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

Abstract

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. Keywords: Epidemiological characteristics, Clinical characteristics, Avian influenza, H7N9 subtype