The COVID-19 pandemic has wrecked a lot of havocs on families and businesses all around the globe but as the year 2021 continues, the number of cases in the United States is already dwindling as more vaccines are being passed around in an attempt to curb the novel illness.

But one bad news is that health officials believes the illness isn’t likely to go away anytime soon. This was according to the US top infectious diseases expert Dr. Anthony Fauci who made it known that the COVID-19 may not be eradicated in the next several years.

“We need to plan that this is something we may need to maintain control over chronically. It may be something that becomes endemic, that we have to just be careful about,” he said at a webinar hosted by think tank Chatham House in November.

Which is why we need to discuss what an endemic disease is and how the novel coronavirus causing the respiratory illness COVID-19 will become an endemic.

Experts say there are multiple endemic diseases in the United States that could foreshadow what the disease caused by the coronavirus may look like in the upcoming years.

So what is an endemic disease?

According to the CDC, an endemic disease is the constant presence and /or usual prevalence of a disease within a population within a certain geographic area.

According to Dr. Donald Burke who is a professor of epidemiology at the University of Pittsburg Graduate School of Public Health made it known that an endemic disease spreads at a baseline level every year without causing major disruption to anyone’s life.

“Things that are endemic are present for long periods of time without interruption, continuously circulating in the population,” like the common cold, he said.

With this definition, its very possible that an endemic disease can become an outbreak or an epidemic at another country since it will cause a disruption to lives and economy in the other country/region where its not an endemic according to Dr. Pritish Tosh who is an infectious diseases physician and researcher at the Mayo Clinic.

A good example would be the case of malaria which is considered an endemic in parts of Africa due to the presence of mosquitos carrying the parasite but the illness could become an epidemic in the United States if it were not contained.

What’s the difference between an epidemic and an endemic?

The main difference between the two cases is that an epidemic disease is a sudden increase of a disease above what is normally expected among the population within a specific area according to the CDC’s definition.

One thing that is noteworthy is the fact that a disease will not just be called an epidemic because it’s caused by pathogens like viruses and bacteria. An example is diabetes and obesity which exists in a large enough proportions in the US and can both be considered as epidemics.

Another thing could be a sudden addiction to drug use such as opioids which has been labelled “opioid epidemic” on the US as a result of the sudden soar of number of addicts in relative to the general population of the giving region/country (this case, the United States.)

The part of the word “epi” means “to be upon,” Burke said, and “demic” comes from “demos,” which means “people.”

“Epidemic means something that comes out and is among the people,” he said. “Things that are epidemic are things that are unusual that are not there and then appear.”

Endemic means “something that’s within the people,” he added. Many epidemics have turned into endemics as they become more prevalent within the given area.

One thing that should also be noted is that because a disease is labelled “endemic” doesn’t mean the disease will be forever. Some endemic diseases have been eliminated in the U.S. after achieving herd immunity through vaccines and natural infection.

What are some endemic diseases?

According to Burke, the four common cold coronaviruses which are relatives of the novel coronavirus (SARS-CoV-2) which is the culprit of the current COVID-19 are considered endemic in many places across the globe including the United States.

“We don’t notice them,” he said. “They’re transmitted, they’re constant.”

Many childhood diseases also are endemic, he said. A good example of such would be measles which used to be endemic in the U.S.

“In the old days … they were commonplace. Everybody got them,” Burke said. But childhood vaccines helped impede transmission, almost eliminating the measles from the U.S.

But even with modern medicine, measles is still considered an endemic illness in some parts of the world. Now according to the definition, when an endemic disease is then introduced to a another region, it could lead to an epidemic outbreak.

What if COVID-19 becomes an endemic

Whether the COVID-19 will be an endemic disease is open for debate but experts believes the illness is here to stay.

“It appears as though this virus is likely to remain endemic in populations at least for several years, possibly indefinitely,” Tosh said.

A January study found that the virus “could join the ranks of mild, cold-causing … human coronaviruses in the long run,” according to Emory University and Penn State University scientists.

Based on a model that was published on Science, the SARS-CoV-2 was compared to the four other common cold coronaviruses as well as the SARS and MERS viruses both of which surfaced back in 2003 and 2012 respectively.

Researchers determined from the model that if the novel coronavirus continues to circulate in the general population and most people are exposed to it from childhood, it could be added to the list of common colds.

With newer cases of mutated strains of the novel coronavirus already being reported in countries like the United Kingdom and South Africa, health experts are also realizing these highly transmissible variants are more resistant to vaccines with Tosh saying there could be more variants as vaccines forces the novel coronavirus to mutate.

“It will be difficult to project what this will look like five years from now,” he said. “But I think we can anticipate some kind of COVID endemicity over the next several years.”

This article originally appeared on USA TODAY: COVID-19 likely to become endemic, experts say. Here’s what it means.