CASE 5
The patient was a 2 ½ year old male, who was admitted to the hospital in August with fever and respiratory distress. Patient was well until one day before when he developed fever, rhinorrhea and congestion. On the day of admission, he was brought to the ER because he seemed to have trouble breathing. His medical history was significant for developmental delay and numerous episodes of aspiration pneumonia. Family history revealed that a 7 year-old sibling and several of his "swim-team" members had pharyngitis and conjunctivitis 10 days ago.
On examination, the child’s temperature was 40.80C. He was tachypnic with a respiratory rate of 40. The heart rate was 160. He had moderate mucoid nasal discharge. He had subcostal retractions and nasal flaring. His throat was red and there was exudate on both tonsils.
On auscultation of his lungs, there were scattered rhonchi, but no wheezes noted. A chest radiograph revealed no new findings. He was put in respiratory isolation in the pediatric wards. Blood and nasopharyngeal cultures were sent to the microbiology laboratory. A nasopharyngeal wash specimen was positive for adenovirus (was detected by shell vial technique at 480 and confirmed by staining with monoclonal antibodies).
BACKGROUND
Etiology: Adenoviruses are DNA viruses; at least 51 distinct serotypes divided into 6 subgenera (A to F) cause human infections.
Human adenovirus infections are ubiquitous. Adenoviruses are most important clinically because of their capacity to cause acute infections of the respiratory system and conjunctivae. Adenoviruses cause 5-8% of acute respiratory disease in infants and children including pneumonia. The serotype of adenovirus that causes infection and the type of disease induced is closely related to the age of the patient. (See following table)
The incidence of adenovirus-induced respiratory tract disease is increased slightly in late winter, spring, and early summer. Enteric disease occurs during most of the year and primarily affects children younger than 4 years of age. Adenovirus infections are most communicable during the first few days of an acute illness, but persistent and intermittent shedding for longer periods, even months, is frequent. The incubation period for respiratory tract infection varies from 2 to 14 days; for gastroenteritis, it is 3 to 10 days.
|
Diseases Caused by Adenoviruses |
||
|
Group Affected |
Syndromes |
Common Causal |
|
Neonates |
Fatal disseminated infection |
3, 7, 21, 30 |
|
Infants |
Coryza, pharyngitis (most asymptomatic) |
1, 2, 5 |
|
Children |
Upper respiratory disease |
1, 2, 4-6 |
|
Young children |
Acute respiratory disease and pneumonia |
3, 4, 7 |
|
Adults |
Epidemic keratoconjunctivitis |
8, 19, 37 |
|
Immuno-compromised |
Pneumonia with dissemination, urinary tract infection |
5, 31, 34, 35, 39, 42-47 |
Types 1, 2, 5 and 6 are frequently isolated from the situ tonsils and adenoids of young children. The children may be asymptomatic or may have upper respiratory infection at the time of isolation.
Type 3, 4 and 7 are most frequently isolated from young adults with acute upper and lower respiratory disease. Military recruits seem particularly likely to be infected with these agents, as they are to be infected with mycoplasmal and meningococcal organisms. The reasons for the increased infection rates are probably related to the crowding of a susceptible population.
Case 5