Influenza-associated severe acute respiratory infections in 2 sentinel sites in Lebanon-September 2015 to August 2016

Background: Given the sparse information on the burden of influenza in Lebanon, the Ministry of Public Health established a sentinel surveillance for severe acute respiratory infections (SARI) to identify the attribution of influenza to reported cases. We aim to highlight the proportion of influenza-associated SARI from September 1st, 2015 to August 31st, 2016 in 2 Lebanese hospitals. Methods: The study was conducted in 2 sentinel sites located in Beirut suburbs and southern province of Lebanon. WHO's 2011 standardized SARI case definition was used. Data from September 1, 2015 to August 31, 2016 were reviewed, and all-cause hospital admission numbers were obtained. Nasopharyngeal swabs were collected and tested by RT-PCR. Descriptive and bivariate analyses were conducted using STATA 13. Results: The 2 sentinel sites reported 746 SARI cases during the studied time frame: 467 from the southern province site and 279 from the Beirut suburbs site. SARI reports peaked between January and March 2016. All, except 4, cases were sampled, and a co-dominance of influenza B (43%) and influenza A (H1N1) (41%) was evident. A high proportion of cases was reported in children <2 years 274 (37%). The proportional contribution of influenza-associated SARI to all-cause hospital admissions was high in children <2 years in the south (4.5% [95% CI: 3.1-6.5]) and in children <5 years in Beirut (0.7% [95% CI: 0.6-0.8]). Conclusion: This is the first study to highlight the proportion of influenza-associated SARI in 2 hospitals in Lebanon. The findings will be beneficial for supporting respiratory prevention and immunization program policies.