title: Genetic relatedness of infecting and reinfecting respiratory syncytial virus strains identified in a birth cohort from rural Kenya.
abstract: BACKGROUND
  Respiratory syncytial virus (RSV) reinfects individuals repeatedly. The extent to which this is a consequence of RSV antigenic diversity is unclear.
  
  
  METHODS
  Six-hundred thirty-five children from rural Kenya were closely monitored for RSV infection from birth through 3 consecutive RSV epidemics. RSV infections were identified by immunofluorescence testing of nasal washing samples collected during acute respiratory illnesses, typed into group A and B, and sequenced in the attachment (G) protein. A positive sample separated from a previous positive by ≥14 days was defined as a reinfection a priori.
  
  
  RESULTS
  Phylogenetic analysis was undertaken for 325 (80%) of 409 identified infections, including 53 (64%) of 83 reinfections. Heterologous group reinfections were observed in 28 episodes, and homologous group reinfections were observed in 25 episodes; 10 involved homologous genotypes, 5 showed no amino acid changes, and 3 were separated by 21-24 days and were potentially persistent infections. The temporal distribution of genotypes among reinfections did not differ from that of single infections.
  
  
  CONCLUSIONS
  The vast majority of infection and reinfection pairs differed by group, genotype, or G amino acid sequence (ie, comprised distinct viruses). The extent to which this is a consequence of immune memory of infection history or prevalent diversity remains unclear.
authors.affiliation: Kenya Medical Research Institute, Centre for Geographic Medicine Research, Coast, Kenya. cnyaigoti@kilifi.kemri-wellcome.org
authors.forename: Charles N
authors.initials: CN
authors.lastname: Agoti
authors.forename: Alexander G
authors.initials: AG
authors.lastname: Mwihuri
authors.forename: Charles J
authors.initials: CJ
authors.lastname: Sande
authors.forename: Clayton O
authors.initials: CO
authors.lastname: Onyango
authors.forename: Graham F
authors.initials: GF
authors.lastname: Medley
authors.forename: Patricia A
authors.initials: PA
authors.lastname: Cane
authors.forename: D James
authors.initials: DJ
authors.lastname: Nokes
mesh_terms: D002648:Child; D016000:Cluster Analysis; D015331:Cohort Studies; D058872:Epidemics; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D007630:Kenya / Q000453:epidemiology; D016013:Likelihood Functions; D008969:Molecular Sequence Data; D010802:Phylogeny; D015995:Prevalence; D012367:RNA, Viral / Q000737:chemistry; D012008:Recurrence; D018357:Respiratory Syncytial Virus Infections / Q000453:epidemiology / Q000821:virology*; D012136:Respiratory Syncytial Viruses / Q000145:classification / Q000235:genetics*; D012424:Rural Population
chemical_list: D012367:RNA, Viral