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.

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.

Role of Hepatitis C Virus (HCV) core antigen in improving blood transfusion safety in high prevalence, resource limited countries, a step forward.

OBJECTIVE: The aim of the present study was to evaluate the efficacy of hepatitis C virus [HCV] core Ag as an alternative affordable test in resource limited countries blood banks. BACKGROUND: Implementing nucleic acid testing in developing countries with low resources is still unaffordable. Egypt has the highest prevalence of hepatitis C in the world and still in need to efficient affordable transfusion program that reduces the window period for the virus before implementing the complex high cost NAT. STUDY DESIGN AND METHODS: HCV core Ag by ELISA in serum, in the presence or absence of anti-HCV antibodies was compared to HCV- RNA by PCR on total number of 1850 first time and repeat donations from Fayoum University Hospital and Badr University Hospital. RESULTS: Among 1850 healthy voluntary donors, 143 donors with anti-HCV antibody positivity, 105 were determined as positive, 38 were negative for HCV core Ag, and 107 were positive for HCV RNA. CONCLUSION: Hepatitis C virus core antigen-ELISA can be a useful alternative in the developing nations and Greater consideration should be given to its implementation as an additional serological test for blood donors in Egypt as the most cost-effective measure for further improvement of transfusion safety.

Study of red blood cell alloimmunization risk factors in multiply transfused thalassemia patients: role in improving thalassemia transfusion practice in Fayoum, Egypt.

BACKGROUND: ß-Thalassemia is considered the most common chronic hemolytic anemia in Egypt. Alloimmunization can lead to serious clinical complications in transfusion-dependent patients. The objective of this study was to determine the frequency and types of alloantibodies, and, in addition, to study the risk factors that might influence alloimmunization in multiply transfused thalassemia patients in Fayoum, Egypt, with the goal that this study could help minimize some of the transfusion-associated risks in those patients. STUDY DESIGN AND METHODS: A total of 188 multiply transfused thalassemia patients attending Fayoum University Hospital were analyzed. Alloantibody identification was performed by DiaMed-ID microtyping system. RESULTS: Alloimmunization prevalence was 7.98%. The most common alloantibody was D-related; anti-D was the most frequent alloantibody found in eight of the 188 patients (4.25 %), followed by anti-C in two patients (1.1%), anti- E in two (1.1 %), anti-c in two (1.1 %), anti-Fya in two (1.1%), anti-K in one (0.53 %), and an unknown antibody in one patient (0.53%). Higher rates of alloimmunization were found in female patients, in patients with ß-thalassemia intermedia, in splenectomized patients, in D- patients, and in patients who started blood transfusion after 3 years of age. CONCLUSION: The study reemphasizes the need for cost-effective strategy for thalassemia transfusion practice in developing countries. Red blood cell antigen typing before transfusion and issue of antigen-matched or antigen-negative blood can be made available to alloimmunized multiply transfused patients. Early institution of transfusion therapy after diagnosis is another means of decreasing alloimmunization.

Priority needs and wisdom strategy for blood transfusion safety in developing low-resource countries.

OBJECTIVE: To evaluate the implementation of alternative safety measures that reduce the risk of transfusion transmissible infections as an affordable measure in low resource countries. BACKGROUND: It is still difficult in developing countries with limited resources to mandate nucleic acid testing due to its high cost. Although NAT reduces the window period of infection, the developing countries are still in need of an efficient and effective transfusion programme before implementing the complex high cost NAT. STUDY DESIGN AND METHODS: Two thousand eight hundred eighty sero-negative first-time and repeat donations from Fayoum University Hospital blood bank were individually analysed by NAT for HIV, HBV and HCV. Only discriminatory-positive NAT were classified comparing the non-remunerated and family replacement donations. RESULTS: Significant discriminatory-positive differences were observed for HBV NAT results, 2 remunerated donations compared to 0 non-remunerated sero-negative donations. The discriminatory positive differences were also significant for HCV NAT results, 4 remunerated donations compared to 1 non-remunerated sero-negative donation. No sero-negative, discriminatory-positive NAT HIV case was found. Seven out of 8 discriminatory positive cases were from first time donations. CONCLUSION: In order to ensure blood safety, the recruitment and retention of voluntary, non-remunerated repeat donors should be a major commitment for low resource countries in which NAT implementation is costly and not feasible.

The impact of fetal and maternal physiologic factors on umbilical cord blood quality as a source of stem cells in Egyptian population.

BACKGROUND: Umbilical cord blood (UCB) has rapidly become a clinically useful alternative stem cell source. Many variables have been used to evaluate a UCB unit and predict transplant outcomes. The objective of this study was to measure the expression of hematopoietic stem cells in UCB and its relation to certain maternal and neonatal physiologic factors to establish optimum criteria for UCB donor selection. STUDY DESIGN AND METHODS: Two hundred UCB units were collected from normal uncomplicated vaginal and cesarean deliveries. Total volume was noted and immediately assessed for total nucleated cell (TNC) count and CD34+ cell concentration. Assessment of maternal and neonatal variables such as mode of delivery, placental weight, baby's birthweight, and sex was made. RESULTS: The volume of the donations ranged from 42.0 to 126 mL, the TNC count ranged from 5 × 10(9) to 28.7 × 10(9) cells/L, and CD34+ cells ranged from 0.03% to 0.62%. There was a significant positive correlation between cord blood volume and cesarean section (p = 0.01) and placental weight (p = 0.02). There was a significant positive correlation with a p value of less than 0.05 between the number of CD34+ cells and UCB volume and TNC. There was no significant difference between the variables and the TNC count. CONCLUSION: Our study concludes that cord units collected for banking should be obtained by selecting units of larger volumes, of higher TNCs, from female babies with heavy placenta, and from babies delivered via cesarean section.

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.