Pneumonia is an important cause of neonatal infection and accounts for significant morbidity and mortality, especially in developing countries [1,2]. In these countries, the World Health Organization estimates that almost 800,000 neonatal deaths occur each year from acute respiratory infections, mostly pneumonia . In a rural area in central India, for example, mortality secondary to pneumonia in the first month was 29 per 1000 live births; more than one-half of all pneumonia deaths in children occurred in newborns . These figures may be an underestimate because many newborns do not receive medical care.
In developed countries, the estimated incidence of pneumonia in full-term infants is less than 1 percent. However, among ill infants of normal and low birth weight, the incidence may be closer to 10 percent .
By contrast, at autopsy the incidence of neonatal pneumonia ranges from 20 to 32 percent of live-born and from 15 to 38 percent of stillborn infants, although the pathologic features of inflammation of the lung may not always result from infection . In one series, infection was the most common etiology of death in extremely low birth weight infants (56 of 111); congenital pneumonia accounted for 30 of these 56 infections . Pneumonia caused by maternal enteric organisms frequently accompanies chorioamnionitis and/or funisitis in these congenital infections.
The pathogenesis, clinical manifestations, diagnosis, and treatment of neonatal pneumonia are reviewed here. Neonatal sepsis and specific pathogens are discussed separately. (See "Clinical features and diagnosis of sepsis in term and late preterm infants".)
Neonatal pneumonia can have early or late onset. Bacteria are the principal pathogens for both types. (See 'Microbiology' below.)