title: Respiratory syncytial virus and influenza are the key viral pathogens in children <2 years hospitalized with bronchiolitis and pneumonia in Islamabad Pakistan.
abstract: Pneumonia remains a leading cause of morbidity and mortality in developing countries. Comprehensive surveillance data are needed to review the prevention and control strategies. We conducted active surveillance of acute lower respiratory infections among children aged <2 years hospitalized at two hospitals of Islamabad, Pakistan. Viral etiology was determined using real-time PCR on respiratory specimens collected during March 2011-April 2012. The overall mean age was 7.83 ± 5.25 months while no statistical difference between age or sex distribution of patients with positive and negative viral etiology (p > 0.05). The average weight of the study group was 6.1 ± 2.25 kg. ≥1 viral pathogens were detected in 75% cases. Major respiratory viruses included RSV-A: 44%, RSV-B: 23%, Influenza-A: 24.5%, Influenza-B: 7%, Adenovirus: 8.4% and HmPV: 5.2%. A single, dual or multiple viral pathogens were detected in 43%, 27% and 5.2% patients respectively. Common symptoms were cough (95%), apnoea (84%), fever (78%), wheeze (64.5%), nasal congestion (55%) and rhinorrhea (48%). Among the RSV positive cases, 2-6 months age group had highest detection rate for RSV-A (30%, n = 21/69) and RSV-B (20%, n = 14/69) while patients infected with Influenza-A were in 2.1-6 months age group (61%, 23/38). Statistically significant difference was observed between RSV-positive and negative cases for nutrition status (p = 0.001), cigarette/wood smoke exposure (p = 0.001) and concomitant clinical findings. Most patients had successful outcome on combination therapy with bronchodilators, inhaled steroids and antibiotics. Our findings underscore high burden of ALRI in Pakistan. Interventions targeting viral pathogens coupled with improved diagnostic approaches are critical for better prevention and control.
authors.affiliation: Department of Virology, National Institute of Health, Chak Shahzad, Park Road, Islamabad, 44000, Pakistan.
authors.forename: Uzma
authors.initials: U
authors.lastname: Bashir
authors.affiliation: Department of Virology, National Institute of Health, Chak Shahzad, Park Road, Islamabad, 44000, Pakistan.
authors.forename: Nadia
authors.initials: N
authors.lastname: Nisar
authors.affiliation: Department of Virology, National Institute of Health, Chak Shahzad, Park Road, Islamabad, 44000, Pakistan.
authors.forename: Yasir
authors.initials: Y
authors.lastname: Arshad
authors.affiliation: Department of Virology, National Institute of Health, Chak Shahzad, Park Road, Islamabad, 44000, Pakistan.
authors.forename: Muhammad Masroor
authors.initials: MM
authors.lastname: Alam
authors.affiliation: Department of Virology, National Institute of Health, Chak Shahzad, Park Road, Islamabad, 44000, Pakistan.
authors.forename: Asiya
authors.initials: A
authors.lastname: Ashraf
authors.affiliation: Atta-Ur-Rahman School of Applied Sciences, National University of Sciences and Technology, Islamabad, Pakistan.
authors.forename: Hajra
authors.initials: H
authors.lastname: Sadia
authors.affiliation: Department of Virology, National Institute of Health, Chak Shahzad, Park Road, Islamabad, 44000, Pakistan.
authors.forename: Birjees Mazher
authors.initials: BM
authors.lastname: Kazi
authors.affiliation: Department of Virology, National Institute of Health, Chak Shahzad, Park Road, Islamabad, 44000, Pakistan. zaidis@pak.emro.who.int.
authors.forename: Syed Sohail Zahoor
authors.initials: SS
authors.lastname: Zaidi
mesh_terms: D001988:Bronchiolitis / Q000453:epidemiology / Q000628:therapy / Q000821:virology*; D002675:Child, Preschool; D005260:Female; D006760:Hospitalization; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D009980:Influenza A virus / Q000235:genetics / Q000302:isolation & purification* / Q000502:physiology; D007251:Influenza, Human / Q000453:epidemiology / Q000628:therapy / Q000821:virology*; D008297:Male; D010154:Pakistan / Q000453:epidemiology; D011014:Pneumonia / Q000453:epidemiology / Q000628:therapy / Q000821:virology*; D018357:Respiratory Syncytial Virus Infections / Q000453:epidemiology / Q000628:therapy / Q000821:virology*; D018113:Respiratory Syncytial Virus, Human / Q000235:genetics / Q000302:isolation & purification* / Q000502:physiology