ABSTRACT
Background: Evolution evidence of Coronavirus disease 2019 (COVID-19) and viral clearance time remains limited in tropical settings. Understanding this is crucial for public health control measures at community-level. We evaluated the viral dynamics of SARS-CoV-2 infection and factors associated with positivity duration in COVID-19 cases in Cameroon. Method(s): We conducted a prospective cohort-study of SARS-CoV-2 positive cases from the first to third wave (March 2020-October 2021) in Yaounde- Cameroon. RT-PCR was performed on nasopharyngeal swabs. SARS-CoV-2 positivity duration was evaluated from the first to last positive test before a negative result. Epi-info V.7.0 was used for data analyses with p< 0.05 considered statistically significant Results: A total of 282 participants were enrolled. The mean age was 41+/-14 years, with male predominant (62.1%). We had 15.6% symptomatic cases and cough most common (59.09%). The overall median positivity duration was 15[IQR: 9-23] days with 15[ IQR: 13-16] in the first, 17[ IQR: 11-26] in the second and 8[ IQR: 4-12] in the third wave (p= 0.007). Positivity duration was significantly higher in males (16 versus 14 days, p=0.03) and people aged >40 years (15 versus 14 days, p=0.02). Positivity duration was not affected by presence or absence of symptoms (p=0.80). No significant correlation was found with viral load (r=0.03;p=0.61). Considering baseline (24.7+/-7.2Ct) and last viral load (29.3+/-5.9 Ct), the DELTACt (4.6+/-1.3) and positivity duration (15 days) revealed a kinetic in viral decay of 0.3+/-0.087 Ct/day. Conclusion(s): A median positivity duration of 15 days is in accordance with viral clearance around 2 weeks for optimal confinement at community-level. Men and/or the elderly stand at higher risk of prolonged infection. Given the viral decay (0.3 Ct daily), we suggest personalized confinement periods. The variability of positivity duration according to phases could be function of strains which could be a factor of positivity duration.