Emerging Infectious Diseases (EIDs) are illnesses caused by newly identified pathogens or those that have recently increased in incidence or geographic range. These diseases can arise from various sources, including bacteria, viruses, and parasites, and often result from changes in environmental conditions, human behavior, or increased global travel. Factors contributing to the emergence of EIDs include urbanization, climate change, and antimicrobial resistance. Surveillance and research are crucial for understanding and controlling these diseases, as they can pose significant public health threats and lead to outbreaks, as seen with diseases like COVID-19 and Zika virus.