Leprosy, malaria, COVID: What is an endemic? What is an epidemic? What you need to know

According to the Centers for Disease Control, there's another thing to worry about when visiting Florida: Leprosy.

In a recent research letter published on the CDC website, the authors say there is "rising evidence that leprosy has become endemic in the southeastern United States" in the last decade, especially in central Florida, where leprosy cases accounted for nearly 20% of all the new cases in the country in 2020.

Meanwhile, we're coming off the COVID-19 pandemic, a monkeypox epidemic and what is malaria right now, anyway? What is the difference between endemic, epidemic and pandemic?

What is an endemic?

When a disease outbreak is consistently present but limited to a specific region, it's called endemic, according to the CDC. The disease spread and the number of cases is predictable.

Cases of the flu are endemic, for example. We're always going to have some level of flu and we've adjusted to dealing with it.

If there is an outburst in cases of a disease, it might become an epidemic.

What is an epidemic?

When cases of a disease are rising over what is normally expected in that area, especially if it's a sudden change, it's called an epidemic. Major epidemics have included yellow fever, smallpox, measles, and polio but the term covers any unexpected increase in disease.

The term epidemic is also used to describe other rising health hazards, such as diabetes and obesity. In the media and popular culture, it can mean a rapid spread of any undesirable condition, such as an addiction to opioids, gun violence, or loneliness.

A disease may be endemic to some regions and an epidemic in others. Mpox, formerly known as monkeypox, was considered endemic for years in Central and West Africa, but a global outbreak started in May 2022. As of May 10, more than 30,000 cases had been reported in the United States. Cases peaked in August of that year and have been down since but outbursts are still possible.

Epidemics also can be seasonal. West Nile virus, a mosquito-borne virus that causes mild to severe illness, is endemic to the U.S. (meaning it's not uncommon, it's been regularly reported in nearly all the states) but there are annual epidemics in some parts of the country in the late summer months.

What is a pandemic?

When you get an epidemic that is spreading over several countries or continents and affecting a lot of people, it's called a "pandemic."

COVID-19 started as an epidemic in Wuhan, China in December 2019. By March 11, 2020, after more than 118,000 cases in 114 countries and 4,291 deaths, the World Health Organization declared it to be a pandemic.

COVID went on to infect almost 700 million people worldwide, causing just under 7 million deaths as of July 31, according to Worldometer. As of July 20, state records show that 7,646,882 Floridians have been infected with COVID and 89,330 have died. But thanks to the availability of effective vaccines, the rate of infection and death has slowed dramatically in the last year.

There isn't a set number of cases or deaths that make an epidemic into a pandemic. The designation is based on how rapidly and widespread a disease spread is, and how uncontrollable it appears to be.

Is the COVID pandemic over? Is COVID endemic now?

In September 2022, President Joe Biden made the seemingly offhand comment in a "60 Minutes" interview that while we still had a problem with COVID, the pandemic was "over." That was a little premature. At the time, nearly 3,000 Americans were dying every week and the World Health Organization (WHO) still called it "an acute global emergency."

COVID continues to affect and kill people around the world, but most of the U.S. population has some immunity against the coronavirus from vaccines, boosters and previous infections. But some level of COVID will be here to stay and new mutations may drive up more outbursts and more epidemics.

“We’re in the middle,” said Dr. Jessica Justman, associate professor of medicine in epidemiology and senior technical director of ICAP at Columbia University’s Mailman School of Public Health. “I hope that we are moving towards endemic, but I can’t say that we’re endemic because I don’t feel like things are predictable, yet.”

In May, the Biden administration ended the extended COVID national emergency and the public health emergency. The World Health Organization Emergency Committee on COVID-19 recommended that since the disease was now well-established and ongoing, it no longer fit the definition of a Public Health Emergency of International Concern (PHEIC).

"This does not mean the pandemic itself is over," the WHO website said, "but the global emergency it has caused is, for now."

Is leprosy endemic in Florida?

Leprosy, the common term for Hansen's disease, is on the rise and Central Florida is seeing a lot of new cases.

Leprosy is a disease that primarily infects the skin and nerves in the skin, though it can sometimes infect other parts of the body like the lining in the airway passages of the nose, according to the Florida Department of Health. It has been around for thousands of years, with the earliest known records appearing in China and India around 600 B.C. The disease is not easily spread, easy to treat, and about 95% of people have natural protective immunity, according to the FDOH. But going without treatment can result in permanent nerve damage.

According to a report from dermatologists Aashni Bhukhan, DO, Charles Dunn, MD, and Rajiv Nathoo, MD, the number of reported leprosy cases across the country has doubled over the past decade with 159 new cases reported in the U.S. in 2020.

Nearly 70% of these new cases were reported in Florida, California, Louisiana, Hawaii, New York and Texas, and Central Florida alone accounted for nearly 20% of the total new cases in the U.S., according to data from the National Hansen’s Disease Program.

In the research letter, the authors point out that previous leprosy cases resulted from people traveling from areas outside the country where leprosy is endemic, but the Central Florida cases seem to have been locally acquired.

"Those trends, in addition to decreasing diagnoses in foreign-born persons, contribute to rising evidence that leprosy has become endemic in the southeastern United States," the authors wrote. "Travel to Florida should be considered when conducting leprosy contact tracing in any state."

Is malaria an epidemic in Florida?

Not yet. There have been at least eight cases of locally acquired malaria reported in the U.S. in the last two months, seven of them in Sarasota County (the other was in Cameron County, Texas). This is the first time the disease has had a local spread in 20 years.

Malaria is a serious and sometimes life-threatening disease caused by the bite of a female mosquito from the genus Anopheles. It is usually acquired when visiting an area where malaria is endemic, such as tropical Africa, and can cause fever, chills, headaches, muscle aches and fatigue. Untreated, malaria can lead to impaired consciousness, difficulty breathing, convulsions, abnormal bleeding and more, which can ultimately lead to death.

But so far it's a public health concern over an outbreak, not an epidemic.

The CDC issued a public health alert in June advising doctors, public health authorities and the public about the risk and what to look for. "Despite these cases," the letter said, "the risk of locally acquired malaria remains extremely low in the United States."

This article originally appeared on The Daytona Beach News-Journal: Florida leprosy cases could make it endemic disease; what that means