Bloodsucking Hookworm Parasites Crawl Into Victims Through the Feet, Scientists Discover

Scientists have decoded the DNA of a parasite that affects an estimated 700 million impoverished people across the globe.

The parasitic Necator Americanus hookworm causes infections among poor populations in Africa, Asia and South America.

Feeding on the blood of victims, the nematode lives in the small intestine, causing intestinal inflammation and iron/protein-deficiency anaemia.

Larval invasion of the skin can also cause localised itching, particularly in the hands and feet. In children, the worms can cause stunted growth and learning difficulties.

Researchers at the Washington University School of Medicine in St Louis have decoded the hookworm's genome and have uncovered clues as to how it infects and survives in humans, as well as developing new therapies and treatments to cure the disease.

Their findings were published in Nature Genetics.

Less than a sixth of hookworm infections are fatal although the aneamia can be dangerous for pregnant women. In some cases, it can lead to maternal deaths and low birth weights in newborn children, which can contribute to death.

Makedonka Mitreva, assistant professor of medicine and genetics and the author of the study, said: "We now have a more complete picture of just how this worm invades the body, begins feeding on the blood and successfully evades the host immune defences.

"This information will accelerate development of new diagnostic tools and vaccines against the infection."

She added that the medicine currently used to combat the disease was failing in some countries, as excessive use leads to drug resistance.

Albendazole, a deworming drug, is used as mass treatment programs in areas with endemic infection.

The new research into the parasite and infection has allowed researchers to discover molecules in the worm that can be attacked with alternative drug treatments.

Mitreva added: "We also prioritised those drug targets so that scientists can quickly follow up on the ones that appear to be most promising."

Necator Americanus are most common in areas of extreme poverty where there is no indoor plumbing. The worm's eggs are excreted by infected individuals and contaminate the soil.

The eggs hatch and the larvae enter the body of a victim through their feet. They travel up the bloodstream to the lungs, where they are coughed up and swallowed into the small intestine.

Mitreva added that the research could help cure other autoimmune conditions. In the US, hookworms have gained attention for their potential in immunotherapy. They have been studied in their treatment of inflammatory bowel disease, asthma, allergies and multiple sclerosis.

She said: "It is our hope that the new research can be used as a springboard not just to control hookworm infections but to identify anti-inflammatory molecules that have the potential to advance new therapies for autoimmune and allergic diseases."