tetano
Editor, Senior Moderator
Open Forum Infect Dis. 2019 Sep 30;6(10)
fz421. doi: 10.1093/ofid/ofz421. eCollection 2019 Oct. [h=1]The Epidemiology and Burden of Influenza B/Victoria and B/Yamagata Lineages in Kenya, 2012-2016.[/h]
Emukule GO[SUP]1[/SUP], Otiato F[SUP]2[/SUP], Nyawanda BO[SUP]2[/SUP], Otieno NA[SUP]2[/SUP], Ochieng CA[SUP]2[/SUP], Ndegwa LK[SUP]1[/SUP], Muturi P[SUP]3[/SUP], Bigogo G[SUP]2[/SUP], Verani JR[SUP]1[/SUP], Muthoka PM[SUP]4[/SUP], Hunsperger E[SUP]1[/SUP], Chaves SS[SUP]1,[/SUP][SUP]5[/SUP].
[h=3]Author information[/h] 1 Centers for Disease Control and Prevention - Kenya Country Office, Nairobi, Kenya. 2 Kenya Medical Research Institute, Kisumu and Nairobi, Kenya. 3 IHRC, Nairobi, Kenya. 4 Kenya Ministry of Health, Nairobi, Kenya. 5 Influenza Division, National Center for Immunization and Respiratory Diseases, US Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
[h=3]Abstract[/h] [h=4]Background:[/h] The impact of influenza B virus circulation in Sub-Saharan Africa is not well described.
[h=4]Methods:[/h] 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).
[h=4]Results:[/h] 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.
[h=4]Conclusions:[/h] 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.
? The Author(s) 2019. Published by Oxford University Press on behalf of Infectious Diseases Society of America.
[h=4]KEYWORDS:[/h] Kenya; Victoria; Yamagata; burden; hospitalization; incidence; influenza B; lineage
PMID: 31660376 PMCID: PMC6804754 DOI: 10.1093/ofid/ofz421
Free PMC Article
fz421. doi: 10.1093/ofid/ofz421. eCollection 2019 Oct. [h=1]The Epidemiology and Burden of Influenza B/Victoria and B/Yamagata Lineages in Kenya, 2012-2016.[/h] Emukule GO[SUP]1[/SUP], Otiato F[SUP]2[/SUP], Nyawanda BO[SUP]2[/SUP], Otieno NA[SUP]2[/SUP], Ochieng CA[SUP]2[/SUP], Ndegwa LK[SUP]1[/SUP], Muturi P[SUP]3[/SUP], Bigogo G[SUP]2[/SUP], Verani JR[SUP]1[/SUP], Muthoka PM[SUP]4[/SUP], Hunsperger E[SUP]1[/SUP], Chaves SS[SUP]1,[/SUP][SUP]5[/SUP].
[h=3]Author information[/h] 1 Centers for Disease Control and Prevention - Kenya Country Office, Nairobi, Kenya. 2 Kenya Medical Research Institute, Kisumu and Nairobi, Kenya. 3 IHRC, Nairobi, Kenya. 4 Kenya Ministry of Health, Nairobi, Kenya. 5 Influenza Division, National Center for Immunization and Respiratory Diseases, US Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
[h=3]Abstract[/h] [h=4]Background:[/h] The impact of influenza B virus circulation in Sub-Saharan Africa is not well described.
[h=4]Methods:[/h] 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).
[h=4]Results:[/h] 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.
[h=4]Conclusions:[/h] 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.
? The Author(s) 2019. Published by Oxford University Press on behalf of Infectious Diseases Society of America.
[h=4]KEYWORDS:[/h] Kenya; Victoria; Yamagata; burden; hospitalization; incidence; influenza B; lineage
PMID: 31660376 PMCID: PMC6804754 DOI: 10.1093/ofid/ofz421
Free PMC Article