Certain infectious or parasitic diseases is a chapter in ICD-11 that covers conditions caused by pathogenic microorganisms such as bacteria, viruses, fungi, parasites, and other infectious agents. These diseases arise when such organisms enter the human body, multiply, and disrupt normal physiological functions, leading to localized or systemic illness. The chapter includes a wide range of conditions, from common and self-limiting infections to severe, life-threatening diseases, and accounts for both acute and chronic infections that may affect individuals of all ages.
This chapter also addresses infectious and parasitic diseases based on their mode of transmission, clinical presentation, and etiological agents. It includes illnesses spread through direct contact, airborne routes, contaminated food or water, vectors such as insects, and zoonotic sources. Accurate classification within this chapter supports disease surveillance, outbreak control, treatment planning, and public health interventions, making it essential for monitoring global health trends and guiding preventive and therapeutic strategies.