>Knowing basically what it takes to infect a hive, I find it hard to
believe that there would be enough AFB spores on a hive tool to infect
another hive. Has anyone done a study to show it does? Or are we simply
putting on a show?

Dr Eric Mussen related to me many years ago about experiments that he had
run, attempting to infect larvae with AFB.  He found that it took a LOT of
spores to infect larvae, and discounted transmission via hive tools.

The best book on the subject is "The Elimination of American Foulbrood
Disease without the use of Drugs" by Dr Mark Goodwin, who has studied the
subject exhaustively.

In one experiment:
"Twenty-five pairs of honey bee...colonies were established with the hives
in each pair touching and the entrances facing the same direction. One
colony in each pair had a light American foulbrood (AFB) infection (50
larvae with clinical symptoms) while the other (control) was uninfected.
The pairs remained together for 5-388 days (average 103 days). Any heavily
infected colonies (50 larvae with clinical symptoms) were removed from the
trial. Only 2 of the control colonies developed AFB."

Dr Goodwin states that the two main causes of AFB spread are by the
movement of extracted frames, and the swapping of infected frames of brood.

He further states that: "Such things as hive tools, smokers and gloves, as
well as the soil in front of hives, foundation, and queen bees, are of
little consequence as sources of spread of the disease."

-- 
Randy Oliver
Grass Valley, CA
www.ScientificBeekeeping.com

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