World Health Organization states that the diseases that can be spread directly or indirectly from one person to another are infectious. Pathogenic microorganisms, such as bacteria, viruses, parasites or fungi, cause infectious or communicable diseases. Bites transmit, some from insects or animals, and others are acquired by ingesting contaminated food or water or being exposed to organisms in the environment (WHO, Infectious Disease).
According to the Lancet Global Burden of Disease Study in 2016, communicable diseases contributed to 27.5% deaths. Infectious and associated diseases made up most of the disease burden in most states in 1990. Out of the total disease burden in India measured as Disability Adjusted Life Years (DALYs) in 1990, 61% is due to communicable, maternal, neonatal and nutritional diseases. The good news is that it had dropped to 33% in 2016 (Institute of Health Metrics and Evaluation, 2017). Diseases of infectious etiology such as diarrhoea, pneumonia, tuberculosis, and HIV are included. Deaths due to under-nutrition and maternal and neonatal deaths come from communicable diseases. Despite this decrease, 5 of 10 individual leading causes of disease burden belonged to the infectious disease group: i.e. diarrheal diseases, lower respiratory infections, iron-deficiency anemia, preterm birth complications, and tuberculosis (GBD 2016). Diarrhea and lower respiratory infections are the top two disease burden infections in 2016.