Peer Review Report For: Epidemiology of first cases of SARS-CoV-2 infection, from March to April 2020, in Gabon [version 2; peer review: 2 approved]

Background After the first cases of coronaviruses disease 2019 (COVID-19) in China in January 2020, the epidemic spread around the world. Few data are available from Central Africa. We conducted a study to monitor this emerging disease in Gabon, a Central Africa country. Methods In order to set up an epidemiological surveillance of COVID-19 in Gabon, we led molecular investigations on nasopharyngeal and oropharyngeal samples from the 1161 first suspected cases of COVID-19. A Reverse Ttranscriptase Polymerase Chain Reaction (RT-PCR) was performed using primers and probes targeted the E gene and polymerase gene according to the kit Tib-Molbiol. Results We diagnosed the first case of COVID-19 on March, 12 2020. Among those suspected cases, 83 were confirmed cases. There was no significant difference in prevalence of SARS-CoV-2 between age groups (p = 0.14). Seventy-three percent were asymptomatic. The viral loads were significantly higher in the nasopharyngeal samples than in the oropharyngeal samples (p=0.03). There was no significant difference in viral loads between age groups (p=0.9895) and no correlation between clinical symptoms and viral loads (p=0.06042). Conclusion In conclusion, this study provides the first molecular data from Gabon concerning the COVID-19 pandemic. The data showed that most of the infected people were asymptomatic. The viral load was higher in the nasopharyngeal samples.