Comparison of Omicron and Delta Variants of SARS-CoV-2: A Systematic Review of Current Evidence.

INTRODUCTION: Severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) caused the outbreak of coronavirus disease 2019 (COVID-19) in late 2019 in Wuhan, China. In early 2020, the disease spread rapidly around the world. Since the pandemic, SARS-CoV-2 has evolved dramatically into a wide variety of variants endowed with devastating properties. As of March 6, 2022, five SARS-CoV-2 variants of concern, including Alpha, Beta, Gamma, Delta, and Omicron strains have been identified. Due to the crucial importance of understanding the differences between the Omicron and Delta variants, this systematic review was conducted. METHODS: This systematic review investigated new variants of Omicron SARS-CoV-2 based on cur-rent studies. Online databases were searched for English articles as of January 03, 2023. Selection of publications was a two-step process of title/abstract and full-text assessment against eligibility crite-ria. The relevant data from the included articles were systematically collected and organized in a designed table for analysis. To ensure the quality of the review, the PRISMA checklist and Newcas-tle-Ottawa Scale (NOS) of quality assessment were utilized. RESULTS: The data extracted from 58 articles were analyzed, including 10003 pieces of evidence. Lower risk of hospitalization, ICU admission, and mortality after vaccination were reported in the Omicron variant compared to the Delta variant. Additionally, the Delta variant led to more severe clinical symptoms in comparison to the Omicron variant. CONCLUSION: The Omicron variant of SARS-CoV-2 results in less severe disease outcomes as com-pared to Delta. Nevertheless, it remains crucial to maintain ongoing monitoring, implement contain-ment measures, and adapt vaccination protocols to effectively address the evolving variants.

Estimating Hidden Population Size of COVID-19 Using Respondent- Driven Sampling Method - A Systematic Review.

INTRODUCTION: Currently, the ongoing COVID-19 pandemic is posing a challenge to health systems worldwide. Unfortunately, the true number of infections is underestimated due to the existence of a vast number of asymptomatic infected individual's proportion. Detecting the actual number of COVID-19-affected patients is critical in order to treat and prevent it. Sampling of such populations, so-called hidden or hard-to-reach populations, is not possible using conventional sampling methods. The objective of this research is to estimate the hidden population size of COVID-19 by using respondent-driven sampling methods. METHOD: This study is a systematic review. We have searched online databases of PubMed, Web of Science, Scopus, Embase, and Cochrane to identify English articles published from the beginning of December 2019 to December 2022 using purpose-related keywords. The complete texts of the final chosen articles were thoroughly reviewed, and the significant findings are condensed and presented in the table. RESULTS: Of the 7 included articles, all were conducted to estimate the actual extent of COVID- 19 prevalence in their region and provide a mathematical model to estimate the asymptomatic and undetected cases of COVID-19 amid the pandemic. Two studies stated that the prevalence of COVID-19 in their sample population was 2.6% and 2.4% in Sierra Leone and Austria, respectively. In addition, four studies stated that the actual numbers of infected cases in their sample population were significantly higher, ranging from two to 50 times higher than the recorded reports. CONCLUSIONS: In general, our study illustrates the efficacy of RDS sampling in the estimation of undetected asymptomatic cases with high cost-effectiveness due to its relatively trouble-free and low-cost methods of sampling the population. This method would be valuable in probable future epidemics.

Ocular manifestations of COVID-19: A systematic review of current evidence.

Introduction: COVID-19 caused by SARS-CoV-2, commonly presents with symptoms such as fever and shortness of breath but can also affect other organs. There is growing evidence pointing to potential eye complications. In this article, we aim to systematically review the ocular manifestations of COVID-19. Methods: We conducted a systematic review to explore the ocular manifestations of COVID-19. We searched online databases including PubMed, Embase, Scopus, and Web of Science up to September 4, 2023. After a two-stage screening process and applying inclusion/exclusion criteria, eligible articles were advanced to the data extraction phase. The PRISMA checklist and Newcastle-Ottawa Scale (NOS) were used for quality and bias risk assessments. Results: We selected and extracted data from 42 articles. Most of the studies were cross-sectional (n = 33), with the highest number conducted in Turkey (n = 10). The most frequent ocular manifestation was conjunctivitis, reported in 24 articles, followed by photophobia, burning, chemosis, itching, and ocular pain. Most studies reported complete recovery from these manifestations; however, one study mentioned visual loss in two patients. Conclusion: In general, ocular manifestations of COVID-19 appear to resolve either spontaneously or with supportive treatments. For more severe cases, both medical treatment and surgery have been employed, with the outcomes suggesting that complete recoveries are attainable.

Current ART, determinants for virologic failure and implications for HIV drug resistance: an umbrella review.

OBJECTIVE: The purpose of this study is to investigate the incidence of determinants for virologic failure and to identify predisposing factors to enhance treatment efficacy. Tackling this global public health issue is the key to reducing the rate of virological failure and increasing the success of treatment for those living with HIV. METHODS: This umbrella review delves into various aspects of current anti-retroviral therapy (ART) which is the primary treatment for human immunodeficiency virus (HIV) infection. Comprehensive searches were conducted in online databases including PubMed, Embase, Scopus, and Web of Science, up to May 26, 2023. Following the screening and selection of relevant articles, eligible articles were included in the data extraction. This study adhered to the PRISMA guideline to report the results and employed the NIH quality and bias risk assessment tool to ensure the quality of included studies. RESULTS: In total, 40 review studies published from 2015 to 2023 were included. The bulk of these studies concurred on several major factors contributing to HIV drug resistance and virological failure. Key among these were medication adherence, baseline and therapeutic CD4 levels, the presence of co-infections, and the advanced clinical stage of the infection. CONCLUSION: The resistance to HIV drugs and instances of determinants for virologic failure have a profound impact on the life quality of those infected with HIV. Primary contributors to this scenario include insufficient adherence to treatment, decreased CD4 T-cell count, elevated viral levels, and certain treatment regimens. Implementing appropriate interventions could address these issues. Sub-Saharan Africa exhibits elevated rates of determinants for virologic failure, attributed to the delay in HIV testing and diagnosis, and late initiation of antiretroviral therapy (ART). It is essential to undertake further research aimed at enhancing the detection of resistance in HIV patients and mitigating viral failure by addressing these underlying causes.

The relationship of hip fracture and thyroid disorders: a systematic review.

Introduction: Bone density regulation is considered one of the systems affected by thyroid hormones, leading to low bone density that can result in pathologic fractures, including hip fractures. This review aimed to update clinicians and researchers about the current data regarding the relationship between hip fractures and thyroid disorders. Methods: English papers were thoroughly searched in four main online databases of Scopus, Web of Science, PubMed, and Embase. Data extraction was done following two steps of screening/selection using distinct inclusion/exclusion criteria. This study used the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) checklist and the Newcastle-Ottawa Scale (NOS) as bias assessment. Results: In total, 19 articles were included in the research. The risk of hip fractures in women with differentiated thyroid cancer (DTC) is higher than hip fractures caused by osteoporosis. Men with hyperthyroidism and subclinical hyperthyroidism are at higher risk for hip fracture. Also, a decrease in serum thyroid stimulating hormone (TSH) may be associated with an increased risk of hip fracture. Conclusion: Reaching a consensus conclusion regarding the association between subclinical thyroid dysfunction and hip fracture is not feasible due to the heterogenicity of evidence; however, there may be a higher risk of fracture in individuals with subclinical hyperthyroidism.

The Effectiveness of Face Masks in Preventing COVID-19 Transmission: A Systematic Review.

INTRODUCTION: Since the beginning of the COVID-19 pandemic, face masks have been among the cornerstones of COVID-19 prevention. Therefore, evaluating their preventive effects against COVID-19 is crucial. This review aimed to systematically search for the systematic review articles that explored the role of various types of face masks in preventing COVID-19. METHODS: We browsed the keywords of this study in the online databases of Scopus, Web of Science, PubMed, and Cochrane on 10th January 2023 and retrieved all the relevant systematic review articles. The records were downloaded into an Endnote file, and the duplicates were removed. A two-step screening process consisting of title/abstract and full-text screenings was conducted to select the most relevant articles. To ensure the validity and reliability of the results, this study adhered to the PRISMA protocol. RESULTS: A total of 28 systematic reviews were included in this review. Most studies found that face masks are beneficial against viral respiratory infections, such as COVID-19. Different types of masks were evaluated in included studies. It appeared that mask efficacy depends on the material, layers, fitting on the face and user compliance. N 95 respirator had maximum efficacy, especially when used continuously. CONCLUSION: Face masks have a beneficial effect against COVID-19. Home masks are less protective than surgical masks or N95 personal breathing masks. Besides, the use of masks may elicit a false sense of security in people, which may lead to poor hand hygiene and violation of social distancing. Therefore, the necessary training should be provided to the public to increase awareness and encourage the right practice of using the mask, emphasizing the preventive effects of washing hands, social distancing, and using a face mask against COVID-19.

Effects of Smoking on COVID-19 Management and Mortality: An Umbrella Review.

Introduction: Smoking status appears to lead to a poor prognosis in COVID-19 patients. However, findings from the studies conducted on this topic have not been consistent, and further exploration is required. Methods: The objective of this umbrella review was to examine the effects of smoking on COVID-19 management and mortality. Online databases that included PubMed, Embase, Scopus, and Web of Science were searched using relevant keywords up to July 27, 2022. Articles were restricted to the English language, and the PRISMA protocol was followed. Results: A total of 27 systematic reviews, published from 2020 to 2022, were included. Individual studies included in the systematic reviews ranged from 8 to 186, with various population sizes. The consensus from the majority of systematic reviews was that COVID-19 smoker patients experience greater disease severity, disease progression, hospitalization rate, hospital admission duration, mechanical ventilation, ICU admission, and mortality rate. Conclusions: COVID-19 patients with a history of smoking (current and former) are vulnerable to adverse hospital outcomes and worse COVID-19 progression. Effective preventive and supportive approaches are required to decrease the risk of COVID-19 morbidity and mortality in patients with a history of smoking.

Post-Exposure Prophylaxis for COVID-19: A Systematic Review.

INTRODUCTION: SARS-CoV-2 cause pneumonia can spread across the lung and lead to acute respiratory distress syndrome (ARDS) in severe cases. Post-exposure prophylaxis has shown great potential to prevent the transmission of some viral infections; however, such results for COVID-19 are still inconclusive. METHODS: Therefore, the aim of this study was to systematically review the resources that utilized postexposure prophylaxis (PEP) for COVID-19 and the possible clinical benefits of such drugs. An organized search of relevant literature was done using the keywords and search queries on public databases of Cochrane, PubMed, Web of Science and Scopus from December 2019 to August 23, 2021. Original resources that had the inclusion criteria were included after two-phase title/abstract and full-text screenings. This review adhered to the Preferred Reporting Items for Systematic Reviews and Meta- Analysis (PRISMA) statement. RESULTS: Out of 841 retrieved records 17 resources were appropriate to include in the systematic review. Hydroxychloroquine with a daily dose of 400-800 mg and a duration of 5-14 days was the most frequently used agent for PEP. Chloroquine was recommended to use to control treatment in patients with mild to severe COVID-19 pneumonia. Other agents like Lopinavir-ritonavir (LPV/r), angiotensinconverting enzyme inhibitors (ACEIs), Angiotensin receptor blockers (ARBs), Vitamin D, arbidol, thymosin drugs, and Xin guan no.1 (XG.1, a Chinese formula medicine) have also been applied in some studies. CONCLUSION: Current evidence demonstrated no established clinical benefits of any drug as PEP in individuals with COVID-19. However, scarce indication occurs for the beneficial effects of some agents, but more studies are needed to explore such effects.

Gut microbiota and COVID-19: A systematic review.

Background and Aims: Alteration in humans' gut microbiota was reported in patients infected with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). The gut and upper respiratory tract (URT) microbiota harbor a dynamic and complex population of microorganisms and have strong interaction with host immune system homeostasis. However, our knowledge about microbiota and its association with SARS-CoV-2 is still limited. We aimed to systematically review the effects of gut microbiota on the SARS-CoV-2 infection and its severity and the impact that SARS-CoV-2 could have on the gut microbiota. Methods: We searched the keywords in the online databases of Web of Science, Scopus, PubMed, and Cochrane on December 31, 2021. After duplicate removal, we performed the screening process in two stages; title/abstract and then full-text screening. The data of the eligible studies were extracted into a pre-designed word table. This study adhered to the PRISMA checklist and Newcastle-Ottawa Scale Bias Assessment tool. Results: Sixty-three publications were included in this review. Our study shows that among COVID-19 patients, particularly moderate to severe cases, the gut and lung microbiota was different compared to healthy individuals. In addition, the severity, and viral load of COVID-19 disease would probably also be influenced by the gut, and lung microbiota's composition. Conclusion: Our study concludes that there was a significant difference in the composition of the URT, and gut microbiota in COVID-19 patients compared to the general healthy individuals, with an increase in opportunistic pathogens. Further, research is needed to investigate the probable bidirectional association of COVID-19 and human microbiome.

Estimating Methods of the Undetected Infections in the COVID-19 Outbreak: A Systematic Review.

INTRODUCTION: The accurate number of COVID-19 cases is essential knowledge to control an epidemic. Currently, one of the most important obstacles in estimating the exact number of COVID-19 patients is the absence of typical clinical symptoms in a large number of people, called asymptomatic infections. In this systematic review, we included and evaluated the studies mainly focusing on the prediction of undetected COVID-19 incidence and mortality rates as well as the reproduction numbers, utilizing various mathematical models. METHODS: This systematic review aims to investigate the estimating methods of undetected infections in the COVID-19 outbreak. Databases of PubMed, Web of Science, Scopus, Cochrane, and Embase, were searched for a combination of keywords. Applying the inclusion/exclusion criteria, all retrieved English literature by April 7, 2022, were reviewed for data extraction through a two-step screening process; first, titles/abstracts, and then full-text. This study is consistent with the PRISMA checklist. RESULTS: In this study, 61 documents were retrieved using a systematic search strategy. After an initial review of retrieved articles, 6 articles were excluded and the remaining 55 articles met the inclusion criteria and were included in the final review. Most of the studies used mathematical models to estimate the number of underreported asymptomatic infected cases, assessing incidence and prevalence rates more precisely. The spread of COVID-19 has been investigated using various mathematical models. The output statistics were compared with official statistics obtained from different countries. Although the number of reported patients was lower than the estimated numbers, it appeared that the mathematical calculations could be a useful measure to predict pandemics and proper planning. CONCLUSION: In conclusion, our study demonstrates the effectiveness of mathematical models in unraveling the true burden of the COVID-19 pandemic in terms of more precise, and accurate infection and mortality rates, and reproduction numbers, thus, statistical mathematical modeling could be an effective tool for measuring the detrimental global burden of pandemic infections. Additionally, they could be a really useful method for future pandemics and would assist the healthcare and public health systems with more accurate and valid information.

Virtual clinic in pregnancy and postpartum healthcare: A systematic review.

Background and Aims: To monitor the health status of pregnant women moment by moment, new technologies in the field of telemedicine can be used, such as virtual visits and virtual clinics. During the COVID-19 pandemic, by using these technologies, useful and satisfactory services have been provided to pregnant mothers. The aim of this study is to specify the applications, features, and infrastructure of a comprehensive virtual clinic in the field of gynecological and pregnancy care. Methods: A systematic review search was conducted through the scientific databases from February 2013 to February 2022 using Scopus, Web of Science, and PubMed. Furthermore, manual searches in Google Scholar and the reference lists of included studies were carried out. Results: In this systematic review we included 16 articles that reported experiences in virtual clinics in pregnancy and postpartum healthcare. The involved studies were experimental, cohort, and cross-sectional studies. The target group users were pregnant or women who gave birth and families of neonatal. The application of virtual clinics was for the visit, consultation, monitoring, follow-up, and home care virtually. Highly satisfaction scores of caregivers after virtual visits and consultation were reported. There were some challenges during virtual visits and consultation; the most important challenge was a poor internet connection. Conclusion: The reviewed studies show promising outcomes according to patient and provider satisfaction. We predict that telehealth will become a growingly significant part of gynecological care in the future.

Complications of COVID-19 Vaccines during Pregnancy; a Systematic Review.

Introduction: Rare serious complications have been documented after COVID-19 vaccination as clinical research proceeded and new target populations, such as children and pregnant women, were included. In this study, we attempted to review the literature relevant to pregnancy complications and maternal outcomes of COVID-19 immunization in pregnant women. . Methods: We searched the databases of PubMed, Scopus, Cochrane, and Web of Science on 31 August 2022. The records were downloaded and underwent a two-step screening; 1) title/abstract and then 2) full-text screening to identify the eligible studies. We included English original studies that evaluated the adverse effects of COVID-19 vaccines during pregnancy. Information such as the type of study, geographical location, type of vaccine injected, gestational age, maternal underlying diseases, and complications following the vaccination were extracted into pre-designed tables. Results: According to the findings of included studies, in most of them vaccination had a positive impact and no negative effects were observed. Also, no medical history was reported in 11 articles, and pregnant women had no underlying diseases. Some serious adverse events were reported after vaccination, including miscarriage, paresthesia, uterine contraction, vaginal bleeding, preterm birth, major congenital anomalies, intrauterine growth restriction, and seizure. . Conclusion: Because of limited data availability and the cross-sectional design of most studies, we could neither infer causation between vaccines and incidence of adverse effects nor comment with certainty about any possible adverse outcome of COVID-19 vaccines in vaccinated pregnant women. Consequently, more longitudinal and experimental studies are needed to define the exact adverse effects of COVID-19 vaccines in pregnant women.

Prevalence of sexually transmitted infections and associated risk behaviors in prisoners: A systematic review.

Background and Aims: Sexually transmitted infections (STIs) are one of the major health concerns globally. Generally, prisoners are at higher risks for STIs due to risk factors including; drug-use, high-risk sexual behaviors, densely populated prisons, and poor living conditions. Therefore, we aimed to conduct a systematic review to evaluate the existing data on STI prevalence, and its associated risk factors among prisoners. Methods: We conducted a systematic search of the literature using the keywords in Scopus, PubMed, Web of Science, and Google Scholar online databases. We selected all the relevant original studies in English through title/abstract and full-text screening process. . Results: Based on the inclusion and exclusion criteria, we selected and reviewed 32 studies out of 96 identified papers. The most important STI-associated risk factors among prisoners were drug use, low educational levels, and unsafe sex. The prevalence of STIs was heterogenous in selected studies and was reported as follows; Human Immunodeficiency Virus (HIV) (0%-14.5%), hepatitis B viruses (HBV) (0.04%-27.23%), hepatitis C viruses (HCV) (0.17%-49.7%), Syphilis (0.2%-22.1%), Chlamydia Trachomatis (CT) (1.02%-6.7%), Gonorrhea (0.6%-7.8%), and herpes simplex virus-2 (HSV-2) 22.4%. Conclusion: This systematic review indicates that the prevalence of STIs (HIV, HBV, HCV, Syphilis, Chlamydia Trachomatis, Gonorrhea, and HSV-2) among prisoners appears to be higher than the general population, with drug abuse, low educational levels, and unsafe sex as major risk factors.

Safety and Adverse Events Related to Inactivated COVID-19 Vaccines and Novavax;a Systematic Review.

Introduction: Knowledge of the safety of vaccines is crucial, both to prevent and cure them and to decrease the public hesitation in receiving vaccines. Therefore, this study aimed to systematically review the adverse events reported for inactivated vaccines and Novavax. Methods: In this systematic review, the databases of PubMed, Scopus, Cochrane, and Web of Science were searched on September 15, 2021. Then we identified the eligible studies using a two-step title/abstract and full-text screening process. Data on the subjects, studies, and types of adverse events were extracted and entered in a word table, including serious, mild, local, and systemic adverse events as well as the timing of side effects' appearance. Results: Adverse effects of inactivated coronavirus vaccines side effects were reported from phases 1, 2, and 3 of the vaccine trials. The most common local side effects included injection site pain and swelling, redness, and pruritus. Meanwhile, fatigue, headache, muscle pain, fever, and gastrointestinal symptoms including abdominal pain and diarrhea were among the most common systemic adverse effects. Conclusion: This systematic review indicates that inactivated COVID-19 vaccines, including Sinovac, Sinopharm, and Bharat Biotech, as well as the protein subunit vaccines (Novavax) can be considered as safe choices due to having milder side effects and fewer severe life-threatening adverse events.

Safety and Adverse Events Related to COVID-19 mRNA Vaccines; a Systematic Review.

Introduction: Knowledge of vaccine-related adverse events is crucial as they are among the most important factors that cause hesitation in receiving vaccines. Therefore, we aimed to systematically review the adverse events related to the mRNA vaccines reported in the literature. . Method: A systematic literature search was carried out in the databases of Scopus, PubMed, Cochrane, and Web of Science. We selected original studies that explored the side effects of mRNA COVID-19 vaccines using a two-phase (title/abstract and full-text) screening process. . Results: Cardiac complications were the most commonly reported severe adverse events. It appeared that systemic adverse reactions are more common after the second dose of vaccines. The number of adverse effects reported after the Pfizer vaccine was higher than other vaccines, mostly due to its earlier approval and more widespread use throughout the world. Cardiac adverse events had a higher prevalence but no significant association has been found between COVID-19 mRNA vaccines and cardiac adverse events except for myopericarditis. . Conclusion: Vaccines play a crucial role in controlling the COVID-19 pandemic and decreasing mortalities and the results of the present review acknowledge the fact that the benefits outweigh the adverse events of these vaccines. .