The goitre prevalance and urinary iodine status of primary school children in Lesotho

Abstract

English: Iodine deficiency has been called the world's most significant cause of mental retardation. Studies conducted since 1960 have indicated iodine deficiency as public health problem in Lesotho. The ICCIDD has been instrumental in focusing the world's attention on 100 and the goal of virtual elimination of 100 as a public health problem by the year 2000 was accepted by the united systems in 1990. This goal was reaffirmed by the e" World Health Assembly in 1993, which also provided a strategic guidance including emphasis on salt iodisation. The main objective of this study was to estimate the current 100 situation in Lesotho 5 years after the 1993 National Micronutrient Survey which was followed by iodised oil capsule supplementation as a short term intervention and the introduction of the legislation on universal salt iodisation as a long term intervention. This was a cross sectional study where stratified random sampling was used to select 5 schools in each of the 10 districts of Lesotho. All children aged 8 to 12 years from the selected schools participated in the study. The size of the thyroid gland was determined by palpation and graded according to the Joint criteria of the WHO/UNICEF/ICCIDD (1994). Casual urine samples were obtained from 10 children in each school in the morning during school hours and frozen until they were analysed for urinary iodine level using the Sandell-Kolthoff reaction involving alkaline ashing at the National University of Lesotho. Using a structured questionnaire, iodised oil supplementation coverage was determined. Salt samples brought by children were also analysed for the presence of iodine using the rapid (spot) test kits. The SAS package was used for statistical analysis of the results at the University of Orange Free State. 4071 primary school children were palpated and responded to the questionnaire, 4071 salt samples and 500 urine samples were analysed. The median urinary iodine concentration of 26.3IJg/l, which ranged from 22.3IJg/1to 47.91Jg/l and from 25.7IJg/1 to 27.2IJg/1 in the different districts and ecological zones respectively, indicated moderate 100. The prevalence of goitre, which increased with age and was higher in females than males, ranged from 2.2 to 8.8 percent and from 2.3 to 6.3 percent in the different districts and ecological zones respectively indicating mild to normal iodine deficiency. The adjusted prevalence of goitre for the whole country was 4.9 percent, indicating the absence of 100. 94.2 percent of salt samples were iodised. Coverage on iodised oil capsules supplementation, which was 55.1 percent, was not adequate. Lesotho was found in this study as having mild to moderate 100, which is still of public health concern according to WHO/UNICEF/ICCIOO (1994). Iodine deficiency was higher in the Mountains than in the Lowlands. However there is an improvement in controlling 100 in Lesotho as observed from the results of the present study and those of the previous studies. The use of iodised salt and iodised oil capsules has most likely contributed to a decrease in the 100 prevalence. Similar studies using ultrasonography and the titration method need to be conducted in the future. More iodised oil supplementation is recommended in the Mountains and in schools, which never received the capsules and this needs to be coupled with efficient awareness programs. An effective monitoring program needs to be initiated to ensure that the entire population use adequately iodised salt.

Afrikaans: Jodiumtekort is bekend as die belangrikste oorsaak van verstandelike vertraging in die wêreld vandag. Studies wat sedert 1960 uitgevoer is, identifiseer jodiumtekort as 'n publieke gesondheidsprobleem in Lesotho. Die Internasionale Raad vir Kontrole van Jodiumtekortversteurings (ICCIDD) het 'n belangrike rol gespeelom die aandag van die wêreld op jodiumtekortversteurings te plaas, asook aanvaarding van die doelwit deur die Verenigde Sisteme in 1990 om Jodiumtekortversteurings as 'n publieke gesondheidsprobleem teen die jaar 2000 uit te wis .. Die doelwit is deur die 6de Wêreld Gesondheidsbyeenkoms in 1993 herbevestig en strategiese riglyne is ook gegee, insluitend beklemtoning van die jodering van sout. Die hoofdoel van die studie was om 'n beraming te doen van die huidige situasie tov jodiumtekortversteurings in Lesotho, 5 jaar na die 1993 Nasionale Mikrovoedingstofopname. Na die 1993 Nasionale Mikrovoedingstofopname is die gejodeerde oliekapsule supplementasieprogram as 'n korttermyn intervensie en aanvaarding van die wetgewing tov universele soutverryking met jodium as 'n langtermyn intervensie ingestel. 'n Dwarssnitstudie is uitgevoer en 'n gestratifiseerde ewekansige metode van steekproeftrekking is gebruik om 5 skole in elk van die 10 distrikte in Lesotho te selekteer. AI die kinders tussen 8 en 12 jaar van die geselekteerde skole het aan die studie deelgeneem. Die kropgeswelgrootte is mbv palpetering bepaal en gradeer volgens die gesamentlike kriteria opgestel deur die WêreldgesondheidsorganisasieNerenigdenasies se KinderfondsIInternasionale Raad vir Kontrole van jodiumtekortversteurings (WHO/UNICEFIICCIDD, 1994). Luk raak urine monsters is soggens gedurende skoolure van 10 kinders in elke skool geneem en gevries tot met ontleding dmv Sandell-Kolthoff alkalieseas reaksie toets deur die Nasionale Universiteit van Lesotho. 'n Gestruktureerde vraelys is gebruik om die gejodeerde oiliesupplementasie dekking te bepaal. Soutmonsters wat deur die kinders na die skool gebring is, is mbv die 'vinnige toetstoerusting'-metode geanaliseer om die teenwoordigheid van jodium in die monsters te bepaal. Die SAS-pakket is deur die Departement Biostatistiek van die UOVS gebruik vir die statistiese ontleding van die resultate. 4071 primêre skoolkinders is palpeer en het vraelyste beantwoord en 4071 soutmonsters en 500 urine monsters is ontleed. Die mediaan van die urinêre jodiumkonsentrasie was 26.3/-lg/1 en het respektiewelik tussen 22.3/-lg/1 en 47.9/-lg/1 en tussen 25.7/-lg/1 en 27.2/-lg/1 in die verskillende distrikte en ekologise zones gewissel, wat op 'n matige voorkoms van jodiumtekortversteurings dui. Die voorkoms van kropgeswel wat met ouderdom toegeneem het was hoër onder seuns as dogters, en het respektiewelik van 2.2 tot 8.8 persent en van 2.3 tot 6.3 persent in die verskillende distrikte en ekologiese zones gewissel wat dui op 'n matige tot normale jodiumtekort. Die aangepaste voorkoms van kropgeswel was vir die hele land 4.9 persent wat daarop dui dat Jodiumtekortversteurings op die grens van uitwissing is. 94.2 persent van die soutmonsters was gejodeer. Die dekking deur die gejodeerde oliesupplementasieprogram was 55.1 persent, wat as ontoereikend beskou word. In Lesotho is 'n ligte tot matige voorkoms van jodiumtekortversteurings gevind wat steeds as 'n publieke gesondheidsprobleem volgens die WHO/UNICEF/ICCIDD (1994), bestempel word. Die voorkoms van jodiumtekort was hoër in die bergagtige areas as in die laer ligginde gebiede. Die huidige en vorige studies dui op 'n verbetering in die kontrole van jodiumtekortversteurings. Die gebruik van gejodeerde sout en gejodeerde oiliekapsules het waarskynlik tot die afname in die voorkoms van jodiumtekortversteurings bygedra. In soortgelyke toekomstige studies behoort die ultrasonografiese en titrasie metodes gebruik te word. Die verspreiding van gejodeerde oliekapsules, gepaard met bewustheidsprogramme in die bergragtige areas en in skole wat voorheen nie die supplementasie ontvang het nie, word aanbeveel. 'n Doeltreffende moniteringsprogram moet inisieer word om te verseker dat die totale populasie gejodeerde sout gebruik.