Community SARS-CoV-2 dynamics and cycle threshold use to enhance public health surveillance in the Dominican Republic

Abstract

To propose appropriate containment measures and optimize surveillance strategies, it is of utmost importance to understand the dynamics of SARS-CoV-2 transmission within different age groups and its symptomatic and asymptomatic presentations. This study aimed to understand the cycle-threshold (Ct) of SARS-CoV-2 within individuals attending hospital-based facilities in the Dominican Republic. A total of 3,309 saliva samples were analysed from 14 provinces, which yielded a positivity rate of 18.01% (n=596) across 24 sites. Saliva specimens and levels of viral RNA were quantified by RT-qPCR. Overall mean Ct values were 29.3 cycles and significantly correlated with community positivity rate (r=-0.034, p=0.04). There was no significant difference in mean Ct values between studied age groups [F (19, 30) = 0.65, p = 0.5] and no significant correlation between mean Ct by age groups and community positivity. When comparing asymptomatic and symptomatic patients by age groups, the patients between 5 and 17 years old demonstrated a statistically significant mean difference in Ct values with 27.5 and 32.4 cycles, respectively (t (14) = -2.3, p = 0.03). Results identified in this study demonstrate how understanding community viral load is crucial for optimal SARS-CoV-2 surveillance and should be evaluated in the context of transmissibility dynamics.