Preventing the scourge of konzo

Tackling one of tropical Africa's crippling epidemic diseases has been an interesting and demanding retirement project, as HOWARD BRADBURY AM writes.

It was when I first saw the poverty and deprivation of poor people in India in 1974 that I decided to include food chemistry as part of my research on physical and biological chemistry.

Supported by the Australian Centre for International Agricultural Research (ACIAR), the group I was in analysed the root crops of the South Pacific for their nutrients.

We confirmed that the widely-eaten plant cassava - also known as tapioca - contained a poisonous cyanide compound.

Consumption of cyanogens from a cassava meal can cause acute intoxication and, sometimes, death.

A large, non-lethal intake of cyanogens over several weeks, coupled with malnutrition, is associated with konzo, an upper motor neuron disease that causes irreversible paralysis of the legs, particularly in children and young women.

Konzo occurs in eight African countries and it is worst in the Democratic Republic of Congo (DRC), where there are an estimated 100,000 cases.

Konzo epidemics may also occur due to drought or war.

I saw a need to work on cassava cyanide diseases and, after 'retiring' from the Chemistry Department at ANU in December 1988, I moved to the Botany Department, now part of the ANU Research School of Biology, and concentrated on this new research area.

In tropical Africa in 1994, there was no simple method of measuring the cyanogen content of their staple food cassava, so we were funded by ACIAR to develop a test kit. 

As cyanide is detoxified in the body to thiocyanate, we also developed a kit to assess urinary thiocyanate.

Since 1996, these kits have been given away for free to health workers in developing countries and sold in first world countries.