Overshadowed by Ebloa, H7N9 influenza A quietly simmers with pandemic potential

March 18th, 2015

At some point while Ebola was stealing the infectious disease headlines from MERS, we completely forgot about another pathogen quietly simmering with pandemic potential in China: Avian influenza A (H7N9).

According to the World Health Organization, China recently reported three additional laboratory-confirmed cases of human infection with H7N9, including 1 death. The cases included a 54-year-old female from Shihezi City, Xinjiang Uyghur Autonomous Region who developed symptoms on 19 October. The patient died on 1 November. Exposure to live poultry is unknown.

In addition, a 58-year-old female from Changzhou City, Jiangsu Province developed symptoms on 24 October. The patient was admitted to a hospital on 28 October. She is now in critical condition. The patient has a history of exposure to a live poultry market. The third case is a 45-year-old female from Changzhou City, Jiangsu Province who developed symptoms on 3 November. The patient was hospitalized on 5 November. Her current condition is mild. The patient has a history of exposure to a live poultry market.

This particular H7N9 virus had not previously been seen in either animals or people until it was found in March 2013 in China. However, since then, infections in both humans and birds have been observed. The disease is of concern because most patients have become severely ill. Most of the cases of human infection with this avian H7N9 virus have reported recent exposure to live poultry or potentially contaminated environments, especially markets where live birds have been sold.

Fortunately, the virus does not appear to transmit easily from person to person, and sustained human-to-human transmission has not been reported. The concern is that flu viruses are known to mutate and reassort, and H7N9 may become more transmissible. As of Oct 2, the WHO reported a total of 453 laboratory-confirmed cases of human infection with H7N9, including 175 deaths. A diagnosis of infection with an avian influenza virus should be considered in individuals who develop severe acute respiratory symptoms while travelling or soon after returning from an area where avian influenza is a concern

The WHO advises that travelers to countries with known outbreaks of avian influenza should avoid poultry farms, contact with animals in live bird markets, entering areas where poultry may be slaughtered, and contact with any surfaces that appear to be contaminated with feces from poultry or other animals. Travelers should also wash their hands often with soap and water and follow good food safety and hygienic practices.