CBS News is reporting the death of a bus driver infected with H5N1 in Shenzhen, Guangdong Province, China. He apparently had no direct contact with poultry, and 120 close contacts were asymptomatic. This was the first case of human H5N1 reported in China since June 2010. A couple of operational perspectives:
- Be dubious of any report of "no activity" of H5N1 in Asia. Humans report only what they are inclined to tell people based on their ability to recognize disease- note this kind of problem exists right here inside the United States as well. China's a very big country, and no one truly knows precisely what level of H5N1 is exhibiting in animals or humans at any given moment. Obviously a human fatality is more likely to provoke recognition (and hopefully) reporting.
- "No direct contact with poultry"- maybe... maybe not. There remains a large swath of uncertainty regarding environmental contact through restaurants, the bus the man drove, etc. Point being, don't jump immediately to the conclusion that human-human transmission has occurred without sucking on a large crystal of sodium chloride. But that said, limited human-human transmission is believed to have occurred in the past- the key is sustained human-human transmission.
- Of course, the man's occupation as a bus driver is the key piece of information jacking people up- i.e. the thought of multiple undefined contacts in a city of 10 million people is enough to force any public health officer into a cold sweat.
- "120 close contacts were asymptomatic"- ok, but if one wants to negate a hypothesis of sustained human-human transmission, it would be useful to do serologies on these folks.
So run down the hypothesis of sustained human-human transmission. Check for reports of influenza-like illness in Shenzhen. Specifically for reports of medical clinics and hospitals reporting an increase in influenza-like illness. Fatalities are only the tip of a much larger iceberg if we are dealing with an efficiently transmitting virus.
As a final point, Chinese officials should be thanked for reporting this important event.