Bioscope ‘05

by Dr. Barbara Price

Chicklets:

Chicken and poultry, by the numbers:

• Total world chicken production 64,957,921 tonnes in 2003, 32.5 billion chickens. It takes 38-40 days to reach the
  average chicken mass of 2 kg
• Total chicken export in 2003, 5.6 million metric tons
  
• Top chicken exporters US (44.5%), Brazil (23.8%), EU (12.5%), Thailand (7.82%), China (7.29%) and Canada (1.43%)
  
• Top chicken importers Russia (28.7%), Japan (15.6%), EU (13.4%), Saudi Arabia (8.58%), China (PRC) (7.80%), Mexico (6.46%), Hong Kong (5.41%)
  
• Chickens in Hong Kong are vaccinated twice, about 8 days and again about 28--30 days.
  
• Canada says China has not shared samples of the H5N1 virus since the spring of 2004; so do we know what strain the Chinese vaccine will be for?
  
• British Medical Journal editorial: “The lack of sustained human-to-human transmission suggests that this AH5N1 avian virus does not currently have the capacity to cause a human pandemic.”
  
• Hanoi-based Central Institute of Hygiene and Epidemiol- ogy: Vietnam will produce H5N1 vaccines by culturing in monkey cells to produce a deactivated form of the virus.
  
• Wild ducks are carriers of H5N1 in China.

Vaccination plans.

          Vaccinations are almost the last choice in defending against infections. If we cannot find a way to kill the virus, then our choice is to add reinforcements to our immune system. Thus the spread of infection depends on the results of many individual or personal skirmishes.
          China has announced it will vaccinate all its poultry against the deadly avian flu. That’s a lot of chickens; the Chinese eat 14 billion chickens a year (plus a lot of ducks). Most of the poultry is grown on small farms (along with ducks and pigs) in rural China. As in many of the poorer farming communities around the world, the livestock commonly move in with the farmers for the colder seasons, ensuring good contact for poultry, pigs and humans. Vietnam, a much smaller country with fewer chickens, but a big chicken exporter is concerned about achieving all its vaccinations and claimed it needed 100,000 trained vaccination workers. And the vaccinators, since they are not killing the virus, must be careful not to spread the virus to the next farm.
          In 1971—1973, vaccinators in California were partly responsible for the spread of Newcastle disease in the chickens they were vaccinating. Needed: 550 million injections per week for chickens and ducks in China. That would be 80,000 TRAINED vaccinators working 10 hours/day for 7 days/week, vaccinating 100 chickens per hour, without travel! And at roughly 1 mL of vaccine/chicken (for 2 doses) that is 14 million liters of vaccine. And this has to be done every four weeks. Also needed, protective clothing, gloves, boots, masks and cleaning equipment.