Journal Article

Unmasking Viral Causes of Hospitalized Respiratory Infection: Five Years of Respiratory Virus Surveillance in Vietnam by Multiplex Real-Time PCR Assay

Nguyen, Dung N. T., Quek, Camelia, Vo, Chien D., Pham, Anh H., Ha, Quang D., Tran, Ngoc V., Nguyen, Nhung V., Pham, Huong T., Pham, Son T., Tran, Duy K., Nguyen, Thanh V., Pham, Van H., Nguyen, Thao H. T., Tran, Nhu H. T.

2026

Overview

Aim of the study: To investigate the detection rate of respiratory viruses identified by multiplex real-time PCR (MPL real-time PCR) in respiratory specimens collected from hospitalized patients with acute lower respiratory tract infections (LRTI) over a five-year period (2020–2024), and to emphasize the importance of MPL real-time PCR testing in identifying respiratory viruses responsible for severe lower respiratory tract infections requiring hospitalization. Subjects and Methods: This cross-sectional retrospective study analyzed 15,936 respiratory specimens collected from hospitalized patients between 2020 and 2024. Seventeen respiratory viruses were detected using MPL real-time PCR. Statistical comparisons were performed using the chi-square test. Results and Discussion: The overall respiratory virus detection rate was 31.88% and was significantly higher in children than in adults (52.98% vs. 18.10%). The most frequently detected viruses were rhinovirus, influenza A, respiratory syncytial virus, and parainfluenza virus type 3, while influenza A and SARS-CoV-2 predominated in adults. During the peak of the COVID-19 pandemic in 2021, SARS-CoV-2 accounted for 78.92% of detected viruses, accompanied by marked suppression of other respiratory pathogens. Measles virus re-emerged in 2024, predominantly affecting children (17.65%). Most Respiratory virus-positive cases (82.8%) involved single-agent infections. Conclusions: Hospitalized acute LRTI cases often lack distinctive clinical signs to identify viral pathogens. MPL real-time PCR provides simultaneous multi-virus detection, enabling accurate etiological diagnosis and strengthening hospital-based viral surveillance, particularly in resource-limited settings.

• Publisher: MDPI AG,Multidisciplinary Digital Publishing Institute (MDPI)
• Subject: Acids / acute lower respiratory infection (LRTI) / Adolescent / Adult / Adults / Aged / Causes of / Child / Child, Preschool / Coronaviruses / COVID-19 / Cross-Sectional Studies / Female / Hospital patients / Hospitalization / Hospitalization - statistics & numerical data / Humans / Infant / Infection / Influenza / Influenza A / Lung diseases / Male / Measles / Middle Aged / Middle East respiratory syndrome / Multiplex Polymerase Chain Reaction - methods / multiplex real-time PCR (MPL real-time PCR) / Pandemics / Parainfluenza / Pathogens / Patients / Pediatrics / Physiological aspects / Polymerase chain reaction / R&D / Real-Time Polymerase Chain Reaction - methods / Research & development / Respiratory diseases / Respiratory syncytial virus / Respiratory tract infection / respiratory tract infection (RTI) / Respiratory tract infections / Respiratory Tract Infections - diagnosis / Respiratory Tract Infections - epidemiology / Respiratory Tract Infections - virology / respiratory viruses / Retrospective Studies / Rhinovirus / Severe acute respiratory syndrome coronavirus 2 / Testing laboratories / Thermal cycling / Vietnam - epidemiology / Viral infections / Virus Diseases - diagnosis / Virus Diseases - epidemiology / Virus Diseases - virology / Virus research / Viruses / Viruses - classification / Viruses - genetics / Viruses - isolation & purification / Young Adult