Valeur du Scanner Thoracique dans le Diagnostic de la COVID-19 à l’Hôpital Gynéco-Obstétrique et Pédiatrique de Douala

RESUMEIntroduction. La prise en charge des malades suspects de COVID-19 est amelioree par la rapidite du diagnostic. Le delai diagnostic est relativement long avec le test de Reaction en Chaine de la Polymerase en Temps Reel (RT-PCR), mais plusieurs etudes suggerent que ce delai peut etre raccourci par le scanner thoracique. Le but de notre etude etait donc d’evaluer les sensibilite, specificite, valeur predictive positive (VPP) et valeur predictive negative (VPN) de l’examen de tomodensitometrie (TDM) thoracique pour depister la COVID-19, en considerant la RT-PCR des secretions nasopharyngees comme examen de reference. Materiels et methodes. Il s’agit d’une analyse retrospective des  resultats de l’examen de TDM thoracique des 146 patients suspects de pneumonie liee a la COVID-19, ayant prealablement fait un test de RT-PCR, realise a l’Hopital Gyneco-Obstetrique et Pediatrique de Douala, Cameroun, durant la periode allant d’avril a juillet 2020. Resultats. Sur un total de 146 patients suspects de pneumonie liee a la COVID-19, 131 (89,7%)  avaient un resultat de RT-PCR positif au SARS-coV-2  et 116 (79,5 %) patients avaient un examen de TDM thoracique evocateur de COVID-19. Les sensibilite, specificite, VPP et VPN de l’examen de TDM thoracique etaient estimees respectivement a 80,2%, 26,7%, 90,5%  et 13,3% dans cette population d’etude. Conclusion. Le scanner thoracique a une VPP elevee mais une VPN tres faible dans la pratique clinique de routine a Douala. C’est donc un bon outil de depistage de la pneumonie liee a la COVID-19, mais qui necessite la confirmation par un examen de RT-PCR des secretions nasopharyngees. en cas de resultat positif ABSTRACTObjective. The management of patients suspected with COVID-19 is improved by the speed of diagnosis, whose relatively long time with the Real-Time Polymerase Chain Reaction (RT-PCR) test, can be shortened thanks to the contribution of thoracic CT scan. So, the aim of our study was to evaluate the sensitivity, specificity, positive predictive value and negative predictive value of chest CT scan in the diagnosis of COVID-19, considering an RT-PCR examination of the nasopharyngeal secretions as a THE REFERENCE test. Materials and methods. This was a retrospective analysis of the chest CT-scan of 146 patients suspected with COVID-19 pneumonia, from April to July 2020, in Douala. Results. Out of 146 patients suspected with COVID-19-related pneumonia, 131 (89.7%) had a positive RT-PCR result of SARS-coV-2 and 116 (79.5%) patients had a chest CT-scan suggestive of COVID-19. The sensitivity, specificity, positive predictive value and negative predictive value of TDM were estimated to be 80.2%, 26.7%, 90.5% and 13.3%, respectively. Conclusion. Thoracic CT scan has high a sensitivity and PPV, but a very low NPV in routine clinical practice in Douala. As such, it is is a good diagnostic tool for COVID-related pneumonia. However, it requires confirmation by an RT-PCR examination of the nasopharyngeal secretions in the event of a positive result.