Chronic Pulmonary Complications of Early Influenza Virus Infection in Children^1–3

Abstract

In 3 male patients, chronic pulmonary sequelae followed influenza virus infection at 5, 24, and 42 months of age. Varying degrees of interstitial fibrosis, bronchial and bronchiolar erosions and metaplasia, obliterative bronchiolitis, and interstitial chronic inflammatory infiltrates were found on lung biopsy. Influenza A/Hong Kong/68 (H3N2) virus was isolated from the lung tissue of one patient 8 weeks after the onset of illness. This is the longest persistence of infectious virus in lung tissue yet reported. Persistent radiographic abnormalities included peribronchial thickening, interstitial densities, bronchiectasis, obliterative bronchiolitis, and segmental atelectasis. Pulmonary function tests showed an obstructive restrictive pattern, with mild improvement after bronchodilation and with deterioration after exercise. These observations suggest that influenza virus infection may be more serious in infants and young children than has been previously recognized and may contribute to the pathogenesis of unexplained interstitial pneumonitis, pulmonary fibrosis, obliterative bronchiolitis, and bronchiectasis.

Enhanced Viral Replication and Modulated Innate Immune Responses in Infant Airway Epithelium following H1N1 Infection

“…Regardless of the etiology, alveolar damage such as that detected in the H1N1-infected infant monkeys in this study may lead to secondary bacterial infection. These findings are consistent with epidemiologic data suggesting that influenza infection is more likely to progress to bronchiolitis and pneumonia in infant hosts (1,2,57). However, comparative in vivo infections of adult rhesus monkeys with pandemic H1N1 will be necessary to fully understand the contribution of age to influenza pathogenicity.…”

“…The Centers for Disease Control and Prevention estimates that 20,000 children under the age of 5 years are hospitalized each year due to influenza-related illnesses (1,2). During the 2009 H1N1 pandemic, children showed an increased risk of severe outcomes and a higher death rate than that of previous influenza seasons (3-7).…”

Pneumonia in Childhood and Impaired Lung Function in Adults: A Longitudinal Study

“…Viruses known to cause pneumonia in infancy and early childhood, such as adenovirus and influenza A, can cause severe, irreversible structural damage to the developing lung in susceptible subjects. [28][29][30] It is thus possible that a range of susceptibilities may exist in the population such that some young children may develop less severe impairment, as observed in this study.…”

Constrictive Bronchiolitis after Treatment of Colon Cancer with 5-Fluorouracil

“…In children the disease rarely follows bronchiolitis due to adenovirus, influenza virus, measles virus, or Mycoplasma pneumoniae [8][9][10][11] . The condition is also related to certain autoimmune conditions like rheumatoid arthritis [12][13][14] , ulcerative colitis [15,16] , psoriatic arthritis [17] , pemphigus vulgaris and Stevens-Johnson syndrome [18,19] .…”