South African Bees in Trouble: American Foulbrood Disease (AFB)

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The plight of the humble honey bee is not merely an 'Overseas Problem'. Our own honey bees are increasingly at risk due to the lack of proper quarantine and trade regulations during beekeeping and the selling of bee products.

African Honey Bee,
Apis mellifera scutellata,
pollinating nectarine flower

Bees are related to wasps and ants as they belong to the Hymenoptera order of Insects, characterised by their restricted waists. There are an estimated 20 000 species of bees, which include bumble bees, solitary bees and colony forming bees such as the European/Western Honey Bee, Apis mellifera.

In South Africa, we have two indigenous honey bees (i.e originating and only found here) that are a subspecies or race of the European Honey Bee. The African Honey Bee (Apis mellifera scutellata) has the widest spread, found in central and southern Africa, whereas the Cape Honey Bee (Apis mellifera capensis) is found in the far southern extremes of the country (around the fynbos area). Please see the South African Bee Industry Organisation (SABIO) website for more information on the biology of our native bees.

A devastating disease has slowly been etching its way through bee colonies in the Western Cape and a recent report on 27 January 2015 has stated that the situation has gone out of control! (Ref 1) This was the first time that I have heard of this disease effecting our honey bees and was appalled to notice how underplayed and little attention had been given to this by the government and beekeepers alike and how uninformed the general public has been left. I am an avid promoter of the use of beneficial insects in the vegetable garden and the honey bee is one of the most important.

Bees are crucial to human food production, a role often overlooked. It is estimated that one third of our plant products depends on the natural behaviour of bees (Ref 2). Imagine a world without bees where humans would need to hand pollinate each and every flower in order to have food such as squash, apples, pears, nuts, peaches, berries and carrots... (Please see to Ref 2 for a comprehensive outlook on the economic value of bees and pollination). Therefore, I decided to do a bit of research and write a post to get the information out to my readers and hopefully raise some awareness amongst South Africans.

African Honey Bees are known to be more robust and resilient to pest and disease than the European Honey Bee. This natural immunity has left the African Honey Bees mostly unaffected by the global Collony Collapse Disorder (CCD) reported extensively in Europe and America (See my previous posts on this here Jan 2012 and Oct 2013). Ameican Foulbrood Disease (AFB) is caused by a bacterium known as Paenibascillus larvae, so named due to the fact that it infects honeybee larvae (also known as 'the brood'; these are larvae up to 3 days old) when they consume food contaminated with bacterial spores (Ref 3). The bacteria multiply in the midgut of the larvae and digest the gut wall resulting in the death of the larvae. The remaining body disintegrates into a sticky mass and later becomes a desiccated husk, which remains contaminated with spores. Although adult bees are not effected by the bacterium, they remain passive carriers of the spores for up to 2 months after consumption of contaminated food such as honey. Spores can attach to adult bee bodies after contact with contaminated hives, dead larvae or beekeeping equipment. This ensures rapid spread of the spores and infection within and between bee colonies. Colonies soon collapse when more than 100 larvae are infected.

Field Test for American Foulbrood Disease:
Dead larvae are touched with a toothpick,
If a sticky substance or 'rope' develops then
hive samples need to be sent for testing.

AFB disease was recorded in the Western Cape during February 2009, a 150 years after the last recorded infection (Ref 4 & 5). Illegally important honey contaminated with bacterial spores was suggested as the point of origin (Ref 5). AFB spores are highly stable and resistant to most environmental conditions such as high heat (Ref 3). These spores remain viable for up to 50 years and infected hives need to be burned or irradiated with gamma radiation as no known cure for the disease exists (Ref 3), ultimately killing the bees. Other control methods include dipping hives in paraffin wax to trap and prevent the spread of spores, whereas antibiotics simply treat the symptoms and does not destroy bacterium spores, leaving bees susceptible to re-infection (Ref 4). Up until the 2009 outbreak South Africa had no regulations or control methods concerning AFB and I struggle to find whether any such protocols have been developed since.  The KwaZulu-Natal Bee Farmers Association merely has links to two videos with information concerning AFB and European Foulbrood Disease (a milder form). This is the same association that claimed 'not to be concerned about AFB reaching KZN' (Ref 5) during 2009 and in the most recent report of 2015 (Ref 1), as well as on their website, they express increasing fears of the spread of AFB disease to KZN.

AFB is highly contagious and proper control methods include the timely diagnosis and unfortunate destruction of both the hives and infected equipment. This is a disease that is well documented amongst the 'domestic hives', i.e. those kept by humans for either commercial or recreational purposes. Data concerning AFB in wild populations is lacking (Ref 3). It is known that African Honey Bees abandon their hives when disturbed and are extremely hygienic, which may result in a self-cleansing situation amongst wild populations, effectively decreasing the infection and spread of AFB (Ref 3). Also no great losses of bee colonies or further outbreaks have been reported for the period of 2009-2011, which is likely more attributed to no monitoring or surveillance being implemented (Ref 3). This would suggest that the African Honey Bees may be resilient against AFB infection, but scientists (Ref 3) argue that this might not hold up when the load of bacterial spores reaches a breaking threshold in bee hives.

It seems that this threshold has been reached amongst the Western Cape domestic bees and although honey infected with AFB disease is safe to be consumed by humans (Ref 7) it does not diminish the seriousness of the situation. Bees have been 'ravaged' in the Western Cape according to the latest 2015 report (Ref 1). Diseases such as AFB have a natural spread progression, initially low levels are present in a country and nobody takes serious steps to control it, then it increases and spreads and within a blink of an eye it reaches epidemic proportions - we are already seeing this happen with foot and mouth disease in South Africa (Ref 8) and I hope that South Africa will react quickly enough to stop AFB from becoming a nation wide outbreak.

African Honey Bee,
Apis mellifera scutellata,
pollinating basil flowers

I typically do not report 'doom and gloom senarios' neither am I a fan of hype or sensationalising, but this truly troubles me and the fact that yet again nothing serious is being done about it irks me. I hope that this article reaches as many people as possible and that we can limit the spread of this disease (the most fatal brood disease known to honey bees). I place here a link to a document: American Foulbrood from the NSW Government in Australia who are currently battling with the AFB disease. This document contains a comprehensive outline of AFB, what it is, how it is transmitted and how to recognize the symptoms in bee hives. I know that South Africa is more concerned with the dwindling number of Rhinos at the present moment, but if we neglect our bees because they are merely seen as a nuisance, neither human nor rhino would survive.


FactSheet - American Foulbrood: Disease Symptoms, Spread, Diagnosis and Control Measures. Nov, 2012. Doug Somerville, Technical Specialist Bees, Goulburn. Agriculture NSW, Livestock Systems



References:

1) Disease threatens bee farmers. Jan 27, 2015. Chelsea Pieterse, The Witness, www.Fin24.com

2) Nicola Bradbear. 2009. Chapter 8: THE VALUE OF BEES FOR CROP POLLINATION. pg 69-79. Food and Agriculture Organization of the United Nations, Rome   [For the Entire Book: Click Here]

3) Human H. et. al. 2011. The Honey Bee Disease American Foulbrood - An African Perspective. African Entomology: 19(2) 551-557.

4) Millions of Bees infected by killer disease. May 4, 2009. Staff Reporter. Main & Guardian.

5) KZN Beekeepers not worried about disease. May 5, 2009. Stephen Coan. The Witness.

6) Cape Bee Farmers could be crippled by foul brood disease outbreak. April 1, 2009. Eyewitness News.

7) American Foulbrood Disease in South Africa. Vitacare.

8) Foot-and-Mouth Disease Eats Up Farming. Jan 14, 2015. Graeme Hosken. Times Live.

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