Prevalence of viral aetiology of acute lower respiratory Tract infection in children under five years at Kenyatta National hospital

Abstract

BACKGROUND Acute lower respiratory tract infection (ALRI) is a major cause of morbidity and mortality worldwide. Studies in various parts of the world indicate that viruses playa major causative role in childhood ALRI and the incidence is increasing. Some are preventable through chemoprophylaxis or immunoprophylaxis and costs attributable to care could be averted. It was hoped that the results of the study would be of use in local guidelines on management of ALRI. OBJECTIVE. The main purpose of the study was to determine the prevalence of viral etiology in ALRI and the concerned viral strains. METHODS This was a three-month cross sectional study done at pediatric filter clinic and pediatric general wards at Kenyatta National Hospital (KNH). A total of 285 children less than five years of age. presenting with ALRI were identified using World Health Organization (WHO) criteria for diagnosis of ALRl. A definitive diagnosis was made by culture and direct immunoflorescence of nasopharyngeal aspirates. Blood cultures were done in patients with pneumonia to exclude bacterial co-infection. RESULTS The study subjects had a median age of 8 months (IQR 4-17.5), with 65% of the children less than I year of age. One ninety three children (68%) had pneumonia while 81 (28%) and (4%) had bronchiolitis and laryngotracheobronchitis (LTB) respectively One fifty four children were found to have viruses in their nasopharyngeal aspirates giving a prevalence of 54%. The most prevalent virus was respiratory syncytial virus (RSV) present in 49 (32%) of the total viral isolates. Other viruses identified in decreasing order of frequency were; parainfluenza virus in 43(28%) enterovirus 38 (25%), influenza 14 (9%), unknown 14(9%) and adenovirus 12(8%). Ninety children (47%) with pneumonia had posjtive viral isolates and the commonest viral type isolated was enterovirus. Fifty six children (69%) with bronchiolitis had positive viral isolates and the commonest viral type isolated was RSV while 8 (73%) of the children with LTB had positive viral isolates and the commonest virus isolated was parainfluenza. CONCLUSION. The prevalence of viral infection among children less than five years presenting with ALRI at KNH is 54%. The commonest viral isolate was RSV .