Most of you have probably heard recent news reports of a new influenza virus circulating in China. Questions are starting to come in so I thought this would be a good time to give some background on this important subject. Here is what we know so far. In late February and early March, the Chinese health authorities notified the World Health Organization (WHO) that they had identified a new strain of influenza (H7N9) that had caused serious illness or death in several patients. This strain had not been found to infect humans before. Early analysis of the virus indicates that is from an avian source, in other words, another type of bird flu that has adapted to be able to cause disease (fever, cough and other symptoms) in humans. About the same time, massive die-offs of pigs, ducks and swans began to occur in China and many of the bodies of these animals were dumped into Chinese rivers that supply water to Shanghai and other major cities. The Chinese government currently maintains that there is no connection between these events, but time will tell. Recently, pigeons in a Shanghai bird market were found to be dying, and laboratory tests confirmed they were infected with H7N9. An excellent article on the outbreak and its potential implications can be found here. As of April 6th, a total of 18 cases have been laboratory confirmed with influenza A(H7N9) virus in China, including six deaths, ten severe cases and two mild cases. It is likely that other infections have gone unrecognized. These cases are spread over a wide geographic area and apparently had no contact with each other. This suggests that there is either widespread infection in animals with frequent human exposures or the infection may be spreading person-to-person. The WHO, CDC and the Chinese health authorities are working urgently to understand what is happening.
What does all this mean and what can I do?
The situation is concerning because if H7N9 influenza can transmit effectively from person-to-person, it is likely to spread quickly around the world (a pandemic). Very few of us will have any natural immunity to this virus and antiviral medicines have limited efficacy. There is currently no vaccine available, although vaccine manufacturers and governments are already taking initial steps to formulate and test a vaccine. Health authorities in Thailand and other regional countries are stepping up efforts to detect any H7N9 cases in travelers, pigs or poultry. For the time being, there is not too much you and I can do except to follow the situation closely and stay healthy. Properly cooked poultry and eggs are still perfectly safe to consume. If someone you know has a recent history of travel to China and becomes ill with fever and respiratory symptoms, they should promptly consult a competent medical doctor and inform their doctor of their travel history. I will follow this situation closely and keep you updated as things develop.