COVID-19 is the infectious disease caused by the novel member of the coronavirus family - SARS-CoV-2. “CO” stands for corona; “VI” for virus; ”D” for disease; “19” the year in which is discovered. This new virusand disease were unknown before the outbreak began in Wuhan, China, in December 2019. The rapid expansion of COVID-19 cases in number and geographic distribution prompted the World Health Organization (WHO) to declare a global health emergency. On March 11, 2020, COVID-19 was officially classified by the WHO as a pandemic. As till June 6th, 2022, the pandemic has caused over 6.3 million deaths across the globe.
The incubation period is three to five days on average, partly depending on the variant, but it may be as long as 14 days. The clinical spectrum of COVID-19 ranges from asymptomatic infection to critical and fatal illness, and therefore, by WHO criteria, COVID-19 is classified in four stages: mild, moderate (pneumonia), severe (severe pneumonia) and crtitically severe (acute respiratory distress syndrom, and complication like sepsis and septic). The basic criteria for classification are grounded on the status of ventilation and oxygenation, radiological findings on the lungs and the presence of symptoms and signs that indicate a disorder of the general condition. The most common symptoms of COVID-19 are fever, fatigue and dry cough, while some patients may experience mialgia, anosmia, nasal congestion, sore throat and diarrhea. The proportion of infections that are asymptomatic is uncertain, but some estimates suggest that up to 40% of infections are asymptomatic. Most people (about 80 percent) recover without the need for therapy and hospitalization. Severe disease was reported in 14%, and critically severe disese in 5% of patients, with overall case fatality ratio of 2.3%. Severe disease also occurs in otherwise healthy individuals of any age, but mainly occurs in older adults with a wide range of comorbidities. Also, many sociodemographic characteristics of patients, as well as unhealthy lifestyle habits, were found to be more or less significant risk factors for severity and poor outcome of COVID-19. With exception of genetic variability, almost all available and known risk factors, symptoms and signs of the disease, and diagnostic procedures have been involved in the development of more than 100 different currently available prediction models related to COVID-19 severity and outcome. However, although the proposed models showed good predictive performance, their usefulness in routine clinical practice appears to be rather unreliable.
Among the European countries, Serbian population was ranked as at the highest risk of serious clinical forms of COVID-19. With an aim to timely and as precisely as possible assess the risk of SARS-Cov-2 infection, severe COVID-19 course and COVID-19-related death in our population, we intend to propose a more comprehensive set of recommendations for detecting high-risk patients among the general Serbian population, which would help and improve decision making in the process of COVID-19 protection, diagnosis and treatment. The proposed multi- and inter-disciplinary approach would combine genetic and epigenetic variability with patient sociodemographic and clinical characteristics, with an aim of gaining a better insight into risk actors for susceptibility to SARS-Cov-infection, the development of severe forms of the disease and the COVID-19-related death.