Epidemiology and seasonality of respiratory viral infections in hospitalized children in Kuala Lumpur, Malaysia: a retrospective study of 27 years

Abstract

BackgroundViral respiratory tract infections (RTI) are relatively understudied in Southeast Asian tropical countries. In temperate countries, seasonal activity of respiratory viruses has been reported, particularly in association with temperature, while inconsistent correlation of respiratory viral activity with humidity and rain is found in tropical countries. A retrospective study was performed from 1982-2008 to investigate the viral etiology of children (≤ 5 years old) admitted with RTI in a tertiary hospital in Kuala Lumpur, Malaysia.MethodsA total of 10269 respiratory samples from all children ≤ 5 years old received at the hospital's diagnostic virology laboratory between 1982-2008 were included in the study. Immunofluorescence staining (for respiratory syncytial virus (RSV), influenza A and B, parainfluenza types 1-3, and adenovirus) and virus isolation were performed. The yearly hospitalization rates and annual patterns of laboratory-confirmed viral RTIs were determined. Univariate ANOVA was used to analyse the demographic parameters of cases. Multiple regression and Spearman's rank correlation were used to analyse the correlation between RSV cases and meteorological parameters.ResultsA total of 2708 cases were laboratory-confirmed using immunofluorescence assays and viral cultures, with the most commonly detected being RSV (1913, 70.6%), parainfluenza viruses (357, 13.2%), influenza viruses (297, 11.0%), and adenovirus (141, 5.2%). Children infected with RSV were significantly younger, and children infected with influenza viruses were significantly older. The four main viruses caused disease throughout the year, with a seasonal peak observed for RSV in September-December. Monthly RSV cases were directly correlated with rain days, and inversely correlated with relative humidity and temperature.ConclusionViral RTIs, particularly due to RSV, are commonly detected in respiratory samples from hospitalized children in Kuala Lumpur, Malaysia. As in temperate countries, RSV infection in tropical Malaysia also caused seasonal yearly epidemics, and this has implications for prophylaxis and vaccination programmes.

Molecular Diagnosis of Human Adenovirus in Children with Upper Respiratory Tract Infections

“…A similar study in which high HAdV infections (47.6%) were shown at the age group ≤ 1 to ≥3 years compared to age group 3-≤ 6 years and 6-≤ 15 years at 28.1%, 11%, respectively [35]. The study finding is also, comparable to other studies of HAdV infection in other part of the world indicating that children under the age of 3 years were most susceptible to HAdV infection [36][37][38]. In previous experiments for the detection of HAdV in RTI, we observed that Children at age between 6 to 15 years usually have a lower rate of infection.…”

Risk factors of prolonged hospital stay in children with viral severe acute respiratory infections

“…Other commonly implicated causes are human rhinoviruses, human corona viruses, enteroviruses, and human bocavirus [5][6][7][8][9]. Seasonality is one of the features of respiratory viruses, and geographical variation related to temperature, rainfall, and relative humidity have been identified in epidemiological studies [10,11].…”

Weather and its effects on RSV A and B infections in infants and children in Korea

“…7 In temperate countries, seasonal variation of activity of respiratory viruses has been reported, particularly in association with temperature. 8 RSV have been reported to peak during winter in both of the northern and southern hemispheres. 9 RSV activity tends to rise in the coldest months in temperate regions, where winter outbreaks are common, and in the warmest months in subtropical climates.…”