Key Points For definitions of the abbreviations in green see Table 9.
ÎPneumonia is the single greatest cause of death in children worldwide. Each year, more than 2 million children younger than 5 years die from pneumonia, representing approximately 20% of all deaths in children within this age group.
ÎIn the developed world, the annual incidence of pneumonia is approximately 3-4 cases per 100 children younger than 5 years. Incidence varies inversely with age.
ÎVaccines have dramatically decreased the incidence of infections, including community-aquired pneumonia (CAP).
ÎPathogens responsible for "atypical pneumonia" have been identified in 3% to 23% of children studied, with Mycoplasma pneumoniae more often identified in older children.
ÎViral etiologies of CAP have been documented in up to 80% of children younger than 2 years. In contrast, investigations of older children, 10-16 years, who had both clinical and radiographic evidence of pneumonia, documented a much lower percentage of viral pathogens.
ÎRespiratory syncytial virus (RSV) is consistently the most frequently detected virus, representing up to 40% of identified pathogens in those younger than 2 years, but rarely identified in older children with CAP. Less frequently detected are adenoviruses, bocavirus, human metapneumovirus, influenza A and B viruses, parainfluenza viruses, coronaviruses and rhinovirus.
Note: 2% to 33% of children hospitalized with CAP are simultaneously infected by 2 or more viruses.
