Background
Respiratory syncytial virus (RSV) is the leading cause of severe lower respiratory infections with nearly all children experiencing at least one infection by the age of two [1]. It is a major health threat which causes about 2350/100,000 hospitalization among children less than one year of age in the United States [2].
Clinical symptoms of RSV infection among children include prominent wheezing, severe bronchiolitis, cough, and shortness of breath [3]. It has been known that prematurely born infants, children with congenital heart defects or bronchopulmonary dysplasia, elderly and immunosuppressed patients have the highest risk of developing severe RSV infections [4]. Meanwhile, a study showed that 73% of hospitalized patients are children with no underlying medical conditions [5].
The classification of RSV varies antigenically and genetically. Based on the reaction of the monoclonal antibody to the surface antigen, RSV can be divided into two major subgroups: RSV-A and RSV-B [6]. Globally, molecular analysis showed that RSV-A has 11 known genotypes (GA1-GA7, SAA1, CB-A, NA1-4 and ON1), whereas RSV-B has 24 known genotypes (GB1-GB4, SAB1-SAB4, URU1-2, CBB, CB1, GB5 and BA1-12) [7].
In the Philippines, RSV is the most common respiratory viral pathogen next to rhinovirus (HRV) among children with severe pneumonia [8]. However, few reports have been published that described the genetic variability of RSV among children. This study examined the epidemiological features of children with RSV infection and characterized the RSV samples by molecular techniques to identify the prevalence and genotypes that circulated in the Philippines from 2006 to 2016.
In this study, we investigated the epidemiological features of children with RSV infections and characterized the RSV strains by molecular techniques to identify the prevalence and genotypes that circulated in the Philippines.