In the simplest definition, an endemic disease is a disease that is always present in a particular species or population. For example, the common cold is endemic to humans. There is no way to rid a population of an endemic disease, without technological advances in modern medicine.
Just because a disease is endemic does not mean it is harmless. In fact, some of the most common endemic diseases in humans (apart from the common cold) are HIV, syphilis, and more. These diseases cause harm to the sufferer, but because they are ever present in the human biome, they are endemic diseases.
Endemic Disease Vs. Epidemic Disease
Some people may get these terms confused because of their similar spelling and pronunciation. However, there is a big difference between the two. While an endemic disease is always present and generally has a traceable “base” level of infections among a population, epidemics are not.
Epidemics are unusual surges of disease in a particular population or region. Epidemics are usually fast-rising cases of a certain disease or virus, which are unusually high in volume and tend to only affect a specific area. Pandemics are a global version of an epidemic.
Can a Disease Go from Epidemic to Endemic?
The short answer here is yes. Though, the epidemic will need to be large enough to build her immunity. Once enough people have been exposed to the disease during an epidemic or pandemic, herd immunity quickly builds.
Once most of the population has similar immune defenses against a disease, the disease may become endemic. This is because the disease can be spread quietly, not affecting most who get it, due to herd immunity. However, vulnerable populations like kids and the elderly can always be more dramatically impacted by diseases, even endemic ones.
An endemic disease is a disease that has become prevalent among a certain population. Endemic diseases perpetuate themselves among a species. The species typically build herd immunity against endemic diseases, but this does not mean endemic diseases are not still damaging to vulnerable populations.
Epidemic or pandemic outbreaks can slowly evolve into endemic diseases over time. However, vulnerable populations will always be in harm’s way when it comes to any of these diseases. Although herd immunity is robust, it’s always best to vaccinate (when possible), practice good hygiene, and stay home if you are sick with any disease- endemic or not.