The Epidemiology of Severe Community-Acquired Viral Lower Respiratory Tract Infection in Children Aged 5 Years and Below in Sarawak

The epidemiology of acute lower respiratory infections (ALRIs) in children younger than five years of age has not been explored in Borneo using molecular techniques. Understanding the burden of disease in Sarawak setting is important in order to improve strategies to reduce the overall morbidity and mortality of acute respiratory disease. A three years prospective study was conducted from November 2012 to October 2015 among children with ARTIs aged five years and below who were admitted into the High Dependency Unit and Intensive Care Unit at 3 major hospitals in Sarawak which included Sarawak General Hospital (SGH), Sibu Hospital and Bintulu Hospital. A Multiplex PCR/RT-PCR approach was used to detect 18 respiratory viruses. Nasal flocked swab (NS), nasopharyngeal aspirates (NPA) or endotracheal tube secretion (ETT) from eligible children were collected. A total of 1204 viruses were detected in 902 of the total 1165 (77%) hospital admission episodes. The most frequent detected viruses were RSV (n=434, 37.2%), followed by HAdV (n=339, 29.1%) and HRV/EV (n=200, 17.2%). Co-detections were common, occurring in 270/902 (30%) of ARTIs. The most prevalent co-detections were RSV-HAdV (n=90) followed by HAdV-HRV (n=60). Overlapping seasonal trends of RSV and HAdV were observed. HAdV activity was positively associated with temperature while HPIV positively associated with temperature and negatively associated with rainfall. Pneumonia remains the main leading cause of ALRI in Sarawak mainly caused by RSV and HAdV. Acute bronchiolitis was mainly associated with RSV while HAdV, HRV and HPIV was associated with acute exacerbation of bronchial asthma, newly diagnosed bronchial asthma and viral wheeze to a similar degree. In conclusion, this three years study provided an important profile of the epidemiology of ALRIs in hospitalized children in Borneo. RSV, HAdV and HRV were predominant viruses found. More effort should be put into the development plan for other respiratory viruses such as RSV and HAdV rather than influenza virus alone. From a public health perspective, information on the prevalence and seasonality of respiratory viruses are crucial to be used as a basis to optimize the timing of interventions for future vaccination programs such as RSV vaccines. Keywords: Epidemiology, acute lower respiratory infections, etiology, multiplex-PCR, childre