Outbreak Investigation of Typhoid Fever in the District of Gabes, South of Tunisia.

Typhoid fever is a significant public health concern in many parts of the world, particularly in developing countries with poor sanitation and hygiene conditions. In July 2016, an outbreak of typhoid fever occurred in Ghannouche, located in the south of Tunisia. This paper reports the results of a field investigation undertaken to identify possible transmission pathways and risk factors in order to propose control and preventive measures. A retrospective cohort study including a passive and active case finding, as well as an environmental and bacteriological investigation was conducted from July to September 2016. A case was defined as a person residing or having stayed in Ghannouche and having presented from the beginning of June clinical signs suggestive of typhoid fever, with, for a confirmed case, laboratory isolation of S.Tyhi, and for a probable case, an epidemiological link with a confirmed case. Attack rates were determined, and risk ratios were estimated with respect to exposures. Unadjusted and adjusted odds ratios were estimated using binary logistic regression. Among the 628 subjects investigated, 102 cases of typhoid fever were identified (74 confirmed and 28 probable) with an overall attack rate of 16.24%. Over 56% of cases were male and those under 10 years old were most affected (38.2%% of cases) with a median age of 12 years (interquartile range 5 to 25 years). The main clinical signs were fever (95%) and diarrhea (57%). Young age (adjusted OR = 0.95 and 95% CI = 0.93-0.97), low level of education (adjusted OR = 4.76 and 95% CI = 1.34-16.81), and the habitat type Arab or rudimentary house (adjusted OR = 4.93 and 95% CI = 2.61-8.27) were the socio-demographic factors independently associated with typhoid fever. Typhoid fever was found to be associated with drinking softened water (adjusted OR = 2.64 and 95% CI = 1.16-4.82), eating raw fruit and vegetables from family gardens (adjusted OR = 6.13 and 95% CI = 3.66-11.06), and using uncontrolled waste disposal (adjusted OR = 3.52 and 95% CI = 2.03-6.94). A total of 110 drinking water samples were analyzed; out of the 38 samples of softened water, 12 were non-compliant and 5 were positive for Salmonella. The screening activity identified two asymptomatic carriers, one of whom was a softened water seller. We concluded that drinking softened water from informal or unauthorized sale units, consuming fruit and vegetables from family gardens, uncontrolled dumping of household waste, and poor socio-economic conditions increase the risk of typhoid fever in this region. Many recommendations were implemented to stop this outbreak and to prevent further episodes.

The Prevalence, Genotype Distribution and Risk Factors of Human Papillomavirus in Tunisia: A National-Based Study.

There are limited national population-based studies on HPV genotypes distribution in Tunisia, thus making difficult an assessment of the burden of vaccine-preventable cervical cancer. In this context, we conducted a national survey to determine the HPV prevalence and genotypes distribution and the risk factors for HPV infections in Tunisian women. This is a cross-sectional study performed between December 2012 and December 2014. A liquid-based Pap smear sample was obtained from all women and samples' DNAs were extracted. Only women with betaglobin-positive PCR were further analysed for HPV detection and typing by a nested-PCR of the L1 region followed by next-generation sequencing. A multiple logistic regression model was used for the analysis of associations between the variables. A total of 1517 women were enrolled in this study, and 1229 out of the 1517 cervical samples were positive for the betaglobin control PCR and tested for HPV. Overall HPV infection prevalence was measured to be 7.8% (96/1229), with significant differences between the grand regions, ranging from 2% in the North to 13.1% in Grand Tunis. High-risk HPV genotypes accounted for 5% of the infections. The most prevalent genotypes were HPV 31 (1%), 16 (0.9%), 59 (0.7%). HPV18 was detected only in four cases of the study population. Potential risk factors were living in Grand Tunis region (OR: 7.94 [2.74-22.99]), married status (OR: 2.74 [1.23-6.13]), smoking habit (OR: 2.73 [1.35-5.51]), occupation (OR: 1.81 [1.09-3.01]) and women with multiple sexual partners (OR: 1.91 [1.07-3.39]). These findings underscore the need to evaluate the cost effectiveness of HPV vaccine implementation, contribute to the evidence on the burden of HPV infections, the critical role of sexual behaviour and socioeconomic status, and call for increased support to the preventive program of cervical cancer in Tunisia.

Humoral and Cellular Immunogenicity of Six Different Vaccines against SARS-CoV-2 in Adults: A Comparative Study in Tunisia (North Africa).

BACKGROUND: The mass vaccination campaign against SARS-CoV-2 was started in Tunisia on 13 March 2021 by using progressively seven different vaccines approved for emergency use. Herein, we aimed to evaluate the humoral and cellular immunity in subjects aged 40 years and over who received one of the following two-dose regimen vaccines against SARS-CoV-2, namely mRNA-1273 or Spikevax (Moderna), BNT162B2 or Comirnaty (Pfizer-BioNTech), Gam-COVID-Vac or Sputnik V (Gamaleya Research Institute), ChAdOx1-S or Vaxzevria (AstraZeneca), BIBP (Sinopharm), and Coronavac (Sinovac). MATERIAL AND METHODS: For each type of vaccine, a sample of subjects aged 40 and over was randomly selected from the national platform for monitoring COVID-19 vaccination and contacted to participate to this study. All consenting participants were sampled for peripheral blood at 3-7 weeks after the second vaccine dose to perform anti-S and anti-N serology by the Elecsys® (Lenexa, KS, USA) anti-SARS-CoV-2 assays (Roche® Basel, Switzerland). The CD4 and CD8 T cell responses were evaluated by the QuantiFERON® SARS-CoV-2 (Qiagen® Basel, Switzerland) for a randomly selected sub-group. RESULTS: A total of 501 people consented to the study and, of them, 133 were included for the cellular response investigations. Both humoral and cellular immune responses against SARS-CoV-2 antigens differed significantly between all tested groups. RNA vaccines induced the highest levels of humoral and cellular anti-S responses followed by adenovirus vaccines and then by inactivated vaccines. Vaccines from the same platform induced similar levels of specific anti-S immune responses except in the case of the Sputnik V and the AstraZeneca vaccine, which exhibited contrasting effects on humoral and cellular responses. When analyses were performed in subjects with negative anti-N antibodies, results were similar to those obtained within the total cohort, except for the Moderna vaccine, which gave a better cellular immune response than the Pfizer vaccine and RNA vaccines, which induced similar cellular immune responses to those of adenovirus vaccines. CONCLUSION: Collectively, our data confirmed the superiority of the RNA-based COVID-19 vaccines, in particular that of Moderna, for both humoral and cellular immunogenicity. Our results comparing between different vaccine platforms in a similar population are of great importance since they may help decision makers to adopt the best strategy for further national vaccination programs.

Epidemiologic patterns of hepatitis A infection during the pre-vaccination era: A population-based survey in Tunisia in 2015.

BACKGROUND: In the 1980s, Tunisia was considered a country of high endemicity for hepatitis A virus (HAV). Since 2000, an epidemiologic shift has led to an increased incidence of symptomatic and severe forms of HAV infection. OBJECTIVES: In 2015, we conducted a cross-sectional nationwide household-based hepatitis A virus (HAV) seroprevalence study in the total population regardless of age, sex, or geographic origin using a stratified sampling design to make an overview of the HAV epidemiologic situation in Tunisia before vaccine implementation. RESULTS: A total of 6,322 individuals were enrolled. The HAV prevalence was 78.8%. The anti-HAV IgG seropositivity rate increased from 16% for ages 5-9 years to 45% for ages 10-14 years, 67% for ages 15-19 years, 87% for ages 20-24 years, and >90% for older age groups, which suggested an age at midpoint of population immunity (AMPI) in late adolescence. It was significantly higher in rural areas (P < 10-3) and varied significantly between and within regions (P < 10-4). CONCLUSIONS: In this study, although the overall AMPI suggestsintermediate endemicity, the regional AMPI varies from intermediate to very high endemicity profiles attributable to different socioeconomic determinants and conditions of sanitation and hygiene. In addition, it provides insights for the best decisions in terms of vaccination strategies.

[Clinical and epidemiological features of COVID-19-related deaths in Tunisia before the emergence of VOCs (March 2020-February 2021)]. / Caractéristiques cliniques et épidémiologiques des décès COVID-19 en Tunisie avant l'émergence des VOCs (mars 2020-février 2021).

Introduction: the purpose of this study was to describe the clinical and epidemiological features of COVID-19-related deaths in Tunisia notified at the ONMNE (National Observatory of New and emerging Diseases) between 2nd March 2020 and 28th February 2021 and to compare COVID-19-related deaths recorded in Tunisia with the international data. Methods: we conducted a national prospective longitudinal descriptive study of data collected from the National Surveillance System of SARS-CoV-2 infection of the ONMNE, Ministry of Health. All COVID-19-related deaths that occurred in Tunisia between March 2020 and February 2021 were included in this study. Data were collected from hospitals, municipalities and regional health departments. Death notifications were collected from multiple data sources (triangulation): The Regional Directorate of Basic Health Care, the ShocRoom (Strategic Health Operations Center), public and private health facilities, the Crisis Unit of the Presidency of the Government, the Directorate for Hygiene and Environmental Protection, the Ministry of Local Affairs and the Environment, as part of the follow-up of confirmed cases by the ONMNE team, positive RT-PCR / TDR post mortem results. Results: during this study, 8051 deaths were recorded, corresponding to a proportional mortality of 10.4%. The median age was 73 years, with an interquartile range of 17 years. Sex-ratio (M/F) was 1.8. The crude death rate was 69.1/100 000 inhabitants and fatality rate was 3.5%. The analysis of the epidemic curve showed 2 peaks of deaths on 29th October 2020 and 22nd January 2021, with 70 and 86 deaths notified respectively. The spatial distribution of mortality showed that the southern Tunisian region had the highest mortality rate. Patients aged 65 and over were most affected (73.7% of cases) with a crude mortality rate of 570.9/100,000 inhabitants and a fatality rate of 13.7%. Conclusion: prevention strategy based on public health measures must be reinforced by the rapid deployment of anti-COVID-19 vaccination, especially for people at risk of death.

Identification of transmission chains and clusters associated with COVID-19 in Tunisia.

BACKGROUND: The aim of this study was to characterize the transmission chains and clusters of COVID-19 infection in Tunisia. METHODS: All cases were confirmed by Reverse Transcriptase Polymerase Chain Reaction of a nasopharyngeal specimen. Contact tracing is undertaken for all confirmed cases in order to identify close contacts that will be systematically screened and quarantined. Transmission chains were identified based on field investigation, contact tracing, results of screening tests and by assessing all probable mode of transmission and interactions. RESULTS: As of May 18, 2020, 656 cases out of a total of 1043 confirmed cases of Coronavirus disease 2019 belong to 127 transmission chains identified during the epidemic (mean age 42.36 years, Standard deviation 19.56 and sex ratio 0.86). The virus transmission is the most concentrated in the governorate of Tunis (31.5%), Ariana (10.2%) and Ben Arous (10.2%). Virus transmission occurred 50 times (9.72% of secondary transmission events) between two different governorates. A maximum of seven generations of secondary infection was identified, whereas 62% of these secondary infections belong the first generation. A total of 11 "super spreader" cases were identified in this investigation. Four large clusters have been identified. The evolution of secondary cases highlighted two peaks: one in 2nd April and a second in 16 th April whereas imported cases caused local transmission of virus during the early phase of the epidemic. CONCLUSION: Correct contact tracing and early active case finding is useful to identify transmission chains and source of infection in order to contain the widespread transmission in the community.

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.

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.

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.

Modeling zoonotic cutaneous leishmaniasis incidence in central Tunisia from 2009-2015: Forecasting models using climate variables as predictors.

Transmission of zoonotic cutaneous leishmaniasis (ZCL) depends on the presence, density and distribution of Leishmania major rodent reservoir and the development of these rodents is known to have a significant dependence on environmental and climate factors. ZCL in Tunisia is one of the most common forms of leishmaniasis. The aim of this paper was to build a regression model of ZCL cases to identify the relationship between ZCL occurrence and possible risk factors, and to develop a predicting model for ZCL's control and prevention purposes. Monthly reported ZCL cases, environmental and bioclimatic data were collected over 6 years (2009-2015). Three rural areas in the governorate of Sidi Bouzid were selected as the study area. Cross-correlation analysis was used to identify the relevant lagged effects of possible risk factors, associated with ZCL cases. Non-parametric modeling techniques known as generalized additive model (GAM) and generalized additive mixed models (GAMM) were applied in this work. These techniques have the ability to approximate the relationship between the predictors (inputs) and the response variable (output), and express the relationship mathematically. The goodness-of-fit of the constructed model was determined by Generalized cross-validation (GCV) score and residual test. There were a total of 1019 notified ZCL cases from July 2009 to June 2015. The results showed seasonal distribution of reported ZCL cases from August to January. The model highlighted that rodent density, average temperature, cumulative rainfall and average relative humidity, with different time lags, all play role in sustaining and increasing the ZCL incidence. The GAMM model could be applied to predict the occurrence of ZCL in central Tunisia and could help for the establishment of an early warning system to control and prevent ZCL in central Tunisia.

Zoonotic Cutaneous Leishmaniasis Prevalence Among Farmers in Central Tunisia, 2014.

OBJECTIVE: Zoonotic cutaneous leishmaniasis (ZCL) is endemic in central Tunisia and is more prevalent in rural agricultural areas. The aim of this work was to determine ZCL prevalence among farmers and to test their availability to take ownership of the problem and participate actively to fight and address the disease. METHODS: A sample of farmers from Sidi Bouzid, central Tunisia, was selected randomly. Farmers were interviewed using a standardized questionnaire about ZCL lesion occurrence, its date of onset among family members, and the farmers' availability to contribute to fighting this disease. RESULTS: ZCL occurred in at least one of the family members of 38.5% interviewed farmers. The disease was endemic with recurrent epidemics every 4 or 5 years. ZCL among farmers was associated with irrigation management. With regard to ZCL preventive measures, the majority of farmers agreed and expressed willingness to collaborate (93.1%), to follow health care facilities instructions (73.1%), and to join the nongovernmental organization (NGO) (56.9%). However, they did not agree to reduce irrigation activities mainly at night, to live far from their irrigated fields, or to sleep out of their houses at night. CONCLUSIONS: ZCL is more prevalent in farmers engaged in irrigation activities. Farmers are not agreeable to reducing their activity to avoid exposure to the sand fly bites. Thus, population involvement and commitment is required to implement effective control measures to fight and address ZCL.

Psychological and Psychosocial Consequences of Zoonotic Cutaneous Leishmaniasis among Women in Tunisia: Preliminary Findings from an Exploratory Study.

BACKGROUND: The incidence of zoonotic cutaneous leishmaniasis (ZCL) makes it the most widespread parasitic disease in Tunisia and the Arab world. Yet, few studies have addressed its psychological and psychosocial effects. The purpose of this study was to examine the psychosocial impact of ZCL scars among Tunisian women. METHODS: We conducted an exploratory study, we administered Revised Illness Perception Questionnaire (IPQ-R), World Health Organization Quality Of Life-26 (WHOQOL-26) and Psoriasis Life Stress Inventory (PLSI) to a group of girls and women with ZCL scar in the region of Sidi Bouzid. This group was randomly selected from volunteers who came to primary health care facilities to seek for treatment for any pathology. RESULTS: Descriptive statistics showed that the collected scores from the three scales exhibit heterogeneous distributions: IPQ-R (M = 63.6, SD = 15.6), PSLI (M = 9.5, SD = 6.7), WHOQOL-Physical (M = 63, SD = 12.9), WHOQOL-Psychological (M = 52.6, SD = 11.1), WHOQOL-Social (M = 61.8, SD = 17.5), and WHOQOL-Environmental (M = 47.8, SD = 13.3). The correlation analyses performed on Inter and intra-subscales showed that the emotional representations associated with ZCL were correlated with the loss of self-esteem and feelings of inferiority (r = 0.77, p<0.05). In addition, high education level and the knowledge about ZCL are positively correlated with cognitive and emotional representation in the IPQ-R (r = 0.33, p<0.05). "Rejection experiences" and the "anticipation and avoidance of stress" were respectively negatively correlated with age (r = -0.33, p<0.05 and r = -0.31, p<0.05). Correlations between the scores on IPQ-R domains and PLSI factors were significant. The results showed that anticipation of rejection and avoidance of stress are strongly correlated with a negative perception of ZCL. Quality of life scores were not correlated with either age, education level, time of illness, or the number of facial or body scars. However, the correlations between quality of life scores and the multiple IPQ-R domains were all insignificant. Finally, there was a negative correlation between the scores on the perceived quality of social life and the knowledge about ZCL (r = -0.34, p<0.05). CONCLUSIONS: This makes it vital to strengthen preventive health education. Conducting studies on ways to establish a holistic support system for managing ZCL, a system that covers the psychological challenges and the barriers it causes to women's social and professional integration, is a vital first step.

[High risk areas for echinococcosis-hydatidosis in Tunisia]. / Identification des zones à risque élevé pour l'échinococcose-hydatidose en Tunisie.

AIM: The study was conducted in order to identify high risk areas for hydatidosis in Tunisia witch would be eligible for a Hydatidosis control program initiation. METHODS: The most recent epidemiological investigation on surgical incidence of hydatidosis was used to classify governorates according to their incidence rate. A "global hydatidosis risk score" was calculated for each governorate, combining some parameters related to the hygiene conditions of the population, the literacy rate, the canine density and livestock census. Spearman correlation coefficient was used to compare scores and surgical incidences. Mapping analysis has been conducted. The surgical incidence rate of hydatidosis classifies each governorate regarding occurrence of human cases. The global hydatidosis risk score, by governorate, pointed out the most exposed areas to the disease. RESULTS: The mapping analysis showed a good agreement between the incidence rate of the disease and the global hydatidosis risk score and made it possible to identify the population of the center and the west of the country as a most exposed population for the diseases. CONCLUSION: In order to have a chance for implementation, hydatidosis control program should target the three jointed governorates of Kasserine, Siliana and Kef, which have the highest incidence rates and the worst scores.