Epidemiology And Communicable Diseases
Epidemiology is the branch of medicine that deals with the study of the distribution and determinants of health-related states or events in specified populations, and the application of this study to the control of health problems. Communicable diseases, also known as infectious diseases, are illnesses that are transmitted from one person to another through various means, such as through direct contact, through the air, or through contaminated food or water.
In the study of epidemiology, one crucial aspect is the identification of the source of a communicable disease outbreak. This is often accomplished through the use of epidemiological investigation techniques, such as case-control studies and cohort studies. These techniques allow researchers to identify risk factors for the disease, as well as the specific populations that are most at risk for contracting the illness.
An example of a communicable disease that has been studied extensively through epidemiology is tuberculosis (TB). TB is caused by the bacterium Mycobacterium tuberculosis and is spread through the air when an infected person coughs or sneezes. In the early 20th century, TB was a leading cause of death worldwide. Through the use of epidemiological investigation techniques, researchers were able to identify populations that were at higher risk for contracting TB, such as those living in crowded and poorly ventilated housing. This led to the implementation of public health measures, such as improved housing and increased access to TB treatment, which have helped to reduce the incidence of TB.
Other communicable disease that has been the subject of epidemiological study is HIV/AIDS. HIV, the virus that causes AIDS, is primarily spread through sexual contact, but can also be transmitted through sharing needles or from mother to child during childbirth. In the early years of the HIV/AIDS epidemic, epidemiological investigation techniques were used to identify the populations that were most at risk for contracting the virus. This included men who have sex with men, people who inject drugs, and people living in certain geographic regions with high rates of HIV transmission. This knowledge led to targeted public health interventions, such as harm reduction programs for people who inject drugs and increased access to HIV testing and treatment.
Epidemiology plays a crucial role in the understanding and control of communicable diseases. Through the use of epidemiological investigation techniques, researchers are able to identify the source of a disease outbreak and the populations that are most at risk. This knowledge can then be used to develop and implement effective public health interventions, as demonstrated by the examples of TB and HIV/AIDS.

Centers for Disease Control and Prevention. (2021). Tuberculosis (TB). Retrieved from https://www.cdc.gov/tb/
UNAIDS. (2021). HIV/AIDS. Retrieved from https://www.unaids.org/en/hiv-aids
World Health Organization. (2019). Epidemiology and communicable diseases. Retrieved from https://www.who.int/publications/i/item/9789240010611