Final answer:
An emerging infectious disease is a disease that is either new to humans or has a rapidly increasing incidence or spread. These diseases can be caused by various pathogens including viruses, bacteria, and protozoa, and often result from human actions such as habitat encroachment.
Step-by-step explanation:
What is an Emerging Infectious Disease?
An emerging infectious disease refers to an illness that is new to the human population or one that has significantly increased in incidence or geographic range in the recent past. This can include diseases that are newly identified in humans, those that were previously existing but now showing a surge in cases, or infections that have spread to new areas where people lack immunity. Often, these diseases originate from animals (zoonoses) and can be spurred by various factors, including human encroachment on wildlife habitats, global travel, climate change, and changes in land use.
Examples of emerging infectious diseases comprise Ebola, Zika virus, and novel influenza strains like H1N1. They can be of viral, bacterial, or protozoal origin. It is essential to note that emerging diseases can also be 're-emerging,' which are diseases that were previously under control but have resurfaced. The World Health Organization (WHO) monitors these diseases closely due to their potential impact on public health.
Question 2 would be the correct answer: An infectious disease that is newly found in a human population.