Smittestoffer

Smittestoffer, a term commonly used in Nordic public health literature, refers to biological agents that can cause infection or disease in humans, animals, or plants. The category encompasses bacteria, viruses, fungi, parasites, and prions. Some definitions also include other infectious agents and their components that can initiate disease. The concept focuses on the properties that enable transmission and pathogenicity, rather than on disease outcomes alone.

Smittestoffer spread through various routes. Direct contact, respiratory droplets and airborne particles, contaminated surfaces, vectors such as mosquitoes, food or water contamination, and sexual transmission are all recognized pathways. Environmental persistence, such as survival on surfaces or in water, influences transmission risk. The infectious dose and the pathogen's virulence, together with the host's age, health, and immune status, determine whether exposure leads to illness.

Public health practice aims to reduce the burden of smittestoffer through surveillance, vaccination, hygiene measures, safe food handling, antimicrobial stewardship, and appropriate isolation or quarantine when indicated. The study of these agents spans microbiology, epidemiology, and immunology, and it informs guidelines for infection control in healthcare, workplaces, and communities.

Examples of well-known smittestoffer include influenza viruses, rhinoviruses, SARS-CoV-2, Mycobacterium tuberculosis, Escherichia coli pathotypes, Staphylococcus aureus, noroviruses, and malaria parasites (Plasmodium species). The term emphasizes the source of risk and the object of preventive action, rather than the disease itself.