This Flesh-Eating Parasite Wears Human Cells as a Disguise—And Scientists May Finally Know How to Stop It

Some of the deadliest threats to human life don’t come in the form of wars or natural disasters—they come from parasites, invisible to the naked eye, yet devastating in impact.

One such organism, Entamoeba histolytica, has long puzzled and horrified microbiologists with its ability to destroy human tissue and outmaneuver the immune system. But after nearly two decades of investigation, scientists may finally have a strategy to stop it.

A Parasite That Dissolves Its Victims

E. histolytica infects around 50 million people annually, typically through contaminated water or food in regions with poor sanitation.

Most experience mild gastrointestinal symptoms, but for up to 100,000 people each year, the infection becomes fatal. The amoeba starts in the colon, then eats through tissue to reach the liver, lungs, and even the brain.

It can kill anything you throw at it, any kind of human cell.”
— Katherine Ralston, microbiologist at UC Davis

Ralston, the study’s lead author, has studied E. histolytica since 2011. Her earlier research helped uncover a gruesome process called trogocytosis, where the amoeba bites off pieces of living cells, causing them to leak and die.

But the real breakthrough came when she and her team discovered how the parasite escapes immune detection.

A Killer in Disguise

You could see little parts of the human cell being broken off.”
— Ralston, describing early observations of the parasite

In 2022, Ralston’s lab found that E. histolytica cloaks itself using the remains of its victims. It steals key surface proteins from human cells and wears them like armor. This disguises the parasite from complement proteins—vital immune defenders that normally tag intruders for destruction.

This discovery revealed the parasite’s macabre stealth mechanism, but there was a new obstacle: E. histolytica is genetically complex, with a genome vastly larger than many viruses and bacteria. It wasn’t until 2021 that researchers developed an RNA interference (RNAi) library to systematically test all 8,734 of its genes.

The Genetic Battle Plan

We now see a light at the end of the tunnel, and we think this could be achievable.”
— Wesley Huang, co-author of the study

Now, in a new study published in Trends in Parasitology and reported by Popular Science, the team outlines its most advanced strategy yet.

By combining RNAi with CRISPR, they aim to tag amoeba proteins with fluorescent markers, track their function, and disable key genes to disrupt its disguises and reproduction. This could pave the way for vaccines or drugs that finally neutralize one of the deadliest parasites on Earth.

Science is a process of building. You have to build one tool upon another, until you’re finally ready to discover new treatments.”
— Ralston

The tools are finally here. Now, the race to stop E. histolytica may be winnable.