Words by Ingrid Nilsson
BSc (Hons) in Biomedicine & Molecular Biology
Crater-like ulcers, purulent nasal discharge, swollen lymph nodes and abscesses in the skin, lungs, spleen and liver: sounds nice, doesn’t it? These are not symptoms you want to find in your equine friend, or indeed yourself. They characterise a nasty disease of both horses and humans called ‘Glanders’, which has recently been discovered in a horse in Germany and has induced a swiftly imposed 6-month (minimum) Australian import ban of live horses and semen from this country. This article examines glanders, the case study in Germany, and the potential impact on the horse industry in Europe and Australia.
What is Glanders, exactly?
Glanders is a potentially fatal bacterial disease of solipeds (one hoof per foot) – ie. horses, donkeys, mules. It has also been found in camels and in the occasional horse-eating lion at Iranian zoos (Worms and Germs blog, full list of references available on THM website). It is caused by a gram-negative, aerobic bacterium called Burkholderia mallei (Wittig in Scholz; Currie). Genetic sequencing studies suggest that B. mallei has evolved from the closely related B.pseudomallei, which causes Melioidosis in humans, which is found in tropical regions (including Australia) and has the Latin meaning: “Distemper of asses” (Currie).
Symptoms depend on the form of the disease, of which there are three: skin, nose and lung (they sound better in German: hautrotz, nasenrotz and lungenrotz. Rotz literally translates as “snot”). You may have heard the skin form described as ‘Farcy’, which involves lumps (0.5-2.5cm) and ulcers that spread over the skin and lymph glands (‘farcy buds’), discharging a very characteristic oily, yellow pus that is extremely infectious (Lopez). An infected horse can catch B.mallei this way by the pus contacting the second horse’s nose, mouth or small wound in the skin. The nasal form is more of the same, only the ulcers and discharge come from the nose. The lung form involves more of these ubiquitous ulcers along with pneumonia (Howe). Unsurprisingly, the horse will look sick – fever, malaise and swollen lymph nodes. If untreated, these ulcers can spread into the blood and through the lymph and infect all the organs, usually the liver, spleen and muscles (Robins). The horse will probably die within 10 days (Robins). Although scientists like to group things neatly, in reality one horse will often have some combination of hautrotz, nasentrotz and lungenrotz , most commonly skin and lung symptoms (Khan).
Glanders can also be an acute (short-lived) disease, sub-acute (a bit longer lasting) or chronic (stuck with it). Donkeys tend to get the acute disease (Mota), horses the chronic form (Dungworth) and mules, as a cross between donkey and horse, can get any of the above (Khan). Whether or not the infection is acute or chronic depends on many variables, such as infection route, amount of bacteria (inoculating dose) and health of the infected animal (Currie).
I’ve never heard of Glanders. Is it new?
Not exactly. Hippocrates and Aristotle wrote about it 300-400 years BC (Howe) and the actual infectious agent was pin-pointed for the first time in 1882 (from a horse liver) by Friedrich Löeffler (more on his eponymous institute later) and Wilhelm Schütz (ref). Military strategists of the 20th Century were quick to deduce that a glanders epidemic in either or horses or humans would be an effective form of sabotage – the German army infected Allied steeds with B.mallei in WW1 (Wheelis in Currie and in Khan), WW2 PoWs had it thrust on them by the Japanese (Darling & Woods), and Russia purportedly attempted to develop it into a bio-weapon against horses of the Afghan Mujhaheddin (Alibek).
The reason glanders is relatively unheard of in Australia, is due to the diligence of the developed world in keeping it out, via routine testing, surveillance, and ‘stamping out’ of any positive cases destined for import. There was a glanders epidemic in the USA in the late 19th Century, after the horses were moving hither and thither during the Civil War (Quigly) but it was eliminated by 1934 (and by 1938 in Canada, following a 34 year landmark campaign that slaughtered over 13,000 horses and cost over $1M in compensation (Derbyshire). The British wiped it out by 1928 (ref).
Glanders is however, endemic in the Middle East, Africa, Asia and Brazil (Verma in Scholz) and outbreaks do occur regularly in these regions, along with occasional cases in Eastern Europe. The last case in Germany was in 1955 (ref). It is a notifiable disease to both local veterinary authorities and the World Organisation for Animal Health (OIE) (Scholz) and horses are generally banned from import into Australia, USA and Europe from these countries.
Dr Leo Jeffcott, FEI vet at the Beijing Oympics: “Finding a number of serologically positive horses around Beijing in 2004, was a major reason for moving the equestrian events to Hong Kong! Glanders may still be a threat.” Experience from Beijing was applied to the 2010 Asian Games in Guangzhou and Nanjing, and formed the basis of OIE experts working with the FEI to create and develop principles of ‘Equine Disease Free Zones (EDFZ)’ for the future safety and well being of competition horses (Murray, OIE).
Has there ever been a glanders case in Australia?
Once, in a circus horse in 1891. The horse was culled in quarantine. Our neighbours in New Zealand have never had a case.
Can I catch it?
Yes, unfortunately. B.mallei has earned itself a spot on the CDC’s list of potential bio-warfare nasties – Category B: the 2nd highest threat category that includes diseases like typhus and cholera (CDC web). Increased worldwide trading of horses and semen inflates the risk of human infections (Scholz) – in fact horses travel by air more than any other non-human species. Due to the paucity of human cases, a lot of assumptions are based on research done with B.pseudomallei, however it is believed to be more contagious than pseudomallei (Srinivasan). People who have been infected have tended to have had long-term occupational exposure to the bacterium, eg vets, abbatoir workers, lab staff (Currie). Transmission is through a cut in the skin, or via mucous membranes (eg eyes, nose, mouth). Less commonly, B.mallei can be inhaled (CRBE web). Symptoms are similar to those suffered by horses.
I don’t like it – how do I get rid of it?
Assuming you lived in the year 1795 or so and were inflicted with “One of the filthiest disorders that happens to a horse”, you would simply ask your farrier to take “a quart of Old Lant and boiling therein 2 pounds of rusty steel, 2 ounces each of Ashes of Green Broom and Liver of Antimony” – voila, three tasty drinks for your horse per day. If you were a bit short on Old Lant, you could try a drench made from “White wine, fine tobacco, honey of roses and an egg yolk.” You would of course need to follow up by “Rubbing the valves and glands from ear to ear…with hot Horse muck from the dunghill.” (Practical Treatise of Farriery)
In enlightened times, we know from many lab studies that B.mallei is susceptible to several antibiotics. However in practice, there are so few cases occurring in countries that can afford to research them, that there is a knowledge-gap of what actually works in a real-life situation. Dr Leo Jeffcott: “There are not many people with real glanders experience (in Australia) these days.” Antibiotic treatment is “cumbersome”, entailing a long course of combination therapy (Eates in Scholz) and is simply unavailable and / or unaffordable in the countries where glanders is endemic. Unfortunately, the only real solution is culling of the infected animal – both to ease suffering and prevent spread of the disease.
For humans, diabetics are seemingly at higher risk of infection, and will be sicker. This is exemplified by the young US army microbiologist who contracted glanders in 2001 after being a bit blasé about wearing gloves when working with B.mallei in the lab (Srinivasan). Strangely enough, given the project he was working on, diagnosis took a long time… and it took 12 months to fully recover. The death rate for humans with glanders ranges from 40% to 95% depending on where the infection spreads and whether or not it is treated.
Can my horse or I be vaccinated against it?
There are no vaccines available for glanders. In January 2015, researchers published one of the first glanders candidate vaccine trials in non-human primates, using a gold nano-particle glyconjugate vaccine for animals infected with aerosol B.mallei (Torres). This is exciting – however there are generally many years and hurdles to overcome before these early studies are translated into usable products.
So what’s the story in Germany?
One horse has tested positive.
In late November last year, a Holsteiner show jumping horse (born May, 2008 – Horsetalk NZ article), was sold to the USA and underwent routine blood testing whilst in quarantine in the town of Bippen, in the Osnabrück region of Niedersachsen (Lower Saxony). The glanders test came back positive, which caused some alarm as glanders is a notifiable disease, and Germany has not had a case for over 50 years.
The blood sample was forwarded to the national reference laboratory for glanders, the Friedrich-Loeffler Insitute (FLI), for additional testing. Tests on the original, plus a second blood sample were again positive, by two different methods (Complement fixation and Western blot), so the horse was culled as per standard regulations, and autopsy performed. Organ tests were negative for glanders, however small scabs were found on the skin and these tested positive via a third type of test (Real-time PCR) – it was officially glanders (OIE). The stable in question, along with 3 or 4 others in Schleswig-Holstein and North Rhine-Westphalia (Lubeck News Online) that had housed the infected horse at some point, were placed into lockdown and underwent disinfection procedures during the testing period. All horses (approximately 70) were subjected to repeated blood testing and all tested negative. Therefore the glanders outbreak was considered to be ‘contained’ on the very same date as it began – in effect, it was an outbreak of a single case only and the authorities were satisfied that it hadn’t spread (OIE).
How did the local horse community take the news?
There appears to be some confusion in German media about the positive status of the horse, and its impact on the country’s ‘glanders-free’ status. When interviewed by Lubeck News Online, Herr Hinerk Köhlbrandt, owner of a stable that had at one point held the infected horse (in Eastern Holstein), questions the validity of the testing “Because each of my 17 horses tested negative.” News outlets local to the Bippen stable where the positive test was made, report a ‘Preliminary all clear…we have reason to hope’ from their local vet chief, prior to results from the FLI subsequently proving the opposite result (de NDR article). Guido Klatte, from International Horse Shipping Services stated his belief to Eurodressage online that “the disease was not confirmed in the horse… it was probably a false positive…Germany does not have glanders.” Others were more circumspect, with two show jumping events in Neumünster and Friedrichsude cancelled and riding schools shutting their doors during the lockdown period. Neumünster barn owner Nils Kuhnke believed in being alert, but not alarmed. “A little care and avoiding unnecessary contact with other horses and stables should be enough, initially.” (Holsteinischer Courier).
When THM contacted Dr Mandy Elschner, Head of the Glanders Working Group at the FLI, her institute’s PR spokesperson confirmed Dr Elschner’s earlier statements that Germany has indeed lost its ‘glanders-free status’.
So could the test have been a false positive?
Extremely unlikely. The gold standard for glanders diagnosis is a bacteria-containing sample from the animal that is then grown into a colony in a petri-dish (Blue 1998). This method wasn’t possible in this case due a lack of nasal or skin discharge, however several different types of testing were done, at a local lab and at an internationally-regarded specialist lab, and together these results point to glanders. In the past, an immunological ‘mallein’ skin test was the only test available, and this is still used to cheaply and rapidly test large herds in endemic countries. This has been replaced in more modern labs by the Complement Fixation test (CFT), which is superior to other types of blood testing in this instance (Al-Ani) as it is less susceptible to cross-contamination (Sprague). CFT was used at both labs in the Bippen case. Detection is even more specific for B.mallei if CFT is combined with the Western blot test (WB)(Eslchener), which is precisely what was done at the FLI. Finally, a special glanders RT-PCR test (“Burkdiff”) has been developed for use by the OIE to differentiate B.mallei from other similar bacteria such as B. pseudomallei (“Burkdiff”) (Bowers 2010), and skin samples from the Bippen horse’s autopsy did indeed test positive to the RT-PCR – effectively sealing the deal.
But the horse “wasn’t sick”?
The crux of this case is that it is entirely possible for the horse to carry a chronic infection and test positive, without having so much as a sniffle (Hungerford). Additionally, if the bacterial load is sufficiently low, it won’t be enough to cause symptoms (CRBE web).
OK, it IS glanders. How did the horse get infected then?
This is the million dollar question. The OIE report clearly states that the horse was born and raised in Germany, never travelled, never had contact with a horse known to be infected, and did not pass the infection on to any of its stablemates. Rumours of possible contact with South America were discounted. Epidemiological studies – ie. the ‘how’ of the infection – are continuing by unnamed German authorities, and if the FLI have any leads on these, their PR machine is keeping mum. “The epidemiological investigations are not our responsibility therefore we are not able to give further information about this topic. As far as we know, no more positive animals were found by testing contact populations and contact animals to date. The rules for trade with horses and products are changed, however we are not involved in these regulations and have no information about the affected farms.”
Glanders is more likely to spread in crowded, stressful and unhygienic circumstances, and humidity and wet also encourages growth (Aiello). Flies may act as a vector (Lopez) and there have been reports of mare-foal and stallion-mare transmissions (ref in Khan).
Guido Klatte mentions the possibility of cross-contaminated objects being the source of the ‘false’ positive. Information in this area is a little unclear. Most research indicates that B.mallei does not survive well outside the host animal (Currie), and it does not ‘live’ in soil, water or plants (CBRNE web). However historically, authors suggest that the glanders bacilli can live in water for 100 days (Löeffler) in environments such as water troughs (Kinsley). “Bacteria can live on food, water, equipment and tissues for about a month,” according to vet Lidwein Verdegaal in her interview with Eurodressage (eurodressage.com). An Australian government-produced guide for horse owners refers to glanders being able to survive in soil for as long as 2 months (RIRDC). Like many bacteria, B.mallei doesn’t much ‘like’ sunlight, heat and disinfectants (Nicoletti).
Has this sort of thing happened before?
Yes, in October 2008 a horse returned a positive test in Sao-Paulo, a part of Brazil where the disease had not previously occurred. Consequently the FEI delayed the Global Champions Tour CSI-5* Final show jumping competition in order to allow EU authorities time to consider. In the end the event went ahead and European horses did compete. Brazilian horses were not allowed into the EU at this time, so a new route had to be found to get the Brazilian Endurance team to the World Endurance champs in Malaysia in November that year (The Horse website).
There was an extensive study done of back-to-back glanders outbreaks in 2010/2011 in Bahrain, whereupon 80% of the entire population of horses and donkeys in Bahrain were tested by the OIE Reference Lab in Dubai. This represents over 6,700 horses, 250 donkeys and 3 camels. Genotyping studies (comparing genetic sequences with an outbreak in the United Arab Ermirates in 2004) hinted at a “complex epidemiological background…involving two clusters of several different strains…this suggests repeated importation to the region from similar geographic sources.” (Scholz). Of note, Bahrain and Kuwait were late in reporting outbreaks in 2009-2010 and were thereafter banned from exporting horses to the EU (DEFRA).
Interestingly, there was another suspected EU case in August 2011, where a horse imported from Lebanon to Switzerland had glanders pop up in serological screening upon arrival, right on the heels of a glanders outbreak in Beirut. The horse had stopped over in Germany on the way. Secondary testing proved negative, and the UK DEFRA report indicated that this was an example where the initial serological screening test can be false positive, citing the need for the sort of detailed follow-up testing and epidemiological investigation that is occurring right now in Germany. It transpired that the Beirut outbreak started with horses transported illegally from endemic country Syria (which does not consider glanders to be a notifiable disease). (Defra)
So will I be able breed my German-sired foal this year?
THM asked Glenis Dyason (International Horse Breeders) and Christoph Hinkel (representing Paul Schockemohle’s Breeding Station), for their take on the glanders situation.
Glenis: “The Australian Department of Agriculture is reviewing the whole situation before the breeding season 2015 and we will know more then. But as it stands, stallions collected after 26 Nov 2014 in Germany cannot come in until the review, and the import vet certificates have been amended accordingly. There will be some semen hopefully collected before this date that we can bring in, but new stallions will be problematic. EU countries apart from Germany have to test for glanders for semen to qualify. Hopefully this will become the status quo for Germany after the review. Lots of suppliers already do test for glanders.”
What is the general feeling amongst the German breeders – is it a serious problem? Or do you think like Guido Klatte that it is just a false positive…
Christoph: “For sure it is a serious problem, it hasn’t shown up for over 50 years in the whole of Europe, and suddenly it has shown up and no-one knows where it comes from, and how this one horse actually got it. For sure, we take it seriously, and our government takes it seriously, but for the moment there is not much we can do. We are lucky that only this one horse tested positive, so far all the other horses have tested negative. On one hand it is lucky and good that only one horse tested positive but on the other hand, it is a little strange, because it doesn’t seem possible that he didn’t infect other horses.”
Have other countries banned frozen semen from Germany – or just Australia?
“So far as I know, they have changed the rules in Australia, and now you are only allowed to import semen from a time before this glanders showed up. We can send semen to Britain because it is part of Europe and for the whole of Europe you don’t have to test for glanders, but this will probably also change – in the past glanders was not a question so there was no need to test the semen for glanders. For the moment, luckily it is no problem to send semen in Europe.”
And the United States?
“I don’t know to be honest. In the beginning of the season, we exported semen to the United States without any problem, but this was just before the problem. Now maybe the United States is testing for glanders, and maybe now we cannot export to them.”
Do you think you will have enough frozen semen that you collected before the cut-off date to take care of your Australian customers?
“I hope we have enough from 2014 to send to Australia, but it is difficult to say because I don’t know which stallions will be popular and how much semen we have. When we have not enough semen, and we lose business, what can I do? We cannot change it.”
Selling horses out of Germany, is it only Australia that is not taking horses from Germany?
“No, there are many countries testing for glanders. I think the whole of South America is testing for glanders, so this will also become a problem. It all depends how it develops. If there was only one case and nothing more shows up, then they will maybe change the rules back to how they were, but if more cases show up, we will have a serious problem.”
The final word (for now)?
Dr Mark Schipp, Chief Veterinary Officer with the Ag Dept has stated that any lifting of import bans will take a minimum of 6 months “but we’re waiting on the response from the German authorities on the cause of disease before we review the situation. ” (Weekly Times). Glanders can take as little as 1-2 days to several months to become apparent, although 2-6 weeks is an average incubation period (Centre for Food Security and Public Health in DEFRA report)(Currie). The variable incubation time is presumably why the ban needs to be so long, in addition to the time needed to identify and eradicate the source of the spread.
Dr Schipp has also cautioned that: “Any horses that had been in contact with German horses – eventers for example – may have additional testing requirements that would delay or add cost to the movement of horses or semen to Australia.” (Weekly Times).
Meanwhile in the UK, Thoroughbred breeders and racing representatives have been assured by Dr Richard Newton (Head of Epidemiology and Disease Surveillance at The Animal Health Trust) that “The risk to thoroughbred horses in Germany currently appears very low – there is very little contact between show jumpers, breeders and Thoroughbred horses. So the threat to UK Thoroughbred horses appears minimal.” (Owner Breeder mag).
Australian authorities are no doubt mindful of the message from the Bahrain outbreaks. “The failure of initial eradication… in 2010…is evidence for the need for continued surveillance and abatement measures even after all animal cases appear to be cleared…infected animals may be asymptomatic and serologically negative.” (Scholz) As RIRDC reminds us in ‘Equine Exotic Diseases – a manual for horse owners’, “In Australia, we are fortunate to be free of many of the serious infectious diseases that can infected horses. A large part of this freedom is due to our strict but fair quarantine regulations, but it is up to all of us to maintain this privileged position.”(RIRDC).
Stay tuned for updates as the breeding season approaches….
Glanders – the Aussie connection
On his way to the WEG in Lexington in 2010, James Paterson Robinson’s Niack de l’Abbaye was held because he was considered a ‘terror threat’ after he returned an ‘anti-complimentary’ result for glanders. An anti-complementary test is not a positive, but is a null and void result, so the US Department of Agriculture said that the stallion was not allowed in, as glanders was classed as a Category B bio-terrorist threat. This was something of a problem since the WEG was only 7 days away, and there was only one lab in the world whose results they would accept – in Iowa. Luckily for JPR and the horse, the second UPS package actually made it, and the test proved negative and James got to ride in Lexington…