Infectious diseases are disorders caused by pathogenic microorganisms such as bacteria, viruses, fungi, or parasites that can be transmitted from one person to another, or from animals to humans. These diseases can spread through various means, including direct contact with an infected person, exposure to contaminated objects or surfaces, inhalation of airborne particles, or through a vector like a mosquito or tick. Infectious diseases can range from mild to severe and can affect different parts of the body. Examples of common infectious diseases include the flu, tuberculosis, malaria, HIV/AIDS, and COVID-19.
