Influenza A(H1N1)pdm09 epidemiology in the Eastern Province of Saudi Arabia

Objectives: The influenza A(H1N1)pdm09 virus caused a worldwide pandemic in 2009-2010 and has since remained in seasonal circulation. This study was conducted to determine any variations in the influenza A(H1N1)pdm09 status according to sex, age group, sample type, or location within the Eastern Province of the Kingdom of Saudi Arabia. Methods: Samples from 749 patients with suspected Middle East respiratory coronavirus who presented to Johns Hopkins Aramco Healthcare facilities in the Eastern Province of Saudi Arabia were tested reflexively for influenza A/H1N1 2009 by the Ministry of Health using the RealTime ready Influenza A/H1N1 Detection Set for real-time PCR. The sample types included nasopharyngeal swabs (n= 677), expectorated deep cough sputum (n=32), induced sputum (n =17), and tracheal aspirates (n= 23). Results: The incidence of influenza A(H1N1)pdm09 was higher among younger patients; 27.94% of patients in the 0-19-year age group tested positive compared to only 3.51% of patients in the >= 80-year age group. The incidence of influenza A(H1N1)pdm09 was higher in Ras Tanura city compared to other locations in the Eastern Province. Conclusions: Younger individuals in the Eastern Province of the Kingdom of Saudi Arabia had a relatively higher risk of influenza A(H1N1)pdm09 infection. Additionally, an outbreak of influenza A(H1N1)pdm09 may have occurred in Ras Tanura city between April 2015 and February 2016. (C) 2018 The Authors. Published by Elsevier Limited on behalf of King Saud Bin Abdulaziz University for Health Sciences.