Susceptibility of influenza viruses circulating in Western Saudi Arabia to neuraminidase inhibitors

Objectives: To investigate the sensitivity of circulating influenza viruses in Western Saudi Arabia to neuraminidase inhibitors (NAIs); mainly, zanamivir and oseltamivir. Methods: Respiratory samples were collected from patients presenting with respiratory symptoms to King Abdulaziz University Hospital, Jeddah, Kingdom of Saudi Arabia (KSA) between September 2013 and October 2014. All samples were tested prospectively by real-time reverse-transcription polymerase chain reaction for influenza A and B viruses. Positive samples were then inoculated on Madin-Darby Canine Kidney (MDCK) cells and isolated viruses were examined for their sensitivity to NAIs using fluorescent neuraminidase inhibition assay. Results: Out of 406 tested samples, 25 samples (6.2%) were positive for influenza A/pdmH1N1 virus, one sample (0.25%) was positive for influenza A/H3N2 virus, and 7 samples (1.7%) were positive for influenza B Yamagata-like virus. Screening of isolated influenza A and B viruses (9 out of 33) for their sensitivity to NAIs showed no significant resistance to available NAIs. Conclusion: Our results show that circulating influenza viruses in Jeddah are still sensitive to NAIs.