Seroprevalence of Anti-SARS-CoV-2 Antibodies in Blood Donors from Nuevo Leon State, Mexico, during 2020: A Retrospective Cross-Sectional Evaluation.

The progression and distribution of the SARS-CoV-2 pandemic are continuously changing over time and can be traced by blood donors' serological survey. Here, we investigated the seroprevalence of anti-SARS-CoV-2 antibodies in blood donors in Nuevo Leon, Mexico during 2020 as a strategy for the rapid evaluation of the spread of SARS-CoV-2 and asymptomatic case detection. We collected residual plasma samples from blood donors who attended two regional donation centers from January to December of 2020 to identify changes in anti-SARS-CoV-2 IgG prevalence. Plasma samples were analyzed on the Abbott Architect instrument using the commercial Abbott SARS-CoV-2 IgG chemiluminescent assay. We found a total of 99 reactive samples from 2068 analyzed plasma samples, resulting in a raw prevalence of 4.87%. Donors aged 18-49 years were more likely to be seropositive compared to those aged >50 years (p < 0.001). Weekly seroprevalence increased from 1.8% during the early pandemic stage to 27.59% by the end of the year. Prevalence was 1.46-fold higher in females compared to males. Case geographical mapping showed that Monterrey city recorded the majority of SARS-CoV-2 cases. These results show that there is a growing trend of seroprevalence over time associated with asymptomatic infection that is unnoticed under the current epidemiological surveillance protocols.

Assessment of software-derived predictive algorithms for platelet yield and blood cell count after apheresis.

INTRODUCTION: Algorithms have been developed to predict the platelet yield after apheresis from the donor's data, as well as the effect on the blood cell count, to extract an acceptable platelet number without affecting the donor. However, the evaluation of these algorithms has not been widely reported. This study aimed to assess the accuracy of the predictive algorithms of the Trima Accel v. 6 blood collection system. METHODS: Platelet concentrates (PCs) obtained by apheresis were analyzed. Platelet count and hematocrit were compared pre- and post-apheresis. Calculated post-apheresis platelet count (CPAPC), hematocrit (CPAH), and platelet yield (CPY), and their actual values were correlated. The bias of the algorithms was assessed with Bland-Altman plots, and the prediction of the extraction of single or double platelet products was evaluated. RESULTS: Two hundred and seventy-nine PCs were analyzed. Post-apheresis platelet count (PAPC) and hematocrit were decreased. A moderate correlation was observed between CPY and the actual yield, with a negative bias, and a trend to increase alongside the magnitude of the measurements. CPAPC and CPAH were strongly correlated with their actual values without bias. Prediction of single or double platelet product extraction showed a significant agreement with the actual outcomes. CONCLUSIONS: The predictive algorithm for the platelet yield showed bias, and a trend to underestimate the actual platelet yields when they are higher. The algorithms for the prediction of the PAPC and hematocrit did not show bias, proving their accuracy. Prediction of a single or double platelet product extraction has a strong agreement with the APY.

Serological screening in donors in Mexico: advances and technology / Tamizaje serológico en donadores de México: avances y tecnología

The residual risk of transfusion-related infections has decreased dramatically in countries that have routinely implemented serological screening. Most of the donation in Mexico is from replacement practice, a risk factor for positive serology. In Mexico, the altruistic donation is only 2.7%. The heterogeneity of technical factors, regional factors and internal policies of each center influences the variability of data on the prevalence of positive screening, as well as the prevalence of confirmed cases. The main advantage of nucleic acid technology is the detection of donors in the period of serological window or occult infections, being occult hepatitis reports in Mexican donors from 1 to 3.4%. The limitation of available technology, the scope of the clinic and perspectives, invites us to improve technology and health policies in the interest of transfusion safety.

El riesgo residual de las infecciones relacionadas a la transfusión ha disminuido drásticamente en los países que han implementado rutinariamente el tamizaje serológico. La mayor parte de la donación en México es de reposición, factor de riesgo para serología positiva, y en donde la donación altruista es de apenas 2.7%. La heterogeneidad de factores técnicos, regionales y políticas internas de cada centro influyen en la variabilidad de datos en prevalencia del tamizaje positivo, así como en la prevalencia de casos confirmados. La principal ventaja de la tecnología de ácidos nucleicos es la detección de donadores en periodo de ventana serológico o de infecciones ocultas, con reportes de hepatitis ocultas en donadores de 1-3.4% en México. Las limitantes de la tecnología disponible, el alcance de la clínica y de las perspectivas, nos invita a la mejora tecnológica y de las políticas sanitarias en aras de la seguridad transfusional.