THE scourge of hookworm, a parasite which ravages communities in many tropical regions including northern Australia, could be eliminated following the results of recent research into treatment against the worm.

Scientists from Murdoch University’s Division of Veterinary & Biomedical Sciences, working with the WA Health Department, Fremantle Hospital and an isolated community, have shown for the first time that the grip of these parasites can be broken, and drug resistance prevented by a carefully administered and monitored treatment regime.

The researchers undertook a sustained control programme in the community of 300 people in the remote Kimberley region of Western Australia. Over the seven-year study, the presence of hookworm fell from 76% in 1994 to just 2% in 1999.

Murdoch parasitologist Andrew Thompson said the research gave new hope for Aboriginal communities which had been widely debilitated by the parasite.

“Enteric parasites such as hookworm are important causes of illness in Aboriginal communities in northern Australia,” Professor Thompson said.

“Their most insidious effect is on children and women, contributing to chronic anaemia, poor weight gain and failure to thrive. It results in a lack of energy for learning and working.

“The adult worm causes bleeding in the gut of infected people, all day and every day.”

Murdoch Associate Professor of Pharmacology and Chemotherapy Jim Reynoldson, was responsible for an initial mass treatment of the whole community with the new drug albendazole. He said because hookworm was so insidious, community members often did not notice how poor a person’s performance was at school or work.

“Teachers in the pilot community have noted how much more wide-awake their pupils were after the successful dosing regime for hook worm,” Prof Reynoldson said

Dr Stuart Garrow, who heads the Health Department’s Kimberley Public Health Unit, said because the whole community had been treated and the process closely monitored there had been no opportunity for resistance to the new drug to develop in the parasite.

“The parasite load was reduced, with fewer eggs in the soil and a greatly reduced chance of re-infection,” Dr Garrow said.

“This success could not have been achieved without the keen cooperation of the community, which negotiated and signed an agreement to ensure the control programme was successful.

“The worm doesn’t do well when the cycles is broken and the important factor was that the proper drug regime was followed, allowing no opportunity for the parasites to build-up resistance.”

The hookworm’s life cycle means that eggs pass through the digestive system into the soil where they can live for some time. When conditions are ripe, they evolve to larvae, penetrate through bare feet and travel through the lymph system to the lungs, where they are often coughed up and then swallowed.

Previous attempts to control hookworm in this community, including environmental and health education strategies, were hampered by the parasite’s resistance to the widely-used treatment drug pyrantel. In 1994, the whole community was treated with albendazole, and since 1996, this drug has been administered at a single dose of 400mg to all children over one year of age every six months and all adults annually, resulting in the reduction of hookworm from 76% to 2%.

This control programme was the first study in Australia to document the effectiveness of community-based albendazole anti-parasite treatments linked to other community, eco-system orientated initiatives.

Work is continuing to extend this control programme to other communities in tropical Australia and the team is investigating how to achieve the World Health Organisation’s goal of an effective, population-wide drug treatment strategy to delay the emergence of drug resistance, while the benefits of drug treatment continue.