Circulation and characterization of seasonal influenza viruses in Cambodia, 2012‐2015

Archive ouverte

Horwood, Paul, F. | Karlsson, Erik, A. | Horm, Srey Viseth | Ly, Sovann | Heng, Seng | Chin, Savuth | Darapheak, Chau | Saunders, David | Chanthap, Lon | Rith, Sareth | Y, Phalla | Chea, Kim Lay | Sar, Borann | Parry, Amy | Ieng, Vanra | Tsuyouka, Reiko | Deng, Yi-Mo | Hurt, Aeron, C. | Barr, Ian, G. | Komadina, Naomi | Buchy, Philippe | Dussart, Philippe

Edité par CCSD ; Wiley Open Access -

International audience. Background: Influenza virus circulation is monitored through the Cambodian in- fluenza-like illness (ILI) sentinel surveillance system and isolates are characterized by the National Influenza Centre (NIC). Seasonal influenza circulation has previ- ously been characterized by year-round activity and a peak during the rainy season (June-November).Objectives: We documented the circulation of seasonal influenza in Cambodia for 2012-2015 and investigated genetic, antigenic, and antiviral resistance characteris- tics of influenza isolates.Patients/Methods: Respiratory samples were collected from patients presenting with influenza-like illness (ILI) at 11 hospitals throughout Cambodia. First-line screen- ing was conducted by the National Institute of Public Health and the Armed Forces Research Institute of Medical Sciences. Confirmation of testing and genetic, anti- genic and antiviral resistance characterization was conducted by Institute Pasteur in Cambodia, the NIC. Additional virus characterization was conducted by the WHO Collaborating Centre for Reference and Research on Influenza (Melbourne, Australia).Results: Between 2012 and 2015, 1,238 influenza-positive samples were submitted to the NIC. Influenza A(H3N2) (55.3%) was the dominant subtype, followed by in- fluenza B (30.9%; predominantly B/Yamagata-lineage) and A(H1N1)pdm09 (13.9%). Circulation of influenza viruses began earlier in 2014 and 2015 than previously de- scribed, coincident with the emergence of A(H3N2) clades 3C.2a and 3C.3a, respec- tively. There was high diversity in the antigenicity of A(H3N2) viruses, and to a smaller extent influenza B viruses, during this period, with some mismatches with the north- ern and southern hemisphere vaccine formulations. All isolates tested were suscepti- ble to the influenza antiviral drugs oseltamivir and zanamivir.Conclusions: Seasonal and year-round co-circulation of multiple influenza types/sub- types were detected in Cambodia during 2012-2015.

• Description
• Sujet/Public
• Outil
• Outil d'anticipation
• Mémoire et thèse
• Gestion