Iodine status five years after the mandatory salt iodization legislation indicates above requirement: a cross sectional study in Northwest Ethiopia

The advancement of Ethiopia's salt iodization programme-The success story of the central iodized facilities

The objective of this article is to characterize the value of centralized iodization facilities (CIFs) to advance Ethiopia's salt iodization programme and its impact on the population iodine status. The analysis is based on a review of publications relating to salt iodization and iodine deficiency control efforts in Ethiopia. The country has made remarkable progress in improving iodized salt coverage, leading to improved iodine intake across its population that would otherwise be at high risk of iodine deficiency disorders. Establishment of central processing facilities, more frequent monitoring and generation of data and encouraging private sector investment have been instrumental in this achievement. Ethiopia has thus achieved and sustained greater than 89% HH iodized salt coverage from its lowest point of 15% coverage and subsequently improved iodine intake across its population. Iodine intake sufficiency in a population is assessed by median urinary iodine concentration (MUIC). The lessons learned and the experience with CIFs have applicability in several other countries where fragmented salt production continues to create barriers to achieve higher iodized salt coverage.

Prevalence of iodine deficiency and associated factors among school-age children in Ethiopia: a systematic review and meta-analysis

BACKGROUND

Currently, iodine deficiency has become a significant burden globally; where 2 billion people and 29.8% of school-age children are iodine deficient. It is a leading cause of preventable brain damage among children, resulting in impaired cognitive and motor development. Even though salt iodization was started to be implemented to alleviate this burden in Ethiopia, primary studies assessing iodine deficiency in the country show highly variable findings, and no systematic review was conducted to determine the pooled prevalence of the problem which makes it difficult to assess the effect of the intervention as well as to design appropriate and timely measures. Therefore, this systematic review and meta-analysis aimed to determine the pooled prevalence of iodine deficiency and the common factors affecting its occurrence among school-age children in Ethiopia.

METHOD

To obtain the eligible studies, databases (EMBASE, Scopus, Hinari, and PubMed), websites (Google and Google Scholar), and references of the eligible studies were searched systematically. Data were extracted using an Excel spreadsheet and analyzed using the STATA 17 version. The I2 test was used to assess heterogeneity between the studies. A DerSimonian and Laird random-effects model was used to estimate the pooled prevalence and pooled odds ratio. A funnel plot and Egger's test were used to detect publication bias.

RESULT

A total of 15 eligible studies, representing 15,611 school-age children, were included in the systematic review and meta-analysis. The pooled prevalence of iodine deficiency among school-age children in Ethiopia was found to be 58% (95%CI 44.00-77.00), while the highest prevalence was recorded in the Oromia Region, which was 64% (95% CI 49-79). Goitrogenic food consumption (adjusted odds ratio (AOR) 2.93, 95% CI 1.60-5.35) and being female (adjusted odds ratio (AOR) 1.87, 95% CI 1.43-2.44) showed a significant association with the prevalence of iodine deficiency.

CONCLUSION

Iodine deficiency among school-age children in Ethiopia was noticeably high. Goitrogenic food consumption and the sex of the child were determinant factors for the occurrence of iodine deficiency among the children. Therefore, appropriate advice should be given to households to limit goitrogenic foods in the diet of their children by giving due attention to their female children.

Mandatory Versus Voluntary Implementation of Salt Iodization Program for the Last Two Decades in Ethiopia: A Comparative Review of Existing Literatures

BACKGROUND

Ethiopian government was implementing mandatory salt iodization program for the last decade to eliminate iodine deficiency disorders, but several recent studies reported mixed findings.

OBJECTIVE

This review aimed to assess the difference in implementation of iodized salt program 10 years before and after mandatory salt iodization being implemented in Ethiopia since 2011.

METHODS

In Ethiopia, legislation that enforces salt producers to iodize all salts used for human consumption started in February 2011. All studies about iodine deficiency and iodized salt conducted in Ethiopia in the last 2 decades were searched. Searches were performed in PubMed database. Google Scholar, Iodine Global Network, and Ethiopian Public Health Institute websites were also searched.

RESULTS

A total of 235 titles and abstracts were identified. After scanning the abstracts and full papers, 43 articles were remained for final data synthesis. In this review, all studies conducted before 2011 reported a urinary iodine concentration (UIC) value of < 100 μg/L and 66.7% of them reported a goiter prevalence of > 30%. On the other hand, among studies conducted after 2011, 88.9% reported UIC value < 100 μg/L and 73.7% reported goiter prevalence of > 30%. Household availability of adequately iodized salt increased from nearly 20% in pre 2011 to more than 50% in post 2011 period.

CONCLUSION

Despite the efforts made by the Ethiopian government on mandatory salt iodization for the last decade, iodine deficiency is sustained in the country. Moreover, the goal of universal salt iodization program is offtrack and needs urgent revision.

REGISTRATION

Registered on PROSPERO register with reg. no CRD42021251124.

Association of Salt Iodization and Urine Iodine Concentration in Schoolchildren from Public Schools in Northeast of Brazil

Iodine deficiency (ID) is recognized as a leading risk factor for child development. Universal salt iodization (USI) is an effective and well-established intervention strategy for the prevention of iodine deficiency disorders (IDD). To evaluate the levels of iodine in household salt samples and the urinary iodine concentration (UIC) in schoolchildren aged 6 to 14 years in public schools in Bahia, Brazil. A cross-sectional study was conducted with 1231 students (6 to 14 years old) from 17 public schools in Bahia. The iodine concentration was evaluated in salt and UIC samples. The adapted Sandell-Kolthoff reaction was used to determine urinary iodine levels. A spectrophotometer (UV-Vis) was used to examine the reduction of ceric ammonium sulfate. A standard iodine solution using a potassium iodate was used to extrapolate the iodine concentrations. The total of 665 salt samples had a median iodine concentration of 24 mg/kg (25th-75th percentile 17.0 to 28.5 mg/kg). The largest proportion (79.6%) of salt samples had iodine concentration in the recommended range, 17.6% of the samples presented iodine at a salt concentration below the established level (<15 mg/kg) and a small proportion was above it (2.8%). The general mean urinary iodine concentration (MUIC) was 217.53 ± 28.30 μg/L and median was 205.50 μg/L. The students evaluated and the salt samples analyzed showed satisfactory results, as recommended by Brazilian legislation and nutritional recommendations of the World Health Organization (WHO).

Iodine status five years after the adjustment of universal salt iodization: a cross-sectional study in Fujian Province, China

Background

Universal salt iodization program was introduced to China to eliminate iodine deficiency disorders in 1995. In 2012, Fujian Province decreased the concentration of iodized table salt according to the national unified requirement. This study aimed to assess the effect on iodine status after the adjustment, providing evidence for further adjustment in Fujian Province.

Methods

Sampling units were selected by multistage cluster sampling method. In each sampling unit, table salt was collected from 30 households. A total of 2,471 people in 2009 and 4,806 people in 2017 provided urine samples and were included in this cross-sectional analysis. Median iodized salt concentration and median urine iodine concentration were present by median and interquartile range.

Results

Median iodized salt decreased from 29.8 mg/kg in 2009 to 23.9 mg/kg in 2017. The median urinary iodine concentrations for school-age children in 2017 in coastal urban area, non-coastal urban area, coastal rural area and non-coastal rural area were 163.6µg/L (interquartile range = 100.1–252.0µg/L), 198.9µg/L (interquartile range = 128.0-294.0µg/L), 181.8µg/L (interquartile range = 114.1–257.0µg/L) and 218.2µg/L (interquartile range = 148.1-306.5µg/L), respectively. The median urinary iodine concentrations for adults in 2017 in these areas were 151.1µg/L (interquartile range = 98.3-231.7µg/L), 168.7µg/L (interquartile range = 109.6–242.0µg/L), 167.7µg/L (interquartile range = 105.7-245.7µg/L) and 182.7µg/L (interquartile range = 117.1-258.9µg/L). The median urinary iodine concentrations for pregnant women in 2017 in these areas were 157.7µg/L (interquartile range = 106.9-223.8µg/L), 141.5µg/L (interquartile range = 97.7-207.6µg/L), 127.3µg/L (interquartile range = 90.0-184.5µg/L) and 144.8µg/L (interquartile range = 99.9-184.5µg/L). The median urinary iodine concentrations for lactating women in 2017 in these areas were 122.7µg/L (interquartile range = 84.1–172.0µg/L), 123.7µg/L (interquartile range = 70.7-184.7µg/L), 105.8µg/L (interquartile range = 67.1-152.3µg/L) and 110.2µg/L (interquartile range = 74.1-170.3µg/L).

Conclusions

The overall urinary iodine concentrations among school-age children, adults and lactating women dramatically decreased after implementing the new standard. Almost all of them were iodine adequate, suggesting we reached the expected aim of iodized salt adjustment. However, pregnant women were iodine insufficient after adjustment. Therefore, we should continue the surveillance of iodine status of populations and focus on the additional iodine supplement strategies for pregnant women.

Excessive intake of iodine and low prevalence of goiter in school age children five years after implementation of national salt iodization in Shebedino woreda, southern Ethiopia

Background

Iodine is a trace element required for the synthesis of thyroid hormones. The multiple effects of iodine deficiency on human health are called iodine deficiency disorders (IDDs). IDDs have been common nutritional problems in Ethiopia. In 2012, Ethiopia launched a national salt iodization program to address IDDs. The objective of this study was to assess the effects of this program after 5 years by measuring urinary iodine concentration (UIC) and prevalence of goiter in school age children as well as household salt iodine concentration (SIC).

Methods

A school-based cross-sectional design was employed. After ethical approval, 408 children from eight randomly selected primary schools provided urine samples. UIC was analyzed by inductively coupled plasma mass spectrophotometry (ICP-MS). A 10 g salt sample was collected from each household of a sampled child. SIC was analyzed with a digital electronic iodine checker (WYD, UNICEF) and goiter was assessed by palpation.

Results

The mean (±SD) age of the children was 9 ± 2 years. The prevalence of goiter was 4.2% and no child had grade 2 goiter. The median (IQR) UIC was 518 (327, 704) μg/L and UIC ranged from 3.1 to 2530 μg/L. Of the salt samples, 15.6% were not adequately iodized (< 15 ppm), 39.3% were adequately iodized (≥15 to ≤40 ppm), and 45.1% were > 40 ppm. SIC ranged from 4.2 to 195 ppm. Of the mothers, 92% said iodized salt prevents goiter and 8% mentioned prevents mental retardation.

Conclusions

In 2017 iodine deficiency was no longer a public health problem in the study area. However, the high variability in UIC and SIC and excessive iodine intake are of great concern. It is vital to ensure that salt is homogenously iodized at the production site before being distributed to consumers.