Infectology is the science and study of conditions that are caused by an invasion of the human body by pathogens such as bacteria, viruses, parasites or fungi that then multiply and cause damage to the organism.

The infectologist knows the various ways a human can pick up infectious diseases, and the tests that are needed to diagnose them. The patient is then prescribed the medicine that is appropriate to treat the viral, bacterial, parasitical or fungal infection.

The infectologist plays an important part in combating serious viral diseases such as AIDS or hepatitis. He selects the correct drug or combination of drugs for these patients, constantly monitors the outcome of the therapy and adjusts it as and when necessary.

The infectologist also knows how infections are disseminated in the environment. He adopts the procedures that are needed to prevent this from happening, such as immunisations or the disinfection of rooms and equipment.