The Epidemiology and Burden of Influenza B/Victoria and B/Yamagata Lineages in Kenya, 2012–2016

Details

• Alternative Title:
  Open Forum Infect Dis
• Personal Author:
  Emukule, Gideon O ; Otiato, Fredrick ; Nyawanda, Bryan O ; Otieno, Nancy A ; Ochieng, Caroline A ; Ndegwa, Linus K ; Muturi, Peter ; Bigogo, Godfrey ; Verani, Jennifer R ; Muthoka, Philip M ; Hunsperger, Elizabeth ; Chaves, Sandra S
• Description:
  Background
  
  The impact of influenza B virus circulation in Sub-Saharan Africa is not well described.
  
  Methods
  
  We analyzed data from acute respiratory illness (ARI) in Kenya. We assessed clinical features and age-specific hospitalization and outpatient visit rates by person-years for influenza B/Victoria and B/Yamagata and the extent to which circulating influenza B lineages in Kenya matched the vaccine strain component of the corresponding season (based on Northern Hemisphere [October–March] and Southern Hemisphere [April–September] vaccine availability).
  
  Results
  
  From 2012 to 2016, influenza B represented 31% of all influenza-associated ARIs detected (annual range, 13–61%). Rates of influenza B hospitalization and outpatient visits were higher for <5 vs ≥5 years. Among <5 years, B/Victoria was associated with pneumonia hospitalization (64% vs 44%; P = .010) and in-hospital mortality (6% vs 0%; P = .042) compared with B/Yamagata, although the mean annual hospitalization rate for B/Victoria was comparable to that estimated for B/Yamagata. The 2 lineages co-circulated, and there were mismatches with available trivalent influenza vaccines in 2/9 seasons assessed.
  
  Conclusions
  
  Influenza B causes substantial burden in Kenya, particularly among children aged <5 years, in whom B/Victoria may be associated with increased severity. Our findings suggest a benefit from including both lineages when considering influenza vaccination in Kenya.
  
  
• Subjects:
  Influenza, Human Influenza B Virus
• Source:
  Open Forum Infect Dis. 2019; 6(10)
• Pubmed ID:
  31660376
• Pubmed Central ID:
  PMC6804754
• Document Type:
  Journal Article
• Place as Subject:
  Kenya
• Volume:
  6
• Issue:
  10
• Collection(s):
  CDC Public Access
• Main Document Checksum:
  urn:sha256:d82a527b8ec921cf8693a150cb2db55c0cea7ee881b3cd22c53655bd2fef56bd
• Download URL:
  https://stacks.cdc.gov/view/cdc/89273/cdc_89273_DS1.pdf
• File Type:
  [PDF - 1.72 MB ]