section_path: Epidemiology
section_name: Epidemiology
paragraph_text: Epidemiology
  
  An estimated 1,680 million people died of infectious diseases in the 20th century and about 10 million in 2010.
  
  The World Health Organization collects information on global deaths by International Classification of Disease (ICD) code categories. The following table lists the top infectious disease by number of deaths in 2002. 1993 data is included for comparison.
  
  The top three single agent/disease killers are HIV / AIDS, TB and malaria. While the number of deaths due to nearly every disease have decreased, deaths due to HIV/AIDS have increased fourfold. Childhood diseases include pertussis, poliomyelitis, diphtheria, measles and tetanus. Children also make up a large percentage of lower respiratory and diarrheal deaths. In 2012, approximately 3.1 million people have died due to lower respiratory infections, making it the number 4 leading cause of death in the world.