Regional analysis: patterns of influenza B circulation in the Americas Rakhee Palekar, MD, MPH PAHO/WHO

Background Influenza A subtype H1, H3, etc Influenza B distinct lineages emerged in 1970’s B-Yamagata & B-Victoria co-circulated since 2001

Influenza in Americas, 2010−2015 North America Central America, Caribe, South America

Relative Proportion of Influenza B THINK ABOUT HOW ELSE TO PRESENT THESE DATA

Influenza B in United States, 2001−2015 Percent Influenza Season

Influenza B Regional Analysis Questions to answer: What is the burden of influenza B relative to influenza A What is the burden of B/Yam relative to B/Vic 3. How does the epidemiology of influenza A differ from influenza B 4. How does the epidemiology of B/Yam differ from B/Vic Compile epidemiologic data from influenza B cases Compare to influenza A Compare B/Yam to B/Vic

Influenza B Regional Analysis Period of analysis: 2010-2015 All countries in Americas eligible to participate Data needed to answer analysis questions: Counts of influenza A and B cases (including B lineage) Epidemiologic characteristics of influenza A and B cases (date of illness onset, hospitalization, treatment, risk factors, vaccination, death) Compile epidemiologic data from influenza B cases Compare to influenza A Compare B/Yam to B/Vic

Influenza B in LAC*, 2010−2015 ADD LINES to separate the seasons ADD N for YAM and VIC *Argentina, Bolivia, Brazil, Colombia, Costa Rica, Chile, CARPHA, El Salvador, Ecuador, Guatemala, Jamaica, Mexico, Panama, Paraguay, Peru , Uruguay

Predominant Influenza B Lineage,2012 Country with vaccine mismatch ADD MISMATCH

Predominant Influenza B Lineage,2013 Country with vaccine mismatch

Predominant Influenza B Lineage,2014 Country with vaccine mismatch Mexico

Hospitalized Influenza B-Yam & B-Vic Cases*, 2012−2015 B/VICTORIA n=409 % (n) B/YAMAGATA n=686 P VALUE Co-morbid conditions 24.4 (100) 29.3 (201) 0.08 Vaccinated 9.8 (40) 14.0 (96) 0.04 Deceased 4.6 (19) 3.8 (26) 0.49 http://www.socscistatistics.com/tests/ztest/Default2.aspx Argentina,Chile,Colombia,Costa Rica,Cuba,Ecuador,El Salvador,Guatemala,Jamaica,Mexico,Panama,Paraguay,Peru,Uruguay *Argentina,Chile,Colombia,Costa Rica,Cuba,Ecuador,El Salvador,Guatemala,Jamaica,Mexico,Panama,Paraguay,Peru,Uruguay

Conclusions Influenza B important each season in all subregions of the Americas Both B lineages circulate in the Americas with variable predominance Vaccine mismatch from year to yearimportant to answer questions about vaccine impact to determine benefit of quadrivalent vaccine More data needed from countries to better delineate epidemiology of B lineages and compare A and B cases

Next Steps Receive data from additional countries (May-June 2016) Complete analysis (June 2016) Share results with participating countries to receive feedback (July 2016)

Gracias! Contact flu team at flu@paho.org and palekarr@paho.org to participate in the analysis