CDC issues health advisory on human infections with novel avian influenza

The U.S. Centers for Disease Control and Prevention issued a health advisory on Friday related to human infections with novel influenza A (H7N9) viruses in China.

As of Thursday, Chinese public health officials reported 14 cases of human infection with the virus from four different provinces in China. All of the patients were hospitalized with severe respiratory illness. Six of the patients died as a result of the illness.

Three of the cases occurred in Zhejiang province, four in Jiangsu province, one in Anhui province and six in Shanghai. Thirteen of the cases were in adults between 27 and 87 years of age and one case occurred in a four-year-old child. Chinese public health officials did not identify any person-to-person transmission of the virus or an epidemiological link between the cases.

The CDC said the cases serve as a reminder that avian and swine origin influenza can infect and cause severe respiratory illness in humans.

"In recent years, human infections with highly pathogenic avian influenza A (H5N1) virus in several Asian countries and Egypt, highly pathogenic avian influenza A (H7N3) virus in Mexico, and variant influenza A (H3N2)v viruses in the United States have been reported," the CDC said. "The clinical presentation of human infection with avian influenza A viruses varies considerably -- from mild illness, including conjunctivitis, fever, and cough, to severe illness, including fulminant pneumonia leading to death in cases of H5N1 and in these recent cases of H7N9 virus infections."

The CDC recommended that clinicians consider the possibility of novel influenza A (H7N9) virus infection in people who have respiratory illness and an appropriate exposure or travel history.

There have been no cases of human infection with avian influenza A (H7N9) detected in the United States.