ABSTRACT
Lower respiratory tract infection was the fourth leading cause of mortality worldwide in 2012, accounting for 3.1 million deaths (5.5%) worldwide (World Health Organization factsheet). Bacterial pneumonia is a disease that mostly affects those toward the extremes of age, being more common in the very young and in the elderly (Figure 29.1). Prior to the introduction of the 7-valent pneumococcal vaccine pneumonia, hospitalizations in the United States were estimated at 1.3 per 1,000 in the under-twos, although these incidences have been significantly reduced following the widespread introduction of vaccination in childhood. Worldwide, however, infant mortality remains high, and in 2015, an estimated 922,000 (15.5%) deaths in the under-fives were due to pneumonia.
