Epidemiological and clinical characteristics of humans with avian influenza A (H7N9) infection in Guangdong, China, 2013-2017

Objective: To describe the demographics and clinical characteristics of patients with A (H7N9) infection, to test the differences in the distribution of demographics and clinical characteristics by clinical severity, and to explore potential factors associated with clinical severity. Methods: This retrospective study was conducted to collect epidemiological and clinical information regarding the confirmed cases in Guangdong through field investigation and review of medical records. Results: Of the 256 cases, 100 (39.0%) patients died, and 168 (65.6%) patients were admitted to ICUs. The male-to-female ratio was approximately 2.0: 1, and the median age was 56 years (range, 1 to 88). Among the 215 patients accepting oseltamivir treatment, the median time from the onset of illness to oseltamivir treatment was 5 days (range, 0 to 16); 35 patients received zanamivir treatment after a median of 8 days (range, 0 to 23). The univariable logistic regression models demonstrated that time from the onset of illness to oseltamivir treatment (OR = 1.10, 95% CI = 1.01-1.10) and zanamivir treatment (OR = 1.05, 95% CI = 1.02-1.07) were associated with the death of patients. Conclusions: Preventive measures should focus on high-risk populations, such as the elderly and the groups with high frequency exposure to live poultry. Earlier oseltamivir and zanamivir treatment were recommended. (C) 2017 The Author(s). Published by Elsevier Ltd on behalf of International Society for Infectious Diseases.