Case of the Month

Juanita Lishman, Lisa Frigati, Helena Rabie. Division of Pediatric Infectious Diseases, Department of Pediatrics and Child Health Stellenbosch University and Tygerberg Hospital 

A 2 year 10-month-old girl presents with a five-day history of a fever and a runny nose, cough with post-tussive vomiting, and conjunctivitis. 

She was previously well with no prior admissions. She was born at term; her immunizations were up to date and she was HIV unexposed. There were no contacts at home with tuberculosis or COVID-19 and no household smokers. There was also no history of atopy. 

On initial examination she was tachycardic and tachypnoeic with oxygen saturation of 91% in room air. She had signs of respiratory distress including alar flare, intercostal and subcostal recession. On auscultation of her lungs she had bilateral inspiratory crepitations and a soft expiratory wheeze. The rest of the assessment was normal. 

Low flow oxygen was initiated and the saturation improved. Further management included oral antibiotic and inhaled B2agonist – to which she was responsive. 

Chest X-ray (Fig 1) showed bilateral infiltrates with air bronchograms, most prominent in the right upper and middle lobe. C-reactive protein that was slightly elevated at 26mg/L with a normal white Cell Count of 9.21 x 10⁹/L. Her HIV test was negative.

Fig 1: Chest radiograph of 2 year 10-month-old girl with severe lower respiratory tract infection.

Question 2: Describe the adenoviral syndromes and their associated serotypes

Adenovirus  subgroups A and F typically cause infection of the gastrointestinal tract, and subgroups B, C and E shows tropism for the respiratory tract. Epidemic kerato- conjunctivitis is predominantly caused by serotypes of subgroup D. 

Typical clinical presentations of adenovirus include pharyngoconjunctival fever. This syndrome typically affects children more than adults and presents with acute onset high fever, pharyngitis and conjunctivitis that initially affects one eye and then 3-4 days later the other eye becomes involved. Outbreaks can occur in childcare facilities and swimming areas. Epidemic keratoconjunctivitis is more common in adults and has a slower onset with simultaneous bilateral eye involvement. Adenovirus, types 40 and 41 have been associated with gastroenteritis as well as intussusception. 

Pneumonia, as in this case, is often more severe in children and can lead to a need for respiratory support and even death in previously healthy children. The white cell count and CRP in children with adenovirus can be raised and this therefore may be confused with a bacterial infection. Adenovirus is by far the most common cause of post-infectious bronchiolitis obliterans in children. In these children mechanical ventilation is an independent risk factor to develop post-infectious bronchiolitis obliterans. In addition, adenovirus is commonly found in the lower airways of children with protracted bacterial bronchitis and bronchiectasis suggesting a role in the development of chronic lung disease in children without cystic fibrosis as well as a role in symptom exacerbation in children with established bronchiectasis.Adenovirus is common cause of viral myocarditis, in some reports up to 60% of cases are attributed to adenovirus.

Question 4: How Can adenovirus be diagnosed?

Diagnosis is mostly made using a PCR assay on a nasopharyngeal aspirate or swab, throat swab, sputum sample, or bronchoalveolar lavage fluid. PCR can also be performed on urine, stool, CSF as well as histological specimens. This allows for rapid diagnosis of adenovirus. 

In tissues, characteristic intranuclear inclusions can be noted and the virus identified on electron microscopy or through immunohistochemistry.

Other strategies include viral antigen assays these are  test of choice for serotype 40 and 41 and culture, the latter is no longer routine.

A live oral vaccine against serotypes 4 and 7 was  used by the US military

In other settings the main stay of prevention remains good prevention and cleaning practice. 

The Committee on Infectious Diseases of the American Academy of Pediatrics recommends the following:

• For patients with conjunctivitis and for patients with gastroenteritis who are incontinent or in diapers, contact precautions should be maintained for the duration of the illness.
• For those with respiratory tract infections, contact and droplet precautions are recommended for the duration of the hospitalization.
• Disposable gloves and hand washing should be used when caring for infected patients.
• Healthcare personnel with known or suspected adenoviral conjunctivitis should avoid direct patient contact until symptoms have resolved.