American Foul Brood Disease in South Africa
American Foul Brood disease (not fowl brood or breed) is a bacterial infection affecting queen, drone and worker larvae but is not infectious to humans. American foulbrood (AFB) disease does not affect adult bees but can be spread by the ‘nurse bees’ that feed larvae. AFB has recently received significant media attention in South Africa due to the outbreak in the Western Cape. Beekeepers and honey manufacturers are concerned that AFB may decimate the local honey industry if the disease continues to spread.
AFB is caused by Bacillus larvae which occurs in two stages – vegetative (active) and spores (inactive). It is the Bacillus larvae spore that is infectious to honey bees. Upon entering a bee, the spore germinates and the bacteria (vegetative states) multiplies until larval death. AFB is only infectious to larvae that are less than 53 hours old.
The main concern among the public is the health effects of consuming infected honey. AFB is not infectious to humans and any spores within honey poses no threat to humans. The concern relating to AFB is primarly an economic concern considering the vast honey industry within South Africa which employs thousands of workers.
Honey and honey products are safe to consume and should not be discarded or avoided due to AFB. In the light of this current dilemma, any consumer scare fuelled by ignorance will only contribue to the rapid demise of the local honey industry. At a time when the world is panicking over swine flu (2009 H1N1 flu), it is easy for ignorant consumers to make totally unfounded associations with different infectious diseases.
Unlike swine flu, AFB is not capable of a zoonotic infection – humans infected by animal or insect carriers. The outbreak of AFB is a significant concern to the bee and honey industry and unfortunately the only method to eradicate AFB is to destroy any infected colonies or those that are suspected of being infected.
At a time when the world is reeling from an economic slowdown and South Africa is carefully weathering the storm, let us not be taken by media hype. Supporting our local industries are essential for maintaining the health of the South African economy and South African honey is one of those local products that are safe and nutritious.
Thank you for the information Mbongeni. Much apprecited.
from what I’v practically noted in the field/hives, its not all the hives that are filled with propolis at the entrance, especially those that are still young. In a way, this is not really practical. this is a regional issue that needs quick attention it is very difficult to control the boundaries of bees thus they can introduce a disease from the neibouhood this disease. it is simple if your beea are affected burn them and the hive. we also need to scrutines the import and export permits of the honey products because at the present moment a number of people do not follow these regulations and the policies stipulated.
Firstly I don’t see myself as a professional, but I have a few hives which I keep part-time. The beekeepers in the country have discussed a lot of issues around AFB and I hope I can give you a satisfactory answer as I understand it.
The AFB bacteria is just like any other disease bacteria and spreads by means of contact (luckily not air-borne). As I understand it, the bacteria or spores might have been brought into the country by means of imported honey or equipment. In some way this found it’s way into some of our beehives. We can only speculate on how this happened.
Now you want to know why the propolis did not stop it from getting into the hive. The problem with any medicine is that it only works on contact. The whole hive and especially the entrance to the hive is covered in propolis so that most of the incoming disease is stopped.
Modern beekeeping practices however sidesteps this safety protocol. The usual practice of harvesting honey is to open up the whole hive, take out the full honey frames and replace it with empty frames. If these empty frames is contaminated with AFB, then the beekeeper unwittingly spreads the disease among his hives. We are introducing practices now to reduce this spread by keeping the same frames connected to the same hive and not spread it around.
It is just like a wound in your skin. Normally your skin protects you against bacteria, but if the bacteria finds a way directly into your body, then it starts multiplying inside. Then the body’s immune system is compromised. In the same way we are compromising the hive’s natural defences by exposing it to outside diseases.
Other bees will also start robbing honey when they find an open or poorly defended (sick) hive and this can also spread the disease.
With the pollination season we spread the disease even further by moving hives to orchards around the country. That is why they are trying to inspect all the hives before the start of pollination season.
Interesting question. As far as we are aware, AFB spores are present in the larval food so they are already within the hive. Propolis shields the hive from parasites, bacteria and viruses that may enter from the outside environment.
In terms of any spore, fungal or bacterial, it is extremely hardy and able to withstand certain chemical agents. Spores are the protective mechanism for microorganisms to shield themselves under harsh conditions.
Hope this explanation proves useful but it would be interesting to hear from a professional in the bee and honey industry.
If propolis is used to keep bactarial and viral infections out the hive why are our bees being infected? Does the propolis not protect the hive from AFB? Please could someone advise.