Fight against parasite getting advanced

An Australian researcher is hoping his work sequencing the genome of a giant parasitic worm will lead to a more effective treatment for a condition that affects more than one billion people worldwide.

The worm hinders the development of children and kills tens of thousands of people, mainly in South East Asia, South America and parts of Africa.

Here's Simon Lauder.

SIMON LAUDER: For the past year and a half University of Melbourne parasitologist Dr Aaron Jex has been taking a very close look at one of the world's most troublesome parasites.

AARON JEX: It's a very big, big worm. It's about 30cm. I mean there are some people that would say nematodes are pretty, quite attractive. But you know I guess to each their own.

SIMON LAUDER: Dr Jex says the giant intestinal roundworm infects about a billion people and its impact can be compared with malaria and tuberculosis.

AARON JEX: The most significant effects tend to be in children where you can get chronic, from the affects of the parasite which is mainly malnutrition you can get chronic disease, effects on their physical and cognitive development. And that can last them through the rest of their life.

SIMON LAUDER: So really they're literally stunted by this parasite.

AARON JEX: Yeah absolutely, yep. The challenge with the parasite is that it tends to affect people in very impoverished communities. And so the amount of information that's available for those people is limited.

But tens of thousands or more would die from this parasite annually, yeah.

SIMON LAUDER: Can you explain how it's comparable with tuberculosis and malaria?

AARON JEX: Mainly in prevalence. In really heavily affected regions, in heavily endemic regions it might be up to 90 or in excess of 90 per cent of the population would have the parasite.

The effect in terms of overall comparison to malaria, tuberculosis, is the overall effect on quality of life because it affects so many individuals. And because that effect can start from childhood and last for the rest of their life the sum effect is quite substantial.

SIMON LAUDER: There are already treatments for the condition known as ascariasis but none that are lasting.

AARON JEX: You can treat someone for ascariasis and then because the environment is still contaminated they can become infected again. And so especially in young children you have to re-treat constantly for most of their school age.

But the challenge with that is if you are constantly re-treating you're breeding resistance to the drug and there will emerge populations of parasites that will not be affected by this drug.

And that's a problem because there are a limited number of drugs available and there are a limited number of new drugs.

SIMON LAUDER: Dr Jex is a part of a large international team of scientists who have just finished mapping the genome of Ascaris Suum which is very closely related to the one that infects humans but easier to study.

SIMON LAUDER: He says it will help find new treatments for ascariasis which has been identified by the World Health Organization as a key neglected disease.

AARON JEX: This has revealed a lot of new information about how the parasite interacts with the human host. And the hope is that by doing that we'll be on an avenue towards being able to develop vaccines against these parasites. But it's a very difficult feat.

But obviously when you think of a parasite that causes disease in roughly one in six on the planet and hugely affects children, particularly children between the ages of one to five, to be able to even in a small sense be able to develop a new drug that can replace the existing drugs if and when resistance emerges will be a massive thing.