There are various microbes, viruses, fungi, and parasites that can infect a host via several routes of transmission. +Types of infectious agents Agent Description Microorganisms Microorganisms, or microbes are extremely diverse microscopic organisms, including archaea and bacteria, which are commonly grown and studied in<unk> es and can infect<unk>  animals and<unk>  workers. Viruses Viruses infect all types of life forms, from animals and plants to microorganisms, including bacteria and archaea, and are commonly passaged and studied in<unk> es, which can directly or indirectly cause zoonotic infection of<unk>  animals and<unk>  workers. Parasites Parasites may include various types of protozoa, worms and ectoparasites which are studied in<unk> es and which can cause the infection of<unk>  workers and animals. +Routes of transmission Route Description Mucous membranes This occurs when microbes, viruses and/or parasites are transmitted through direct contact with<unk>  workers, or contaminated surfaces, or items such as vials, devices, and/or equipment, to the host's mucous membranes. Respiratory tract This occurs with the dissemination of either airborne droplet nuclei of evaporated droplets containing microorganisms or viruses, or dust particles containing the infectious agent, are transmitted via the host's respiratory tract. Microorganisms carried in this manner can be dispersed widely by air currents and may become inhaled by the infected host within the same room or over a longer distance from the source host, depending on environmental factors. Gastrointestinal tract This occurs with the oral intake of an infectious agent through a pipette, smoking or eating, infecting the host through their gastrointestinal tract. Percutaneous inoculation This occurs with a vector, such as mosquitoes, flies, rats, and other vermin transmit microbes, viruses and/or parasites to a host through a bite or scratch; or the transmission of an agent carrying an infectious pathogen through a needle or syringe.
Laboratory-acquired infection
Hospital-acquired infection
Spillover infection
Intentional contagion of infection
Vaccine adverse event
Blood-borne disease
Transfusion transmitted infection
Foodborne illness