Viral etiology of lower respiratory tract infections in adults in the pre-COVID-19 pandemic era: A cross-sectional study in a single center experience from Cameroon.

Background and Aims: Respiratory viruses are responsible for the majority of lower respiratory tract infections (LRTIs) worldwide. However, there is a gap on the epidemiology of viral LRTIs in adults in sub-Saharan African countries. In Cameroon, like in other countries, the role of viral respiratory pathogens in the etiology of LRTIs in adults is helpful for clinical management. This study aimed to determine the viral aetiologies of LRTIs among hospitalized adults in a reference center for respiratory diseases in the town of Yaounde in Cameroon and its surroundings. Methods: A cross-sectional study was conducted from January 2017 to January 2018 at Jamot Hospital in Yaounde (Cameroon). Clinical and demographic information; BAL and sputa were collected from hospitalized patients meeting LRTI case definitions. The clinical samples were investigated for respiratory pathogens with a commercial Reverse Transcriptase Real-Time Polymerase Chain Reaction (RT-PCR) targeting 21 viruses, cultures for bacterial and fungal infections. Results: The 77 included adult patients with LRTIs had an appropriate clinical sample for microbial investigations. A viral agent was detected in 22.1% (17/77) samples. The main viruses detected included rhinovirus (10/77), coronavirus (hCoV-OC43 and hCoV-229E), and influenza A virus (3/77 each). A concomitant viral and bacterial co-infection occurred in 7.8% of patients (6/77) while viral co-infection occurred in one patient (1.3%). No Severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2) was detected in clinical samples. Most patients were under antimicrobials before getting diagnosed. Conclusions: Respiratory viruses account for 22.1% of LRTIs in hospitalized patients in this study. Despite prior antimicrobial therapy and delay, rhinovirus, coronavirus and influenza A virus were the most detected in patients in the pre-COVID-19 pandemic era in a single center experience from Cameroon.