Thyroid diseases in sub-Saharan Africa
Centre médical Marc Sankalé, BP 5062, Fann Dakar, Sénégal.Sante (Montrouge, France) 11/2006; 17(1):33-9. DOI: 10.1684/san.2007.0058
Thyroid gland diseases vary according to the environment. In sub-Saharan Africa, they are also influenced by population isolation and the absence of food self-sufficiency, both factors affecting the onset and persistence of iodine-deficiency goiters. More cosmopolitan diseases are now added to these thyroid disorders. Women are mainly affected (94.2%), most often with euthyroid goiters (54.7%), followed by Graves disease (13.1%), hypothyroidism (8.8%), thyroiditis (6.6%), toxic multinodular goiters (6.6 %) and unclassified goiters (10%) [Gabon]. The paucity of laboratories specializing in endocrinology and of nuclear medicine facilities, the delay in diagnosis that results in compressive or recurrent goiters, and endemic goiters are all typical in Africa. In children and adolescents, death rates increase with congenital or acquired thyroiditis as with delayed physical or mental development. In this environment, thyroiditis can also be pregnancy-related. Very recent surveys show a prevalence of endemic goiters of 28.6% in the community of Sekota, Ethiopia, 64-70% in Sahel-Sudan (population aged 10-20 years), 20-29% in KwaZulu-Natal (school children), 14.3-30.2% in Namibia (school children), 0.21% (congenital hypothyroidism or cretinism) in Plateau State, Nigeria, 55.2% at Zitenga, Burkina Faso (210 persons 0-45 years), and 10% in Hararé and Wedza, Zimbabwe (newborn TSH >10.1 microIU/mL). The prevalence of goiters is 43.6% in children emigrating from Ethiopia to Israel. Millet from semi-arid zones contains apigenin at a concentration of 150 mg/kg and luteolin at 350 mg/kg, both of which can interfere with thyroid function. The harmful effects of cassava (also known as manioc) are better known: milling cassava reduces its goitrogenic potential. In addition to iodine deficiency, selenium deficiency, and the effect of the thiocyanates in cassava, ion concentrations in soil and drinking water appear to play a role. The proportion of thyroid surgery indicated for hyperthyroidism has tripled, now accounting for 18.5% of all such operations. This disorder is found today in subjects older than 50 years, mainly from rural areas, and caused most often by Graves disease (25 of 51 cases). Graves disease in young women can cause serious problems during pregnancy; in such cases assessment of the minimal effective dose of antithyroid agents is essential. Carbimazole leads to remission in 61% of cases of Graves disease. Hypothyroidism can be auto-immune and often in patent forms because of insufficient screening in Africa: 24 cases in Dakar (1984) and 37 others noticed by us (1998). Single-nodule tumors were assessed in 89 patients in Khartoum: they were found to be simple goiters in 72% of cases, follicular adenoma in 13.5%, cancer in 13.5% (with 6 of the 12 cases follicular, 5 papillary, and 1 anaplastic). The sex ratio for thyroid cancer in Ouagadougou is 0.22, thus mainly women. It affects mainly women in their 30s. Thyroid cancer at Ibadan was found to be papillary carcinoma in 45.3% of cases; follicular forms were seen in 44.5% and this series includes 5% of medullary cancers (7 cases), with a mean age of 34 years. Already 4 other cases from Francophone sub-Saharan Africa have been noticed. Iodine deficiency is suggested to play a role because follicular cancer in southern Africa accounts for up to 55% of thyroid cancers. Thyroid cancers in Algeria are associated with low socioeconomic status and characterized by a high prevalence of cancers discovered at an advanced stage and of anaplastic carcinomas. Oral potassium iodate is recommended: 30 mg of iodate a month or 8 mg every two weeks. Iodized oil has been recommended by some authors, as well as a combination of iodine and sugar, and the iodation of drinking water; these are in addition to the proposed methods of opening up areas by new infrastructure). In conclusion, thyroid disease is due predominantly to iodine deficiency and goitrogenic products, but we also note the increasing emergence of hyperthyroidism, especially Graves disease, atrophic auto-immune hypothyroidism, and thyroid cancer. The insufficiency of infrastructure in transportation, endocrinology, and nuclear medicine are a public health challenge for the third millennium.
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ABSTRACT: Endemic goiter caused by iodine deficiency is still very common in sub-Saharan Africa and is a surgical challenge because of the often large size of the goiters. A retrospective analysis was made of patients who underwent operation for thyroid diseases during a surgical help program in Leo/Burkina Faso during a 7-year period from 2001 to 2008. A total of 253 cases presented with goiters grade III (WHO classification) were operated on: 134 hemithyroidectomies, 108 hemithyroidectomies combined with subtotal contralateral resection, and 11 total thyroidectomies were performed. The recurrent laryngeal injury rate was 0.8%, and the re-exploration rate for bleeding was 1.2%. Median hospital stay was 3.1 days. Histological examinations showed Graves' disease in 6 cases, and multinodular goiter in 231 cases. Follicular cancer was found in 15 cases, and anaplastic carcinoma was found in 1 case. Thyroid surgery can be performed with low complication rates under basic surgical conditions. Because of the size and pathology of the goiters, total thyroidectomy is the method of choice. However, considering the risk of the development of hypothyroidism due to poor understanding or difficult access to medication, a limited resection, e.g., hemithyroidectomy, is the most optimal operative strategy.
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ABSTRACT: Several studies have revealed an increased incidence of thyroid cancer in volcanic areas around the world. Hawaii and the Philippines on the rim of the Pacific Ocean, where the greatest number of volcanoes are located at convergent plate boundaries, are among the regions with the highest incidence of thyroid carcinoma worldwide. Iceland is another region also rich in volcanoes in which the highest incidence of thyroid cancer in Europe is found. The common denominator of these regions is their numerous volcanoes and the fact that several constituents of volcanic lava have been postulated as being involved in the pathogenesis of thyroid cancer. This article aims at presenting pertinent data that could link a volcanic environment to thyroid cancer.
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ABSTRACT: A 24-year-old male thyrotoxic student of a tertiary institution had thyroidectomy in the presence of a persistently elevated thyroxine (T4) and tri-iodothyronine (T3) levels. He was initially managed for hypertension at a private hospital before he was referred to our hospital for expert management. He had symptoms of thyrotoxicosis three years before presentation at our hospital. Physical examination revealed bilateral anterior neck masses and a diagnosis of toxic goitre was made. The serum T3 and T4 were elevated. Chest X-Ray, electrocardiogram and echocardiography showed abnormal findings. He was commenced on antithyroid drugs. Surgery was postponed several times due to persistently elevated thyroid hormones. However, he developed cardiac failure after six months on medical treatment and was treated with digoxin and frusemide. He had thyroidectomy under general anesthesia after his cardiovascular status was optimized in order to prevent further deterioration of his cardiac function. The anesthetic management is presented and discussed.
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