Infektsion

Infektsion is the process by which a pathogenic microorganism enters a host, multiplies, and causes disease. Infections can involve bacteria, viruses, fungi, or parasites and may be localized or disseminated. The outcome depends on factors such as the virulence of the organism, pathogen load, the site of infection, and the host's immune status.

Transmission occurs through contact with contaminated hands or surfaces, respiratory droplets, sexual contact, vectors, contaminated food or water, or exposure during medical procedures. Pathogens may adhere to host cells, invade tissues, produce toxins, or trigger inflammatory and immune responses that contribute to symptoms.

Diagnosis is based on history, clinical examination, and laboratory tests, including cultures, molecular assays, antigen detection, and imaging. Treatment is organism-specific: antibiotics for bacterial infections, antivirals for certain viral infections, antifungals for fungal infections, and antiparasitics for parasitic infections. Supportive care and monitoring are often essential, and antimicrobial stewardship helps prevent resistance and preserves drug effectiveness.

Prevention focuses on vaccination, hygiene, safe food and water, infection control in health care, and safe sex practices. Many infections are preventable or milder with timely intervention. Complications can include pneumonia, meningitis, sepsis, organ dysfunction, and long-term sequelae.