Wording the trajectory of the three-year COVID-19 epidemic in a general population - Belgium.

The trajectory of COVID-19 epidemic waves in the general population of Belgium was analysed by defining quantitative criteria for epidemic waves from March 2020 to early 2023. Peaks and starting/ending times characterised nine waves numerated I to IX based on the daily reported incidence number (symbol INCID) and three "endemic" interval periods between the first four waves. The SIR compartmental model was applied to the first epidemic wave by fitting the daily prevalence pool (symbol I) calculated as the sum of the daily incidence rate and estimated number of subjects still infectious from the previous days. The basic reproductive number R0 was calculated based on the exponential growth rate during the early phase and on medical literature knowledge of the time of generation of SARS-CoV-2 infection. The first COVID-19 wave was well fitted by an open SIR model. According to this approach, dampened recurrent epidemic waves evolving through an endemic state would have been expected. This was not the case with the subsequent epidemic waves being characterised by new variants of concern (VOC). Evidence-based observations: 1) each epidemic wave affected less than a fifth of the general population; 2) the Vth epidemic wave (VOC Omicron) presented the greatest amplitude. The lack of recurrence of the same VOC during successive epidemic waves strongly suggests that a VOC has a limited persistence, disappearing from the population well before the expected proportion of the theoretical susceptible cohort being maximally infected. Fitting the theoretical SIR model, a limited persistence of VOCs in a population could explain that new VOCs replace old ones, even if the new VOC has a lower transmission rate than the preceding one. In conclusion, acquisition of potential defective mutations in VOC during an epidemic wave is a potential factor explaining the absence of resurgence of a same VOC during successive waves. Such an hypothesis is open to discussion and to rebuttal. A modified SIR model with epidemic waves of variable amplitude related not only to R0 and public health measures but also to acquisition of defective fitting in virus within a population should be tested.

Helicobacter pylori and Human Immunodeficiency Virus Co-Infection: Potential Implications for Future Gastric Cancer Risk.

OBJECTIVE: Helicobacter pylori and human immunodeficiency virus (HIV) are both pandemic infections with variable geographic prevalence rates. H. pylori-HIV co-infection at the regional and sub-regional levels with a perspective on gastric cancer incidence is discussed. DESIGN: Based on PRISMA guidelines, national data for H. pylori, HIV, and H. pylori-HIV co-infection were collected for the general population through December 2019. Joint temporal and geographical data for H. pylori and HIV infections in 48 countries were available and used to generate H. pylori-HIV co-infection estimates by cross-sectional analysis. These data were compared with gastric carcinoma statistics for the same countries. RESULTS: The estimated global prevalence rate of H. pylori-HIV co-infection was 1.7 per 1000 people, representing 12.6 million people. Prevalence according to region was, in decreasing order, sub-Saharan Africa 21.9‱, Eastern Europe/Central Asia 4.3‱, Latin America/Caribbean 2.0 ‱, North America/Western/Southern/Northern Europe 1.1‱, Asia/Pacific 0.8‱, and North Africa/Middle East 0.1 ‱. The incidence and mortality rates for gastric carcinoma were higher in East/Pacific Asia, Southern/Andean Latin America, and Eastern Europe regions, and the incidence appeared to be 1.8-fold greater in H. pylori-HIV-infected people in East Asia. CONCLUSIONS: The population at risk of H. pylori-HIV co-infection is estimated to be 12.6 million people (2015 reference year). The heterogeneity of H. pylori-HIV co-infection across regions and sub-regions does not show a clear association with gastric carcinoma. Other methodological approaches with analytical studies (cohort, case-control) are required to measure the potential effect of H. pylori infection and its treatment on the incidence of gastric carcinoma in the large HIV-H. pylori-positive cohort.

Selenium, TGF-Beta and Infectious Endemic Cardiopathy: Lessons from Benchwork to Clinical Application in Chagas Disease.

For over 60 years, selenium (Se) has been known as an essential microelement to many biological functions, including cardiovascular homeostasis. This review presents a compilation of studies conducted in the past 20 years related to chronic Chagas disease cardiomyopathy (CCC), caused by Trypanosoma cruzi infection, a neglected disease that represents a global burden, especially in Latin America. Experimental and clinical data indicate that Se may be used as a complementary therapy to prevent heart failure and improve heart function. Starting from the main questions "Is Se deficiency related to heart inflammation and arrhythmogenesis in CCC?" and "Could Se be recommended as a therapeutic strategy for CCC?", we show evidence implicating the complex and multidetermined CCC physiopathology, discussing its possible interplays with the multifunctional cytokine TGF-ß as regulators of immune response and fibrosis. We present two new proposals to face this global public health challenge in vulnerable populations affected by this parasitic disease: fibrosis modulation mediated by TGF-ß pathways and the possible use of selenoproteins as antioxidants regulating the increased reactive oxygen stress present in CCC inflammatory environments. We assess the opportunity to consider the beneficial effects of Se in preventing heart failure as a concept to be applied for CCC patients.

Primary antibiotic resistance of Helicobacter pylori isolates is twofold more frequent in HIV-positive than HIV-negative individuals: A descriptive observational study.

The antimicrobial susceptibility of Helicobacter pylori strains isolated from HIV-positive individuals is not well characterized. This study aimed to measure the prevalence and long-term trends associated with primary H. pylori antibiotic resistance, evaluate correlations with antibiotic consumption, and compare predictors for H. pylori antibiotic resistance between HIV-positive and HIV-negative individuals. In this longitudinal registry study, we evaluated consecutive adults with and without HIV infection, naïve to H. pylori treatment, who underwent upper gastrointestinal endoscopy and had a positive H. pylori culture, with susceptibility testing available, between 2004 and 2015. Outpatient antibiotic consumption data were based on nationwide aggregated numbers. H. pylori was isolated from gastric biopsies of 3008/8321 patients, 181/477 (37.9%) were HIV-positive and 2827/7844 (36.0%) HIV-negative. Overall cohort mean prevalence of H. pylori primary antibiotic resistance was 11.1% for clarithromycin, 17.8% levofloxacin, and 39.4% metronidazole. The prevalence of H. pylori primary resistance was significantly higher for these three drugs in HIV-positive individuals across the study period. Linear regression showed that the prevalence of clarithromycin and levofloxacin resistance correlated with the country aggregate daily dose consumption of macrolides and quinolones, respectively. Multivariable regression analysis showed that HIV infection is a strong independent risk factor for multiple H. pylori antibiotic resistance. In summary, HIV infection is a risk factor for carrying multi-resistant H. pylori strains and this is correlated with antibiotic consumption. Empirical therapies should be avoided in HIV-positive individuals. These data highlight the need to implement ongoing monitoring of H. pylori antimicrobial susceptibility among HIV-positive individuals. The study is registered at ISRCTN registry, number 13466428: https://www.isrctn.com/ISRCTN13466428.

Familial Aggregation of Endemic Congenital Hypothyroidism Syndrome in Congo (DR): Historical Data.

Familial aggregation of endemic congenital hypothyroidism (CH) in an iodine-deficient population from northern Congo (Democratic Republic (DR)) was analysed on data collected four decades ago (1979-1980). During a systematic survey of 62 families, 46 endemic CH subjects (44 myxedematous and 2 neurological) were identified based on clinical evidence within a village cohort of 468 subjects. A distribution analysis showed that two families presented significant excess of cases versus a random background distribution. Both families were characterised by two healthy parents having all of their five offspring affected by some form of endemic CH. Goitre prevalence in endemic CH was lower than that in the general population, while goitre prevalence in the unaffected part of the cohort (parents and siblings) was similar to that of the general population. Some unidentified genetic/epigenetic factor(s) could contribute to the evolution of some iodine-deficient hypothyroid neonates through irreversible and progressive loss of thyroid functional capacity during early childhood (<5 years old). Besides severe iodine deficiency, environmental exposure to thiocyanate overload and selenium deficiency, factors not randomly distributed within families and population, intervened in the full expression of endemic CH. Further exploration in the field will remain open, as iodine deficiency in Congo (DR) was eliminated in the 1990s.

Evolution of Helicobacter pylori associated with gastroduodenal ulcers or erosions in children over the past 23 years: Decline or steady state?

BACKGROUND: Recent data suggest that in children, the proportion of gastroduodenal ulcers/erosions associated with Helicobacter pylori infection is currently lower than expected. In this study, we trace this proportion over two decades. METHODS: We reviewed the reports of all upper gastrointestinal endoscopies with biopsies for histology and culture over the past 23 years. H pylori status was assessed using several invasive methods. The infection rate during different time periods was compared between children with lesions and controls. RESULTS: A total of 7849 endoscopies were performed in 5983 children (2874 F/3109 M, median age 7.6 years, range 0.1-17.9 years). The endoscopy report was missing in 316 patients. At the first upper gastrointestinal endoscopy, 12.1% of the children presented with gastric and/or duodenal ulcers or erosions with an H pylori infection rate of 35.4%, whereas no such lesions were observed in 87.9% of children in whom the H pylori infection rate was 21.3%. The risk factors associated with such lesions were older age (P < 0.001), male sex (P = 0.002), and H pylori infection (P < 0.0001). Gastric ulcers were not significantly associated with H pylori (24% infected), whereas 52% of duodenal ulcers, 33% of gastric erosions, and 38% of duodenal erosions were associated with H pylori. The proportion of gastroduodenal lesions associated with H pylori remained stable over time. Children with H pylori infection and ulcers were older than those with H pylori infection without ulcers (P < 0.001). CONCLUSIONS: Our study indicates that in our pediatric population, the proportion of ulcers without H pylori infection is higher than previously suggested, and this prevalence has not changed over the past two decades.

Historical aspects of iodine deficiency control.

In 1895, iodine was characterized as an essential element of thyroid tissue by Baumann. The efficacy of iodine to prevent goiter was demonstrated by Marine in Northern USA in 1916-1920. Severe endemic goiter and cretinism had been almost entirely eliminated from continental Western Europe and Northern America before the 1930's; however large populations elsewhere and even some places in Western Europe (Sicily) were still affected up to the 2000's. Public health consequences of iodine deficiency are not limited to endemic goiter and cretinism. Iodine deficiency disorders include also increased neonatal death rate and decreased intellectual development, although these consequences are not included in the current estimation of the Global Burden Disease related to iodine deficiency. Severe iodine deficiency as a public health problem is now largely under control worldwide, but can still affect isolated places, in hard-to-reach and/or politically neglected populations. We emphasize the importance of maintaining international cooperation efforts, in order to monitor iodine status where iodine deficiency is now adequately controlled, and identify at-risk population where it is not. The goal should be now global eradication of severe iodine deficiency. Commercial distribution of iodized salt remains the most appropriate strategy. A randomized clinical trial in New Guinea clearly showed in the 1970's that correcting severe iodine deficiency early in pregnancy prevents endemic neurological cretinism. This supports the essential role of thyroid hormones of maternal origin on the normal fetal development, during the first trimester of pregnancy (i.e. when fetal thyroid is still not functional). A randomized clinical trial in Congo (RD) in the 1970's also showed that correcting severe iodine deficiency during pregnancy prevents myxœdematous cretinism, particularly prevalent in affected Congolese areas.

Serodiagnosis of whooping cough in Belgium: results of the National Reference Centre for Bordetella pertussis anno 2013.

OBJECTIVE: Report on the pitfalls of serodiagnosis of pertussis in Belgium for 2013 by the NRC Bordetella. METHODS: Determine cases of acute infection using an anti-pertussis toxin (PT) IgG antibody ELISA. RESULTS: A total of 2471 serum samples were received. Clinical information on the duration of cough (at moment of blood sampling) is essential for a reliable interpretation of the results. In order to avoid false negative results, 213 samples for which this information was lacking were not tested. For a total of 2179 patients tested, 520 (23.9%) had antibody levels indicative of an acute infection, 261 (12%) samples were diagnosed as positive (indicative of a pertussis infection or vaccination during the last year), 143 (6.7%) samples were classified as doubtful and 752 (34,5%) (35.5%) were diagnosed as negative. The serodiagnosis of pertussis has limited value for the early diagnosis of the disease and PCR analysis on nasopharyngeal swabs is the method of choice during the first 2 weeks and always for young children <1 year old. For sera collected during the first 2 weeks with anti-PT levels below the threshold for acute infection, a second sample collected 2-3 weeks later is needed a definitive diagnosis. For 503 (23.0%) early samples, a second serum sample was requested but not provided. For 85 patients, for whom a second sample was received, 12.9% were eventually diagnosed as having an acute infection. CONCLUSION: In order to generate reliable serodiagnostic results for pertussis, serum samples should preferentially be collected 3 weeks after onset of symptoms.

Thyroid-Stimulating Hormone (TSH) Concentration at Birth in Belgian Neonates and Cognitive Development at Preschool Age.

The main objective of the study was to investigate the effect of MID during late pregnancy, assessed by the thyroid-stimulating hormone (TSH) concentration at neonatal screening, on cognitive development of preschool children. A retrospective cohort study including 311 Belgian preschool children of 4-6 years old was conducted. Children were selected at random from the total list of neonates screened in 2008, 2009, and 2010 by the Brussels new-born screening center. Infants with congenital hypothyroidism, low birth weight, and/or prematurity were excluded from the selection. The selected children were stratified by gender and TSH-range (0.45-15 mIU/L). Cognitive abilities were assessed using Wechsler Preschool and Primary Scale of Intelligence-third edition. In addition, several socioeconomic, parental, and child confounding factors were assessed. Neonatal TSH concentration-a surrogate marker for MID-was not associated with Full Scale and Performance IQ scores in children. Lower Verbal IQ scores were found in children with neonatal TSH values comprised between 10-15 mIU/L compared to lower TSH levels in univariate analysis but these results did not hold when adjusting for confounding factors. Current levels of iodine deficiency among pregnant Belgian women may not be severe enough to affect the neurodevelopment of preschool children.

Neonatal thyroid-stimulating hormone level is influenced by neonatal, maternal, and pregnancy factors.

The percentage of newborns with a neonatal whole blood thyroid-stimulating hormone (TSH) greater than 5 mIU/L has been used as an indicator of iodine deficiency at the population level. However, TSH levels in newborns may be influenced by many factors other than iodine status. The objective of this study was to identify neonatal, maternal, and pregnancy-related determinants of neonatal TSH levels in a retrospective cohort study. The study sample included 313 Belgian mothers and their 4- to 5-year-old children. The children had a neonatal TSH concentration between 0 and 15 mIU/L at neonatal screening, and blood samples were collected 3 to 5 days after birth. Children with suspected congenital hypothyroidism (neonatal TSH level >15 mIU/L), prematurely born (i.e., <37 weeks), or with a low birth weight (i.e., <2500 g) were excluded. Information about maternal and birth-related determinants was collected from the neonatal screening center via a self-administered questionnaire filled in by the mother together with the child's health booklet. Higher TSH levels were found in spring and winter compared to summer and autumn (P = .011). Higher TSH levels were associated with lifetime smoking behavior (up to child birth) in the mother (P = .005), lower weight gain during pregnancy (P = .014), and longer pregnancies (P = .003). This study showed that several neonatal, maternal, and pregnancy-related determinants are influencing neonatal TSH level.

Epidemiology of hypertension and its relationship with type 2 diabetes and obesity in eastern Morocco.

The major objectives of this work are to estimate the hypertension (HT) frequency in the east of Morocco and to study the relationship between HT, type 2 diabetes and obesity. Our sample is composed of 1628 adults aged 40 years and older, recruited voluntarily by using the convenience sampling method through 26 screening campaigns in urban and rural areas of the east of Morocco. We enumerated 516 hypertensive people (31.7%), without significant difference between women (32.5%) and men (30.2%). The known hypertensive people represent 10.1% of the whole sample. The frequency of HT, increases with age and it is more marked in rural (39.9%) than in urban areas (29%) (p < 0.001). It is significantly very high in diabetic subjects (69.9%) than among the non-diabetic ones (27.4%) (p < 0.001). The odd ratio (OR) of the diabetics to HT is 6.16 (IC95% [4.33-8.74]). Among the obese persons, HT is present at (40.8%) vs. (30.2%) among the subjects of normal weight (p < 0.05). The OR of the obese to HT is 1.6 (IC95% [1.26 - 2.04]). In conclusion, our results show a high frequency of HT in the east of Morocco; it affects nearly one third of the adult population aged 40 years and older. The relations between type 2 diabetes and obesity have also been identified and estimated.

Helicobacter pylori Infection in European children with gastro-duodenal ulcers and erosions.

BACKGROUND: To analyze risk factors associated with gastro-duodenal ulcers and erosions in children. METHODS: Open, prospective, multicenter, case-control study carried out in 11 European countries in patients with gastric or duodenal ulcers/erosions and 2 age-matched controls each. Possible risk factors were recorded. Logistic regression models were performed with adjustment for centers and age groups. RESULTS: Seven-hundred thirty-two patients (244 cases, 153 with erosions only and 91 with ulcers, and 488 controls) were recruited. Children receiving antimicrobials or acid suppressive drugs before endoscopy were excluded (202 cases/390 controls remained for risk factor analysis). Helicobacter pylori was detected more frequently in cases than controls but only in 32.0% versus 20.1% in controls (P = 0.001). Independent exposure factors for gastric ulcers were male gender (P = 0.001), chronic neurologic disease (P = 0.015), chronic renal disease (P < 0.001) and nonsteroidal anti-inflammatory drug consumption (P = 0.035). Exposure factors for duodenal ulcers were H. pylori infection (P < 0.001) and steroid consumption (P = 0.031). Chronic renal disease was the only independent factor associated with gastric erosions (P = 0.026), those associated with duodenal erosions being H. pylori infection (P = 0.023), active smoking (P = 0.006) and chronic arthritis (P = 0.008). No risk factor was identified in 97/202 (48.0%) cases. CONCLUSIONS: H. pylori remains a risk factor for duodenal, but not for gastric lesions in children in countries with low prevalence of infection. No risk factor could be identified in half of the children with gastro-duodenal ulcers/erosions.

Neonatal thyroid-stimulating hormone concentrations in Belgium: a useful indicator for detecting mild iodine deficiency?

It has been proposed that neonatal thyroid-stimulating hormone (TSH) concentrations are a good indicator of iodine deficiency in the population. A frequency of neonatal TSH concentrations above 5 mU/L below 3% has been proposed as the threshold indicating iodine sufficiency. The objective of the present study was to evaluate feasibility and usefulness of nation-wide neonatal TSH concentration screening results to assess iodine status in Belgium. All newborns born in Belgium during the period 2009-2011 (n = 377713) were included in the study, except those suffering from congenital hypothyroidism and premature neonates. The frequency of neonatal TSH concentrations above 5 mU/L from 2009 to 2011 in Belgium fluctuated between 2.6 and 3.3% in the centres using the same TSH assay. There was a significant inverse association between neonatal TSH level and birth weight. The longer the duration between birth and screening, the lower the TSH level. Neonatal TSH levels were significantly lower in winter than in spring or autumn and significantly lower in spring and summer than in autumn while significantly higher in spring compared to summer. In conclusion, despite that pregnant women in Belgium are mildly iodine deficient, the frequency of neonatal TSH concentrations above 5 mU/L was very low, suggesting that the neonatal TSH threshold proposed for detecting iodine deficiency needs to be re-evaluated. Although neonatal TSH is useful to detect severe iodine deficiency, it should not be recommended presently for the evaluation of iodine status in mildly iodine deficient regions.

Pharyngitis in low-resources settings: a pragmatic clinical approach to reduce unnecessary antibiotic use.

OBJECTIVE: Existing scoring systems for the diagnosis of group A streptococcus pharyngitis are insensitive or inapplicable in low-resources settings. Bacterial cultures and rapid tests can allow for antibiotic prescription abstention in high-income regions. These techniques are not feasible in many low-resources settings, and antibiotics often are prescribed for any pharyngitis episode. However, judicious antibiotics prescription in the community also is of concern in low-income countries. The objective of this study was to develop a clinical decision rule that allows for the reduction of empirical antibiotic therapy for children with pharyngitis in low-resources settings by identifying non-group A streptococcus pharyngitis. PATIENTS AND METHODS: We prospectively included children with pharyngitis in 3 public hospitals of Brazil during 9 months in 2004. We filled out clinical questionnaires and performed throat swabs. Bilateral chi2 (2-tailed test) and multivariate analysis were used to determine score categories. The outcome measures were sensitivity, specificity, positive likelihood ratio, and posttest probability of non-group A streptococcus infection with the clinical approach as compared with throat culture. RESULTS: A total of 163 of the 220 children had non-group A streptococcus pharyngitis (negative culture). We established a 3-questions decision rule (age and viral and bacterial signs) with 3 possible answers. The use of this score would prevent 41% to 55% of unnecessary antimicrobial prescriptions. The specificity of the score for non-group A streptococcus pharyngitis was >84%. CONCLUSION: Such a clinical decision rule could be helpful to reduce significantly unnecessary antibiotic prescriptions for pharyngitis in children in low-resources settings.

Nutritional epidemiology and thyroid hormone metabolism.

Severe iodine deficiency was the main cause of endemic goiter and cretinism. Most of the previously iodine-deficient areas are now supplemented, mainly with iodized salt. The geographical distribution of severe endemic areas has been progressively reduced, and at present, approximately 200 million people living in remote places are still at risk of severe iodine deficiency. International public health programs should be focused first on reaching these populations, and second on auditing and monitoring the operational work of supplementation programs. This second point is essential to prevent iodine-induced hyperthyroidism or interruptions of iodine supplement distribution, which could be catastrophic for the fetus and the young infant. Echography brings a complementary tool to clinical assessment of goiter by palpation. Inductively coupled plasma-mass spectrometry brings at least a definitive gold standard for iodine measurement and thyroid hormone measurement. Thiocyanate overload has been clearly documented as a goitrogen in Central Africa, and when associated with selenium deficiency, it may be included as risk factor for endemic myxedematous cretinism. Variable exposure to different environmental risk factors is likely the explanation of the variable distribution of two types of endemic cretinism (neurological and myxedematous), and the clinical overlap of the pathogeny of both syndromes is more important than previously described. It is possible that Kashin-Beck osteoarthropathy is another evanescent endemic disease that will disappear with the correction of iodine deficiency.

Better stability of total homocysteine measurement with sodium fluoride than with EDTA.

The total homocysteine (tHcy) plasma concentration increases 10% per hour when whole blood is collected on ethylene diamine tetraacetate (EDTA) and stored at room temperature. The aim of this study was to investigate the stability of tHcy plasma concentration during 24 hours of storage at room temperature in two different collection tubes: EDTA and sodium fluoride (NaF). The evolution of tHcy plasma concentration was also compared in two different populations: healthy individuals (controls) and patients with end-stage renal failure, known to have increased plasma tHcy concentrations. Plasma was separated from erythrocytes at 0, 2, 6 and 24 hours. tHcy was measured with a competitive immunoassay on Immulite 2000 (Diagnostic Products Corporation). Plasma tHcy concentration started to rise significantly on EDTA after two hours of storage in patients and controls in comparison to baseline (defined as time: 0 hour). It remained stable on NaF during the first two hours and started to rise significantly after six hours of storage for both populations. In conclusion, NaF tubes should be preferred to EDTA tubes for tHcy determination in routine clinical chemistry laboratories.

Trace elements, innate immune response and parasites.

Micronutrient deficiencies and infectious disease often coexist and show complex interactions leading to mutually reinforced detrimental clinical effects. Such a combination is predominantly observed in underprivileged people of developing countries, particularly in rural regions. Several micronutrients such as trace elements (zinc, iron, selenium) modulate immune function and influence the susceptibility of the host to infection. Nevertheless, the effect of individual micronutrients on components of innate immunity is difficult to design and interpret. Micronutrient deficiency, in general, has a widespread effect on nearly all components of the innate immune response. Chagas' disease is a pertinent model to study interaction of nutrition, immunity and infection, as it implies many components of innate immunity. An important question is whether alterations on micronutrient intake modify the course of infection. Some interactions of trace elements with innate immunity and acute inflammatory response are reviewed in this article with a special focus on selenium deficiency and Trypanosoma cruzi infection.

Selenium supplementation at low doses contributes to the decrease in heart damage in experimental Trypanosoma cruzi infection.

Chagasic patients with cardiomyopathy have low levels of selenium (Se), a fundamental trace element. We evaluated the effect of supplementing infected mice with Se (0.25-16 ppm). Supplementation with 0.25 or 1 ppm Se led to parasitaemia and survival curves similar to those of the control group. Mice treated with 4-16 ppm showed a dose-dependent decrease of parasitaemia, significant for the highest concentration. This was probably due to a direct effect on the parasites, which were lysed after in vitro incubation with Se. Survival rates did not change significantly; however, heart damage was reduced in infected mice supplemented with 4 ppm Se, as indicated by a lower cardiac isoform of creatine kinase levels. Our results imply that Se supplementation does not lead to a general protection during infection, but may help protect the heart from inflammatory damage. The effect of Se supplementation in the course of T. cruzi infection depends on the host-parasite pair employed.

Selenium and iodine supplementation of rural Tibetan children affected by Kashin-Beck osteoarthropathy.

BACKGROUND: Kashin-Beck disease is an osteoarthropathy endemic in selenium- and iodine-deficient areas around Lhasa, Tibet. OBJECTIVE: We assessed the efficacy of selenium supplementation on disease progression. DESIGN: A double-blind, randomized controlled trial of selenium supplementation was carried out in 324 children aged 5-15 y who had Kashin-Beck disease. Two hundred eighty children received iodized oil before being randomly assigned to receive selenium or placebo, and a control group of 44 subjects was not supplemented at all. Clinical and radiologic signs, selenium status, urinary iodine, and thyroid function were evaluated at baseline and at 12 mo. RESULTS: The frequencies of joint pain, decreased joint mobility, and radiologic abnormalities were not significantly different between the 3 groups at 12 mo. Height-for-age z scores increased significantly in the subjects who received placebo and iodine or selenium and iodine. In contrast, unsupplemented control subjects did not recover from growth retardation. Serum selenium concentrations at 12 mo were within the reference range and were significantly greater in the selenium-iodine group than in the placebo-iodine group. Serum thyroid hormone concentrations were within the reference ranges after the administration of iodine, and these values were not significantly affected by selenium supplementation. CONCLUSIONS: The results of this study do not rule out the possibility that selenium may help to prevent the occurrence of Kashin-Beck disease. However, selenium supplementation had no effect on established Kashin-Beck disease, growth, or thyroid function once iodine deficiency was corrected. These results suggest that iodine, but not selenium, deficiency should be corrected in Tibetan children with Kashin-Beck disease.

Progressive Chagas' cardiomyopathy is associated with low selenium levels.

Selenium (Se) deficiency is linked with some cardiomyopathies. Its status was determined in 170 patients with chronic Chagas' disease from 2 Brazilian regions (Rio de Janeiro and Belo Horizonte), clinically stratified into groups as follows: indeterminate or asymptomatic (IND); cardiac asymptomatic (CARDa); cardiac symptomatic with moderate to severe heart dysfunction (CARDb); and healthy adults (HA), used for comparison. In most HA, Se levels were normal, excluding an overall Se deficiency. Se was significantly lower in CARDb than in HA, IND, or CARDa patients. This was not associated with a concomitant decrease in activity of glutathione peroxidase. Thyrotropin was normal, excluding iodine deficiency. Se correlated positive and significantly with ventricular ejection fraction (assessed via echocardiography). Asymptomatic children with acute Chagas' disease had normal Se as well as 5 noninfectious cases of cardiomyopathy. Low Se was found in 6 of 10 chagasic patients with digestive megasyndromes. Thus, the decrease in Se in chagasic patients seems to be a biological marker for Trypanosoma cruzi infection and related to the progression of pathology.