Title: Clinical Manifestations and Outcome of Viral Acute Lower Respiratory Infection in Hospitalised Children in Myanmar

Abstract Background Acute lower respiratory infection (ALRI) remains the leading cause of death in children worldwide, and viruses have been the major causative factors of ALRI after the introduction of bacterial conjugate vaccines. In Myanmar, ALRI is associated with high morbidity and mortality in children. However, detailed information on ALRI is currently lacking. Methods We conducted a prospective study to investigate the viral aetiologies, clinical manifestations, and outcomes of ALRI in hospitalised children at the Yankin Children Hospital, Yangon, Myanmar from May 2017 to April 2019. The World Health Organization’s definitions of ALRI and severe ALRI were used with minor modifications. For the patients with suspected viral ALRI, a nasopharyngeal swab was obtained, and rapid tests for influenza and respiratory syncytial virus (RSV) were performed, followed by real-time PCR for the 16 respiratory viruses causing ALRI. Clinical information was extracted from the medical records. Results Among the 5463 patients admitted with a diagnosis of ALRI, 570 (10.4%) were randomly enrolled in the study. The median age of the patients was 8 months (interquartile range, 4–15 months). The most common symptoms were cough (93%) and difficulty of breathing (73%), while the most common signs were tachypnoea (78%) and chest indrawing (67%). Sixteen potentially causative viruses were detected in 502 (88%) patients, with RSV B (36%) and rhinovirus (28%) being the most commonly detected. Multiple viruses were detected simultaneously in 221 patients (37%). Severe ALRI was diagnosed in 107 patients (19%). The mortality rate was 5%; influenza virus A (29%) and RSV B (21%) were commonly detected in such cases. Conclusions Viral ALRI in children has significant morbidity and mortality rates in Myanmar. RSV and rhinovirus were the most commonly detected, while influenza virus and RSV were the most common causes of mortality.