Viruses causing severe acute respiratory infections (SARI) in children ≤5 years of age at a tertiary care hospital in Rajasthan, India

Abstract

Background & objectives: Severe acute respiratory infection (SARI) is one of the leading causes of death among children worldwide. As different respiratory viruses exhibit similar symptoms, simultaneous detection of these viruses in a single reaction mixture can save time and cost. The present study was done in a tertiary care children's hospital for rapid identification of viruses causing SARI among children less than or equal to five years of age using multiplex real-time reverse transcription polymerase chain reaction (RT-PCR) kit.

Methods: A total of 155 throat swabs were collected from equal number of children suspected to have SARI and processed for extraction of nucleic acids using automated extraction system. Multiplex real-time RT-PCR was done to identify the viruses in the samples.

Results: The overall positivity for viruses in the study was found to be 72.9 per cent with a co-infection rate of 19.5 per cent. Human metapneumovirus (HMPV) was the predominant virus detected in 25.7 per cent children followed by influenza A (H1N1)pdm09, human rhinovirus (HRV) and human adenovirus (HAdV) in 19.9, 11.0 and 8.8 per cent children, respectively. The HMPV was at its peak in February 2013, HAdV showed two peaks in March-April, 2012 and November 2012-March 2013 while HRV was detected throughout the year.

Interpretation & conclusions: Multiplex real-time PCR helped in rapid identification of viruses. Seventeen viruses were detected in SARI cases with overall positivity of 72.9 per cent. HMPV was the most predominant virus. However, for better clinico-virological correlation, studies are required with complete work up of all the aetiological agents, clinical profile of patients and treatment outcome.

Fig. 1

Graph showing the distribution of different respiratory viruses among children of different age groups (in months). *P < 0.05 (χ2 test, comparison among the different age groups). HMPV A/B, human metapneumovirus A/B; FLUA, influenza A; PAN/H1N1, Pandemic H1N1; FLUB, influenza B; HRV, human rhinovirus; HADV, human adenovirus; RSV A/B, respiratory syncytial virus A/B; HCOV HKU1, human coronavirus HKU1; HCOV OC43, human coronavirus OC43; HCOV NL63, human coronavirus NL63; COR 229E, human coronavirus COR 229E; HPIV-1, human parainfluenza virus 1; HPIV-2, human parainfluenza virus 2; HPIV-3, human parainfluenza virus 3; HPIV-4, human parainfluenza virus 4; EV, enterovirus; HBOV, human bocavirus.

Fig. 2

Seasonal distribution of different respiratory viruses among children. Abbreviations as given in Fig.1.