Data from hundreds of cases of influenza A(H7N9) in China showed that patients aged older than 65 years, patients with secondary bacterial infections and those who initiated neuraminidase inhibitor therapy 5 days or more after symptom onset had an increased risk for death, according to a recent study.
There have been 1,568 reported cases of human H7N9 infection in China since March 2013, but only one in the past year, Yu Chen, PhD, from Zhejiang University, and colleagues noted. The reduction in cases has been credited to an aggressive vaccination campaign in poultry.
According to the study, Chen and colleagues retrospectively collected clinical treatment information from 350 patients hospitalized with H7N9 in China from 2013 through 2017 — including 109 (31.1%) who died — to identify common causes of death and risk factors associated with higher mortality.
Results of the study showed that the median age of infection was 57 years and the median age of mortality was 61 years, compared with 55 years for patients who survived. They found that nosocomial infections, such as Acinetobacter baumannii and Klebsiella pneumoniae, were most commonly associated with secondary bacterial infections, likely because of the high use of supportive therapies, which the researchers said contrasts with previous studies.
The researchers saw no statistical differences in patients with or without underlying disease, contrary to previous studies.
“In conclusion, A H7N9 virus can cause high mortality induced by hypoxemia and multiple organ failure,” the authors wrote. “We analyzed the death factors of patients with H7N9 avian influenza and found that age, time from illness onset to antiviral therapy initiation and secondary infection were the main risk factors for the death of patients. Therefore, it is recommended to use antiviral drugs as early as possible and pay attention to reduce secondary bacterial infections during treatment.” – by Caitlyn Stulpin
Disclosures: The authors report no relevant financial disclosures.