Introduction

Iodine Deficiency is globally estimated to affect more than 1.6 billion people and 150 million are in Africa. In Tanzania the problem of iodine deficiency was reported in the early 19 century and effort to combat it started in 1950s. Due to lack expertise the efforts were not successful until 1970’s when Tanzania Food and Nutrition Centre (TFNC) was formed. Surveys to determine the prevalence of goitre  were conducted nationwide to establish the magnitude of the problem. The survey report showed that 41% of the population was at risk while 25% (equivalent to 5.6million people) were already suffering from iodine deficiency.

 

Effects of Iodine Deficiency

Iodine deficiency causes a spectrum of disorders known as Iodine Deficiency Disorders (IDD). The most common visible effect of iodine deficiency is  enlarged thyroid gland (also known as goiter). In areas where iodine deficiency is common large lump in front of the neck was assumed as fact of life to such an extent that some cultures, making virtue of necessity, took goiter to be sign of beauty and wealth. Severe effects of iodine deficiency results in a condition known as cretinism which is manifested by irreversible mental retardation. Other effects of iodine deficiency are deaf-mutism, dwarfism, coordination abnormalities and spastic paralysis of the lower limbs. Other known effects include decreased energy and learning ability and hence decreased productivity and an increased rate of spontaneous abortions, stillbirths and newborn mortality.

Interventions to control IDD

• Medical treatment: Individual approach using Lugol’s iodine.

• Supplementation: Mass intervention by use of iodized oil capsules

• Fortification: Universal salt iodization of all consumed salt by humans or animals.

• Food diversification: Increased consumption of iodine rich foods such as fish and other sea foods.

Packing of iodised salt

Efforts taken to combat iodine deficiency in Tanzania

TFNC spearheaded a number of activities aimed at controlling IDD in the country as appended below:-

• Conducted baseline surveys to establish magnitude of the ID problem in 1980 -1990
  -Population at risk (living in iodine deficient areas) were  41%
  -IDD affected population was 5.61 million (i.e., 5.0 million with goiter, 160,000 cretins, 450,000 cretinoids and estimated about 30% maternal reproductive deaths are due to iodine deficiency).

• Carried out mass interventions by:-
  -Distributing 16.1million of iodinated oil capsules to more than 6.0 million people living in 27 districts that were categorized as having visible goiter ≥ 10% or total goiter prevalence ≥30%. The intervention covered all people aged 1-45 years.
  -Creating public awareness on IDD problem, prevention and control measures.
  -Conducted operational researches on IDD

• Established process of universal salt iodation.
  - Conducted feasibility studies on  potentials of salt production and marketing in Tanzania; Salt consumption patterns in Tanzania; Inventory of small-scale salt producers and their needs; Improvement of salt iodation levels using hand spray pumps in Bagamoyo district.
  - Empowered salt producers with knowledge of: iodation chemicals, equipment, monitoring tools and skills for production of quality salt product and iodation of salt.

• Enacted salt iodation regulations since 1992. The regulations were effected in January 2006

• Established the National Council for Control of IDD (NCCIDD) as national multi-sectoral coordination body for the IDD control program in 1985.

• Established a Partnership for Prevention and Control of IDD problem. The partnership involve the following stakeholders:-

- Tanzania Food and Nutrition Centre it is body which is spearheading the implementation of IDD control program.
- Ministry of Health and Social Welfare is the Policy making body.
-  Planning Commission is the Policy making body.
- The Tanzania salt Producers Association (TASPA), formed in 1994 is still very active in solving problems related to salt production, quality, marketing and liaising with the government on issues pertained to development of salt industry.
- Program Monitoring and Regulatory bodies are Ministry of Energy and Minerals, Tanzania Food and Drug Authorities (TFDA) and Ministry of Local Governments and Regional Administration.
- Salt standards setting body is the Tanzania Bureau of Standards (TBS).
- Funding Sources: The Government of Tanzania, UNICEF, WHO, JICA, SIDA and Micronutrient Initiative (MI).

• Carried out process and impact monitoring of IDD Control program.
  - Conducted IDD programme evaluation in IDD endemic districts in 1999
  - Conducted national IDD evaluation 2004.

Current status of iodine deficiency problem in Tanzania

• Availability of iodated salt at household: increased from nearly zero in 1980s to 84% in 2004.(WHO criterion for sufficiency >90%).

• Median urinary iodine concentration UIC) is 204ug/l and only 10.5% of individuals had UIC levels below 50ug/l (WHO criterion for adequacy median UIC 100-200Ug/l with individual samples of <20% being below 50ug/l).

• Total goitre prevalence had decreased from 25% in 1980s to 7.0% (2004). In the 27 goiter endemic districts the problem had decreased from an average of 60.7% in 1980s to 12.3% in 2004 (WHO criterion for goiter prevalence not of public health significance should be <5.0%).

• Inventory report: Number of small scale salt producers is now known to be 6000 and all have been equipped with knowledge, skills and iodation facilities (e.g., hand pumps, potassium iodate and test kits)

• Following training and supplies given to small-scale salt producers; the mean and median iodine levels are currently 85.2 ppm and 36 ppm respectively (range 4.3 – 1333.4 ppm, N = 276). 65 % and 26% of salt samples analysed were under- and over- iodated.

Challenges in sustaining IDD Elimination

• Enforcement of the salt regulations is still a major problem.

• Quality of salt produced at salt producing sites especially from small-scale salt producers is not yet meeting the recommended salt standards in order to retain iodine levels after iodation process.

• Future sustainability of the supply of potassium iodate is not yet guaranteed.

• Awareness of IDD problem among the public is still very low.