An endemic disease is a medical condition which is entrenched in a region, in a country or in a continent. This implies that there is a reservoir for the pathogen which is involved in contaminating individuals and this causative agent is either a bacterium, a virus or a parasite. Medical care cures individuals but does not prevent the spread of a disease. This is why the Colonial Medical Corps started very early to implement or even to work out techniques of prevention which can be used in communities to put a check on diseases transmission.

First the Major Endemic Diseases Department started to tackle those deadly or crippling conditions which could at the time be taken care of with medications, vaccines, insecticides, etc... which had to be suitable for treating whole communities at a time. Fights against plague, smallpox, leprosy, sleeping sickness, treponematoses, yellow fever were successful achievements while some others can also be deemed victorious even if they were not fully successful. Preventing some diseases from spreading is well beyond medical possibilities as they are sometimes related to the prevailing socio economic conditions.