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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 R 0 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 R 0 and public health measures but also to acquisition of defective fitting in virus within a population should be tested., (© 2024. The Author(s).)

Objectives: Helicobacter pylori is a worldwide infection, but little is known about the efficacy of treatment for H. pylori infection in HIV-positive patients. The goal of this work was to evaluate outcomes after first-line H. pylori treatment and identify risk factors for failure in HIV-positive patients., Methods: This registry study of unmatched H. pylori-infected HIV-positive patients and HIV-negative obese pre-bariatric surgery controls was performed in a tertiary university hospital. Cases were enrolled from 2006 to 2017, controls from 2007 to 2014, and both received standard of care. An additional 'optimal' subgroup of cases was enrolled prospectively from 2017 to 2019 which was treated only on the basis of antibiogram, drug interaction search and additional support by one referent physician. Helicobacter pylori eradication failure rates were compared according to clinical, microbiological and pathological parameters and treatment., Results: We analysed 258 HIV-positive patients and 204 HIV-negative control patients. Helicobacter pylori eradication failure rates were markedly greater in cases (24.1%) than in controls (8.8%). The proportions of levofloxacin and metronidazole resistance were greater in cases than in controls (P < 0.05). Among cases treated with H. pylori triple therapy (S3T), the 'optimal' subgroup experienced a 9.5% failure rate vs. 28.6% with other strategies (P = 0.01). Risk factors for failure were H. pylori treatment strategy, exposure to antiretroviral treatment, and alcohol status. Overall, positive HIV status was a risk factor for S3T eradication failure., Conclusions: Patients co-infected with H. pylori and HIV frequently failed to eradicate H. pylori and this was related to treatment strategy, antiretroviral exposure and lifestyle., (© 2021 British HIV Association.)

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.

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., (© 2019 John Wiley & Sons Ltd.)

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-β 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-β 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.

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., (© 2021 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.)

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.

The present minireview traces the road leading to discovery of selenium, formerly appointed as a toxic element that became later a bioelement, which is necessary for the proper functioning of living organisms. Selenium occurs in human and animal bodies either in the form of seleno-Lcysteine or its dimeric form seleno-L-cystine as a crucial component of selenoenzymes or selenoproteins. Selenium atom represents an integral component of the enzyme active site of different forms of glutathione peroxidase, which catalyzes conversion of hydrogen peroxide and organic hydroperoxides into the water and corresponding alcohols. A revolutionary breakthrough in the field of endocrinology came with the identification of different forms of iodothyronine deiodinase as selenoenzymes, which play an important role in the metabolism of thyroid hormone. The role of selenium in immune function and autoimmune thyropathies that might be associated with selenium deficiency are reported and discussed. This minireview also brings forward novel directions of organoselenium compounds or selenium nanoparticles in cancer therapy. Based on the update of available literature and the author's experimental experience, the minireview can be devoted to clinicians and medical students., (© 2024 Julius Brtko et al., published by Sciendo.)

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.

SUMMARYThe prevalence of Helicobacter pylori infection is decreasing in developed countries. In this study we included 22 612 patients in whom a first culture of gastric biopsy (routinely performed in our medical centres) yielded an interpretable result over a 20-year period (1988-2007) in Brussels. The effects of patients' age, gender and ethnic background were analysed. The overall proportion of H. pylori-infected patients was 37·7%, with a progressive decline over time (P<10-5). A gender effect was observed in adults. The lowest infection rate was observed in Western European patients (n=11 238) with respectively 36·2% and 15·2% infected subjects in 1988 and 2007, compared to 71·7% and 40% in North African patients (n=3200) (P<10-5). However, no trend of decline was observed over time in North African children aged 9 years. These data show the effects of time, age and ethnicity on the prevalence of H. pylori infection, and its complex heterogeneity in the same cosmopolitan urban area. [ABSTRACT FROM AUTHOR]

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.

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., (Copyright © 2015 Elsevier Inc. All rights reserved.)