To the Editor: The recent editorial by McCarthy and Garrow1 eloquently articulates a case for a coordinated national approach to controlling parasite infections in Aboriginal populations, based predominantly on the authors' experience with chemotherapeutic intervention in one remote community in Western Australia.

While sympathetic to their motives, I am not so optimistic about the outcome of their proposal. For 20 years, Queensland maintained a centrally coordinated Aboriginal health program designed to monitor and eradicate parasitic infections. The program, which used targeted chemotherapy as its core strategy, was very successful with regard to intestinal worms, suppressing trichuriasis almost to extinction (unpublished observation) and virtually eradicating hookworm.2 However, the prevalence of gut protozoan infections (such as giardiasis and cryptosporidiosis) was hardly affected, for the obvious reason that these are relatively short-lived and spread directly person-to-person, which means that personal hygiene is much more crucial to their control. Systematic surveillance ceased after the program was dismantled (for political reasons) in 1990, and anecdotal reports since indicate that hookworm is now returning to Queensland. Again, this is not surprising given the mobility of Indigenous people, and the ability of infective larvae of Ancylostoma duodenale, the local hookworm species, to persist in a dormant state in host tissues, where they are refractory to currently available treatment.3

In support of their case, McCarthy and Garrow presented lymphatic filariasis in Australia as but one successful precedent, implying that it was eradicated "through sustained control programs conducted by dedicated public health agencies . . . using effective drugs".1 This is not supported by historical facts; the disease did disappear from endemic areas, but well before effective chemotherapy became available, and for reasons that are still debatable4 (although mosquito suppression, resulting more from general improvements in living conditions with rising community affluence than from any coordinated activity, is the most likely explanation).

At the community level, parasitic infections of the gut represent not so much a primary problem as a symptom of a more fundamental societal malaise. They will disappear from Aboriginal communities only with a sustained improvement in living conditions (including nutrition, sanitation and personal hygiene), driven by the people themselves when armed with effective public health knowledge. This is a challenge that continues to dwarf the capabilities of all our governments and politicians, at all levels.

In reply: While specific details of control strategies for intestinal parasites vary according to parasite species, available anthelmintic agents and tools for environmental intervention, it is widely accepted that sustained, coordinated programs supported by government, community and health professionals with agreed methods and targets are the key to success.1 Prociv describes the outcome of just such a program for hookworm in Queensland, and the subsequent recrudescence of infection once the program was scrapped.

The program in northern Western Australia succeeded because of commitment by government, community involvement entailing community debate and ownership of the program,2 education, and behavioural change, and improvement in public sanitation facilities as well as chemotherapy.3 We believe that a critical determinant of the outcome of our program was the inclusion of the community in designing the program.

We agree with Prociv that control of filariasis and malaria was achieved in Australia by mosquito control; our statement about the role of sustained public health programs refers to the control of leprosy.4 With respect to the prospects for control of intestinal protozoa as well as helminths, a single-dose regimen with broad-spectrum activity would be ideal. While albendazole shows some useful clinical activity in giardiasis, single-dose regimens of this drug are insufficient to effect cure, as was observed in our study.

While the social and environmental hurdles may appear to "dwarf the capabilities of government", we believe that there is a continuing need for Aboriginal health organisations, health professions and health departments at state and national levels to tackle parasitic infections. The logical approach is to model wider programs on successful local programs, and to avoid drifting into policy and program nihilism.