It affects 740 million people a year. It causes brain disorders, cretinism, miscarriages and goiter. It is the world's single most important and preventable cause of mental retardation. And it is almost unknown. Equally unknown is the success in eradicating it. Calling it "one of our best kept secrets" the World Health Organization has rededicated itself to eliminating Iodine Deficiency Disorder, or IDD, through an intense programme of salt iodisation and iodine delivery within the next decade.

At the World Health Assembly in Geneva, Dr. Gro Harlem Brundtland, the Director- General of the WHO, today outlined a series of measures designed to eradicate IDD within the next decade. She told the Assembly "Iodine Deficiency Disorders constitute the single greatest cause of preventable brain damage in the foetus and infant, and retarded psychomotor development in young children. When elimination of IDD is achieved it will be a major and total public health triumph, ranking with small pox and poliomyelitis."

The World Health Assembly included a call for the Director-General to "mobilize, and collaborate with, international and bilateral development agencies, nongovernmental organizations, and the private sector in support of the efficient and effective iodization of salt by both large- and small-scale salt producers."

It also recommended that WHO "provide technical support to Member States to establish and strengthen systems for monitoring the iodine status of their populations and the quality of iodized salt, to identify the required financial and technical resources for this purpose, and to support Member States in developing links with the salt industry. According to the resolution, the Director-General "is to report to the Health Assembly by 2005 on progress achieved in eliminating iodine deficiency disorders".

IDD: the impact

Iodine deficiency Disorder (IDD) is a significant public health problem in 130 countries, affecting a total of 740 million people. While remarkable measurable progress is being made through universal salt iodization, there are nearly 50 million people who are estimated to still be affected by some degrees of IDD-related brain damage.

One-third of the world's population is estimated to be at risk of IDD. Since the passage of a special resolution at the World Health Assembly in 1990 and subsequent resolutions in 1992 and 1996, the Department of Nutrition for Health and Development (NHD) of WHO has worked tirelessly to establish iodisation programmes around the world.

Over the last decade, extraordinary progress has been achieved by increasing the number of people with access to iodized salt. From 1990 to 1998, the number of countries with salt iodization programmes increased from 46 to 93. Two-thirds of households living in IDD-affected countries now have access to iodized salt. Twenty countries have 90% of their households with access to iodized salt.

The Director of the NHD Department, Dr. Graeme Clugston, points out that " The tragedy is that such a huge global burden of brain damage is still occurring, much of it irreversible, yet less than a single teaspoon of iodine is all a person requires during an entire a lifetime, and the cost amounts to only about 5 cents US per person and per year".

Under the direction of Dr Gro Harlem Brundtland, WHO plans to eradicate IDD within the next decade. In order to achieve that goal, WHO will:

Firstly, reinforce its role, effectiveness and visibility in technical expertise and catalytic financial support to a select number of countries, particularly in Africa and Asia, where national iodised salt programmes have not yet been established, or progress is lagging.

Second, WHO will support countries to ensure that salt is iodized to the correct levels, and it will continue to disseminate its technical findings concerning appropriate indicators for monitoring and evaluating programmes for IDD control.

Third, WHO will reinforce its partnership with the salt industry, whose role is crucial in winning the battle against IDD. It will also continue to collaborate with UNICEF and the International Council for Control of Iodine Deficiency Disorders, two major WHO's international partners in this area.

Mrs Poonam Singh, Executive Director, Sustainable Development and Healthy Environments, points out that the battle against IDD can never cease: "Unlike immunization campaigns, even when IDD is eradicated we must continue to sustain this programme or we will lose ground. Even now we are seeing some countries lagging behind in their iodization efforts. We must instead encourage them to redouble their efforts and assist them to remain vigilent."