What type of infection occurs when an organism invades a host?

A systemic infection occurs when an organism invades a host, spreading throughout the entire body rather than being confined to one area. This type of infection can affect multiple systems and organs, leading to widespread symptoms and requiring more intensive treatment. Systemic infections often arise from pathogens that enter the bloodstream or lymphatic system, making them more serious and potentially life-threatening if not managed properly.

While local infections, chronic infections, and acute infections each describe different patterns or durations of infection, they do not capture the broader implications of an organism invading and spreading throughout the host. Local infections are confined to a specific area, chronic infections persist over a long time, and acute infections are characterized by sudden onset and short duration. However, systemic infection highlights the critical aspect of invasion and dissemination within the host.