Parasitic nematodes (commonly known as roundworms) are a large, diverse and poorly studied group of disease-causing organisms that severely impact the health of humans and animals.

They infect almost a quarter of the global population and significantly impair child growth and development.

Diagnosing these parasites is challenging as many species look identical, meaning common identification techniques typically miss species.

A new publication in The Lancet Microbe by researchers from the University of Melbourne and the University of New South Wales details the development of a novel diagnostic test capable of detecting the entire parasitic nematode community from stool samples of humans and animals.

The authors have leveraged novel sequencing technology to develop this breakthrough test which will enhance our understanding of parasite diversity and improve ways through which parasitic worms can be controlled.

Parasitic nematodes which include different forms of roundworms, like hookworms, threadworms and whipworms infect approximately 1.5 billion people and have a disproportionately negative impact on children and women of childbearing age, particularly in low-to-middle income nations.

The high prevalence of these worms not only causes a significant disease burden on affected populations in the form of impaired growth and development, but also necessitates costly mass drug administration programs.

"These worms cause some of the most common Neglected Tropical Diseases which are a group of diseases that thrives in areas with limited access to clean water, sanitation, and healthcare but are preventable and treatable.

Recent investigations into human-infecting worms have revealed that their diversity is higher than previously thought, meaning that a test able to correctly detect and identify these nematodes is urgently needed to correctly address the diseases they cause." said Dr Vito Colella.

Animal health also suffers from these parasites which can cause weight loss, decreased fertility and even mortality.

This has a pronounced effect on the livestock industry, reducing the quality of animal products, leading to dramatic economic losses. For example, in Australia alone, one species of nematode, the Barber’s pole worm, causes over $436 million in losses to our sheep industry annually.

Our beloved pets may also suffer as cats and dogs infected with parasitic worms may become anaemic, lose weight and even die.

Importantly, some of these worms are transmitted from animals to humans (i.e. they are zoonotic), meaning that a test able to correctly identify these parasites can improve control outcomes.

Conventional methods for diagnosing these parasites typically rely on microscopy to detect eggs or larvae in faeces, however they have poor sensitivity, and many species look identical. Being able to tell different parasitic worms apart is crucial as different species’ effects on host health can vary dramatically.

More advanced molecular methods such as Polymerase Chain Reaction (PCR, which detects the presence of worm DNA) can be effective for identifying parasitic nematode infections. However, these approaches can only identify a few species at once and they struggle to detect rare, unusual or new species, which are common in Neglected Tropical Disease-endemic areas.