Abstract

Coronavirus disease 2019 (COVID-19) has spread to almost every part of the globe. Numerous risk factors have been identified for predisposition to severe infection. Age is reportedly an incredibly significant risk factor due to high fatality in the elderly population. Further, the infection is more predominant in males as compared to females, probably due to the difference in immunity, hormones, and some specific habits (smoking, drinking) that may influence the viral infection. Correlation of blood group with SARS-CoV-2 infection is also reported as individuals with type A blood group are probably more susceptible to the infection since it is native form. Type O blood group is an evolved form, and thus individuals with this group may be less susceptible to the infection. In addition, existing comorbid conditions like hypertension, diabetes, cardiovascular, endocrine, and chronic respiratory diseases are also associated with an increased risk of severe COVID-19. Obesity has also been reported to have a huge impact on the infection rate and post-infection results. There is also an apprehension of vertical transmission from pregnant females to foetus, but this aspect needs to be analysed in detail in future studies. This review summarizes the effects of different risk factors like age, gender, comorbidities, blood group and prenatal transmission on SARS-CoV-2 infection. The correlation of viral infection with genetic predisposition is another factor that can be explored in future studies. Detailed clinical studies involving large patient groups are required across the globe and on different ethnic populations to clearly define the role of risk factors to COVID-19.