Health topics

Infectious diseases

WHO/Chris Black
Boy with baby

Infectious diseases are caused by pathogenic microorganisms, such as bacteria, viruses, parasites or fungi; the diseases can be spread, directly or indirectly, from one person to another. Zoonotic diseases are infectious diseases of animals that can cause disease when transmitted to humans.


  • WHO best practices for naming of new human infectious diseases
    Best practices for the naming of new human diseases, with the aim to minimize unnecessary negative impact of disease names on trade, travel, tourism or animal welfare, and avoid causing offence to any cultural, social, national, regional, professional or ethnic groups.