In the last few years, doctors in the southern U.S. have seen some strange diseases: Chagas disease, parasitic infections of the brain known as neurocysticercosis, dengue, the virus chikungunya and more. All these illnesses fall under the moniker of "neglected tropical diseases," but the people succumbing to them aren’t travelers who picked up them up in distant countries. Instead, they're people who haven’t left their hometowns in Florida, Texas and other states in years, reports Carrie Arnold for Mosaic.

While "tropical" may need to be dropped from the name, the "neglected" label still fits. Arnold reports in detail that some of these diseases used to be part of life for the American South — the hot, humid climate keeps the insects that transmit them happy. But as the years passed and sanitation improved, these diseases faded from the public consciousness and from physicians’ radar.

Increased world travel and a changing climate are some reasons that these tropical diseases have been able to regain a foothold. But the other reasons are social and economic. Poverty disproportionately affects the American South, especially due to the ongoing consequences of centuries of slavery and systemic racism, and "neglected tropical diseases" might better be labeled "diseases of poverty" for their effect on the poor around the world.

Many such diseases have symptoms that can masquerade as other, more familiar diseases, like the flu. Chagas disease can lurk for years without showing a sign, but at the same time, the parasite chews holes in heart muscle that can lead to heart failure. And an expert tells Arnold that though cysticercosis can cause epilepsy-like seizures, it is actually caused by a parasite living in the brain.

For a more in-depth look at the causes and effects of the rise of "diseases of poverty" in the U.S., including the reason why treatments aren’t as effective as they should be, read Arnold’s story. Her take-home message: If attention isn’t paid to the diseases that have been plaguing lower-income countries for decades, more and more people will suffer.