Influenza

Biography

Biography: Mpho Seleka

Abstract

In this study, we aim to describe the circulation patterns of the influenza B/Victoria and B/Yamagata lineages in South Africa and to determine the factors associated with hospitalization for SARI following infection with influenza B/Victoria or B/Yamagata lineages. Data for influenza B in South Africa are limited and the molecular epidemiology was previously described for the period of 1998-2001. The study enrolled patients from three influenza surveillance programs (Viral Watch, SARI and ILI) running in South Africa between year 2005 and 2014. Initially, starting from 2005 to 2008, influenza was diagnosed through virus isolation and antigenic characterization. From 2009, the technology of use was changed to real-time PCR assays. Influenza B vaccine strains recommended for the Southern Hemisphere were mismatched to the dominant circulating lineage in 2005, 2008, 2009 and 2011. Factors associated with infection with a specific influenza B lineage were assessed using the Fisher’s exact test. P-values <0.05 were considered to be statistically significant. Analysis was performed using STATA 13. In SARI cases, the overall frenquency of B/Victoria lineage (181/286 [63.3%]) was higher than that of B/Yamagata lineage (105/286 [36.7%]) from the year 2005 to 2014. The highest incidence of influenza B associated with severe lower respiratory tract infections was seen in the age group 0 to 4 (199/482 [41%]), followed by the age group 25 to 44 (146/482 [40%]), and the age group +65 has the lowest incidence (22/482 [5%]). The overall HIV incidene in the SARI case with influenza B is 99/235 (42%).