Seroepidemiology of Toxoplasmosis in Hemodialysis Patients in Senegal

Toxoplasmosis in immunocompromised patients results in either reactivation of latent toxoplasmosis or acute infection. In the framework of the kidney transplantation program in Senegal, the serological screening of potential pre-transplant and transplanted patients can prevent the disease. This study aimed to assess the seroprevalence of toxoplasmosis in a cohort of hemodialysis patients, candidates for kidney transplantation. To this end, a multicentre cross-sectional study was conducted in 2020 in six dialysis units from five regions. Blood samples and sociodemographic data were collected from each patient. IgG and IgM against T. gondii antibodies were assessed by a chemiluminescent method using Architect ci4100, and statistical analysis was performed using R software. Overall, 211 hemodialysis patients aged from 18 to 77 years were enrolled. The mean age was 42.62 years ± 13.6, and the sex ratio M/F was 1.24. The overall seroprevalence of T. gondii was 41.7%, with the highest value being recorded in the region of Kaolack (44.4%). Patients aged over 60 years were more typically infected, at a proportion of 56.0%. Regarding sex, males elicited a higher prevalence (44.4.%) than females did. Patients of an upper socioeconomic status were less affected, and contact with cats was not associated with toxoplasmosis. By education level, the illiterate group was most affected one. Overall, this first study of toxoplasmosis among Senegalese hemodialysis patients indicates high seroprevalence

Evaluation of the LumiraDx SARS-CoV-2 antigen assay for large-scale population testing in Senegal

Purpose: Real-time reverse-transcription polymerase chain reaction (RT-PCR)-based testing remains the gold standard for the diagnosis of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Due to the high diagnosis demand of SARS-CoV-2 and the limited resources for RT-PCR testing, especially in Low-Income Countries (LICs), antigen-based methods are being considered as an option. The aim of this study was to assess the performance of LumiraDx SARS-CoV-2 antigen assay for large population screening compared to RT-PCR.Methods: This evaluation was conducted on 4146 participants including travelers and participants under household survey and vaccine evaluation studies before injection of the first dose. Oropharyngeal and nasopharyngeal swaps were collected from each participant into 2 mL of viral transport medium (VTM) and 400 μl of VTM were used to assess the performance of LumiraDx SARS-CoV-2 antigen assay, compared to RT-PCR. Results: The prevalence of SARS-CoV-2 of the cohort was 4.5% with RT-PCR and 4.1% with LumiraDx antigen test. Compared to the RT-PCR, the sensitivity and specificity of the LumiraDx antigen SARS-CoV-2 test were 82,7% [95% CI 74.1-89,7] and 99.9% [95% CI 99.6-99.9] respectively. Given the RT-PCR threshold cycle (Ct) range, the sensitivity was 92.1% [95% CI 84.6-96.3] when the Ct value was below or equal 33 cycles, and 38.1% [95% CI 18.9-61.3] when it was above 33 cycles. The inter-rater reliability showed a kappa coefficient of 0.88 when considering all the patients and 0.94 for Ct values below 33 cycles. Conclusion: Our data have shown that the LumiraDx platform can be considered for large-scale testing of SARS-CoV-2