The disease may be caused by a virus, by fungi, or by one of hundreds of strains of bacteria. Pneumonia is a major cause for hospitalization and death.
Many different types of bacteria may cause pneumonia, but the two most common are Streptococcus pneumoniae and Staphylococcus aureus.
Anyone from any age group can be affected with pneumonia, but young children and senior citizens over 65 years old are most susceptible to this infection. Pneumonia is known as the single largest infectious cause of death in children worldwide, with many cases coming out of South Asia and sub-Saharan Africa. Statistics from November 2015 by the World Health Organization (WHO) showed that around 922,000 children died in 2015 because of pneumonia. This infection is said to account for 15 percent of all deaths among children under 5 years old.
These rates resulted in pneumonia being addressed as the eighth leading cause of death in the U.S., tied with influenza; also aggravating meningitis and bacteraemia (blood infections). Flu and pneumonia are connected; many deaths from pneumonia are the result of flu exhausting the immune system, thereby allowing opportunistic pneumonia to take hold.
Roughly 1 million Americans are hospitalized annually because of it, according to 2015 statistics presented by the American Thoracic Society. It is the most common reason why American children are admitted to hospitals, while for adults, it’s one of the two main causes of hospitalization, apart from childbirth.
Pneumonia is the eighth leading cause of death in the USA. Between 47,000 and 63,000 people in the US die from pneumonia each year and this data has not changed since the advent of antibiotics. For example, in 2013 the U.S Centers for Disease Control and Prevention (CDC) recorded 53,282 deaths due to pneumonia; there were 228 deaths among children under 5 years old and 45,345 deaths were reported among elderly people aged 65 and up. Again, according to the CDC, there were 32 deaths among those aged 18-65 from flu reported in a single week in the US in 2015, versus 667 from pneumonia; among those older than 65, there were 77 deaths from the flu and 2,752 from pneumonia.