WHO Says H7N9 is One of the Most Lethal Flu Strains

Posted on April 24, 2013

H7N9 Virus

There continues to be new cases of the H7N9 bird flu strain in China. An image of the H7N9 virus from the CDC is pictured above. So far there have been 108 lab-confirmed cases and 22 deaths. Taiwan has also confirmed a case, but the person did not catch it in Taiwan. He was hospitalized after returning from Shanghai. He is in critical condition.

Reuters reports that a World Health Organization (WHO) expert called H7N9 a very dangerous virus at a briefing. Keiji Fukuda, the WHO's assistant director-general for health security, said, "When we look at influenza viruses, this is an unusually dangerous virus for humans. This is definitely one of the most lethal influenza viruses that we've seen so far."

A Bloomberg story about the outbreak in China describes a patient with very severe symptoms. A woman's lungs became so damaged she suffocated. Patients have also suffered from multi-organ failure, brain damage and muscle breakdown.

The WHO continues to report that there is no evidence of ongoing human-to-human transmission so far. They also have been unable to identify the source of infection.

The virus does currently have an extremely high-fatality rate for an influenza virus at around 20%. The current case number is very low (only a little over 100) so the actual fatality rate for the virus may be much less. There may be some people infected that are not sick and are going unnoticed and unreproted. But even a 1% fatality rate is high for the flu and could kill large numbers of people if it were to gain the ability to spread from person to person. The fatality rate for the 1918 influenza pandemic - which killed at least 50 million people - was over 2.5%.

Photo: CDC