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Retrospective study identifies infection related risk factors in close contacts during COVID-19 epidemic
Peipei Hu1, Mengmeng Ma2, Qinlong Jing2
1Department of Epidemiology, School of Public Health, Sun Yat-sen University, Guangzhou, China.
Insights
Children appear less susceptible to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. Frequent contact with infected individuals and exposure to cough symptoms increase infection risk in close contacts.
Area of Science:
- Epidemiology
- Infectious Diseases
- Public Health
Background:
- Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has caused a global pandemic.
- Understanding transmission dynamics and risk factors is crucial for control.
Purpose of the Study:
- To compare SARS-CoV-2 infection risk between children and adults.
- To identify risk factors for SARS-CoV-2 infection among close contacts of COVID-19 patients.
Main Methods:
- Retrospective cohort study of COVID-19 close contacts in Guangzhou, China.
- Logistic regression and restricted cubic splines were used to analyze risk factors and age-related infection risk.
Main Results:
- The secondary attack rate (SAR) was 4.4% among 1,344 close contacts.
- Household contacts had the highest SAR (17.2%).
- Adults had a higher infection risk than children; age showed a linear positive correlation with infection. Exposure to index cases with dry cough increased infection risk.
Conclusions:
- Children may be less susceptible to SARS-CoV-2 infection.
- Frequent close contact and exposure to cough symptoms are associated with increased infection risk.
Objectives:
This study aimed to compare the risk of infection of children with that of adults and to explore risk factors of infection with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) by following up close contacts of COVID-19 patients.
Method:
The retrospective cohort study was performed among close contacts of index cases diagnosed with COVID-19 in Guangzhou, China. Demographic characteristics, clinical symptoms and exposure information were extracted. Logistic regression analysis was employed to explore the risk factors. The restricted cubic spline was conducted to examine to the dose-response relationship between age and SARS-CoV-2 infection.
Results:
The secondary attack rate (SAR) was 4.4% in 1,344 close contacts. The group of household contacts (17.2%) had the highest SAR. The rare-frequency contact (p < 0.001) and moderate-frequency contact (p < 0.001) were associated with lower risk of infection. Exposure to index cases with dry cough symptoms was associated with infection in close contacts (p = 0.004). Compared with children, adults had a significantly increased risk of infection (p = 0.014). There is a linear positive correlation between age and infection (p = 0.001).
Conclusions:
Children are probably less susceptible to COVID-19. Close contacts with frequent contact with patients and those exposed to patients with cough symptoms are associated with an increased risk of infection.
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