The bird-flu virus that suddenly started killing people last month in China is unquestionably a “serious human health risk,” as the scientists who discovered it have reported in the New England Journal of Medicine. H7N9 contains gene sequences that make it relatively effective, for a bird virus, at infecting humans and other mammals.
People don’t appear to have natural immunity, there’s no vaccine, and so far about one in five known to have caught the virus have died.
Fears grew as 11 more infections and three more deaths were announced over the weekend.
This is no reason to freak out, though. The world is in a better position to monitor flu strains emerging in China than it was 10 years ago. That the Chinese have already reported detailed observations in a major medical journal is evidence of how far their public health system has come since the 2002 outbreak of severe acute respiratory syndrome, which wound up killing 774 people worldwide. Back then, the World Health Organization chastised China for failing to cooperate enough with global health authorities in the early weeks.
China has since built its own Center for Disease Control and Prevention, staffed by many scientists who have trained with infectious-disease specialists worldwide, and it follows globally accepted protocols for responding to a new pathogen. This agency has established a computer network linking all of China’s county hospitals, so that it can stay abreast of any new bird-flu diagnoses in real time.
Flu experts outside China have confidence in the Chinese scientists’ assessment that so far people haven’t been catching the H7N9 flu from other people. Although direct contact with poultry hasn’t been established for all the victims, this is often the case with bird flu; people either don’t remember or don’t know that they have had such contact in their environment or in their food.
There are other reasons to feel less worried about H7N9: In their effort to examine the more than 1,000 people who have been in contact with victims, doctors have found a 4-year-old Beijing boy who is infected with the virus but has shown no flu symptoms. Apparently, then, the illness isn’t always deadly or debilitating. If this is right, then the number of infections could soon rise rather abruptly, as doctors find H7N9 in more symptom-free patients and others with only mild illness.
Now, as doctors begin early treatment with oseltamivir (Tamiflu) or zanamivir (Relenza), the survival rate may also improve significantly.
Two big challenges are to develop a molecular diagnostic test that can specifically detect this virus and to create a vaccine. Scientists in the U.S. and other countries will help with these efforts. China has sent samples of the virus to labs around the world ― another sign of the country’s improved public-health response.
It remains urgent that scientists keep searching for any signs of human-to-human transmission. Flu experts from the U.S., Europe, Australia and Hong Kong have been invited to China, according to Bloomberg News, to help figure out where this bug came from and how it’s being passed around.
Although H7N9 remains cause for worry, the truly global response, this time with China taking the lead, should be a source of comfort.
(Bloomberg)
