Characterization of Hospital Acquired Respiratory Syncytial Virus from Selected Referral Hospitals in Kenya

Abstract

Respiratory Syncytial Virus (RSV) is a major cause of respiratory illness in all ages but occurs more often in children under 2 year. This study evaluated the genetic diversity of G protein gene in samples collected from petients who developed influenza like illnesses while admitted at Kenyatta, New Nyanza and Mbagathi District Hospitals then tested positive for RSV. nasopharyngeal and oropharyngeal samples were collected from patients with new-onset fever (≥38°C) and either cough or sore throat, after being afebrile for at least three days in the wards. Specimen were tested for RSV alongside other viruses using real time polymerase chain reaction (RT-PCR).Those positive were further Subtyped as A or B using the same method. Where subgroup was identified, the attachment G-protein was sequenced and phylogenetically analyzed. Among 248 specimen tested, 37 (14.9%) were RSV positive, 17(45.9%) sequenced successfully. Out of the 17, 9(53%) were RSVA subtype, one being ON1 genotype and 8 NA1 genotype. The remaining 8(47%) were RSV B subtype all genotyped as BA9 and over 80% of the isolates were genetically related. Most positive specimen were from the male patients (59.5%) and from KNH (59.5%).Those aged 5years and above had 79% less odds of contracting RSV than those aged 2 years, Both RSV subtype A and B were observed to be circulating during the study period. The RSV A was circulating in two genotypes, ON1 and NA1, while all RSV B were of genotype BA9 with 69% of the isolates clustering by time and place. The latter findings suggest presence of nosocomial transmission of RSV in the hospitals. This study concludes that Infection control intervention should target those below 2years and recommends further research targeting healthcare workers and visitors who come to see patients in the hospitals.