Epidemiology Of COVID-19 Research Articles

SARS-COV-2 – the pandemic of the XXI century, clinical manifestations – neurological implications

In December 2019, in Wuhan, China, the first cases of infection with SARS-CoV 2 responsible for COVID-19 disease were identified. SARS-CoV 2 was declared a pandemic on March 11, 2020, and since then has attracted the medical world's attention. The threat to humans' health that this emerging pandemic could leave raises awareness on the importance of understanding the mechanisms that underlie the developing conditions. The epidemiology, clinical picture, and pathogenesis of COVID-19 show that this virus presents new strategies to overcome the past defensive medicine. While all the current data has focused on the pulmonary and cardiovascular manifestations, little has been written about the neurological implications of the disease. This review updates new clinical aspects that SARS-CoV 2 expresses in humans by focusing primarily on neurological manifestations. The damage to the nervous system became more apparent - anosmia, ageusia, polyneuritis, meningitis, meningoencephalitis, stroke, acute necrotizing encephalopathy. Oxygen therapy is vital for those in critical health situations. Finally, prevention is the most important element in breaking the epidemiological chain.

Sensitive and visual detection of SARS-CoV-2 using polymerase spiral reaction assay

PurposeTesting of SARS-CoV-2 for large populations is crucial for diagnosis, epidemiology, and surveillance of COVID-19. Currently, reverse transcription (RT) qPCR (RT-qPCR) is being performed worldwide and considered as a gold standard. As an alternative nucleic acid amplification test (NAAT)-based method, RT- polymerase spiral reaction (RT-PSR) assay can be a rapid, robust, and cost-effective point-of-care detection of SARS-CoV-2.Methods & MaterialsInactivated SARS-CoV-2 virus samples were provided by the National Institute of Virology, India for this study. Specific primers targeting Nucleocapsid (N) gene, and RNA-dependent RNA polymerase (RdRp) genes of SARS-CoV-2 were designed for RT-PSR assay. Purified RNA was used for the standardisation of the RT-PSR using in vitro synthesised viral RNA. A simple visual detection of SARS-CoV-2 by the naked eye was optimised using hydroxy naphthol blue dye. The sensitivity of the assay was performed by diluting viral RNA at various concentrations. The limit of detection was estimated and tested with RT-PSR. Computational analysis was performed to determine the specificity of the primers by calculating the percentage of mismatch using various novel coronavirus sequences, other coronaviruses, and other related RNA virus sequences.ResultsTemperature and time for RT-PSR assay were found to be optimum at 63°C and 60 min, respectively, for both the gene targets. RT-PSR assay amplified even at a concentration of 5 ng/µl and could detect ten copies and one copy of RNA targeting RdRp and N gene, respectively. RT-PSR amplified products were visually detected by the naked eye and further verified by agarose gel electrophoresis. Primers used for the RT-PSR assay showed zero percent mismatch with SARS-CoV-2 sequences and mismatch with other viruses.ConclusionThe RT-PSR assay developed in this study could be considered a good alternative to the RT-qPCR assays.

Bioaerosols and airborne transmission: Integrating biological complexity into our perspective

There is broad consensus that airborne disease transmission continues to be the thematic focus of COVID-19, the complexities and understanding of which continues to complicate our attempts to control this pandemic. Masking used as both personal protection and source reduction predominates our society at present and, other than vaccination, remains the public health measure that will faithfully reduce aerosol transmission and overall disease burden (Gandhi and Marr, 2021). Early in the advent of the COVID-19 pandemic, and especially after preliminary recognition of airborne transmission, there was considerable efforts in the application of computational fluid dynamics (CFD) modeling aerosols as well as risk models calculations, the products of which were detailed in the literature (Morawska et al., 2020; Buonanno et al., 2020a) and even disseminated in media destined for the public. As the respiratory pathway emerged as the dominant exposure pathway for SARSCoV-2 transmission, much of what was promoted from CFD was applied to risk models to estimate community infection and in some cases expected clinical outcome. COVID-19 proved to fit the profile of an obligate respiratory-transmitted pathogen, and the plausibility of using aerosol modeling when silhouetted with emerging COVID-19 epidemiology provided ample evidence for promotion of masking and ventilation optimization as a required public health measure. Masking is often included as a factor in developed risk models and it remains an essentially important part of our response to this airborne threat, and ultimately will agnostically reduce disease burden although efforts to improve ventilation in indoor spaces remain a challenge. Arguably the most important concept in the airborne transmission of infectious agents is the biologically active componentry that comprises the aerosol particle and the functional dynamic nature of particle contents. Specifically, the innate generation, transport, and ultimate deposition/disposition of bioaerosols; the aerosol particles that nearly exclusively harbor bioactive components, including viruses, when disease agents are transmitted through the air.

Evaluation of the Relationship Between Vitamin D Deficiency and The Epidemiology of Covid-19

Evaluation of the Relationship Between Vitamin D Deficiency and The Epidemiology of Covid-19

Epidemiology of Pandemic COVID-19 and Its Association with Some Chronic Diseases in Sulaimani City, Iraq

The study aims to provide the epidemiological characteristics of the COVID-19 patients who admitted to Shahid Dr Hemin Teaching Hospital in Sulaimani city, Iraq. It is a cross-sectional study, the data were collected by a convenience sampling method in the hospital, which started from 2nd October to 31th of December 2020. The current study included all the patients who admitted to the hospital, which involved 371 patients. The data were collected from patient’s medical record and a direct interview method was used for filling in the questionnaire form. The collected data were analysed by the SPSS program to produce descriptive statistics such as frequency, percentage, mean and standard deviation while Chi-square test used to find out the association between variables with considering a p-value ? 0.05 as a significant interpretation. The results show that the age of hospitalized COVID-19 patients ranges from 19-95 years old with mean of (63.69±12.73). The age of majority of patients 159 (42.9%) was between 65-79 years old followed by 50-64 years old 124 (33.4%). Male to female ratio was 2:1. Most of the patients were retired 119 (32.1%) in comparison to other occupations and illiterate patients 151(40.7%) were dominance over other patient’s education levels. In addition, majority of patients had hypertension 278(74.9%), diabetes 132 (35.6%) and cardiovascular disease (CVD) 130 (35.0%) and 230 (62.0%) and 141(38.0%) of them were in severe and moderate stage of disease respectively. Also, there was a significant association between the patient’s age group and patients’ outcome while for gender, occupation, and education level, stage of the disease, there were non-significant. The presence of CVD, hypertension and diabetes increase the mortality rate among the patients. In conclusion, age of COVID-19 patient has a great impact on increasing mortality rate and the presence of comorbidities among the patients significantly raise the mortality rate of COVID-19.

Study of the epidemiology of COVID-19 in Ontario elementary and secondary school education workers: an interim analysis following the first school year.

ObjectiveTo estimate the incidence of SARS-CoV-2 in education workers and the factors associated with infection between March 2020 and July 2021.MethodsA prospective cohort study of education workers working ≥8 h per week in Ontario, Canada. Participants self-reported results of tests for SARS-CoV-2 and completed online surveys about demographic information, exposures, and vaccinations against SARS-CoV-2. Participants submitted self-collected dried blood spots. Antibodies to SARS-CoV-2 spike, the receptor binding domain of spike, and nucleocapsid were assessed. Multivariable regression was used to assess risk factors for infection.ResultsOf 2834 participants, 85% were female, 81% were teaching staff, and 86% had received at least one dose of SARS-CoV-2 vaccine. Of the 1983 who had been tested via a respiratory specimen, 4.9% reported a positive test. Five additional participants had serologic testing suggestive of a previous infection (3.6% overall incidence). In multivariable regression analysis, risk factors for infection included exposure to a SARS-CoV-2 infected adult (adjusted incidence rate ratio (aIRR) 13.6; 95% confidence interval 8.6, 21.3) or child (aIRR 2.3; 1.3, 4.2) in the household, or school student (aIRR 1.9; 1.2, 3.2), or travel outside the province within 14 days of testing (aIRR 6.0; 1.5, 23.6).ConclusionIn the first 18 months of the pandemic, education workers had a similar risk of infection with SARS-CoV-2 as other Ontario residents. Practicing protective measures whenever any household member has been exposed to a possible case and at all times when exposed to anyone from outside the home would help reduce the risk of infection.

The COVID-19 pandemic has highlighted the need to invest in care home research infrastructure

The COVID-19 pandemic resulted in catastrophic levels of morbidity and mortality for care home residents. Despite this, research platforms for COVID-19 in care homes arrived late in the pandemic compared with other care settings. The Prophylactic Therapy in Care Homes Trial (PROTECT-CH) was established to provide a platform to deliver multi-centre cluster-randomized clinical trials of investigational medicinal products for COVID-19 prophylaxis in UK care homes. Commencing set-up in January 2021, this involved the design and development of novel infrastructure for contracting and recruitment, remote consent, staff training, research insurance, eligibility screening, prescribing, dispensing, and adverse event reporting; such infrastructure being previously absent. By the time this infrastructure was in place, the widespread uptake of vaccination in care homes had changed the epidemiology of COVID-19 rendering the trial unfeasible. Whilst some of the resources developed through PROTECT-CH will enable the future establishment of care home platform research, the near absence of care home trial infrastructure and nationally-linked databases involving the care home sector will continue to significantly hamper progress. These issues are replicated in most other countries. Beyond COVID-19, there are many other research questions that require addressing to provide better care to people living in care homes. PROTECT-CH has exposed a clear need for research funders to invest in, and legislate for, an effective care home research infrastructure as part of national pandemic preparedness planning. Doing so would also invigorate care home research in the interim, leading to improved healthcare delivery specific to those living in this sector.

Serological Evidence of SARS-CoV-2 Infection in Companion Animals in Pakistan: A Cross-sectional Survey

Background Coronaviruses infect both humans and animals. One of these viruses, SARS-CoV-2, associated with the COVID-19 pandemic, is believed to be zoonotic in nature with its origins from live animal markets in Wuhan, China. The virus has been reported to transmit from humans to other animals and within animal species both naturally and experimentally in many countries. Being a novel virus, studies are needed to understand how it affects animals, possible spread to humans, and other potential roles in the epidemiology of COVID-19 following a one health approach. Objective Therefore, we conducted a cross-sectional sero-survey among companion animals (pet dogs and cats) in twin cities of Islamabad and Rawalpindi, Pakistan with the aim to determine the seroprevalence of COVID-19 among these animals. Methods The study was conducted from November 2020 to April 2021, coinciding with the end of the second wave and the peak of the third wave of COVID-19 in Pakistan. We collected serum samples from 83 animals (68 dogs and 15 cats) from 10 small animal clinics and surgeries in twin cities. The data were collected on the species, age, sex, clinical history, travel history, and confirmation of COVID-19 among the owners or their families, presented with various clinical histories. The samples were tested by ID Screen SARS-CoV-2 double antigen multispecies enzyme-linked immunosorbent assay developed by ID.Vet, France. Results A combined seroprevalence of COVID-19 among these companion animals of 7.23% (6/83; 95% CI 2.7%-15.07%) was found. Further, the seroprevalence of COVID-19 among dogs and cats were 7.35% (5/68; 95% CI 2.43%-16.33%) and 6.67% (1/15; 95% CI 0.17%-31.95%), respectively. Both species were found to be similarly susceptible to COVID-19 (odds ratio 1.11, 95% CI 0.12-10.27; P=.92). Animals in families with a history of COVID-19 among owners were more likely to be seropositive for SARS-CoV-2 (odds ratio 11.8, 95% CI 1.93-71.89; P=.002). Conclusions The results suggest a possible transmission of SARS-CoV-2 from pet owners to their companion animals. However, further studies may be needed to evaluate this hypothesis and the role of pets as potential reservoirs for SARS-CoV-2 infection for humans and other animals.

Cardiac involvement in athletes infected by SARS COV-2 disease

ObjectivesThe aim of the present study was to conduct a review of the current literature evaluating the available evidence to date in terms of epidemiology, pathophysiology and clinical presentation of COVID-19 in relation to cardiovascular involvement, with a special focus on the myocarditis model, in the population of athletes (professional and recreational) who are preparing to return to competitions, with the ultimate aim of guaranteeing maximum safety for resuming sports activities.NewsThe COVID-19 pandemic has resulted in the inevitable cancellation of most sports activities, practiced at both a professional and amateur level, in order to minimize the risk of spreading the infection. Since the number of athletes who tested positive was rather high, the potential cardiac involvement in this peculiar population of subjects contracting the disease in a mild (asymptomatic, slightly symptomatic) or moderate form, has recently raised concerns following the observation of cases of recorded myocardial damage, myocarditis, arrhythmias and a first reported case of Sudden Cardiac Death (SCD) in a 27-year-old professional basketball player. Several studies even seem to confirm the possibility of permanent impairment of the cardiorespiratory system following the infection. Medical history, biomarkers, electrocardiographical and cardiac imaging features appear to be crucial in distinguishing cardiovascular alterations related to COVID-19 infection from typical adaptations to exercise related to athletes' heart.Prospects and ProjectsClarifications and prospective data based on long-term follow-ups on larger populations of athletes are still needed to exclude the development of myocardial damage capable of negatively affecting prognosis and increasing cardiovascular risk in athletes recovered from COVID-19 in asymptomatic (simple positivity to SARS-COV-2) or in a mild form.ConclusionFrom a clinical point of view extreme caution is necessary when planning the return to sport (Return To Play–RTP) of athletes recovered from a mild or asymptomatic form of COVID-19: a careful preliminary medical-sports evaluation should be carried out in order to assess the potential development of myocardial damage that would increase their cardiovascular risk.

‘We are not going to shut down, because we cannot postpone pregnancy’: a mixed-methods study of the provision of maternal healthcare in six referral maternity wards in four sub-Saharan African countries during the COVID-19 pandemic

IntroductionReferral hospitals in sub-Saharan Africa are located in crowded urban areas, which were often epicentres of the COVID-19 pandemic. This paper prospectively assesses how maternal healthcare was provided in six...

A mixed-methods study of maternal health care utilisation in six referral hospitals in four sub-Saharan African countries before and during the COVID-19 pandemic

IntroductionIn sub-Saharan Africa, referral hospitals are important sources of key maternal health services, especially during a crisis such as the COVID-19 pandemic. This study prospectively assessed the effect of the...

Special Issue on COVID-19 and Historical Pandemics Part 2

COVID-19, which originated in Wuhan, China, 2 years ago, became a pandemic, that continues to this day. The Journal of Disaster Research (JDR) edited a special issue, “Special Issue on COVID-19 and Historical Pandemics” at the end of 2020 and an electronic version of the issue was published in January 2021 (JDR Vol.16, No.1, pp. 1-117). Even though one year has passed, life has not yet returned to normal due to the continued spread of COVID-19. Although the percentage of the general public that has been vaccinated continues to increase and various drugs and treatments have been developed, the number of COVID-19 cases also continues to increase. A huge number of COVID-19 cases have been reported, especially in Europe and the Americas. Accordingly, we planned to publish Special Issue Part 2 and called for papers. This Special Issue Part 2 includes 18 manuscripts, which deal with general epidemiology, effects on socioeconomic or educational areas, and clinical medicine, including vaccines and medical treatments. The virus spike protein plays an important role in its intrusion into human cells and the onset of COVID-19 infection. Although SARS-CoV-2 (the pathogenic virus of COVID-19) originated in Wuhan, China, various variant strains with mutation in gene coding in the spike protein have appeared in multiple countries. The WHO classifies these variants into the categories of VOC (variant of concern), VOI (variant of interest), or VUM (variant under monitoring). The definitions of VOC and VOI are as follows. VOC: “A SARS-CoV-2 variant that meets the definition of a VOI and, through a comparative assessment, has been demonstrated to be associated with one or more changes in the degree of global public health significance.” VOI: “Increase in transmissibility or detrimental change in COVID-19 epidemiology, increase in virulence or change in clinical disease presentation, or decrease in effectiveness of public health and social measures or available diagnostics, vaccines and therapeutics.” The WHO uses Greek letters designating the variants. Accordingly as they have appeared, variants have been designated as alpha (α: the UK variant), beta (β: the South Africa variant), and delta (δ: the Indian variant). After the deadline for the manuscript of this special issue, a new variant, omicron (o) originated in South Africa and Botswana, and it immediately began spreading worldwide. Unfortunately, it was impossible to include the manuscript on the omicron variant in this Special Issue Part 2, as the deadline had already passed. As COVID-19 continues to spread, the JDR will plan to edit Part 3 of this COVID-19 special issue.

GAMBARAN EPIDEMIOLOGI COVID-19 DAN HUBUNGANNYA DENGAN PERILAKU PENCEGAHAN DI KOTA SEMARANG

The COVID-19 pandemic caused by the SARSCoV-2 virus in 2019 had caused 2 million deaths in 220 countries in the world until March 2021. The city of Semarang is ranked first in Central Java with 72,329 confirmed cases, with sufferers dominated by men (52.6%) and women (47.4%), and the age range mostly suffered by productive age (20-54 years) as many as 1,142 people (52%).Health behavior according to L. Green is influenced by several factors; predisposing, reinforcing, and enabling. The purpose of this study was to determine the faetures of the epidemiology of COVID-19 and its relationship with preventive behavior in the city of Semarang. The type of research is observational analytic and cross sectional design with simple random sampling technique. The research sample is 55 respondents. Data were analyzed by Chi Square statistical test and logistic regression. The results showed that the factors associated with COVID-19 prevention behavior were gender (p<0.05; PR=2.89), level of knowledge (p<0.01; PR=4.57), and attitude of prevention (p<0.05; p<0.05; PR=3.53). After controlling for other variables, the most influential factor on COVID-19 prevention behavior was the level of knowledge (p=0.007). There is a relationship between gender, level of knowledge, and prevention attitudes with COVID-19 prevention behavior, but there is no relationship between age, employment status, education level, role of health services, vaccination status, history of social contact with COVID-19 patients. 19 with COVID-19 preventive behavior. The advice for this research is to always follow the development of information from trusted sources regarding COVID-19 and always obey health protocols.

COVID-19 Cases and Hospitalizations by COVID-19 Vaccination Status and Previous COVID-19 Diagnosis - California and New York, May-November 2021.

By November 30, 2021, approximately 130,781 COVID-19-associated deaths, one in six of all U.S. deaths from COVID-19, had occurred in California and New York.* COVID-19 vaccination protects against infection with SARS-CoV-2 (the virus that causes COVID-19), associated severe illness, and death (1,2); among those who survive, previous SARS-CoV-2 infection also confers protection against severe outcomes in the event of reinfection (3,4). The relative magnitude and duration of infection- and vaccine-derived protection, alone and together, can guide public health planning and epidemic forecasting. To examine the impact of primary COVID-19 vaccination and previous SARS-CoV-2 infection on COVID-19 incidence and hospitalization rates, statewide testing, surveillance, and COVID-19 immunization data from California and New York (which account for 18% of the U.S. population) were analyzed. Four cohorts of adults aged ≥18 years were considered: persons who were 1) unvaccinated with no previous laboratory-confirmed COVID-19 diagnosis, 2) vaccinated (14 days after completion of a primary COVID-19 vaccination series) with no previous COVID-19 diagnosis, 3) unvaccinated with a previous COVID-19 diagnosis, and 4) vaccinated with a previous COVID-19 diagnosis. Age-adjusted hazard rates of incident laboratory-confirmed COVID-19 cases in both states were compared among cohorts, and in California, hospitalizations during May 30-November 20, 2021, were also compared. During the study period, COVID-19 incidence in both states was highest among unvaccinated persons without a previous COVID-19 diagnosis compared with that among the other three groups. During the week beginning May 30, 2021, compared with COVID-19 case rates among unvaccinated persons without a previous COVID-19 diagnosis, COVID-19 case rates were 19.9-fold (California) and 18.4-fold (New York) lower among vaccinated persons without a previous diagnosis; 7.2-fold (California) and 9.9-fold lower (New York) among unvaccinated persons with a previous COVID-19 diagnosis; and 9.6-fold (California) and 8.5-fold lower (New York) among vaccinated persons with a previous COVID-19 diagnosis. During the same period, compared with hospitalization rates among unvaccinated persons without a previous COVID-19 diagnosis, hospitalization rates in California followed a similar pattern. These relationships changed after the SARS-CoV-2 Delta variant became predominant (i.e., accounted for >50% of sequenced isolates) in late June and July. By the week beginning October 3, compared with COVID-19 cases rates among unvaccinated persons without a previous COVID-19 diagnosis, case rates among vaccinated persons without a previous COVID-19 diagnosis were 6.2-fold (California) and 4.5-fold (New York) lower; rates were substantially lower among both groups with previous COVID-19 diagnoses, including 29.0-fold (California) and 14.7-fold lower (New York) among unvaccinated persons with a previous diagnosis, and 32.5-fold (California) and 19.8-fold lower (New York) among vaccinated persons with a previous diagnosis of COVID-19. During the same period, compared with hospitalization rates among unvaccinated persons without a previous COVID-19 diagnosis, hospitalization rates in California followed a similar pattern. These results demonstrate that vaccination protects against COVID-19 and related hospitalization, and that surviving a previous infection protects against a reinfection and related hospitalization. Importantly, infection-derived protection was higher after the Delta variant became predominant, a time when vaccine-induced immunity for many persons declined because of immune evasion and immunologic waning (2,5,6). Similar cohort data accounting for booster doses needs to be assessed, as new variants, including Omicron, circulate. Although the epidemiology of COVID-19 might change with the emergence of new variants, vaccination remains the safest strategy to prevent SARS-CoV-2 infections and associated complications; all eligible persons should be up to date with COVID-19 vaccination. Additional recommendations for vaccine doses might be warranted in the future as the virus and immunity levels change.

Epidemiology, Transmission, Clinical Features, Diagnosis, Treatment, and Prevention of COVID19: An Updated Review

Introduction: The novel coronavirus disease of 2019 (COVID-19) appeared almost two years ago in China and quickly created a pandemic and affected all aspects of human life. The virus, termed SARS-CoV-2, is generally asymptomatic but contagious and might have originated from bats. Nowadays, the mechanisms underlying the infection and the incidence of SARS-CoV-2 are distinguishable from previous coronaviruses. Early diagnosis and supportive treatment are necessary to cure the patients with COVID-19. Early evidence recommended that children are just likely as adults to become infected with this novel virus. It is now established that children are more often show gastrointestinal manifestations than adults do, and many children affected by SARS-CoV-2 are asymptomatic. Over 300 vaccine projects are recently developed by the scientific community to treat COVID-19 disease; however, these vaccines might lose efficacy by a number of unpredicted issues, including the emergence of new SARS-CoV-2 mutants. Conclusion: Due to the high prevalence and worldwide widespread of COVID-19, many studies are underway to find treatment modalities and develop new vaccines or antiviral substances to fight the virus. The COVID-19 pandemic is not only a challenge to global health but also has globally affected mental, social, and economic health. Moreover, the post-corona pandemic condition will undoubtedly have many Socioeconomic Challenges. This review study has been focused on epidemiology, virology, transmission methods, clinical features, laboratory findings, and prevalent mutations of the SARS-CoV-2 virus. We hope that information provided within this article will significantly benefit researchers currently investigating COVID-19 patients.

Metrics to relate COVID-19 wastewater data to clinical testing dynamics

Wastewater surveillance has emerged as a useful tool in the public health response to the COVID-19 pandemic. While wastewater surveillance has been applied at various scales to monitor population-level COVID-19 dynamics, there is a need for quantitative metrics to interpret wastewater data in the context of public health trends. 24-hour composite wastewater samples were collected from March 2020 through May 2021 from a Massachusetts wastewater treatment plant and SARS-CoV-2 RNA concentrations were measured using RT-qPCR. The relationship between wastewater copy numbers of SARS-CoV-2 gene fragments and COVID-19 clinical cases and deaths varies over time. We demonstrate the utility of three new metrics to monitor changes in COVID-19 epidemiology: (1) the ratio between wastewater copy numbers of SARS-CoV-2 gene fragments and clinical cases (WC ratio), (2) the time lag between wastewater and clinical reporting, and (3) a transfer function between the wastewater and clinical case curves. The WC ratio increases after key events, providing insight into the balance between disease spread and public health response. Time lag and transfer function analysis showed that wastewater data preceded clinically reported cases in the first wave of the pandemic but did not serve as a leading indicator in the second wave, likely due to increased testing capacity, which allows for more timely case detection and reporting. These three metrics could help further integrate wastewater surveillance into the public health response to the COVID-19 pandemic and future pandemics.

Evaluation of the Relationship between Vitamin D Deficiency and the Epidemiology of COVID-19

Evaluation of the Relationship between Vitamin D Deficiency and the Epidemiology of COVID-19

Insights into COVID-19 Epidemiology and Control from Temporal Changes in Serial Interval Distributions in Hong Kong

Insights into COVID-19 Epidemiology and Control from Temporal Changes in Serial Interval Distributions in Hong Kong

Variants of the COVID Virus before the Onset of Omicron

COVID-19 belongs to a group of Coronavirus diseases that SARS-CoV-2 causes. The virus spreads from one person to another via the respiratory droplets from an infected individual produced when such an individual coughs, talks, or sneezes. The symptoms of the diseases range from mild to severe, and individuals at age extremities, that are, very old (from 65 years of age), are highly exposed to severe complications. The symptoms manifest from the second day, fourteen days after exposure to the virus. COVID strains keep on changing as a result of mutations in the viral genomic composition. Different variants of COVID-19 exist; these variants vary in severity, as reported by the World Health Organization. There are thousands of variants of COVID in the world; the virus mutates all the time, making the changes inconsequential. Some of the mutations make the virus more infectious, and some mutated viral strains tend to be dominant. Variants of concern include those that have the most potentially concerning changes. India is among the nations where the virus strains have been reported to dominate and spread to other nations. The virus is claiming the lives of many individuals, with every strain spreading from one country to another. The article will address the research review on types of COVID variants and COVID-19 epidemiology in the world

Changing Epidemiology of COVID-19 in Children and Adolescents Over Four Successive Epidemic Waves in South Africa, 2020-2022

Changing Epidemiology of COVID-19 in Children and Adolescents Over Four Successive Epidemic Waves in South Africa, 2020-2022