epidemiologies.
• Most common known pathogens
- Types 1, 2, 3, 5, and 7 cause respiratory illness.
- Type 3 causes pharyngoconjunctival fever.
- Types 4, 7, and 21 cause acute respiratory disease.
- Several other types may cause epidemic keratoconjunctivitis.
ASSOCIATED CONDITIONS
• Hemorrhagic cystitis (can be caused by adenovirus)
• Viral enteritis
• Intussusception and mesenteric adenitis


DIAGNOSIS
SIGNS AND SYMPTOMS
History
Depends on type (see "Differential Diagnosis"). Common signs and symptoms with most respiratory forms
• Headache
• Malaise
• Sore throat
• Cough
• Fever (moderate to high)
• Vomiting
• Diarrhea
Physical Exam
• Mucosa exhibits patches of white exudates
• Cervical adenitis
TESTS
Cultures and serologic studies, if appropriate
Lab
• Viral cultures from respiratory, ocular, or fecal sources can establish diagnosis:
- Pharyngeal isolate suggests recent infection.
• Antigen detection in stool for enteric serotypes is available.
• Serologic procedures such as complement fixation with a fourfold rise in serum antibody titer identify recent adenoviral infection.
Imaging
Radiographs: Bronchopneumonia in severe respiratory infections
Diagnostic Procedures/Surgery
Biopsy (lung or other) may be needed in severe or unusual cases
Pathological Findings
• Varies with each virus:
- Severe pneumonia may be reflected by extensive intranuclear inclusions.
• Bronchiolitis obliterans may occur.
DIFFERENTIAL DIAGNOSIS
Early diagnosis depends on clinical evaluation. The following are the primary characteristics of the major adenovirus infections:
• Acute febrile respiratory illness
- Nonspecific coldlike symptoms, similar to other viral respiratory illnesses (e.g., fever, pharyngitis, tracheitis, bronchitis, pneumonitis)
- Mostly in children
- Incubation period 2-5 days
- May be pertussislike syndrome (rarely)
• Acute respiratory disease
- Malaise, fever, chills, headache, pharyngitis, hoarseness, dry cough
- Fever lasts 2-4 days
- Illness subsides in 10-14 days
• Viral pneumonia
- Sudden onset of high fever, rapid infection of upper and lower respiratory tracts, skin rash, diarrhea
- Occurs in children aged a few days up to 3 years
- Common; severe illness occurs in subset
• Acute pharyngoconjunctival fever
- Spiking fever lasting several days, headache, pharyngitis, conjunctivitis, rhinitis, cervical adenitis
- Conjunctivitis, usually unilateral
- Subsides in 1 week
• Epidemic keratoconjunctivitis
- Usually unilateral onset of ocular redness and edema, periorbital edema, periorbital swelling, local discomfort suggestive of foreign body
- Lasts 3-4 weeks
TREATMENT
GENERAL MEASURES
• Treatment is supportive and symptomatic.
• Infections are usually benign and of short duration.
Diet
No special diet
Activity
Rest during febrile phases
SPECIAL THERAPY
Complementary and Alternative Medicine
Echinacea has not been shown to be better than placebo for treatment of viral upper respiratory infections. [A]
MEDICATION (DRUGS)
• Acetaminophen, 10-15 mg/kg/dose PO, for analgesia (avoid aspirin)
• Topical corticosteroids for conjunctivitis (after consulting an ophthalmologist)
• Cough suppressants and/or expectorants
• Antihistamine/decongestant combos may decrease cough. [B]
FOLLOW-UP
DISPOSITION
Admission Criteria
Severely ill infants or those with epidemic keratoconjunctivitis or infants with severe pneumonia
• Contact and droplet precautions during a hospitalization are indicated.
PROGNOSIS
• Self-limited, usually without sequelae
• Severe illness and death in very young and in immunocompromised hosts
COMPLICATIONS
Few if any recognizable long-term problems
PATIENT MONITORING
For severe infantile pneumonia and conjunctivitis, daily physical exam until well
REFERENCES
1. Barrett BP, Brown RL, Locken K, Maberry R, Bobula JA, D'Alessio D. Treatment of the common cold with unrefined echinacea. A randomized, double-blind, placebo-controlled trial. Ann Intern Med. 2002;137(12):939-946.
2. Pratter MR. Cough and the Common Cold, ACCP Evidence-Based Clinical Practice Guidelines Chest. 2006;129:72S-74S
3. Fahey T, Smucny J, Becker L, Glazier R. Antibiotics for acute bronchitis. The Cochrane Database of Systematic Reviews 2004, Issue 4. Art. No.: CD000245. DOI: 10.1002/14651858. CD000245.pub2.
4. Morris P, Leach A. Antibiotics for persistent nasal discharge (rhinosinusitis) in children. The Cochrane Database of Systematic Reviews 2002, Issue 4. Art. No.: CD001094. DOI: 10.1002/14651858. CD001094.
5. Spurling GKP, Del Mar CB, Dooley L, Foxlee R. Delayed antibiotics for symptoms and complications of respiratory infections. The Cochrane Database of Systematic Reviews 2004, Issue 4. Art. No.: CD004417. DOI: 10.1002/14651858.CD004417.pub2.