[Six Sigma driven QC management in hepatitis C serology]. / La méthodologie six sigma dans la gestion des contrôles de qualité en sérologie de l'hépatite C.

The Westgard quality control (QC) rules are often applied in infectious diseases serology to validate the quality of results, but this requires a reasonable tradeoff between maximum sensitivity to errors and minimum false rejections. This article, in addition to illustrate the six sigma methodology in the QC management of the (anti-HCV Architect®) test, it discusses the main influencing factors on sigma value. Data from low positive and in-kit control materials spreading over 6 months and using four reagent kits, were used to calculate the precision of the test. The difference between the control material reactivity and the cut-off defined the error budget. Sigma values were > 6, which indicates that the method produces four erroneous results per million tests. The application of the six sigma concept made it possible to argue the choice of the new QC strategy (use of 13S rule with one positive control) and to relax the existing QC rules. This work provides a framework for infectious diseases serology laboratories to evaluate tests performances against a quality requirement and design an optimal QC strategy.

Who are the Best Scientists in Tunisia? Analysis of the 2023 edition of the "Research.com" platform.

AIM: Describe the performance of scientists assigned to Tunisian research structures, according to their academic disciplines, according to the Research.com platform https://research.com/), in 2023. METHODS: This is a reading focused on the productivity of scientists working in Tunisia, of the new 2023 edition of the international Research.com platform, ensuring the monitoring of 26 academic disciplines and 166880 scientists, affiliated with around three thousand research structures, and representing 1% of leading scientists in a discipline. In this platform, the ranking of researchers was based on the D-index indicator (equivalent to the h-index of a given discipline), calculated as of December 21, 2022. RESULTS: Around fifteen of the "Best Scientists", affiliated with Tunisian research structures, were selected by the Research.com platform (2023), belonging to eight disciplines including particularly "Chemistry", "Plant Sciences and Agronomy" and "Engineering and Technology". These researchers were attached to seven establishments including the universities of "Sfax" and "Monastir" and the "Borj Cedria - Sidi Thabet Biotechnology Center". Among these winners: Professors Moncef NASRI (Sfax, "Biology and Biochemistry", D-index=74), Chedly ABDELLY (Borj Cedria, "Agronomy", D-index=72) and Adel M. ALIMI (Sfax, "computer science¼, D-index=44). CONCLUSION: In Tunisia, the list of "Best scientists" in the Research.com ranking (2023) made it possible to identify two colleges of leaders in scientific research ("Health Sciences" and "Fundamental Sciences"), constituting priority consortia for strengthening the national strategy to support the mobility and networking of researchers, as well as the proliferation and visibility of their publications.

Epidemiology of metabolic syndrome in Tunisia. HSHS 5 study.

OBJECTIVE: To measure the prevalence of metabolic syndrome and its components in the HSHS cohort (Hammam Sousse, Tunisia), in 2009, and to identify its determining factors. METHODS: This was a descriptive epidemiological study of the "community based" type having focused on a random sample of people aged 20 and over. The metabolic syndrome was defined according to the criteria of the "International Diabetes Federation" (IDF 2005) and those of the "National Cholesterol Education Program-Adult Treatment Panel III" (NCEP-ATP III, 2001). RESULTS: The study involved 1441 people including 960 women (66.6%). The age- and sex-adjusted prevalences of increased waist circumference, blood pressure, blood sugar and triglycerides, and decreased HDL-cholesterol were respectively 63.2%, 95%CI[62.5-63.8]; 47.7%, 95%CI[47.4-48.6]; 25.7%, 95%CI[25.1-26.2]; 11.9%, 95%CI[11.4-12.3] and 65,6%, 95%CI[65.0-66.2], according to IDF thresholds and 37.4%, 95%CI[36.3-37.6]; 45.7%, 95%CI[45.4-46.6]; 13.8%, 95%CI[13.4-14.2]; 8.4%, 95%CI[8.0-8.7] and 61.9%, 95%CI[61.2-62.5], according to those of the NCEP-ATP III. The prevalence of metabolic syndrome adjusted for age and sex was 36.5% 95%CI[33.0%-38.9%] according to the IDF definition and 23.0% 95%CI[20.4%-25.6%] according to that of NCEP-ATP III. The multivariate study by logistic regression made it possible to retain three significant independent determining factors of the metabolic syndrome: age ≥40 years, low level of physical activity and family history of diabetes mellitus with respectively adjusted ORs of 3.77 95%CI[2.70-5.27], 1.39 95%CI[1.01-1.89], 1.62 95%CI[1.21-2.15], according to IDF and 5.87 95%CI[3.88 -8.88], 1.47 95%CI[1.07-2.01] and 1.45 95%CI[1.07-1.96], according to NCEP-ATP III . CONCLUSION: With this high prevalence rate of the metabolic syndrome, the establishment of an action plan would be essential. This plan should be based on the combination of the promotion of physical activity and screening for the components of the metabolic syndrome, particularly in subjects aged 40 or over, with a family history of diabetes mellitus.

Epidemiology of obesity in Tunisia: HSHS4 study (Hammam Sousse Sahloul Heart Study).

INTRODUCTION: The HSHS study is a community-based survey focused on cardiovascular risk factors. AIM: The objectives of this specific analysis were to determine the prevalence of obesity and overweight in the general population of Hammam Sousse (Tunisia) and to identify their predisposing factors. METHODS: HSHS was conducted with a random sample of households, composed by the EPI (Expanded Program on Immunization) technique. All people aged 20 and over, met on the day of the survey, at their homes, were included. Obesity, overweight and weight overload were defined with reference to Body Mass Index (BMI): Obesity (BMI≥30 kg/m²), Overweight (25≤BMI (25≤BMI <30 kg/m²), weight overload (BMI≥25 kg/m²). Physical activity was evaluated according to the level of energy equivalents (Metabolic Equivalent Task) or MET, this level was considered low below 600 MET min/week. The calculated prevalences were accompanied by their 95%CI (Confidence Intervals). The multivariate study was conducted by logistic regression, measuring the adjusted Odds Ratio (ORa) Results: The study population was composed of 481 men and 960 women, (sex-ratio=0.50). The age ranged from 20 to 96 years with an average of 49.6±16444 years in men and 46.6±16.2 in women (p <0.05). After adjusting for age and sex, the prevalence rates of overweight, obesity, and weight overload were respectively 36.18%, 95%CI [35.38%-36.62%], 28.11%; 95%CI [27.42%-28.58%] and 64.28%; 95%CI [63.38%-64.62%]. Obesity was determined, in addition to female sex, age 40 or over and low level of education, by low level of physical activity (ORa=1.56; 95%CI [1.21-2.03], p<10-2). CONCLUSION: In adults, the prevalence of obesity and overweight were high and determined by insufficient physical activity. The results of this study, which can be extrapolated to other Tunisian cities, should motivate the general population to establish a heart health promotion plan, in partnership with civil society.

[Epidemiology of smoking in the male population in Tunisia. HSHS Study 6].

OBJECTIVES: To determine the prevalence of smoking in the male population of Hammam Sousse (Tunisia), to describe its modalities and to analyse its determining factors. METHODS: This was a "community-based" study, carried out on a random sample of households, including a population of males aged 20 or over. The data were collected, at home, using a specific support consisting of a lifestyle questionnaire, a physical examination, and a biological assessment, oriented towards cardiovascular risk factors. Smoking behaviour covered both forms of cigarettes and Narghile. "Current smokers" included all men declaring that they smoked at the time of the survey, including "regular smokers", who smoked daily at the time of the survey, and "occasional smokers", less than once a day. The group of "non-smokers" at the time of the survey was the sum of "ex-smokers" and those "who had never smoked". The prevalences were calculated after their weighting according to age and the adjusted odds ratios were measured following a multivariate study by logistic regression. RESULTS: The study population was composed of 481 men with an average age of 49.6±16.35 years and a median of 49 years. Mean body mass index and systolic blood pressure were 26.9 kg/m2 ±4.20 and 151.9 mmHg±24.36, respectively. After adjusting for age, the proportions of current users, former users and subjects who had never used tobacco (all forms combined) were respectively 50.4% (95% CI [49.49-51.3]), 17.4% (95% CI [16.71-18.08]) and 30.9% (95% CI [30.06-31.73]). Daily cigarette consumption was characterized by an average onset at age 20.1±6.91 years, an average duration of 27.0±15.22 years and an average amount of 17.6±9.8 cigarettes smoked per day. After adjusting for age, level of education, and socioeconomic level, smoking behaviour was attributed to a single independent risk factor: the presence of a smoker in the family, with an adjusted OR of 45.17 (p (p<10-3) for regular cigarette smokers, and 29.66 for regular tobacco users of all forms. CONCLUSION: Smoking would be a real endemic in Tunisia, threatening the cardiovascular health of the country. The national health system is called upon to strengthen its action plan for the prevention and control of smoking, in all living environments: family, school, work, health centre, etc.

Epidemiology of elderly dependency in Tunisia. HSHS study 7.

AIM: Measure the functional autonomy of elderly people and identify its components and determinants in the HSHS (Hammam-Sousse Sahloul Heart Study) population (phase 2009, Tunisia). METHODS: This study was concerned with the quality of life of elderly people aged 65 years or more, living at home from the HSHS cohort divided into two groups: young-old (65-74 years old) and old-old (≥75 years old). The autonomy was assessed using the "Activities of Daily Living" (ADL) scale ranging from 0 to 6, the "Instrumental Activities of Daily Living" (IADL) scale ranging from 0 to 8 and, the combined scale ranging from zero to 14, iso-weighted at one point per activity. Autonomy in daily activities was retained for an ADL score=6, and an IADL score (F=8; H=5). Subjects with an overall score (sum of ADL and IADL) of 10-14 points were considered globally autonomous. RESULTS: The population study was predominantly female (sex-ratio=0,6) with an important proportion of old-old (M=43%, F=37%). Autonomy rates were by ADL (M=57.4%, F=36.1%, p < 10-2), IADL (M=16%, F=23.9%), and by combined score (M=60.6%, F=69%, p=NS). The typology of dependency was dominated by transferring (M=35%, F=61%) and bathing (M=14%, F=19%) for ADL activities, and shopping (M=36%, F=49%) and the use of means of transport (M=22%, F=43%) for IADL activities. After adjustment, autonomy in daily activities was attributed to two independent factors: male sex (ORa=3.98, CI95% [1.328-11.971]) and age group 65-75 (ORa=4.04, CI95% [2.039- 8.025]). Autonomy in instrumental activities was associated with age group (ORa=31.5, CI95% [4.087-233.514]). Finally, overall autonomy (current and instrumental) was associated independently after logistic regression, with four independent factors, two of which were not modifiable: being female (ORa=3.1, CI95% [1.2-8.1]) and 65 to 75 years (ORa=6.2, CI95% [3.1-12.3]) and two modifiable factors: no recent hospitalization (ORa=3.8, CI95% [1.4-10.4]) and a sufficient level of physical activity (ORa=2.6, CI95% [1.3-5.3]). CONCLUSION: The physical dependency rate of the elderly is very high in Tunisia. The promotion of physical activity, the extension of similar studies and the development of could improve the support of these people.

Variation of soil properties with sampling depth in two different light-textured soils after repeated applications of urban sewage sludge.

Semi-arid agricultural soils have increasingly been subjected to urban sewage sludge (USS) applications due to accelerated soil depletion and shortages in manure supply. Research studies addressing USS reuse have mostly been conducted in cropping systems and focused on changes in topsoil properties of a given texture. Therefore, sludge-soil interactions could be largely influenced by the presence of plants, soil particle composition and depth. In this field study, two agricultural soils (sandy, S and sandy loam, SL) received simultaneously four annual USS applications of 40, 80, and 120 t ha-1 year-1 in absence of vegetation. Outcomes showed the increase of carbon and macronutrients in both soils proportionally to USS dose especially in the topsoil profile (0-20 cm). Subsoil (20-40 cm) was similarly influenced by sludge rates, showing comparable variations of fertility parameters though at significant lower levels. The depth-dependent improvement of soil fertility in both layers enhanced the microbiological properties accordingly, with significant variations in soil SL characterized by a higher clay content than soil S. Besides, positive correlations between increases in sludge dose, salinity, trace metals, and enzyme activities in both soils indicate that excessive sludge doses did not cause soil degradation or biotoxic effects under the described experimental conditions. In particular and despite high geoaccumulation indices of Ni in both soils and profiles, the global concentrations of Cu, Ni, Pb, and Zn were still below threshold levels for contaminated soils. In addition, the maintenance of pH values within neutral range and the increase of organic matter content with respect to control would have further reduced metal availability in amended soils. Therefore, we could closely investigate the effects of texture and depth on the intrinsic resilience of each soil to cope with repetitive USS applications.

Morbidity diagnosed in an internal medicine department of a secondary care center (Msaken, Sousse, Tunisia).

INTRODUCTION: Internal Medicine is an essential component of the clinical platform of regional hospitals (relay between district hospitals and reference university hospitals). OBJECTIVE: To describe the morbidity diagnosed at Medicine department of the regional hospital of Msaken (Sousse, Tunisia), taken as a tracer of intermediate hospitals. METHODS: This descriptive study covered all of the patients hospitalized, during the year 2015, in the Internal Medicine department of the Msaken regional hospital. The data were disseminated through a "Minimum Clinical Summary". Morbidity was classified according to ICD-10. Hospital readmission was tested with reference to <28 days. RESULTS: A total of 594 patients were hospitalized in Internal Medicine, with a sex ratio of 0.95 and a median age of 67 years [54-78]. "Diseases of the respiratory system" were the first category of diagnosed morbidity (58%), dominated by acute bronchitis, followed by "endocrine, nutritional and metabolic diseases" in women (including insulin-dependent diabetes) and category of infectious diseases in men (including erysipelas). The former patients of the service (49%) were twice as numerous among people ≥60 years old (57% vs 30% in those under 60 years). The readmission rate was 19% (29% for men versus 8% for women). The mean length of stay was 7 ± 5.7 days. The transfer rates and hospital mortality were 11.3% and 1.2%, respectively. CONCLUSION: The morbidity diagnosed at the Internal Medicine department of the Msaken regional hospital was dominated by the triad: acute bronchitis, diabetes mellitus and erysipelas, particularly in the elderly. Hence the need to strengthen the training of future family doctors in pulmonology, diabetology and infectious diseases.

Typology of morbidity diagnosed in a pediatric department of a secondary care center (Msaken, Sousse, Tunisia).

INTRODUCTION: Pediatric services are tracer services for the assessment of the integration and performance of the national health system. OBJECTIVES: Describe the typology of morbidity notified to the Pediatrics department of the Msaken regional hospital (Sousse, Tunisia) and the flow of its patients. METHODS: This is a descriptive and exhaustive study, covering all the patients hospitalized in the pediatric ward of Msaken, during the year 2015. The data were collected through medical files and medical registers. admission, based on the Minimum Clinical Summary (RCM) form. The notified diagnoses were coded according to the WHO ICD-10 classification. The main diagnosis was defined by the major pathology that led to the hospitalization. Early readmission was retained before 28 days. RESULTS: A total of 521 children were hospitalized, with a sex ratio of 1.04 and a mean age of 2 ± 3 years; 70% of the patients came from the administrative center of the governorate and 62% were infants (age

Towards new perspectives Support for Prevention to the National Health System in Tunisia.

"Prevention", a component of primary health care since Alma Ata's declaration (1978), has been a strategic axis of health policy in Tunisia for four decades. If the Tunisian Revolutionary Constitution (2014) declared in its Article 38 that "the State guarantees prevention", the regulatory texts, organizing preventive structures and its operational programs, have today become ill-suited with the global burden of disease and current scientific evidence. The analysis of current preventive practices in Tunisia, based on the "health continuum", the taxonomy of "preventive strategies" and the identification of "vulnerable populations", has shown the need to implement prevention activities. "Primordial" and "quaternary" (for the management of cardiovascular diseases and cancers), extension of the fields of health education and epidemiological surveillance, towards Therapeutic Education of Patients / Health Promotion, and health monitoring, and coverage of new groups at risk: adolescents and the elderly. Faced with the multitude of prevention structures and the fragmentation of health programs, the reform of the national preventive policy and its practices should be based on the principles of integration, relevance and efficiency, through the establishment of a National Health Protection Agency (NHPA). This ANP is called upon to launch new prevention support projects including integrated preventive medicine centers (providing periodic health examinations), hospital patient therapeutic education services and home care units. Such a reform, announcing the birth of a new generation of preventive basic health care activities in Tunisia, should be reinforced by a legal, organizational and educational basis.

Improved COVID-19 Testing by Extraction-Free SARS-CoV-2 RT-PCR.

The RNA extraction is an important checkpoint for the detection of SARS-CoV-2 in swab samples, but it is a major barrier to available and rapid COVID-19 testing. In this study, we validated the extraction-free RT-qPCR method by heat-treatment as an accurate option to nucleic acid purification in Algerian population.

Improved RT-PCR SARS-Cov2 results interpretation by indirect determination of cut-off cycle threshold value.

Clinical laboratories of the developing world are overwhelmed with RT-PCR SARS-Cov2 testing demands. It is of paramount importance that each clinical laboratory use an appropriate cut-off value in the interpretation of SARS-Cov2 real-time RT-PCR results, which is specific to their laboratory performances as ISO 15189 recommendations stipulate. We applied an indirect statistical method to a large mixed data set of Ct values (ORF1ab and N) to estimate cut-off Ct value ([~]32 cycles).we conclude that the use of indirect statistical approaches to estimate cut-off value in the interpretation of SARS-Cov2 real-time RT-PCR results may improve differential diagnosis of COVID-19 cases with low risk of infectivity, and may help to better estimates of the burden of COVID-19 disease.

Carbon mineralization, biological indicators, and phytotoxicity to assess the impact of urban sewage sludge on two light-textured soils in a microcosm.

The agricultural reuse of urban sewage sludge (USS) modifies soil properties depending on sludge quality, management, and pedo-environmental conditions. The aim of this microcosm study was to assess C mineralization and subsequent changes in soil properties after USS addition to two typical Mediterranean soils: sandy (Soil S) and sandy loam (Soil A) at equivalent field rates of 40 t ha-1 (USS-40) and 120 t ha-1 (USS-120). Outcomes proved the biodegradability of USS through immediate CO2 release inside incubation bottles in a dose-dependent manner. Accordingly, the highest rates of daily C emission were recorded with USS-120 (3.7 and 3.9 mg kg-1 d-1 for Soils S and A, respectively) after 84 d of incubation at 25 °C. The addition of USS also improved soil fertility by enhancing soil macronutrients, microbial proliferation, and protease activity. Protease showed significant correlation with N, total organic C, and heterotrophic bacteria, reflecting the biostimulation and bioaugmentation effects of sludge. Soil indices like C/N/P stoichiometry and metabolic quotient (qCO2 ) varied mostly with mineralization rates of C and P in both soils. Despite a significant increase of soil salinity and total heavy metal content (lead, nickel, zinc, and copper) with USS dose, wheat germination was not affected by these changes. Both experimental soils showed intrinsic (Soil A) and incubation-induced (Soil S) phytotoxicities that were alleviated by USS addition. This was likely due to the enhancement of biodegradation and/or retention of phytotoxicants originating from previous land uses. Urban sewage sludge amendments could have applications in soil remediation by reducing the negative effects of allelopathic and/or anthropogenic phytoinhibitors.

Impact of urban sewage sludge on soil physico-chemical properties and phytotoxicity as influenced by soil texture and reuse conditions.

Urban sewage sludge (USS) is increasingly applied to agricultural soils, but mixed results have been reported because of variations in reuse conditions. Most field trials have been conducted in cropping systems, which conceal intrinsic soil responses to sludge amendments due to the rhizosphere effect and farming practices. Therefore, the current field study highlights long-term changes in bare soil properties in strict relationship with soil texture and USS dose. Two agricultural soils (loamy sand [LS] and sandy [S]) were amended annually with increasing sludge rates up to 120 t ha-1 yr-1 for 5 yr under unvegetated conditions. Outcomes showed a USS dose-dependent variation of all studied parameters in topsoil samples. Soil salinization was the most significant risk related to excessive USS doses. Total dissolved salts (TDS) in saturated paste extracts reached the highest concentrations of 37.2 and 43.1 g L-1 in S soil and LS soil, respectively, treated with 120 t USS ha-1 yr-1 . This was also reflected by electrical conductivity of the saturated paste extract (ECe ) exceeding 4,000 µS cm-1 in both treatments. As observed for TDS, fertility indicators and bioavailable metals varied with soil texture due to the greater retention capacity of LS soil owing to higher fine fraction content. Soil phytotoxicity was estimated by the seed germination index (GI) calculated for lettuce, alfalfa, oat, and durum wheat. The GI was species dependent, indicating different degrees of sensitivity or tolerance to increasing USS rates. Lettuce germination was significantly affected by changes in soil conditions showing negative correlations with ECe and soluble metals. In contrast, treatment with USS enhanced the GI of wheat, reflecting higher salinity tolerance and a positive effect of sludge on abiotic conditions that control germination in soil. Therefore, the choice of adapted plant species is the key factor for successful cropping trials in sludge-amended soils.

TSH continuous reference intervals by indirect methods: A Comparisons to Partitioned Reference Intervals.

OBJECTIVE: To establish continuous reference intervals for TSH by data mining, using quantile regression with restricted cubic splines model. DESIGN AND METHOD: TSH results (n=13,333) were collected for a four years period (between March 2015 and February 2020). After an exclusion step, TSH results (n=8838) were used to derive continuous reference intervals (i.e. 2.5th and 97.5th percentiles) spanning 18-90 years of age, using quantile regression with restricted cubic splines (RCS) model, then compared to age-partitioned reference intervals generated by Bhattacharya analysis. RESULTS: Despite similar reference intervals to the Bhattacharya analysis, continuous reference intervals appeared to give a more accurate and consistent estimation of the upper reference limits (i.e.97.5thpercentiles) with complex age-related variations in serum TSH concentrations. CONCLUSION: Our results suggest that quantile regression with RCS model appears to be a very useful tool available for clinical laboratories to establish local continuous TSH reference intervals.

Improved COVID-19 testing by extraction free SARS-Cov-2 RT-PCR

The RNA extraction is an important checkpoint for the detection of SARS-CoV-2 in swab samples, but it is a major barrier to available and rapid COVID-19 testing. In this study, we validated the extraction-free RT-qPCR method by heat-treatment as an accurate option to nucleic acid purification in Algerian population.

The satisfaction of patients hospitalized in the surgical departments of a general hospital. Case study of Sahloul hospital in Sousse (Tunisia).

OBJECTIVE: Measure the overall and specific satisfaction rates of patients hospitalized in surgical services in Sahloul University Hospital in Sousse during the year 2018. METHODS: The study population was recruited by a quota sample of hospitalized patients in the surgical departments of Sahloul University Hospital in Sousse. Data collection was done via a patient satisfaction questionnaire, administered to outgoing patients. The questionnaire was composed of 33 items exploring technical, administrative, logistical and relational dimensions. Overall patient satisfaction, called "reactivity", was defined by a concomitant positive response to the three questions exploring satisfaction, recommendation and loyalty. RESULTS: A total of 735 patients hospitalized in six surgical departments were included (general surgery, orthopedics, maxillofacial surgery, urology, neurosurgery and cardiovascular surgery). The rates of "satisfaction", "recommendation" and "loyalty" of the patients were 71%, 70% and 69% respectively, equivalent to an "overall positive reactivity" of 62%, 95% CI [58,5%-65.5%], particularly low in the orthopedic department (43%). The logistics dimension was the least appreciated by patients, including room's condition, with almost 23% overall and 17% in the orthopedic department. CONCLUSION: The responsiveness of patients hospitalized in the surgical services of Sahloul University Hospital was low, particularly for items related to the hotel services in the hospital. Furthermore, plans to improve the quality of care and support the performance of public hospitals should pay close attention to the logistical dimension of patients' hospital stays.