AFB is a bacterial disease of developing honey bee brood. AFB spores infect the larva in the earliest larval stage (newborn to 2 days old), generally through nurse bees supplying infected food. Infection spreads quickly among the larvae, as nurse bees, which carry the bacteria but are not affected by it, move from cell to cell feeding larvae. Only a few spores (<10) may be infectious. Once ingested by the larva, spores germinate into the active vegetative form within larval intestine. There they begin to massively colonize the larval midgut.
 

As the bacteria numbers increase, they escape the larval gut and the infection spreads to all tissues of the developing larva, causing sepsis and cell death. Larvae do not die until just as the larvae are capped – at this stage infected larvae completely breakdown into a glue-like consistency, extremely difficult for house cleaning bees to remove.
 

This is the stage to seek to find AFB in your colony. Look for sunken, greasy looking cappings with tiny perforations, Remove such cappings and look inside If you see a brownish (café-au-lait) decaying larval body that you can’t lift out from the cell it likely is AFB. You need to quickly get a confirmation of the field symptoms (via an AFB test kit, have an expert look at it or send sample off to lab to ID). When conditions become unfavorable for the vegetative form, this bacteria forms spores. Spores can survive decades. A single dead, desiccated larva (called scale) may contain millions of potentially infectious spores.
 

In the 1920s American Foulbrood (AFB) was a huge problem killing hives and causing the loss of thousands of dollars for U.S. beekeepers. Strict state bee laws were subsequently passed and state inspection and registration programs established. After years of enforcement, management and education (and widespread antibiotic use) AFB cases dropped dramatically, and state apiary inspection programs were discontinued, and inspections terminated. There is no current Washington or Oregon inspection service. Controlling American Foulbrood disease, like other diseases, is the responsibility of the beekeeper.
 

This year we have found AFB in nucs sold the Portland area. Because new beekeepers (along with established) are not familiar with AFB and we are not having live meetings to bring frames for examination (nor are labs open to diagnose comb samples), the three Portland area beekeeping groups have established task forces of board and club members to visit, with an invitation, the apiaries of individuals who suspect from field symptoms they have a disease problem.
 

The task force visit is designed to both assist the beekeeper with confirming field symptoms and to discuss possible solutions. There is no fee and no individuals will be identified. With persistent EFB this spring, and PMS likely to appear as the nectar flow dries up, confirmation of probable cause is important because the solutions are varied and different in AFB, EFB and PMS situations.
 

The most important thing that you can do is to learn the signs of AFB/EFB disease and PMS, so that you can take swift action if control is warranted. Both AFB and EFB disease originate when the bees establish contact with an active infestation (via robbing, drifting, beekeeper transfer of infected brood or purchase of nucs) or when pathogens are contacted via honey with spores or when comb with scales are reused (such as might occur in stored equipment from a dead-out that previously succumbed to the disease are put into service). PMS appears with failure to or ineffective mite control. Colonies that are weakened/dying from these disease conditions become weaker and weaker and serve as a source to infect additional colonies in your apiary, feral bee nests and the colonies of neighboring colonies. They are situations where it is important to practice responsible beekeeping.
I have information sheets on AFB, EFB and PMS that are posted on the Cowlitz website. They discuss the field symptoms, how to get confirmation and what might be some solutions if AFB/EFB or PMS is found and confirmed. https://cowlitzbeekeeping.wixsite.com/website/projects