Impact of contact tracing, respect of isolation, and lockdown in reducing the number of cases infected with COVID-19. Case study: Tunisia's response from March 22 to May 4, 2020.

BACKGROUND: Coronavirus disease 2019 (COVID-19) has spread rapidly across the world. Tunisia reacted early to COVID-19, resulting in a low number of infections during the first wave of the pandemic. This study was performed to model the effects of different interventions on the evolution of cases and to compare these with the Tunisian experience. METHODS: A stochastic transmission model was used to quantify the reduction in number of cases of COVID-19 with the interventions of contact tracing, compliance with isolation, and a general lockdown. RESULTS: In the model, increasing contact tracing from 20% to 80% after the first 100 cases reduced the cumulative number of infections (CNI) by 52% in 1 month. Similarly, increased compliance with isolation from 20% to 80% after the first 100 cases reduced the CNI by 45%. These reductions were smaller if the interventions were implemented after 1000 cases. A general lockdown reduced the CNI by 97% after the first 100 cases. Tunisia implemented its general lockdown after 75 cases were confirmed, which reduced the cumulative number of infected cases by 86% among the general population. CONCLUSIONS: This study shows that the early application of critical interventions contributes significantly to reducing infections and the evolution of COVID-19 in a country. Tunisia's early success with the control of COVID-19 is explained by its quick response.

Explaining income-related inequalities in cardiovascular risk factors in Tunisian adults during the last decade: comparison of sensitivity analysis of logistic regression and Wagstaff decomposition analysis.

BACKGROUND: It is important to quantify inequality, explain the contribution of underlying social determinants and to provide evidence to guide health policy. The aim of the study is to explain the income-related inequalities in cardiovascular risk factors in the last decade among Tunisian adults aged between 35 and 70 years old. METHODS: We performed the analysis by applying two approaches and compared the results provided by the two methods. The methods were global sensitivity analysis (GSA) using logistic regression models and the Wagstaff decomposition analysis. RESULTS: Results provided by the two methods found a higher risk of cardiovascular diseases and diabetes in those with high socio-economic status in 2005. Similar results were observed in 2016. In 2016, the GSA showed that education level occupied the first place on the explanatory list of factors explaining 36.1% of the adult social inequality in high cardiovascular risk, followed by the area of residence (26.2%) and income (15.1%). Based on the Wagstaff decomposition analysis, the area of residence occupied the first place and explained 40.3% followed by income and education level explaining 19.2 and 14.0% respectively. Thus, both methods found similar factors explaining inequalities (income, educational level and regional conditions) but with different rankings of importance. CONCLUSIONS: The present study showed substantial income-related inequalities in cardiovascular risk factors and diabetes in Tunisia and provided explanations for this. Results based on two different methods similarly showed that structural disparities on income, educational level and regional conditions should be addressed in order to reduce inequalities.

Premature mortality attributable to smoking among Tunisian men in 2009.

INTRODUCTION: Tobacco smoking is a significant public health threat in the world, a risk factor for many diseases, and has been increasing in prevalence in many developing countries. In this study, we aimed to estimate the burden of premature deaths attributable to smoking among Tunisian men aged 35-69 years in 2009. METHODS: The number of deaths attributable to smoking was estimated using the population attributable risk fraction method. Smoking prevalence was obtained from a nationally representative survey. Causes of death were obtained from the registry of the National Public Health Institute. Relative risks were taken from the American Cancer Society Prevention Study (CPS-II). RESULTS: Total estimated premature deaths attributable to smoking among men in Tunisia were 2601 (95% CI: 2268-2877), accounting for 25% (95% CI: 23.3-26.6) of total male adult mortality. Cancer, cardiovascular and respiratory diseases were the major causes of premature deaths attributable to smoking with 1272 (95% CI: 1188-1329), 966 (95% CI: 779-1133) and 364 (300-415) deaths, respectively. CONCLUSIONS: Tobacco smoking is highly relevant and is related to substantial premature mortality in Tunisia, around double that estimated for the region as a whole. This also has not decreased over the past 20 years. Urgent actions are needed to reduce this pandemic.

Postmenopausal hypertension, abdominal obesity, apolipoprotein and insulin resistance.

This study aimed to evaluate the association of abdominal obesity, apolipoprotein and insulin resistance (IR) with the risk of hypertension in postmenopausal women. We analyzed a total of 242 women aged between 35 and 70 years. Blood pressure (BP), anthropometric indices, lipid profile, fasting glucose, insulin, C-reactive protein (CRP) and apolipoprotein concentrations were measured. Homeostasis model assessment (HOMA) was used to assess IR. Hypertension was defined as a systolic BP (SBP) ≥140 mmHg and/or diastolic BP (DBP) ≥90 mmHg or current treatment with antihypertensive drugs. Women with hypertension showed significantly higher mean values of age, SBP and DBP, waist circumference (WC), fasting plasma glucose (FPG), insulin, HOMAIR and the apolipoprotein B (apoB). When analyses were done according to the menopausal status, higher prevalence of hypertension was observed in postmenopausal women (72.8% vs. 26.0%, p < 0.001) compared to their premenopausal counterparts. Postmenopausal women showed also significantly higher mean values of SBP and DBP, WC, HOMAIR and apoB. Multivariate linear regression analysis revealed that SBP was significantly affected by WC (p = 0.034), apoB (p = 0.038) and log HOMAIR (p = 0.007) in postmenopausal women. The interaction models revealed significant interaction between WC, apoB and log HOMAIR (WC×apoB×log HOMAIR) on SBP (p = 0.001) adjusted for age. In a multivariate logistic regression, adjusting for age and apoB, WC (p = 0.001), log HOMAIR (p = 0.007) and menopause (p = 0.008) were significantly associated with higher risk for hypertension. These results suggest that changes in WC, apoB and IR accompanying menopause lead to a greater prevalence of hypertension in postmenopausal women.

Establishing International Blood Pressure References Among Nonoverweight Children and Adolescents Aged 6 to 17 Years.

BACKGROUND: Several distributions of country-specific blood pressure (BP) percentiles by sex, age, and height for children and adolescents have been established worldwide. However, there are no globally unified BP references for defining elevated BP in children and adolescents, which limits international comparisons of the prevalence of pediatric elevated BP. We aimed to establish international BP references for children and adolescents by using 7 nationally representative data sets (China, India, Iran, Korea, Poland, Tunisia, and the United States). METHODS AND RESULTS: Data on BP for 52 636 nonoverweight children and adolescents aged 6 to 19 years were obtained from 7 large nationally representative cross-sectional surveys in China, India, Iran, Korea, Poland, Tunisia, and the United States. BP values were obtained with certified mercury sphygmomanometers in all 7 countries by using standard procedures for BP measurement. Smoothed BP percentiles (50th, 90th, 95th, and 99th) by age and height were estimated by using the Generalized Additive Model for Location Scale and Shape model. BP values were similar between males and females until the age of 13 years and were higher in males than females thereafter. In comparison with the BP levels of the 90th and 95th percentiles of the US Fourth Report at median height, systolic BP of the corresponding percentiles of these international references was lower, whereas diastolic BP was similar. CONCLUSIONS: These international BP references will be a useful tool for international comparison of the prevalence of elevated BP in children and adolescents and may help to identify hypertensive youths in diverse populations.

Association of genetic variants in the FTO gene with metabolic syndrome: A case-control study in the Tunisian population.

AIMS: Variants in the fat mass and obesity-associated gene (FTO) are associated with obesity and type 2 diabetes. However, the association of FTO variants in the MENA (Middle East and North Africa) region with MetS is largely unknown. In this study, we aimed to investigate the association of FTO gene with MetS and its components in Tunisian population. METHODS: Two variants in the FTO gene were genotyped: rs1421085 T>C and rs8057044 A>G in cases and controls from Tunisian population. Anthropometric and biochemical parameters were assessed. Metabolic syndrome was defined according to the International Diabetes Federation (IDF). RESULTS: The FTO rs1421085 variant conferred an increased risk to MetS (OR=1.61, 95% CI=1.14-2.26, P=0.024) that was abolished when adjusted for fasting plasma glucose (FPG), suggesting that the association may be due to variation in FPG levels. Indeed, this variant was associated to FPG (OR = 1.7, 95% CI=1.23-2.44, P=0.002) independently from BMI or age. The second polymorphism rs8057044 was associated with high blood pressure levels (OR=1.45, 95% CI=1.06-1.99, P=0.019). CONCLUSIONS: This is the first study highlighting the association between FTO gene variants and MetS in Tunisian population. These findings provide evidence that FTO gene may play a critical role in leading to MetS in Tunisian population.

Forecasting Tunisian type 2 diabetes prevalence to 2027: validation of a simple model.

BACKGROUND: Most projections of type 2 diabetes (T2D) prevalence are simply based on demographic change (i.e. ageing). We developed a model to predict future trends in T2D prevalence in Tunisia, explicitly taking into account trends in major risk factors (obesity and smoking). This could improve assessment of policy options for prevention and health service planning. METHODS: The IMPACT T2D model uses a Markov approach to integrate population, obesity and smoking trends to estimate future T2D prevalence. We developed a model for the Tunisian population from 1997 to 2027, and validated the model outputs by comparing with a subsequent T2D prevalence survey conducted in 2005. RESULTS: The model estimated that the prevalence of T2D among Tunisians aged over 25 years was 12.0% in 1997 (95% confidence intervals 9.6%-14.4%), increasing to 15.1% (12.5%-17.4%) in 2005. Between 1997 and 2005, observed prevalence in men increased from 13.5% to 16.1% and in women from 12.9% to 14.1%. The model forecast for a dramatic rise in prevalence by 2027 (26.6% overall, 28.6% in men and 24.7% in women). However, if obesity prevalence declined by 20% in the 10 years from 2013, and if smoking decreased by 20% over 10 years from 2009, a 3.3% reduction in T2D prevalence could be achieved in 2027 (2.5% in men and 4.1% in women). CONCLUSIONS: This innovative model provides a reasonably close estimate of T2D prevalence for Tunisia over the 1997-2027 period. Diabetes burden is now a significant public health challenge. Our model predicts that this burden will increase significantly in the next two decades. Tackling obesity, smoking and other T2D risk factors thus needs urgent action. Tunisian decision makers have therefore defined two strategies: obesity reduction and tobacco control. Responses will be evaluated in future population surveys.

Appraising financial protection in health: the case of Tunisia.

Despite the remarkable progress in expanding the coverage of social protection mechanisms in health, the Tunisian healthcare system is still largely funded through direct out-of-pocket payments. This paper seeks to assess financial protection in health in the particular policy and epidemiological transition of Tunisia using nationally representative survey data on healthcare expenditure, utilization and morbidity. The extent to which the healthcare system protects people against the financial repercussions of ill-health is assessed using the catastrophic and impoverishing payment approaches. The characteristics associated with the likelihood of vulnerability to catastrophic health expenditure (CHE) are examined using multivariate logistic regression technique. Results revealed that non-negligible proportions of the Tunisian population (ranging from 4.5 % at the conservative 40 % threshold of discretionary nonfood expenditure to 12 % at the 10 % threshold of total expenditure) incurred CHE. In terms of impoverishment, results showed that health expenditure can be held responsible for about 18 % of the rise in the poverty gap. These results appeared to be relatively higher when compared with those obtained for other countries with similar level of development. Nonetheless, although households belonging to richer quintiles reported more illness episodes and received more treatment than the poor households, the latter households were more likely to incur CHE at any threshold. Amongst the correlates of CHE, health insurance coverage was significantly related to CHE regardless of the threshold used. Some implications and policy recommendations, which might also be useful for other similar countries, are advanced to enhance the financial protection capacity of the Tunisian healthcare system.

Mediterranean studies of cardiovascular disease and hyperglycemia: analytical modeling of population socio-economic transitions (MedCHAMPS)--rationale and methods.

OBJECTIVES: In response to the escalating epidemic of cardiovascular disease (CVD) in the Mediterranean Region (MR), an international collaboration aiming at understanding the burden of CVD and evaluating cost-effective strategies to combat it was recently established. This paper describes the rationale and methods of the project MedCHAMPS to disseminate this successful experience. METHODS: The framework of MedCHAMPS is exceptional in combining multiple disciplines (e.g. epidemiology, anthropology, economics), countries [Turkey, Syria, occupied Palestinian territory (oPt), Tunisia, UK, Ireland], research methods (situational and policy analysis, quantitative and qualitative studies, statistical modeling), and involving local stakeholders at all levels to assess trends of CVD/diabetes in the society and attributes of the local health care systems to provide optimal policy recommendations to reduce the burden of CVD/diabetes. RESULTS AND CONCLUSIONS: MedCHAMPS provides policy makers in the MR and beyond needed guidance about the burden of CVD, and best cost-effective ways to combat it. Our approach of building developed-developing countries collaboration also provides a roadmap for other researchers seeking to build research base into CVD epidemiology and prevention in developing countries.

Association of MICA-129 polymorphism with nasopharyngeal cancer risk in a Tunisian population.

Major histocompatibility complex (MHC) class I chain-related A (MICA) molecules mediate natural killer (NK) cell activation and T lymphocyte co-stimulation. A polymorphic methionine (met) to valine (val) variation at amino acid position 129 of the alpha2 heavy chain domain is in linkage disequilibrium with other allelic changes and seems to categorize MICA alleles into strong and weak binder of NKG2D receptor and thereby to influence effector cell function. We investigated here whether MICA-129 dimorphism is associated with susceptibility to/or resistance against developing nasopharyngeal cancer (NPC). DNA from 130 NPC patients and 180 healthy individuals from Tunisia were genotyped for MICA-129 variation. We found a higher frequency of MICA-129 val/val genotype in patients than in controls (corrected p value = 0.02) that could suggest a tumor escape mechanism because of failure to activate NK cells by MICA-129 val allele or absence of NK cell activation because of absence of MICA-129 met allele in individuals otherwise predisposed to viral/environmental factors.

Nutritional status of Tunisian adolescents: associated gender, environmental and socio-economic factors.

OBJECTIVE: To assess the nutritional status of Tunisian adolescents and associated factors. DESIGN: A cross-sectional study based on a national stratified random cluster sample. SUBJECTS AND METHODS: In all, 1,295 boys and 1,577 girls aged 15-19 years, of whom 28.4 % had already left school. Socio-economic characteristics of the parents, anthropometric measurements, food behaviours and physical activity of the adolescents were recorded during home visits. RESULTS: Prevalence of underweight, overweight and obesity (WHO/National Center for Health Statistics reference) were, respectively, 8.1 %, 17.4 % and 4.1 % among boys and 1.3 %, 20.7 % and 4.4 % among girls; abdominal obesity was highly prevalent among both sexes. Prevalence of overweight differed by region (from 11.5 % to 22.2 %) and was higher in urban v. rural areas for males (21.7 % v. 10.4 %) but not for females (21.7 % v. 19.2 %). These differences were partially mediated by socio-economic and lifestyle factors for males. For females, influence of cultural factors is hypothesised. In rural areas, overweight was more prevalent among boys of higher economic level households, having a working mother or a sedentary lifestyle; for girls, prevalence increased with the level of education of the mother. In urban areas, prevalence of overweight was related to eating habits: it was higher for boys with irregular snacking habits and for girls skipping daily meals. Urban girls having left school were also more overweight. CONCLUSION: Overweight and abdominal obesity in late adolescence have become a true public health problem in Tunisia with the combined effects of cultural tradition for girls in rural areas, and of rapid economic development for boys and girls in cities.