A laboratory-based study of COVID-19 in Casablanca, Morocco

Background: Given the spread of coronavirus disease 2019 (COVID-19) and its impact on human health, laboratory confirmation of diagnosis is essential. Objective: This study examined the contribution of laboratory diagnosis to the detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the diagnosis of COVID- 19, taking into account patient risk of exposure to SARS-CoV-2, clinical symptoms and comorbidities. Methods: A cross-sectional, laboratory-based study was carried out from 1 April 2020 to 30 April 2020 at the National Reference Laboratory in Morocco using nasopharyngeal samples from patients admitted to the Cheikh Khalifa International University Hospital or other hospitals in Casablanca. A one-step reverse transcription real-time polymerase chain reaction (RT-PCR) was used to detect the presence of the SARS-CoV-2 genome. A national epidemiological investigation form was used to analyze patient exposure risk, clinical symptoms and comorbidities. Results: A total of 793 samples from 375 patients were analyzed and 1150 RT-PCR tests were conducted; 116 patients (30.93%) were COVID-19 positive. Travel to a risk zone, contact with a confirmed COVID-19 case and contact with a person who had been in a risk zone were significantly associated with being positive for COVID-19. Fever and cough were the main symptoms; 7.76 % of positive patients were asymptomatic. Conclusion: This is the first laboratory-based study in Morocco for the diagnosis of COVID- 19. Laboratory diagnosis of COVID-19 by RT-PCR associated with knowledge of exposure risk factors and clinical symptoms and comorbidities remains essential for clinicians for early, appropriate medical management COVID-19 patients.