The national burden of influenza-associated severe acute respiratory illness hospitalization in Rwanda, 2012-2014

Background Estimates of influenza-associated hospitalization are limited in low- and middle-income countries, especially in Africa. Objective To estimate the national number of influenza-associated severe acute respiratory illness (SARI) hospitalization in Zambia. Methods We conducted active prospective hospital-based surveillance for SARI at the University Teaching Hospital (UTH) situated in Lusaka Province during 2011-2014. Upper respiratory tract samples were tested for influenza virus using a reverse transcriptase polymerase chain reaction assay. We estimated age-specific rates of influenza-associated SARI hospitalizations for the UTH using census and secondary data on respiratory hospitalizations following estimation approaches recommended by the World Health Organization. We used the UTH hospitalization rates as a proxy for Lusaka Province. These rates were adjusted for each of the remaining 9 provinces based on their prevalence of risk factors for pneumonia and healthcare-seeking behavior. Rates were expressed per 100,000 population. Results SARI cases accounted for 77.1% (13 389/17 354) of respiratory admissions at the UTH; 82.7% (11 859/14 344) and 50.8% (1530/3010) among individuals aged