Epidemiology of Iodine Deficiency Disorders in the south district of Sikkim, India

77 Pages·2014·11.58 MB·English

Epidemiology of Iodine Deficiency Disorders
in the south district of Sikkim, India
Dissertation submitted in partial fulfillment of the
award of Masters in Public Health Degree.
Bimal Kumar Rai.
Achutha Menon Centre for Health Science Studies,
Sree Chitra Tirunal Institute for Medical Sciences and
Technology, Thiruvananthapuram, Kerala
June, 2003.
" Iodine Deficiency is so easy to prevent that it is a crime to let
a single child be born mentally handicapped for that reason"
LABOUSSE (UNICEF), 1978
This work is dedicated to the victims of Iodine Deficiency.
Bimal Kumar Rai
DECLARATION
I hereby certify that the dissertation tittled "Epidemiology of
Iodine Deficiency Disorders in the south district of Sikkim, India"
is the result of original research and has not been submitted for any
degree in any other University or Institution.
(cid:9)
June, 2003. Dr. Bimal Kumar Rai.
CERTIFICATE
This is to certify that the dissertation tittled "Epidemiology of
Iodine Deficiency Disorders in the south district of Sikkim, India"
is a bonafide record of original research work undertaken by Dr.
Bimal Kumar Rai in partial fulfillment of the requirement for the
award of the Master of Public Health degree under our guidance
and supervision.
Co-Guide Guide
Dr. P. Sankara Sarma, Dr. V. Mohanan Nair,
Additional Professor, Faculty
AMCHSS, SCTIMST, AMCHSS, SCTIMST,
Thiruvanathapuram, Kerala, India. Thiruvanathapuram,
Kerala, India.
CONTENTS
CHAPTER(cid:9) PAGE
1. Introduction and Background(cid:9) 1 — 4
1.1. Problem of Iodine Deficiency Disorders(cid:9) 1
1.2. 1DDs in Sikkim(cid:9) 2
1.3. Rationale of the Study(cid:9) 3
1.4. Objective of the Study(cid:9) 4
2. Review of Literature(cid:9) 5 — 29
2.1. Iodine(cid:9) 5
2.2. Thyroid Gland(cid:9) 6
2.3. Iodine Deficiency(cid:9) 7
2.4. Iodine Deficiency Disorders (IDD)(cid:9) 8
2.5. Endemic Goitre(cid:9) 10
2.6. Endemic Cretinism(cid:9) 13
2.7. IDD and Perinatal mortality(cid:9) 14
2.8. IDD — Magnitude of problem(cid:9) 15
2.9. Assessment of Iodine status of a population(cid:9) 20
2.10. Iodine Supplementation(cid:9) 24
2.11. IDD Control measures(cid:9) 25
3. Methodology(cid:9) 30 - 38
3.1 Geographic and Demographic background of Sikkim(cid:9) 30
3.2 Study Design(cid:9) 30
3.3 Study Population(cid:9) 31
3.4 Study area(cid:9) 31
3.5 Sample Size(cid:9) 31
3.6 Duration of the Study(cid:9) 31
3.7 Sampling method(cid:9) 31
3.8 Parameters studied(cid:9) 32
3.9 Data entry and analysis(cid:9) 38
4. Results(cid:9) 39 - 47
4.1. Sample characteristics(cid:9) 39
4.2. Goitre Prevalence(cid:9) 40
4,3 Urinary Iodine Excretion (UIE)(cid:9) 43
4.4. Iodine Content of Salt at the Household Level(cid:9) 46
5. Discussions(cid:9) 48 57
5.1. Age and Sex Characteristics(cid:9) 48
5.2. Goitre Prevalence(cid:9) 48
5.3. Urinary Iodine Excretion(cid:9) 50
5.4. Iodine content of salt at the household level(cid:9) 52
5.5. Limitations(cid:9) 55
5.6. Strengths(cid:9) 55
5.7. Conclusions(cid:9) 55
5.8. Recommendations(cid:9) 56
6.References and Annexure(cid:9) 57 - 69
ACKNOWLEDGEMENT
I express my deep and sincere thanks to World Health Organization (WHO) and
Government of Sikkim for sponsoring me for Master of Public Health Course at Achutha
Menon Centre for Health Science Studies, Sree Chitra Tirunal Institute for Medical
Sciences and Technology, Thiruvananthapuram, Kerala and for providing me with
financial assistance for this study.
I extend my gratitude to Dr. T.R. Gyatso, Secretary Health and Family Welfare,
Government of Sikkim for his kind advice and permission to undertake this study in
Sikkim.
I express my thanks to Prof K. Mohandas, the Director of Sree Chitra Tirunal
Institute for Medical Sciences & Technology, Kerala for his continuous support.
I express my deep and sincere thanks to Dr. V. Mohanan Nair, my Guide and Dr.
P. Sankaran Sarma, the Co-Guide for their untiring support and valuable advice.
My thanks and gratitude goes to Prof. M.G. Karmarkar, Senior Advisor, ICCIDD,
Dr.C.S. Pandav, Additional Professor, Community Medicine, AIIMS, New Delhi and
Regional Co-ordinator of ICCIDD, South East Asian Region, Dr. R. Sankar, Country
Programme Officer, Micronutrient Initiative, New Delhi, Dr. Dinesh Moorthy and Ms.
Suraksha Sukhla of AIIMS for their technical guidance, supervision and conducting
laboratory analysis of Urinary Iodine Excretion at AIIMS, New Delhi.
I wish to express my thanks to Chief' Medical Officer, Officer In-charge of
Thyroid Centre, Namchi, all Medical Officers of PHC, MPHWs, ANMs, ICDS
Supervisors and ICDS workers who helped me during my field survey.
I am also thankful to all the faculty members of AMCHSS and my colleagues for
the necessary support and the technical inputs for this study. I extend my heartfelt thanks
to Dr. George, the Registrar and Special thanks to Mr. Sundar Jayasing, Assistant
Registrar for their continuous support. I extend my thanks to Dr. Padma Prakash,
Associate editor of Economic and Political Weekly, Mumbai for her editorial support at
the initial stage of this dissertation.
I also express my thanks to all the children and their parents for their active
participation and full co-operation in this study.
My special thanks to Mr. D.B. Chettri of Thyroid Centre, Namchi who has been
the anchorperson for the field survey and the laboratory work. His dedicated service
made this study possible and easy.
I am grateful to Mr. Jyoti Subba and Amber Gurung for their help during field
survey.
Bimal Kumar. Rai.
Epidemiology of Iodine Deficiency Disorders in the south district of Sikkim, India
Abstract
Background and Objective: Iodine Deficiency Disorders (IDD) constitutes a significant
public health problem in several parts of India. Availability of easy and cheap technology
makes it possible for early interventions if prevalence of IDDs is known. Many North-
Eastern states of India were found to be endemic for IDD. In this background this study
was conducted to assess the current status of IDD by estimating the prevalence of goitre
and urinary iodine excretion (UIE) in school age children (6to12 years) and to assess the
iodine content of salt used at the household in the south district of Sikkim, India.
Methodology: Community based cross sectional survey using multistage random
sampling. We studied 600 children in 30 randomly selected Revenue Blocks out of 91 in
south district, Sikkim. Goitre detected at household level by palpation and classified as
per the WHO/UNICEF & ICCIDD joint criteria. Urinary iodine was estimated in On the
Spot" casual urine samples. Iodine content of household salt samples was estimated by
lodometric Titration method.
Results: We found an overall goitre prevalence of 18.0% with girls showing a higher
prevalence (20.1%) than boys (15.4%) though not statistically significant. A steady
increase in goitre prevalence was found with advancing age except for a slight decline at
the age of 12 years. Grade 1 goitre was the commonest type encountered (17.5%).
Median Urinary Iodine was estimated to he 81.3. pg/L, All Household salt samples had
some iodine and 67.3% of households were covered with adequately iodised salt. Goitre
prevalence in our study is lower than earlier reports (56.9% in 1989-91). Median Urinary
Iodine is greater ((23p.WL in 1989-91) and also Household coverage of adequately
iodised salt (40% in 1989-91).
Conclusion: Iodine Deficiency Disorders still remains public health problem in the south
district of Sikkim (hough the prevalence is reduced considerably over the years.
Proportion of Household covered with adequately iodised salt still remains lower than
ideal (90% coverage) inspite of Universal Salt Iodization Programme legislated in the
state. Steps to make available of "adequately iodised salt" by ensuring iodine content at
production, storage, distribution and household use seems to be the ideal intervention.
Proper monitoring and modifying the intervention to suit the current need also look
feasible.
CHAPTER 1.
INTRODUCTION AND BACKGROUND
1.1. Problem of Iodine Deficiency Disorders (IDDs)
Iodine is an essential micronutrient required for the normal physical and mental
growth and development of human beings. Lack of iodine causes several health
consequences that together constitute the Iodine Deficiency Disorders (IDDs). 111 Iodine
deficiency is perhaps the earliest nutritional disease to be recognized. 121 It is the leading
cause of potentially preventable brain damage and mental retardation in the world today.
131 World Health Organization (WHO) estimates that around 2.2 billion people live in
iodine deficient environment worldwide and are at risk. 141 Another million suffer from
other ill effects like mental defects, goitre, reproductive damage, endemic cretinism,
increased perinatal mortality, hypothyroidism and hyperthyroidism,
Adequate evidence is now available, both from controlled trials and successful
iodisation programme, that IDD can successfully be prevented by supplementation.
Moreover the available technology is simple, cheap and in accordance with the concepts
of Primary Health Care. Yet, iodine deficiency continues to be an impediment to
improved quality of life, improved educability of children, economic productivity and
country's development in many parts of the developing world.
Realizing the importance of preventing IDD World Health Assembly in 1990
targeted to eliminate the iodine deficiency as a major public health problem by the year
2000. 151 In the same year, the United Nations World Summit for Children, in New York
endorsed the goal of virtual elimination of 1DD. 161 In 1992, the International Conference
on Nutrition jointly convened by WHO and the United Nations Food and Agriculture
t
i Organization (FAO) held in Rome reaffirmed the goal. 171 In 1993, WHO and UNICEF
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r
recommended Universal Salt Iodisation (USI) as the main strategy for eliminating [DD.
Enormous efforts have been made by international agencies and the national governments
in the last decades and remarkable achievements have been made at the international
level. Yet, elimination of IDD remains a challenge for many of the developing countries.
To contain the problem of 1DDs a National Goitre Control Programme (NGCP)
was launched in India in 1962. It was included in the Prime Minister's 20 Point
Programme in 1983. 181 Later, in 1992, the programme was renamed as National Iodine
Deficiency Disorders Control Programme (NIDDCP). Universal Salt Iodisation (US[)
was the main strategy adopted in the country for elimination of IDD. As a result,
tremendous progress was made by increasing the production of iodised salt from 0.2
million tons in 1983 to 4.6 million tons in 2001. But the proportion of households covered
with adequately iodised salt was only 49% in the country [91 and there are still many states
with significant IDD problem in the country.
1.2. IDDs in Sikkim
Sikkim, the small hilly state in the eastern Himalayas lies in the severely iodine
deficient zone. The state has successfully implemented the iodised salt programme and
made remarkable and measurable progress within the last decades in controlling the IDD.
D°1But the current status of IDDs problem in the state is not fully known.
1.3 Rationale of the Study
Various studies have shown that Iodine Deficiency Disorders is a significant
public health problem for the state of Sikkim. till Almost all of them have shown high
prevalence of goitre and cretinism. State Government was live to the problem and in
1984 a separate IDD cell was established under the Directorate of Health Services. In
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