The World Health Organization (WHO) Collaborating Centres for Reference and Research on Influenza (WHO CCs) tested 13,312 viruses collected by WHO recognized National Influenza Centres between May 2014 and May 2015 to determine 50% inhibitory concentration (IC50) data for neuraminidase inhibitors (NAIs) oseltamivir, zanamivir, peramivir and laninamivir. Ninety-four per cent of the viruses tested by the WHO CCs were from three WHO regions: Western Pacific, the Americas and Europe. Approximately 0.5% (n = 68) of viruses showed either highly reduced inhibition (HRI) or reduced inhibition (RI) (n = 56) against at least one of the four NAIs. Of the twelve viruses with HRI, six were A(H1N1)pdm09 viruses, three were A(H3N2) viruses and three were B/Yamagata-lineage viruses. The overall frequency of viruses with RI or HRI by the NAIs was lower than that observed in 2013–14 (1.9%), but similar to the 2012–13 period (0.6%). Based on the current analysis, the NAIs remain an appropriate choice for the treatment and prophylaxis of influenza virus infections.
Bibliographical noteFunding Information:
We thank all laboratories, mostly NICs of the WHO GISRS ( http://www.who.int/influenza/gisrs_laboratory/national_influenza_centres/list/en/ ), who contributed to this global analysis by submitting influenza virus positive samples (clinical specimens or virus isolates) to WHO CCs for detailed characterisation. We gratefully acknowledge the authors, originating and submitting laboratories of the 2440 sequences downloaded from the GISAID and NCBI-IVR databases, that were additional to those submitted by the authors of this paper. The London WHO CC is funded by the British Medical Research Council through programme U117512723. The Melbourne WHO CC is supported by the Australian Government, Department of Health . The Tokyo WHO CC is supported by Grants-in-Aid for Emerging and Re-emerging Infectious Diseases from the Ministry of Health, Labour and Welfare, Japan and by JSPS KAKENHI Grant number 26460816 . RTCL and SMS are supported by a joint A*STAR-NHMRC grant ( #12/1/06/24/5793 ).
© 2016 The Authors
- Antiviral resistance
- Global analysis
- Influenza virus
- Neuraminidase inhibitors
- Reduced susceptibility