Here are some of the most common portals of entry:
Respiratory Tract: This is one of the most common portals of entry for airborne pathogens like viruses and bacteria, including influenza and tuberculosis. Gastrointestinal Tract: Pathogens enter through ingestion of contaminated food or water, leading to diseases like cholera and salmonella. Skin: Although the skin is a robust barrier, pathogens can enter through cuts, abrasions, or insect bites, leading to infections like tetanus and malaria. Mucous Membranes: These include the conjunctiva of the eyes and the mucous lining of the nose and mouth. Pathogens like the herpes simplex virus use this route. Parenteral Route: This includes the direct entry of pathogens into the bloodstream through needles, bites, or surgical procedures, leading to diseases like HIV and hepatitis B.
