Comparable detection of nasopharyngeal swabs and induced sputum specimens for viral nucleic acid detection of suspected novel coronavirus (SARS-Cov-2) patients in Fayoum governorate, Egypt.

Background: The most commonly utilized samples for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) detection using real-time quantitative reverse transcriptase-polymerase chain reaction (RT-qPCR) are nasopharyngeal swabs (NPS) and oropharyngeal swabs. However, there are some drawbacks. For SARS-CoV-2 detection, induced sputum might be analyzed and may be equivalent to pharyngeal swabs. This study was done to assess the potential superiority of induced sputum over NPS for SARS-CoV-2 detection. Sixty symptomatic COVID-19 patients who attended Fayoum University Hospitals in Fayoum Governorate, Egypt, were included in this cross-sectional descriptive study. Paired NPS and induced sputum samples were collected from each subject on the third and tenth days after symptoms began for RT-qPCR SARS-COV2 diagnosis. Results: At day 3, 52 (86.7%) of NPS and 48 (80.00%) of induced sputum specimens had positive RT-qPCR results with a significant statistical difference (P = 0.001). At day 10, 41 induced sputum samples (68.3%) were negative, while 19 (31.7%) were positive. Only three (5.0%) of the 19 positive induced sputum samples tested positive for NPS. NPS samples had a higher viral load than induced sputum samples at day 3 [25 (41.7%) vs. 23 (38.3%)]. At day 10, induced sputum samples had a higher viral load than NPS [9 (15.0%) vs. 6 (10.0%)]. A statistically significant positive correlation between the viral load value of the NPS and the induced sputum sample at day 3 (r = 0.497, p = 0.00) denoting similarity in the results of the two types of samples. By ROC analysis, the highest area under the curve for the overall CT value of the induced sputum was (0.604), with a statistically significant difference (p value = 0.0418). Conclusion: In the early stages of the disease, induced sputum and NPS tests had comparable results, but NPS yielded more false negative results later in the disease course than an induced sputum sample, which yielded higher sample positivity and viral load than NPS. Furthermore, induced sputum collection is a straightforward, non-invasive, and risk-free method. As a result, induced sputum could be useful for COVID-19 confirmation in patients with radiologically or epidemiologically suspected COVID-19 who have a negative NPS or in difficult-to-diagnose COVID-19 patients.

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.

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.

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.