Shifting Patterns of Influenza Circulation during the COVID-19 Pandemic, Senegal

Historically low levels of seasonal influenza circulation were reported during the first years of the COVID-19 pandemic and were mainly attributed to implementation of nonpharmaceutical interventions. In tropical regions, influenza’s seasonality differs largely, and data on this topic are scarce. We analyzed data from Senegal’s sentinel syndromic surveillance network before and after the start of the COVID-19 pandemic to assess changes in influenza circulation. We found that influenza shows year-round circulation in Senegal and has 2 distinct epidemic peaks: during January–March and during the rainy season in August–October. During 2021–2022, the expected January–March influenza peak completely disappeared, corresponding to periods of active SARS-CoV-2 circulation. We noted an unexpected influenza epidemic peak during May–July 2022. The observed reciprocal circulation of SARS-CoV-2 and influenza suggests that factors such as viral interference might be at play and should be further investigated in tropical settings

Cross-Reactivity of SARS-CoV-2 Laboratory Diagnostics to Endemic Diseases in Africa: A Diagnostic Accuracy Study

Background: Serology is a great tool to assess the level of immunity against SARS-CoV-2 in settings with limited access to molecular diagnostics. However, African populations displays a particular immunological profile with massive circulation of infectious agents from different aetiologies that can affect assays performance.Methods: We evaluated the OMEGA Diagnostics COVID-19 ELISA-IgG and the ID Screen® SARS-CoV-2-N IgG Indirect in Senegal using a panel of 636 blood samples covering several African-endemic diseases and healthy donors to determine test sensitivity and specificity. The sensitivity panel of sera includes 461 serum samples collected from 91 patients hospitalized for COVID-19 disease. COVID-19 cases were confirmed by qRT-PCR and samples were collected on an interval of three days until viral clearance. In addition, 272 sera obtained from COVID-19 negative individuals were selected from a well-documented biobank of sera collected before the COVID-19 outbreak.Finding: High-cross reactivity have been found in individuals with a history of exposure to Chikungunya, HIV, malaria (Plasmodium falciparum), rheumatoid factor as well as healthy donors with respective specificities of 55%, 41.8%, 70%, 70% and 75%. ELISA experiments with commercial assays targeting either SARS-CoV-2 Nucleocapsid protein and Spike 2 protein or nucleocapsid protein only suggest that cross-reactivity might be directed against Spike 2 protein and not Nucleocapsid protein. Further samples characterisation reveals that anti-malaria IgG is the leading cause of such poor specificities, but exposure to other diseases contributed as well.Interpretation: We anticipate that COVID-19 seroprevalence can be biased if assays are not contextualized. Since malaria is endemic in African settings, we propose that a particular attention must be given in serological surveillance of COVID-19 or anti-SARS-CoV-2 antibodies quantification as vaccines are being rolled out

Hydroxychloroquine and Azithromycin Treatment of Hospitalized Patients Infected with SARS-CoV-2 in Senegal from March to October 2020

International audienceAs of today, little data is available on COVID-19 in African countries, where the case management relied mainly on a treatment by association between hydroxychloroquine (HCQ) and azithromycin (AZM). This study aimed to understand the main clinical outcomes of COVID-19 hospitalized patients in Senegal from March to October 20202. We described the clinical characteristics of patients and analysed clinical status (alive and discharged versus hospitalized or died) at 15 days after Isolation and Treatment Centres (ITC) admission among adult patients who received HCQ plus AZM and those who did not receive this combination. A total of 926 patients were included in this analysis. Six hundred seventy-four (674) (72.8%) patients received a combination of HCQ and AZM. Results showed that the proportion of patient discharge at D15 was significantly higher for patients receiving HCQ plus AZM (OR: 1.63, IC 95% (1.09–2.43)). Factors associated with a lower proportion of patients discharged alive were: age ≥ 60 years (OR: 0.55, IC 95% (0.36–0.83)), having of at least one pre-existing disorder (OR: 0.61, IC 95% (0.42–0.90)), and a high clinical risk at admission following NEWS score (OR: 0.49, IC 95% (0.28–0.83)). Few side effects were reported including 2 cases of cardiac rhythmic disorders in the HCQ and AZM group versus 13 in without HCQ + AZM. An improvement of clinical status at 15 days was found for patients exposed to HCQ plus AZM combinatio