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Several diagnostic measures have been employed to precisely detect the SARS-CoV-2 viral infection using viral antigens, nucleic acids, and other serological approaches. The sensitivity and specificity of the serological tests remain a challenging need. Here, we describe the detection of human anti-SARS-CoV-2 IgG and IgM antibodies qualitatively through two optimized in-house ELISA and lateral flow immunoassay. Both approaches are based on the prokaryotic expression of 50 kDa SARS-CoV-2 recombinant nucleocapsid protein. This SARS-CoV-2rN-6×His was used either to coat ELISA plates or to be conjugated to gold nanoparticles followed by colorimetric detection of bound human IgG or IgM. In the LFA, we show the optimization of nanoparticle size, protein-binding capacity, membrane treatment, and finally testing the potential capacity of using either the optimized ELISA or LFA in detecting antibodies raised against viral infection. Assessment of both methods was carried out using human sera-positive and negative SARS-CoV-2 antibodies. The ELISA and LFA tests showed 86%, 96.5% sensitivity, 92%, 93.75% specificity, 97%, 98.2% PPV, and 64%, 88.2% NPV, respectively. In conclusion, both approaches were able to successfully detect human antibodies against SARS-CoV-2 nucleocapsid protein. The importance of both protocols cannot be overstated in the detection and diagnosis of viral infections, especially in developing countries.

Lung infiltrates are frequently observed in patients with COVID-19 infection and require specialized management. Identifying reliable laboratory parameters to reduce the need for chest CT scans in non-desaturation patients is of great interest. This study aimed to investigate the potential of C-reactive protein (CRP) as an indicator to identify the presence of lung infiltrates in early COVID-19 infection. The study was conducted at Al-Azhar University hospitals from May 2021 to March 2022 and included 210 patients with COVID-19 infection confirmed by positive PCR, all of whom were previously healthy, non-smokers, and non-hypoxemic. CRP levels were assessed and correlated with lung infiltrates observed in CT chest examinations. The mean value of CRP was 40.3±14.3 mg/L in males and 36.6±15.2 mg/L among females. One hundred sixty-two patients had pneumonic infiltrates, while 48 had no infiltrates. The mean value of CRP was 45.02±10.2 mg/L in patients with radiological infiltrates and 18.8±7.8 mg/L in patients without radiological infiltrates. Based on our findings, a CRP value greater than 29.8 mg/L was suggested as a cut-off value to indicate the presence of lung infiltrates. CRP is a simple laboratory marker that, at certain limits, may point to the presence of pneumonic infiltrates in early non-hypoxemic patients with COVID-19 infection., Competing Interests: The authors declare no conflict of interest., (©2023 JOURNAL of MEDICINE and LIFE.)

The new coronavirus (SARS-CoV-2) is a respiratory virus causing coronavirus disease (COVID-19). Individuals with COVID-19 can shed the viral genome in their feces, even if they do not have symptoms, and the virus can be detected in wastewater. The current study provides the first surveillance of SARS-CoV-2 RNA genome in the wastewater in Egypt. To study this aim, untreated influent (n = 48) and treated effluent (n = 48) samples were collected between January and December 2021 from the wastewater treatment plant in Giza. The viral RNA genome was determined by reverse transcription-polymerase chain reaction (RT-PCR) (S, E, and N target regions) and real-time quantitative reverse transcription-PCR (RT-qPCR) (N1 and N2 target regions). The RT-PCR assay failed to detect SARS-CoV-2 RNA in all samples analyzed, whereas RT-qPCR succeeded in the detection of N gene of SARS-CoV-2 in 62.5% of untreated influent samples. The RT-qPCR Ct values of those samples tested positive ranged from 19.9 to 30.1 with a mean of 23. The treated effluent samples were negative for viral RNA detected by both RT-PCR and RT-qPCR, indicating the efficiency of the sewage treatment plant in degrading SARS-CoV-2. Our preliminary findings provide evidence for the value of wastewater epidemiology approach for the surveillance of SARS-CoV-2 in the population to assist in the responses of public health to COVID-19 outbreak.

Background: The recently emerged SARS-CoV-2 caused a global pandemic since the last two years. The urgent need to control the spread of the virus and rapid application of the suitable health measures raised the importance of available, rapid, and accurate diagnostic approaches., Objective: The purpose of this study is to describe a rapid in-house optimized ELISA based on the expression of the receptor binding domain (RBD) of the SARS-CoV-2 spike protein in a prokaryotic system., Methods: We show the expression of the 30 kDa recombinant SARS-CoV-2 RBD-6×His in four different E. coli strains (at 28∘C using 0.25mM IPTG) including the expression strain E. coli BL21 (DE3) Rosetta Gami. SARS-CoV-2 rRBD-6×His protein was purified, refolded, and used as an antigen coat to assess antibody response in human sera against SARS-CoV-2 infection., Results: The assessment was carried out using a total of 155 human sero-positive and negative SARS-CoV-2 antibodies. The ELISA showed 69.5% sensitivity, 88% specificity, 78.5% agreement, a positive predictive value (PPV) of 92.3%, and a negative predictive value of 56.5%. Moreover, the optical density (OD) values of positive samples significantly correlated with the commercial kit titers., Conclusions: Specific human antibodies against SARS-CoV-2 spike protein were detected by rapid in-house ELISA in sera of human COVID-19-infected patients. The availability of this in-house ELISA protocol would be valuable for various diagnostic and epidemiological applications, particularly in developing countries. Future studies are planned for the use of the generated SARS-CoV-2 rRBD-6×His protein in vaccine development and other diagnostic applications.

This review was focused on global data analysis and risk factors associated with morbidity and mortality of coronavirus disease 2019 from different countries, including Bangladesh, Brazil, China, Central Eastern Europe, Egypt, India, Iran, Pakistan, and South Asia, Africa, Turkey and UAE. Male showed higher confirmed and death cases compared to females in most of the countries. In addition, the case fatality ratio (CFR) for males was higher than for females. This gender variation in COVID-19 cases may be due to males cultural activities, but similar variations in the number of COVID-19 affected males and females globally. Variations in the immune system can illustrate this divergent risk comparatively higher in males than females. The female immune system may have an edge to detect pathogens slightly earlier. In addition, women show comparatively higher innate and adaptive immune responses than men, which might be explained by the high density of immune-related genes in the X chromosome. Furthermore, SARS-CoV-2 viruses use angiotensin-converting enzyme 2 (ACE2) to enter the host cell, and men contain higher ACE2 than females. Therefore, males may be more vulnerable to COVID-19 than females. In addition, smoking habit also makes men susceptible to COVID-19. Considering the age-wise distribution, children and older adults were less infected than other age groups and the death rate. On the contrary, more death in the older group may be associated with less immune system function. In addition, most of these group have comorbidities like diabetes, high pressure, low lungs and kidney function, and other chronic diseases. Due to the substantial economic losses and the numerous infected people and deaths, research examining the features of the COVID-19 epidemic is essential to gain insight into mitigating its impact in the future and preparedness for any future epidemics.

COVID-19 caused by a novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) originated in Wuhan (Hubei province, China) during late 2019. It has spread across the globe affecting nearly 21 million people with a toll of 0.75 million deaths and restricting the movement of most of the world population during the past 6 months. COVID-19 became the leading health, economic, and humanitarian challenge of the twenty-first century. In addition to the considerable COVID-19 cases, hospitalizations, and deaths in humans, several cases of SARS-CoV-2 infections in animal hosts (dog, cat, tiger, lion, and mink) have been reported. Thus, the concern of pet owners is increasing. Moreover, the dynamics of the disease requires further explanation, mainly concerning the transmission of the virus from humans to animals and vice versa. Therefore, this study aimed to gather information about the reported cases of COVID-19 transmission in animals through a literary review of works published in scientific journals and perform genomic and phylogenetic analyses of SARS-CoV-2 isolated from animal hosts. Although many instances of transmission of the SARS-CoV-2 have been reported, caution and further studies are necessary to avoid the occurrence of maltreatment in animals, and to achieve a better understanding of the dynamics of the disease in the environment, humans, and animals. Future research in the animal-human interface can help formulate and implement preventive measures to combat the further transmission of COVID-19.