Vaccine effectiveness against COVID-19: A test negative case-control study in Tunisia, August 2021.

BACKGROUND: In response to the COVID-19 pandemic, multiple vaccines to protect against COVID-19 disease have been developed rapidly. Precise estimates of vaccine effectiveness (VE) vary according to studies design, outcomes measured and circulating variants. The aim of this study was to evaluate the anti-covid-19 vaccine effectiveness in Tunisia. METHODS: We conducted a matched case-control study from 2nd to 15th August 2021. Cases and controls were subjects over 60 years of age, selected from the National testing database, regardless vaccine status. A standardized questionnaire was administered for cases and controls to collect information about vaccination status. For cases, vaccination status was defined based on the number of doses received before becoming ill and excludes doses received during the previous two weeks. For matched controls, a reference date based on the case's date of illness onset was defined in order to look at the control's vaccination status before its corresponding case became ill. The odds-ratio was calculated using simple conditional logistic regression. The VE (95 % confidence intervals) was calculated as (1 - odds ratio for vaccination) × 100 %. RESULTS: A sample of 977 matched peers for age and Gender, were included between August 2, and August 15, 2021. The overall vaccine effectiveness (VE) was 70 % [95 % CI 62.8-75.8 %]. Among our sample, 68.1 % of the male population and 56.4 % of the female population were vaccinated with a VE of 73 % [95 % CI 62.9-80.3 %] and 67 % [95 % CI 55.8-75.3 %] respectively, regardless vaccine scheme (complete or incomplete). VE was higher for the age group [60-70 years[ (72.3 % [95 % CI 62.8-79.3 %]). VE was 77.6 % [95 % CI 70.9-82.8 %] to prevent both symptomatic and asymptomatic forms of the disease. Moreover, in prevention from severe forms (treated with oxygen-therapy or admission to an Intensive-care-unit) VE was 86.6 % [95 % CI 75.6-92.7 %] and 98.4 % [95 % CI [79.2-99.8 %] in prevention from COVID-19 deaths with a complete anti-Covid vaccination scheme. CONCLUSION: The results of our study showed that the anti-Covid-19 vaccines used in Tunisia are efficient to prevent both SARS-COV-2 infections and severe forms related to the disease. This study provided important data on the performance of vaccines in real-world settings that guide decisions about vaccine sustained use.

Characteristics and prognostic factors of COVID-19 among infected cases: a nationwide Tunisian analysis.

BACKGROUND: The outbreak of coronavirus disease (COVID-19) continues to constitute an international public health concern. Few data are available on the duration and prognostic factors of the disease. We aimed to study the recovery time among a Tunisian cohort of COVID-19 confirmed patients and identify the prognostic factors. METHODS: A retrospective, nationwide study was conducted from March 2 to May 8, 2020, recruiting all patients who were diagnosed with COVID-19, by RT-PCR methods, in Tunisia. Data were collected via phone call interview. Kaplan-Meir Methods and Cox proportional hazards regression models were, respectively, used to study the recovery time and estimate its prognostic factors. RESULTS: One thousand and thirty patients with COVID-19 (aged 43.2 ± 18.2 years, 526 female (51.1%)) were enrolled. Among them 141 (14.8%) were healthcare professionals. Out of 173 patients (17.8%) admitted to the hospital, 47 were admitted in an intensive care unit. Among 827 patients who didn't require specialized care, 55.5% were self-isolated at home, while the rest were in specialized centers. Six hundred and two patients were symptomatic. A total of 634 (61.6%) patients have recovered and 45 (4.4%) patients died. The median duration of illness was estimated to be 31 days (95% CI: [29-32]). Older age (HR = 0.66, CI:[0.46-0.96], P = 0.031) and symptoms (HR = 0.61, CI:[0.43-0.81], P = 0.021) were independently associated with a delay in recovery time. Being a healthcare professional (HR = 1.52, CI: [1.10-2.08], P = 0.011) and patients in home isolation compared to isolation centers (HR = 2.99, CI: [1.85-4.83], P < 10¯3) were independently associated with faster recovery time. CONCLUSION: The duration of illness was estimated to be 1 month. However, this long estimated duration of illness may not equate to infectiousness. A particular attention must to be paid to elderly and symptomatic patients with closer monitoring.

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.

Estimating transmission dynamics and serial interval of the first wave of COVID-19 infections under different control measures: a statistical analysis in Tunisia from February 29 to May 5, 2020.

BACKGROUND: Describing transmission dynamics of the outbreak and impact of intervention measures are critical to planning responses to future outbreaks and providing timely information to guide policy makers decision. We estimate serial interval (SI) and temporal reproduction number (Rt) of SARS-CoV-2 in Tunisia. METHODS: We collected data of investigations and contact tracing between March 1, 2020 and May 5, 2020 as well as illness onset data during the period February 29-May 5, 2020 from National Observatory of New and Emerging Diseases of Tunisia. Maximum likelihood (ML) approach is used to estimate dynamics of Rt. RESULTS: Four hundred ninety-one of infector-infectee pairs were involved, with 14.46% reported pre-symptomatic transmission. SI follows Gamma distribution with mean 5.30 days [95% Confidence Interval (CI) 4.66-5.95] and standard deviation 0.26 [95% CI 0.23-0.30]. Also, we estimated large changes in Rt in response to the combined lockdown interventions. The Rt moves from 3.18 [95% Credible Interval (CrI) 2.73-3.69] to 1.77 [95% CrI 1.49-2.08] with curfew prevention measure, and under the epidemic threshold (0.89 [95% CrI 0.84-0.94]) by national lockdown measure. CONCLUSIONS: Overall, our findings highlight contribution of interventions to interrupt transmission of SARS-CoV-2 in Tunisia.

Eating disorders in type 1 diabetic adolescent.

BACKGROUND: Adolescents with type1 diabetes appear to be at greater risk for developing eating disorders (ED) which are often associated with impaired metabolic control of diabetes. AIM: To estimate the prevalence of ED in a population of adolescents with type 1 diabetes (T1D) and to identify risk factors associated with this disorder in order to propose preventive measures. METHODS: A cross-sectional, population-based study involved 102 adolescents with type 1 diabetes, aged 11-18 years, recruited from the National Institute of Nutrition in Tunis, Tunisia over a period of one-year January 2017-January 2018. RESULTS: The prevalence of ED was 33.3%. It was significantly higher among girls (46.2% vs 20%, p = 0.005). Unspecified ED were predominant with a prevalence of 29.4%. Independent factors associated with ED were female sex, abdominal obesity and quality of life. The risk of developing ED was multiplied by 3.5 for women (adjusted OR = 3.5 and CI95% [1.4-8.6]) and by 5.6 for patients with abdominal obesity (Adjusted OR = 5.6 and CI95% [1.5-20.4]). Impaired quality of life and specifically anxiety about diabetes increased significantly the risk of developing ED in our patients. However, we didn't find significant association between ED and age, family characteristics, duration of diabetes, metabolic balance, treatment and complications of diabetes. CONCLUSION: We concluded that ED should be always suspected in adolescents with T1D especially in girls. Unspecified ED are more common in this group of patients. Treatment of diabetes requires a multidisciplinary care approach including diabetologist, dietician and psychiatrist in order to promote healthy eating and to improve quality of life of adolescents with T1D.

Cost estimation of medical care management of lung cancer in Tunisia.

BACKGROUND: Lung cancer management is very expensive for the Tunisian healthcare system. AIM: The aim of this study was to evaluate the direct costs of treating lung cancer in Tunisia, and to identify the main treatment of high expenditure. METHODS: A retrospective study was conducted in 2012 including all patients admitted between 2008 and 2010 for lung cancer management. The hospital payment system was used to estimate the direct costs of the medical care management of lung cancer. RESULTS: We collected 549 patients and the majority of patients were diagnosed with advanced stages of the disease: 60 % in stage T4 and 59 % in stage M1. 26 % of patients underwent surgery and 44.1 % chemotherapy. The total direct costs of lung cancer management were estimated to be TND 3900 (US$ 1980) per patient. CONCLUSIONS: Chemotherapy accounted for the largest percentage of direct costs (46 %) followed by the cost of the hospital stay. Primary prevention, based on the application of policies to control tobacco, is the best strategy to reduce this morbidity.