Sick I know, but announcements of newly identified
"bugs" both excite and depress me.
It's exciting to watch the developments unfold as scientists from around
the world work to identify the "bug", determine where it came from,
how it's transmitted and what the potential threat to humans is. It's depressing because each time a new
"bug" is found, I kick myself for deciding to enter the world of the
working rather than moving onto a masters in Epidemiology.
While there is still much to learn about the H7N9 Bird
Flu strain, one thing for certain is that the death toll and number of
infections in China from the strain of bird flu first found in humans last
month has ticked up daily. As of April
9, the virus has infected 28 people and killed eight in China. However, none of the people who have had
close contact with the victims have shown symptoms of the flu (at least not
yet), but the WHO is investigating two family clusters to who are suspected of
having H7N9 to determine if transmission between close family members has
occurred. But for now, there is no
evidence of human to human transmission.
So far, the H7N9 virus has only been found in farm-raised
pigeons, chickens and quail and wild birds (which could be concerning as we are
moving into migrating season). It has
yet to be found in pigs or other mammals.
However, one noticeable difference between the new H7N9 outbreak and the
H5N1 avian influenza outbreaks of 1997 and 2003 is in how the virus is
affecting birds. The H7N9 virus does not
seem to be noticeably deadly among birds where as the H5N1 strain was.
According to scientists, the gene sequences confirm that
this is an avian virus, and that it is a low pathogenic form (causes only mild
disease in birds), but most importantly,
the sequences also reveal that there are
some mammalian adapting mutations in some of the genes meaning that the H7N9
virus has already acquired some of the genetic changes it would need to mutate
into a form that could be transmitted from person to person. In which case, if it became easily
transmissible between humans, it could cause a deadly pandemic.
For now, the big question is what will happen in the
Southern Hemisphere which is just heading into their flu season. Although human-to-human transmission has not
been seen yet, should it occur experts are not expecting to see any immunity to
H7N9 if it does happen. While the panic
button hasn't been hit yet, everyone is watching very closely and until more
information is gathered current recommendations are for healthcare workers to manage all patients displaying
influenza-like illness and with travel history to China in the past ten days
with Routine Practices and contact, droplet and airborne precautions.
Bugging Off!
Nicole
