Update on the omicron sub-variants BA.4 and BA.5.

Several nations have recently begun to relax their public health protocols, particularly regarding the use of face masks when engaging in outdoor activities. This is because there has been a general trend towards fewer cases of coronavirus disease 2019 (COVID-19). However, new Omicron sub-variants (designated BA.4 and BA.5) have recently emerged. These two subvariants are thought to be the cause of an increase in COVID-19 cases in South Africa, the United States, and Europe. They have also begun to spread throughout Asia. They evolved from the Omicron lineage with characteristics that make them even more contagious and which allow them to circumvent immunity from a previous infection or vaccination. This article reviews a number of scientific considerations about these new variants, including their apparently reduced clinical severity.

Implication of the emergence of the delta (B.1.617.2) variants on vaccine effectiveness.

INTRODUCTION: COVID-19 vaccines have been developed to compact the current SARS-CoV-2 pandemic and have been administered to people all over the world. These vaccines have been quite effective in reducing the possibility of severe illness, hospitalization and death. However, the recent emergence of Variants of Concern specifically the delta variant, B.1.617.2, had resulted in additional waves of the pandemic. METHODS: We aim to review the literature to understand the transmission and disease severity, and determine the efficacy of the current COVID-19 vaccines. We searched Pubmed, Scopus, and Embase till August 4th 2021, and used the search terms "delta variant", "vaccinations"," breakthrough infections", and "neutralizing antibody". For the meta-analysis, 21 studies were screened in particular and five articles (148,071 cases) were included in the study, and only four were analyzed in the meta-analysis. RESULTS: In this review, both in vitro and in vivo studies showed significant reductions in neutralization rates against delta variants for vaccinated individuals and convalescent patients with prior history of COVID-19. However, There was a lower incidence of infection with SARS-CoV-2 due to Delta variant was found after the second dose of Pfizer-BioNTech, Oxford-AstraZeneca and Moderna vaccines. CONCLUSION: In fully vaccinated individuals, symptomatic infection with the delta variant was significantly reduced, and therefore, vaccinations play an important role to assist the fight against delta variant.

Antibiotics in the pipeline: a literature review (2017-2020).

INTRODUCTION: Antimicrobial resistance (AMR) is an emerging global threat. It increases mortality and morbidity and strains healthcare systems. Health care professionals can counter the rising AMR by promoting antibiotic stewardship and facilitating new drug development. Even with the economic and scientific challenges, it is reassuring that new agents continue to be developed. METHODS: This review addresses new antibiotics in the pipeline. We conducted a review of the literature including Medline, Clinicaltrials.org, and relevant pharmaceutical companies for approved and in pipeline antibiotics in phase 3 or new drug application (NDA). RESULTS: We found a number of new antibiotics and reviewed their current development status, mode of action, spectra of activity, and indications for which they have been approved. The included studies from phase 3 clinical trials were mainly utilized for the treatment of acute bacterial skin and skin structure infections, community-acquired bacterial pneumonia, and pneumonia acquired in the healthcare settings. The number of these agents is limited against high priority organisms. The identified antibiotics were based mainly on previously known molecules or pre-existing antimicrobial agents. CONCLUSION: There are a limited number of antibiotics against high priority organisms such as multi-drug-resistant Pseudomonas aeruginosa, and carbapenem-resistant Enterobacteriaceae. New antimicrobial agents directed against the top priority organisms as classified by the World Health Organization are urgently needed.

New-onset and relapsed liver diseases following COVID-19 vaccination: a systematic review.

BACKGROUND: Liver diseases post-COVID-19 vaccination is extremely rare but can occur. A growing body of evidence has indicated that portal vein thrombosis, autoimmune hepatitis, raised liver enzymes and liver injuries, etc., may be potential consequence of COVID-19 vaccines. OBJECTIVES: To describe the results of a systematic review for new-onset and relapsed liver disease following COVID-19 vaccination. METHODS: For this systematic review, we searched Proquest, Medline, Embase, PubMed, CINAHL, Wiley online library, Scopus and Nature through the Preferred Reporting Items for Systematic Reviews and Meta Analyses PRISMA guideline for studies on the incidence of new onset or relapsed liver diseases post-COVID-19 vaccination, published from December 1, 2020 to July 31, 2022, with English language restriction. RESULTS: Two hundred seventy-five cases from one hundred and eighteen articles were included in the qualitative synthesis of this systematic review. Autoimmune hepatitis (138 cases) was the most frequent pathology observed post-COVID-19 vaccination, followed by portal vein thrombosis (52 cases), raised liver enzymes (26 cases) and liver injury (21 cases). Other cases include splanchnic vein thrombosis, acute cellular rejection of the liver, jaundice, hepatomegaly, acute hepatic failure and hepatic porphyria. Mortality was reported in any of the included cases for acute hepatic failure (n = 4, 50%), portal vein thrombosis (n = 25, 48.1%), splanchnic vein thrombosis (n = 6, 42.8%), jaundice (n = 1, 12.5%), raised liver enzymes (n = 2, 7.7%), and autoimmune hepatitis (n = 3, 2.2%). Most patients were easily treated without any serious complications, recovered and did not require long-term hepatic therapy. CONCLUSION: Reported evidence of liver diseases post-COIVD-19 vaccination should not discourage vaccination against this worldwide pandemic. The number of reported cases is relatively very small in relation to the hundreds of millions of vaccinations that have occurred and the protective benefits offered by COVID-19 vaccination far outweigh the risks.

Microbial Natural Products with Antiviral Activities, Including Anti-SARS-CoV-2: A Review.

The SARS-CoV-2 virus, which caused the COVID-19 infection, was discovered two and a half years ago. It caused a global pandemic, resulting in millions of deaths and substantial damage to the worldwide economy. Currently, only a few vaccines and antiviral drugs are available to combat SARS-CoV-2. However, there has been an increase in virus-related research, including exploring new drugs and their repurposing. Since discovering penicillin, natural products, particularly those derived from microbes, have been viewed as an abundant source of lead compounds for drug discovery. These compounds treat bacterial, fungal, parasitic, and viral infections. This review incorporates evidence from the available research publications on isolated and identified natural products derived from microbes with anti-hepatitis, anti-herpes simplex, anti-HIV, anti-influenza, anti-respiratory syncytial virus, and anti-SARS-CoV-2 properties. About 131 compounds with in vitro antiviral activity and 1 compound with both in vitro and in vivo activity have been isolated from microorganisms, and the mechanism of action for some of these compounds has been described. Recent reports have shown that natural products produced by the microbes, such as aurasperone A, neochinulin A and B, and aspulvinone D, M, and R, have potent in vitro anti-SARS-CoV-2 activity, targeting the main protease (Mpro). In the near and distant future, these molecules could be used to develop antiviral drugs for treating infections and preventing the spread of disease.

Promising Antimycobacterial Activities of Flavonoids against Mycobacterium sp. Drug Targets: A Comprehensive Review.

Tuberculosis (TB) caused by the bacterial pathogen Mycobacterium tuberculosis (Mtb) remains a threat to mankind, with over a billion of deaths in the last two centuries. Recent advancements in science have contributed to an understanding of Mtb pathogenesis and developed effective control tools, including effective drugs to control the global pandemic. However, the emergence of drug resistant Mtb strains has seriously affected the TB eradication program around the world. There is, therefore, an urgent need to develop new drugs for TB treatment, which has grown researchers' interest in small molecule-based drug designing and development. The small molecules-based treatments hold significant potential to overcome drug resistance and even provide opportunities for multimodal therapy. In this context, various natural and synthetic flavonoids were reported for the effective treatment of TB. In this review, we have summarized the recent advancement in the understanding of Mtb pathogenesis and the importance of both natural and synthetic flavonoids against Mtb infection studied using in vitro and in silico methods. We have also included flavonoids that are able to inhibit the growth of non-tubercular mycobacterial organisms. Hence, understanding the therapeutic properties of flavonoids can be useful for the future treatment of TB.

Tools to Alleviate the Drug Resistance in Mycobacterium tuberculosis.

Mycobacterium tuberculosis (Mtb), an acid-fast bacillus that causes Tuberculosis (TB), is a pathogen that caused 1.5 million deaths in 2020. As per WHO estimates, another 4.1 million people are suffering from latent TB, either asymptomatic or not diagnosed, and the frequency of drug resistance is increasing due to intrinsically linked factors from both host and bacterium. For instance, poor access to TB diagnosis and reduced treatment in the era of the COVID-19 pandemic has resulted in more TB deaths and an 18% reduction in newly diagnosed cases of TB. Additionally, the detection of Mtb isolates exhibiting resistance to multiple drugs (MDR, XDR, and TDR) has complicated the scenario in the pathogen's favour. Moreover, the conventional methods to detect drug resistance may miss mutations, making it challenging to decide on the treatment regimen. However, owing to collaborative initiatives, the last two decades have witnessed several advancements in both the detection methods and drug discovery against drug-resistant isolates. The majority of them belong to nucleic acid detection techniques. In this review, we highlight and summarize the molecular mechanism underlying drug resistance in Mtb, the recent advancements in resistance detection methods, and the newer drugs used against drug-resistant TB.

Updates on Measles Incidence and Eradication: Emphasis on the Immunological Aspects of Measles Infection.

Measles is an RNA virus infectious disease mainly seen in children. Despite the availability of an effective vaccine against measles, it remains a health issue in children. Although it is a self-limiting disease, it becomes severe in undernourished and immune-compromised individuals. Measles infection is associated with secondary infections by opportunistic bacteria due to the immunosuppressive effects of the measles virus. Recent reports highlight that measles infection erases the already existing immune memory of various pathogens. This review covers the incidence, pathogenesis, measles variants, clinical presentations, secondary infections, elimination of measles virus on a global scale, and especially the immune responses related to measles infection.

Evaluation of Bi-Lateral Co-Infections and Antibiotic Resistance Rates among COVID-19 Patients in Lahore, Pakistan.

Background and Objective: Bacterial infections are among the major complications of many viral respiratory tract illnesses, such as influenza and coronavirus disease-2019 (COVID-19). These bacterial co-infections are associated with an increase in morbidity and mortality rates. The current observational study was conducted at a tertiary care hospital in Lahore, Pakistan among COVID-19 patients with the status of oxygen dependency to see the prevalence of bacterial co-infections and their antibiotic susceptibility patterns. Materials and Methods: A total of 1251 clinical samples were collected from already diagnosed COVID-19 patients and tested for bacterial identification (cultures) and susceptibility testing (disk diffusion and minimum inhibitory concentration) using gold standard diagnostic methods. Results: From the total collected samples, 234 were found positive for different bacterial isolates. The most common isolated bacteria were Escherichia coli (E. coli) (n = 62) and Acinetobacter baumannii (A. baumannii) (n = 47). The E. coli isolates have shown the highest resistance to amoxicillin and ampicillin, while in the case of A. baumannii, the highest resistance was noted against tetracycline. The prevalence of methicillin resistant Staphylococcus aureus (MRSA) was 14.9%, carbapenem resistant Enterobacteriaceae (CRE) was 4.5%, and vancomycin resistant Enterococcus (VRE) was 3.96%. Conclusions: The results of the current study conclude that empiric antimicrobial treatment in critically ill COVID-19 patients may be considered if properly managed within institutional or national level antibiotic stewardship programs, because it may play a protective role in the case of bacterial co-infections, especially when a patient has other AMR risk factors, such as hospital admission within the previous six months.

Evaluation of Hematological, Biochemical Profiles and Molecular Detection of Envelope Gene (gp-41) in Human Immunodeficiency Virus (HIV) among Newly Diagnosed Patients.

The Human Immunodeficiency Virus (HIV) is a highly morphic, retrovirus that rapidly evolves through mutation as well as recombination. Because of the immunocompromised status in HIV patients, there is often a higher chance of acquiring different secondary infections followed by liver cirrhosis, hepatitis B & C, and HIV-associated nephropathy. The current study was conducted to see the prevalence of secondary infections, hematological and biochemical markers for liver and renal associated diseases, and to detect the envelope gene (GP41) in newly diagnosed HIV patients. A total of 37 samples were collected from HIV-positive patients registered in different hospital settings under the National AIDS control program. The collected samples were processed for hepatitis B, hepatitis C, hematological analysis, and biochemical analysis. To identify the envelope gene in newly diagnosed HIV patients, polymerase chain reaction (PCR) was performed using four gene-specific primers. The HIV infections were seen more in male as compared to females. A significant decrease in complete blood count was observed in HIV patients when compared to healthy individuals. There was a significant increase in aspartate aminotransferase (AST), alanine aminotransferase (ALT), urea, and creatinine observed in HIV patients. No significant difference was observed in alkaline phosphatase (ALP), total bilirubin, and albumin levels when compared to healthy control. Anemia was observed in 59.4% of HIV patients. A total of three (8.1%) patients were found to be co-infected with hepatitis B and one (2.7 %) was co-infected with hepatitis C. Out of these 37 tested samples, a total of four showed the successful amplification of the envelope gene. This study provides platform for the health care facilitators to regularly monitor the signs, symptoms and clinical biomarkers of HIV-associated infections to prevent toxicity at an early stage to improve the quality of life (QoL) and minimize the mortality rate in HIV patients. Envelope gene mutating frequently results in drug resistance, and thus future research on polymorphism analysis will reveal points of substitutions to improve drug designing.

An Overview on Phenotypic and Genotypic Characterisation of Carbapenem-Resistant Enterobacterales.

Improper use of antimicrobials has resulted in the emergence of antimicrobial resistance (AMR), including multi-drug resistance (MDR) among bacteria. Recently, a sudden increase in Carbapenem-resistant Enterobacterales (CRE) has been observed. This presents a substantial challenge in the treatment of CRE-infected individuals. Bacterial plasmids include the genes for carbapenem resistance, which can also spread to other bacteria to make them resistant. The incidence of CRE is rising significantly despite the efforts of health authorities, clinicians, and scientists. Many genotypic and phenotypic techniques are available to identify CRE. However, effective identification requires the integration of two or more methods. Whole genome sequencing (WGS), an advanced molecular approach, helps identify new strains of CRE and screening of the patient population; however, WGS is challenging to apply in clinical settings due to the complexity and high expense involved with this technique. The current review highlights the molecular mechanism of development of Carbapenem resistance, the epidemiology of CRE infections, spread of CRE, treatment options, and the phenotypic/genotypic characterisation of CRE. The potential of microorganisms to acquire resistance against Carbapenems remains high, which can lead to even more susceptible drugs such as colistin and polymyxins. Hence, the current study recommends running the antibiotic stewardship programs at an institutional level to control the use of antibiotics and to reduce the spread of CRE worldwide.

COVID-19 and mucormycosis superinfection: the perfect storm.

BACKGROUND: The recent emergence of the Coronavirus Disease (COVID-19) disease had been associated with reports of fungal infections such as aspergillosis and mucormycosis especially among critically ill patients treated with steroids. The recent surge in cases of COVID-19 in India during the second wave of the pandemic had been associated with increased reporting of invasive mucormycosis post COVID-19. There are multiple case reports and case series describing mucormycosis in COVID-19. PURPOSE: In this review, we included most recent reported case reports and case-series of mucormycosis among patients with COVID-19 and describe the clinical features and outcome. RESULTS: Many  of the mucormycosis reports were eported from India, especially in COVID-19 patients who were treated and recovered patients. The most commonly reported infection sites were rhino-orbital/rhino-cerebral mucormycosis. Those patients  were diabetic and had corticosteroids therapy for controlling the severity of COVID-19, leading to a higher fatality in such cases and complicating the pandemic scenario. The triad of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), corticosteroid use and uncontrolled diabetes mellitus have been evident for significant increase in the incidence of angioinvasive maxillofacial mucormycosis.  In addition, the presence of spores and other factors might play a role as well. CONCLUSION: With the ongoing COVID-19 pandemic and increasing number of critically ill patients infected with SARS-CoV-2, it is important to develop a risk-based approach for patients at risk of mucormycosis based on the epidemiological burden of mucormycosis, prevalence of diabetes mellitus, COVID-19 disease severity and use of immune modulating agents including the combined use of corticosteroids and immunosuppressive agents in patients with cancer and transplants.

Antimicrobial susceptibility of gram-positive and gram-negative bacteria: a 5-year retrospective analysis at a multi-hospital healthcare system in Saudi Arabia.

BACKGROUND: Studying time-related changes in susceptible pathogens causing healthcare-associated infections (HAIs) is vital in improving local antimicrobial and infection control practices. OBJECTIVES: Describe susceptibility patterns to several antimicrobials in gram-positive and gram-negative pathogens isolated from patients causing HAIs at three private tertiary care hospitals in Saudi Arabia over a 5-year period. METHODS: Data on trends of antimicrobial susceptibility among bacteria causing HAIs events in children and adults at three tertiary private hospitals located in Riyadh and Qassim, Saudi Arabia, were collected retrospectively between 2015 and 2019 using the surveillance data datasets. RESULTS: Over a 5-year period, 38,624 pathogens caused 17,539 HAI events in 17,566 patients. About 9450 (53.8%) of patients who suffered HAIs were females and the average age was 41.7 ± 14.3 years (78.1% were adults and 21.9% were children). Gram-negative pathogens were 2.3-times more likely to cause HAIs compared to gram-positive bacteria (71.9% vs. 28.1%). The ranking of causative pathogens in decreasing order was: Escherichia coli (38%), Klebsiella species (15.1%), and Staphylococcus aureus (12.6%). Gram-positive isolates were mostly susceptible to linezolid (91.8%) whereas they were resistant to ampicillin (52.6%), cefoxitin (54.2%), and doxycycline (55.9%). Gram-negative isolates were mostly sensitive to tigecycline (95%) whereas they were resistant to cefotaxime (49.5%) and cefixime (59.6%). During the 5 years, there were relatively stable susceptibility patterns to all tested antimicrobials, except for cefotaxime which shown a susceptibility reduction by 41.4%, among Escherichia coli and Klebsiella species. An increase in the susceptibility of Acinetobacter and Enterobacter and Citrobacter species to all studied antimicrobials was observed except for colistin that had a slight sensitivity reduction in 2019 by 4.3% against Acinetobacter species. However, we noted reduced sensitivity of MRSA, CoNS and Enterococcus species to gentamicin; and increased resistance of MRSA to linezolid and vancomycin. CONCLUSION: The observed increase in susceptibility of gram-positive and gram-negative bacteria to studied antimicrobials is important; however, reduced sensitivity of MRSA, CoNS and Enterococcus species to gentamicin; and increased resistance of MRSA to linezolid and vancomycin is a serious threat and calls for effective antimicrobial stewardship programs.

Examining the Clinical Prognosis of Critically Ill Patients with COVID-19 Admitted to Intensive Care Units: A Nationwide Saudi Study.

Backgroundand Objectives: COVID-19 is a novel infectious disease caused by a single-stranded RNA coronavirus called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We aimed to conduct a nationwide multicenter study to determine the characteristics and the clinical prognostic outcome of critically ill COVID-19 patients admitted to intensive care units (ICUs). Materials and Methods: This is a nationwide cohort retrospective study conducted in twenty Saudi hospitals. Results: An analysis of 1470 critically ill COVID-19 patients demonstrated that the majority of patients were male with a mean age of 55.9 ± 15.1 years. Most of our patients presented with a shortness of breath (SOB) (81.3%), followed by a fever (73.7%) and a cough (65.1%). Diabetes and hypertension were the most common comorbidities in the study (52.4% and 46.0%, respectively). Multiple complications were observed substantially more among non-survivors. The length and frequency of mechanical ventilation use were significantly greater (83%) in the non-survivors compared with the survivors (31%). The mean Sequential Organ Failure Assessment (SOFA) score was 6 ± 5. The overall mortality rate of the cohort associated with patients that had diabetes, hypertension and ischemic heart disease was 41.8%. Conclusion: Age; a pre-existing medical history of hypertension, diabetes and ischemic heart disease; smoking cigarettes; a BMI ≥ 29; a long mechanical ventilation and ICU stay; the need of ventilatory support; a high SOFA score; fungal co-infections and extracorporeal membrane oxygenation (ECMO) use were key clinical characteristics that predicted a high mortality in our population.

Efficacy of stem cell therapy in patients with chronic liver disease: an umbrella review of systematic reviews.

BACKGROUND: Stem cell therapy offers promising benefits like modulating immune responses, reducing inflammation, and aiding liver regeneration. This umbrella review seeks to compile evidence from systematic reviews to assess the efficacy of stem cell therapy for improving liver function and survival rates in chronic liver disease patients. METHODS: We searched electronic databases up to February 15, 2024. The selection process focused on systematic reviews comparing stem cell therapy with standard care or a placebo. The primary outcomes evaluated were changes in liver enzymes, the MELD score, and survival rates. Nested Knowledge software was utilized for screening and data extraction. All statistical analyses were performed using R software, version 4.3. RESULTS: Our umbrella review included 28 systematic reviews. The meta-analysis showcased a notable improvement in survival rates with a pooled RR of 1.487 (95% CI: 1.281 to 1.727). In non-randomized studies, albumin levels exhibited an SMD of 0.786 (95% CI: 0.368 to 1.204), indicating positive therapeutic effects. For ALT, the meta-analysis revealed a decrease in levels with an SMD of -0.499 (95% CI: -0.834 to -0.164), and for AST, an overall SMD of -0.362 (95% CI: -0.659 to -0.066) was observed, suggesting hepatoprotective effects. No significant changes were observed in total bilirubin levels and MELD scores in RCTs. CONCLUSION: Stem cell therapy exhibits potential as a novel treatment for chronic liver diseases, as it has demonstrated improvements in survival rates and certain liver function markers. More high-quality RCTs are needed in the future to fully ascertain the efficacy of stem cell therapy in this patient population.

Stem cell therapy for COVID-19 treatment: An umbrella review.

BACKGROUND: COVID-19 has presented significant obstacles to healthcare. Stem cell therapy, particularly mesenchymal stem cells (MSCs), has emerged as a potential treatment modality due to its immunomodulatory and regenerative properties. This umbrella review aims to synthesize current evidence from systematic reviews on the safety and efficacy of stem cell therapy in COVID-19 treatment. METHODS: A thorough literature search was performed across Embase, PubMed, Cochrane and Web of Science from December 2019 to February 2024. Systematic reviews focusing on the use of stem cell therapy for COVID-19 were included. Evidence was synthesized by meta-analysis using R software (V 4.3) for each outcome. The certainty of evidence was assessed using the GRADE approach. RESULTS: A total of 24 systematic reviews were included. Stem cell therapy was associated with reduced mortality (RR 0.72, 95% CI: 0.60-0.86); shorter hospital stays (MD -4.00 days, 95% CI: -4.68 to -3.32), and decreased need for invasive ventilation (RR 0.521, 95% CI: 0.320 to 0.847). Symptom remission rates improved (RR 1.151, 95% CI: 0.998 to 1.330), and a reduction in CRP levels was noted (SMD -1.198, 95% CI: -2.591 to 0.195), albeit with high heterogeneity. For adverse events, no significant differences were found between stem cell therapy and standard care (RR 0.87, 95% CI: 0.607 to 1.265). The certainty of evidence ranged from low to moderate. CONCLUSION: Stem cell therapy demonstrates a potential benefit in treating COVID-19, particularly in reducing mortality and hospital stay duration. Despite these promising findings, the evidence is varied, and future large-scale randomized trials are essential to confirm the efficacy and optimize the therapeutic protocols for stem cell therapy in the management of the disease. The safety profile is encouraging, with no significant increase in adverse events, suggesting a viable avenue for treatment expansion.

Psychogenetic, genetic and epigenetic mechanisms in Candida auris: Role in drug resistance.

In recent years, we are facing the challenge of drug resistance emergence in fungi. The availability of limited antifungals and development of multi-drug resistance in fungal pathogens has become a serious concern in the past years in the health sector. Although several cellular, molecular, and genetic mechanisms have been proposed to explain the drug resistance mechanism in fungi, but a complete understanding of the molecular and genetic mechanisms is still lacking. Besides the genetic mechanism, epigenetic mechanisms are pivotal in the fungal lifecycle and disease biology. However, very little is understood about the role of epigenetic mechanisms in the emergence of multi-drug resistance in fungi, especially in Candida auris (C. auris). The current narrative review summaries the clinical characteristics, genomic organization, and molecular/genetic/epigenetic mechanisms underlying the emergence of drug resistance in C. auris. A very few studies have attempted to evaluate the role of epigenetic mechanisms in C. auris. Furthermore, advanced genetic tools such as the CRISP-Cas9 system can be utilized to elucidate the epigenetic mechanisms and their role in the emergence of multi-drug resistance in C. auris.

SARS-CoV-2 infection and multi-organ system damage: A review.

The SARS-CoV-2 infection causes COVID-19, which has affected approximately six hundred million people globally as of August 2022. Organs and cells harboring angiotensin-converting enzyme 2 (ACE2) surface receptors are the primary targets of the virus. However, once it enters the body through the respiratory system, the virus can spread hematogenously to infect other body organs. Therefore, COVID-19 affects many organs, causing severe and long-term complications, even after the disease has ended, thus worsening the quality of life. Although it is known that the respiratory system is most affected by the SARS-CoV-2 infection, many organs/systems are affected in the short and long term. Since the COVID-19 disease simultaneously affects many organs, redesigning diagnostic and therapy policies to fit the damaged organs is strongly recommended. Even though the pathophysiology of many problems the infection causes is unknown, the frequency of COVID-19 cases rises with age and the existence of preexisting symptoms. This study aims to update our knowledge of SARS-CoV-2 infection and multi-organ dysfunction interaction based on clinical and theoretical evidence. For this purpose, the study comprehensively elucidates the most recent studies on the effects of SARS-CoV-2 infection on multiple organs and systems, including respiratory, cardiovascular, gastrointestinal, renal, nervous, endocrine, reproductive, immune, and parts of the integumentary system. Understanding the range of atypical COVID-19 symptoms could improve disease surveillance, limit transmission, and avoid additional multi-organ-system problems.

Global emerging Omicron variant of SARS-CoV-2: Impacts, challenges and strategies.

Newly emerging variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are continuously posing high global public health concerns and panic resulting in waves of coronavirus disease 2019 (COVID-19) pandemic. Depending on the extent of genomic variations, mutations and adaptation, few of the variants gain the ability to spread quickly across many countries, acquire higher virulency and ability to cause severe disease, morbidity and mortality. These variants have been implicated in lessening the efficacy of the current COVID-19 vaccines and immunotherapies resulting in break-through viral infections in vaccinated individuals and recovered patients. Altogether, these could hinder the protective herd immunity to be achieved through the ongoing progressive COVID-19 vaccination. Currently, the only variant of interest of SARS-CoV-2 is Omicron that was first identified in South Africa. In this review, we present the overview on the emerging SARS-CoV-2 variants with a special focus on the Omicron variant, its lineages and hybrid variants. We discuss the hypotheses of the origin, genetic change and underlying molecular mechanism behind higher transmissibility and immune escape of Omicron variant. Major concerns related to Omicron including the efficacy of the current available immunotherapeutics and vaccines, transmissibility, disease severity, and mortality are discussed. In the last part, challenges and strategies to counter Omicron variant, its lineages and hybrid variants amid the ongoing COVID-19 pandemic are presented.