Development and comparative evaluation of SARS-CoV-2 S-RBD and N based ELISA tests in various African endemic settings.

Management of the COVID-19 pandemic relies on molecular diagnostic methods supported by serological tools. Herein, we developed S-RBD- and N- based ELISA assays useful for infection rate surveillance as well as the follow-up of acquired protective immunity against SARS-CoV-2. ELISA assays were optimized using COVID-19 Tunisian patients' sera and prepandemic controls. Assays were further validated in 3 African countries with variable endemic settings. The receiver operating curve was used to evaluate the assay performances. The N- and S-RBD-based ELISA assays performances, in Tunisia, were very high (AUC: 0.966 and 0.98, respectively, p < 0.0001). Cross-validation analysis showed similar performances in different settings. Cross-reactivity, with malaria infection, against viral antigens, was noticed. In head-to-head comparisons with different commercial assays, the developed assays showed high agreement. This study demonstrates, the added value of the developed serological assays in low-income countries, particularly in ethnically diverse populations with variable exposure to local endemic infectious diseases.

ABO blood groups and risk of covid-19

INTRODUCTIONCoronavirus pandemic has been the subject of a large number of publications, some of which have shown an increased risk of contracting Covid-19 in carriers of blood group A.AIMSIn this study we looked at the profile of blood group phenotype of a series of Tunisian patients with covid-19 admitted to Abderrahman Mami hospital in Ariana .METHODSOur study included 51 Tunisian patients with SARS-CoV-2 infection admitted to Abderrahmane Mami hospital between late march 2020 and early May 2020. The distribution of blood groups in Covid-19 patients was compared with that of a control group of 1506 patients with no Covid-19 infection as well as with the distribution of blood groups in a population of 63375 voluntary blood donors.RESULTSOur series, although limited in size, showed a higher prevalence of blood group A among Covid-19 patients, statistically significant compared to ABO blood group distribution among Tunisian blood donors and among a control group of patients without Covid -19.CONCLUSIONthese results are in line with data from the literature, particularly on larger series in China.

Features of patients with 2019 novel coronavirus admitted in a pneumology department: The first retrospective Tunisian case series.

AIM: On 2 March 2020, Tunisia has reported the first confirmed case of COVID-19. Since then, the disease has affected about 700 persons in the country. The purpose of our study was to report epidemiological, clinical, radiological and therapeutic features of patients with 2019-nCoV infection admitted in the pneumology department. METHODS: We extracted the data of the consequetive 20 patients managed in the department of pneumology B at Abderrahmen Mami hospital, from March, 26 to April, 8, 2020. RESULTS: The median age was 61 years old [41-85]. There were 9 men and 11 women.  Underlying disorders were observed in 16 patients (80%). Five patients were health care workers. Three patients did not have any known exposure. Common symptoms included fever (100%), shortness of breath (70%) and cough (70%). Computed tomography scans showed bilateral ground glass opacities in 7/9 cases. Fifteen patients received both chloroquine and azithromycin. Fourteen patients (70%) were discharged before April, 8, 2020. Reported complications were: hypokalemia (3 cases), pulmonary embolism (2 cases) and QT prolongation (1 case). One patient died from acute cardiac injury. CONCLUSION: Knowing the different aspects of moderate and severe forms of the disease can contribute to advance in infection control strategies.