Evaluation of pooling strategy of SARS-CoV-2 RT-PCR in limited resources setting in Egypt at low prevalence.

Sample pooling testing for SARS-COV-2 can be an effective tool in COVID-19 screening when resources are limited, yet it is important to assess the performance before implementation as pooling has its limitations. Our objective was to assess the efficacy of pooling samples for coronavirus 2019 (COVID-19) compared to an individual analysis by using commercial platforms for nucleic acid testing. A total of 2200 nasopharyngeal swabs for SARS-COV-2 were tested individually and in pools of 4, 8, and 10. The cycle threshold (Ct) values of the positive pooled samples were compared to their corresponding individual positive samples. In pool size 10 samples, an estimated increase of 3-Ct was obtained, which led to false negative results in low viral load positive samples. Pooling SARS COV-2 samples is an effective strategy of screening to increase laboratories' capacity and reduce costs without affecting diagnostic performance. A pool size of 8 is recommended.

Impaired Pancreatic ß-Cell Function in Critically Ill Children.

Critical illness hyperglycemia (CIH) is common in the pediatric intensive care unit (PICU). Increased glucose production, insulin resistance (IR), and pancreatic ß-cell dysfunction are responsible mechanisms. We aimed to investigate ß-cell function in the PICU and to uncover its relation to clinical and laboratory variables and ICU mortality. We prospectively recruited 91 children. Pancreatic ß-cell function was assessed by using a homeostasis model assessment (HOMA)-ß. Patients with ß-cell function <40.0% had significantly higher Pediatric Risk of Mortality III (PRISM III) scores, higher rates of a positive C-reactive protein (CRP), lower IR, and a longer hospital stay. The patients with 40-80% ß-cell function had the highest IR. Intermediate IR was found when the ß-cell function was >80%. ICU survivors had better ß-cell function than ICU non-survivors. A multivariate logistic regression analysis revealed that higher PRISM III score and HOMA-ß <80.0% were significant predictors of mortality. In conclusion, ß-cell dysfunction is prevalent among PICU patients and influences patient morbidity and mortality.

Potential Use of Antigen-Based Rapid Test for SARS-CoV-2 in Respiratory Specimens in Low-Resource Settings in Egypt for Symptomatic Patients and High-Risk Contacts.

OBJECTIVE: Because of the rapidly emerging SARS-CoV-2 pandemic and its wide public health challenges, rapid diagnosis is essential to decrease the spread. Antigen-based rapid detection tests are available; however, insufficient data about their performance are available. METHODS: The lateral-flow immunochromatographic BIOCREDIT COVID-19 antigen test was evaluated using nasopharyngeal swabs in a viral transport medium from patients with confirmed infection, contacts, and exposed healthcare professionals at Fayoum University Hospital in Egypt. Test performance was determined in comparison to the SARS-CoV-2 real-time reverse-transcription polymerase chain reaction (RT-PCR) test. RESULTS: Three hundred ten specimens from 3 categories-patients with confirmed diagnoses of COVID-19, contacts, and exposed healthcare professionals-were included; 188 specimens were RT-PCR-positive, from which 81 were detected by rapid antigen test. Overall sensitivity was 43.1%. Sensitivity was significantly higher in specimens with high viral loads. CONCLUSION: Poor sensitivity of the BIOCREDIT COVID-19 test does not permit its use for diagnosis, and it can only be used in conjunction with RT-PCR for screening.

Combining serology and molecular typing of weak D role in improving D typing strategy in Egypt.

BACKGROUND: Rh discrepancies are a problem during routine testing because of partial and weak D phenotypes. Some blood units with weak and partial D expression may escape detection by serology. Limitations of serology can be overcome by molecular typing. The objective of study was to compare currently used serologic methods with molecular analysis to determine the potential application of molecular methods to improve D typing strategies and to estimate the frequency of weak D types among the Arab population. STUDY DESIGN AND METHODS: Fifty blood donor and patient samples with discrepant results of D phenotyping were subjected to routine serology to define the D phenotype including monoclonal anti-D immunoglobulin M and indirect antiglobulin test. Commercially available panels of monoclonal anti-D were used for identification of partial D and weak D phenotypes. Genomic DNA was evaluated using allele-specific amplification polymerase chain reaction with sequence-specific primers to define weak D type. RESULTS: Molecular typing confirmed most of the serology results; three samples that were not clear-cut serologically were identified by molecular typing, two samples as weak D Type 4.2 (DAR), and one sample as weak D Type 4.0. Another two samples identified by serologic panel as weak D were unresolved by molecular typing. A sample with partial D Type II by serology revealed a Weak D Type 4.0 by molecular typing. Results interestingly showed the high frequency of weak D Type 4.2 (DAR) in Egypt. CONCLUSION: RHD molecular typing can solve discrepancies during routine testing due to partial and weak D phenotypes for better transfusion outcome.