Adenovirus infections

Description of Medical Condition

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 (AFRI) affecting primarily children
• Acute respiratory disease (ARD) affecting adults
• Viral pneumonia affecting children and adults
• Acute pharyngoconjunctival fever (APC) affecting children, particularly after summer swimming
• Acute follicular conjunctivitis affecting all ages
• Epidemic keratoconjunctivitis (EKC) affecting adults
• Intestinal infections leading to enteritis, mesenteric adenitis and intussusception

System(s) affected: Pulmonary, Gastrointestinal, Renal/Uroiogic, Nervous, Hemic/Lymphatic/lmmunologic, Musculoskeletal, Cardiovascular

Genetics: N/A

Incidence/Prevalence in USA: Very common infection, estimated at 2-5% of all respiratory infections. More common in infants and children.

Predominant age: All ages

Predominant sex: Male = Female

Medical Symptoms and Signs of Disease

Common signs and symptoms with most respiratory forms

• Headache
• Malaise
• Sore throat
• Cough
• Fever (moderate to high)
• Vomiting
• Diarrhea
• Mucosa exhibits patches of white exudate

Primary characteristics of the major adenovirus infections

• Acute febrile respiratory illness:
  • Nonspecific cold-like symptoms, similar to other viral respiratory illnesses (fever, pharyngitis, tracheitis, bronchitis, pneumonitis)
  • Mostly in children
  • Incubation period 2 to 5 days
  • May be pertussis-like syndrome rarely
• Acute respiratory disease:
  • Malaise, fever, chills, headache, pharyngitis, hoarseness and dry cough
  • Fever lasts 2 to 4 days
  • Duration: 10 to 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 is usually unilateral
  • Duration: about 1 week
• Epidemic keratoconjunctivitis
  • Usually unilateral onset of ocular redness and edema, periorbital edema, periorbital swelling, local discomfort suggestive of foreign body
  • Duration: 3 or 4 weeks

What Causes Disease?

• Adenovirus (DNA viruses 60-90 nm in size with 47 known serotypes; 3 types cause gastroenteritis); difficult to eliminate from skin and environmental surfaces
• Different serotypes have different epidemiologies
• Most common known pathogens are:
  • Types 1, 2, 3, 5, 7 cause respiratory illness
  • Type 3 causes pharyngoconjunctival fever
  • Types 4, 7, 21 cause acute respiratory disease
  • Several other types may cause epidemic keratoconjunctivitis

Risk Factors

• Large number of people gathered in a small area (military recruits, college students at the beginning of the school year, daycare centers, community swimming pools, etc.)
• immunocompromised at risk for severe disease

Diagnosis of Disease

Differential Diagnosis

Non-viral upper respiratory infection

Laboratory

• 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 four fold rise in serum antibody titer identifies recent adenoviral infection

Drugs that may alter lab results: N/A

Disorders that may alter lab results: N/A

Pathological Findings

• Varies with each virus, severe pneumonia may be reflected by extensive intranuclear inclusions
• Bronchiolitis obliterans may occur

Special Tests

Cultures and serologic studies if appropriate

Imaging

X-ray: bronchopneumonia in severe respiratory infections

Diagnostic Procedures

Biopsy (lung or other) may be needed in severe or unusual cases

Treatment (Medical Therapy)

Appropriate Health Care

Ambulatory except for severely ill infants or those with epidemic keratoconjunctivitis or infants with severe pneumonia. Contact and droplet precautions during a hospitalization are indicated.

General Measures

Treatment is supportive and symptomatic. Infections are usually benign and of short duration.

Activity

Rest during febrile phases

Diet

No special diet

Patient Education

Avoid aspirin in children. Give instructions for nasal spray, cough preparations, frequent hand washing.

Medications (Drugs, Medicines)

Drug(s) of Choice

• Acetaminophen, 10-15 mg/kg/dose, for analgesia (avoid aspirin)
• Topical corticosteroids for conjunctivitis (after consulting an ophthalmologist)
• Cough suppressants and/or expectorants

Contraindications: Refer to manufacturer’s literature

Precautions: Refer to manufacturer’s literature

Significant possible interactions: Refer to manufacturer’s literature

Alternative Drugs

N/A

Patient Monitoring

For severe infantile pneumonia and conjunctivitis: daily physical exam until well

Prevention / Avoidance

• Live types 4 and 7 adenovirus vaccine orally in enteric coated capsule reduces incidence of acute respiratory disease
• Frequent hand washing among office personnel and family members

Possible Complications

Few if any recognizable long-term problems

Expected Course / Prognosis

• Self-limited, usually without sequelae
• Severe illness and death in very young and in immunocompromised hosts

Miscellaneous

Associated Conditions

• Hemorrhagic cystitis (can be caused by adenovirus)
• Viral enteritis
• Intussusception and mesenteric adenitis

Age-Related Factors

Pediatric: Viral pneumonia in infants may be fatal

Geriatric: Complications more likely

Pregnancy

No special precautions

International Classification of Diseases

079.0 Adenovirus

462 Acute pharyngitis

480.0 Pneumonia due to adenovirus

See Also

Conjunctivitis, acute Intussusception Pneumonia, viral

Severe acute respiratory syndrome (SARS)

Other Notes

Conjunctivitis sometimes called “pink eye”