Asymptomatic versus symptomatic SARS-CoV-2 infection: a cross-sectional seroprevalence study

Abstract

Background Although symptomatic SARS-CoV-2 infection predisposes patients to develop complications, the asymptomatic SARS-CoV-2 infection state is of public health importance being a hidden source of infection. Moreover, the asymptomatic state may camouflage the actual burden of the disease. Methods Data of 1434 seropositive participants for SARS-CoV-2 spike (anti-S) and/or nucleocapsid antibodies (anti-N) were retrieved from a larger cross-sectional survey on COVID-19. Relevant data were retrieved from records including socio-demographic, medical, and behavioral characteristics of seropositive participants as well as history of COVID-19 symptoms during the last 6 months. Symptomatic/asymptomatic SARS-CoV-2 infection was categorized based on the history of the presence or absence of COVID-19 symptoms. Results The rate of asymptomatic SARS-CoV-2 infection was 34.9%. There was a statistically significant difference between symptomatic and asymptomatic participants regarding age, residence, medical conditions, habits, and infection control measures. The number of symptoms was positively correlated with anti-S titer and both were positively correlated with adult body mass index. Slum areas residence, client-facing occupation or being a healthcare worker, having lung disease, having blood group type A, never practicing exercise or social distancing, never using soap for hand washing, and minimal engagement in online working/studying were independent factors associated with the symptomatic state. Patients having less than three symptoms were less likely to be diagnosed by any means. Conclusions One-third of SARS-CoV-2 infections in our study were asymptomatic. This mandates applying proper measures to prevent transmission even from apparently healthy individuals. Modifiable factors associated with symptomatic infection should be controlled to reduce the risk of COVID-19 complications.

Epidemiology of COVID-19 and the Utility of Cycle Threshold (Ct) Values in Predicting the Severity of Disease

“…A significant proportion of COVID-19-positive patients in our study were symptomatic (80%), whereas only 20% of patients were asymptomatic. These findings were consistent with reports by Li et al (29.4% in 2020) [14] and El-Ghitany et al (34.9% in 2021) [15], which showed a lower proportion of asymptomatic cases. However, these findings were contrary to the observations from many other Indian studies which reported an outranged prevalence of asymptomatic cases, including a hospital-based study by Soni et al (2020) that reported 57.8 % asymptomatic cases [12], and a study by Krishnasamy et al that reported 48.5% in 2020 from Chennai [16].…”

Hypoalbuminemia, Hyper-a-1/–a-2-Globulinemia Associated with High CRP and IL-6 in COVID-19 Patients in Togo

“…In our study, COVID-19 symptomatic subjects were significantly more aged than COVID-19 asymptomatic and uninfected subjects. These results are similar to those of El-Ghitany et al who found that the proportion of symptomatic SARS-CoV-2 infection was significantly more in all age categories except the age group aged less than 15 years [21]. Indeed COVID-19 is a disease which severity is associated to age [22,23].…”

COVID-19 Antibody Levels among Various Vaccination Groups, One-Year Antibody Follow-Up in Two University Hospitals from Western and Central Turkey

“…Various studies have demonstrated that individuals who experience symptomatic COVID-19 tend to develop higher antibody levels compared to those who are asymptomatic [ 15 ]. Furthermore, a trend of decreasing antibody levels has been observed in infected individuals, typically starting around the third month after infection [ 16 ].…”