avian influenza. the story so far.

The New England Journal of Medicine has an article on the state of play with Avian Influenza (H5N1).
The report begins: “The unprecedented epizootic of avian influenza A (H5N1) viruses among birds continues to cause human disease with high mortality and to pose the threat of a pandemic.”

It is quite a technical (at least for me) report, but in a nutshell:

1. Despite widespread exposures to poultry infected with avian influenza A (H5N1) viruses, influenza A (H5N1) disease in humans remains very rare, with 340 cases as of December 14, 2007.
2. Influenza A/H5N1 is now well established amongst the poultry of large parts of Asia, Africa and the Middle East.
3. 90% of infected patients are 40 years or younger with the highest incidence occurring between 10 & 19 years of age.
   Most of those affected were previously healthy.
   Of the 6 pregnant women who were affected, 4 died, with the survivors suffering spontaneous abortions.
4. Most transmission of the virus to humans originates from birds… although human-to-human transmission has probably occurred during very close, unprotected contact with a severely ill patient.
   Important nursing implications are that respiratory secretions and all bodily fluids, including feces, from an infected patient should be considered potentially infectious.
5. The incubation period appears to be between 2 and 7 days.
   Patients typically develop a severe pneumonia that progresses rapidly to an acute respiratory distress syndrome (ARDS). If a patient is going to die, time from onset of the disease to death is around 10 days.
6. Rapid diagnostic tests to see if a patient has “influenza” have been found to be insensitive and produce many false negatives.
7. The overall mortality rate is around 61%.

Most hopeful scenario; animal to human transmission remains rare.
Worst case scenario; hospitals overwhelmed with really sick, really infectious patients requiring high and complex levels of care. Screw up and catch it….61% kill rate.
Be afraid nurses. Be very afraid.

[ Further reading:
How prepared is your hospital?
How to protect yourself during a pandemic. ]