Children playing feet away from open pools of raw sewage; drinking water pumped beside cracked pipes of untreated waste; human faeces flushed back into kitchen sinks and bathtubs whenever the rains come; people testing positive for hookworm, an intestinal parasite that thrives on extreme poverty.

These are the findings of a new study into endemic tropical diseases, not in places usually associated with them in the developing world of sub-Saharan Africa and Asia, but in a corner of the richest nation on earth: Alabama.

Scientists in Houston, Texas, have lifted the lid on one of America’s darkest and deepest secrets: that hidden beneath fabulous wealth, the US tolerates poverty-related illness at levels comparable to the world’s poorest countries. More than one in three people sampled in a poor area of Alabama tested positive for traces of hookworm, a gastrointestinal parasite that was thought to have been eradicated from the US decades ago.

The long-awaited findings, revealed by the Guardian for the first time, are a wake-up call for the world’s only superpower as it grapples with growing inequality. Donald Trump has promised to “Make America Great Again” and tackle the nation’s crumbling infrastructure, but he has said very little about enduring chronic poverty, particularly in the southern states.

The study, the first of its kind in modern times, was carried out by the National School of Tropical Medicine at Baylor College of Medicine in conjunction with Alabama Center for Rural Enterprise (ACRE), a non-profit group seeking to address the root causes of poverty. In a survey of people living in Lowndes County, an area with a long history of racial discrimination and inequality, it found that 34% tested positive for genetic traces of Necator americanus.

The parasite, better known as hookworm, enters the body through the skin, usually through the soles of bare feet, and travels around the body until it attaches itself to the small intestine where it proceeds to suck the blood of its host. Over months or years it causes iron deficiency and anemia, weight loss, tiredness and impaired mental function, especially in children, helping to trap them into the poverty in which the disease flourishes.

Hookworm was rampant in the deep south of the US in the earlier 20th century, sapping the energy and educational achievements of both white and black kids and helping to create the stereotype of the lazy and lethargic southern redneck. As public health improved, most experts assumed it had disappeared altogether by the 1980s.

Read more: Hookworm, a disease of extreme poverty, is thriving in the US south. Why? | US news | The Guardian