P. Ezhilarasan
Mankind has faced infectious diseases repeatedly throughout its evolutionary history. Some of these diseases that recently affected human populations are black plague, smallpox, tuberculosis, Spanish flu, Russian flu, AIDS, Ebola, Asian flu, Avian flu, Hong Kong flu, SARS, swine flu, MERS, Zika, and finally human coronavirus disease (COVID-19). Bacteria, viruses, fungi, and worms/helminths are among the pathogens that cause infectious disorders (Kotra, 2007). For humans, pathogens transmission may occur by other people, animals, or environmental sources. As infective organisms, like humans, benefit from modern transportation facilities, infectious diseases are much faster and imminent dangers than before. In the classification of infectious diseases, the concepts of endemic, outbreak, epidemic, and pandemic appear. The amount of disease found only in a particular population is called the endemic level of the disease. An outbreak is defined as an unpredictable increase in the number of people showing a health condition or the occurrence of cases in a new region. When the disease spreads over a wider geographical area, the concept of epidemic emerges. When the epidemic spreads all over the world, the disease is now defined as a pandemic disease (Piret and Boivin, 2020). Throughout human history, epidemics and pandemics have constantly changed people's lifestyles due to their striking effects and still continue to do so. The COVID-19 pandemic we are currently experiencing is also changing everyone's lives in a remarkable way, and its effects on the future cannot be fully predicted. Learning about the factors, progress, and 6 Recent Advances In Biological Sciences effects of COVID-19 and past epidemics will at least help us to be prepared for infectious diseases.
Covid – 19