21 Horses Dead In Beirut Racetrack Outbreak
A somewhat confusing report in Lebanon's The Daily Star describes an outbreak of disease at Beirut's Hippodrome (racetrack) that has resulted in the deaths of 21 horses; 2 from disease and 19 that were euthanized as part of the outbreak response.
It's not specifically stated in the report, but the commentary about glanders, a highly infections disease caused by the bacterium Burkholderia mallei, suggests that glanders has been diagnosed or is strongly suspected. The two affected horses had been imported from Syria, which has been the source of other glanders outbreaks, and the disease is present in multiple countries in the region, so it's a likely cause. The reason for euthanasia of the 19 "healthy" (presumably exposed) horses is unclear. Hopefully it was done because they were identified as infected, however the report suggests that euthanasia preceded diagnosis.
Little information was provided about the response, beyond culling, with only a statement that "all relevant procedures had been taken." Additionally, a quarantine and testing requirement for horses entering Lebanon was announced by the mayor (presumably, a federal body has mandated this since I doubt the mayor of Beirut can set national importation policy). Measures for controlling glanders outbreaks are fairly well described and involve extensive investigation of horse contacts and movement, screening of potentially exposed horses, euthanasia of positive horses, quarantine of potentially exposed farms and use of stringent infection control practices. Hopefully a proper response is being undertaken here.
Beirut's mayor stated that there was "no possibility that the disease could be spread to humans," but that isn't consistent with glanders since this is a potentially serious disease in people as well. Two grooms that worked with the first two horses were tested and so far are negative and healthy. The likelihood of someone getting infected from an infected horse isn't great, but it's a very nasty disease so care must be taken and investigation of human contacts is important.
The Agriculture Ministry will apparently release its "all-clear" report in 6 months (assuming no more cases crop up). Let's hope that things truly are "all clear" in 6 months, with a subsequent report (presumably after official confirmation that the outbreak is over) thereafter. More details about the extent of testing and the results would be nice in the short term, to get a better understanding whether this is truly just a case of a couple of infected horses being imported with no transmission outside of the initial group, but political issues often limit the information flow in glanders outbreaks.
Image: Beirut Hippodrome (click for source)
Lions and tigers and glanders
Glanders, a very serious disease of horses, donkeys and mules caused by infection with the bacterium Burkholderia mallei, has made the news again in a rather unusual manner – it has been reported as the cause of an outbreak in lions and a tiger at an Iranian zoo in Tehran.
The story goes that two Amur tigers arrived at the Tehran zoo from Eastern Russia in April 2010 as part of an exchange program between the two countries. The tigers were supposed to be used to help restore the tiger population in northern Iran on the Miankaleh nature reserve, but their living quarters there were apparently still not ready, and thus they were being kept at the zoo. One of the tigers died in December 2010.
And that’s were the story starts to get a little dicey. The Iranians claim the tigers were imported already carrying the disease, and that the last case of glanders at the zoo was 50 years ago. The tigers had already been at the zoo for eight months - although the incubation period for glanders can be months in some cases, it is normally only weeks. The Russians of course insist that the tigers were completely healthy when they were transferred – they’d been thoroughly examined and quarantined prior to being moved. (This makes the most sense to me, since transporting an animal such a long distance is a major stress and increases the risk of illness, and transporting an animal that is already sick would be even more risky. Not a chance I would take with two members of a species of which there are fewer than 900 individuals left in the world.) They also pointed out that a sick tiger from the cold regions of Russia would be much more likely to succumb to illness during the very hot Iranian summer, not during the winter.
Another report said that three lions at the zoo also died from glanders in the last two months, and subsequently another 14 lions were diagnosed with the disease, all of which were put down by the authorities. The main concern seemed to be the spread of the disease from the big cats to the feral cat population, and then to the human population. This second report states that “the tiger died after being fed contaminated meat, though it is possible it could also be related to the glanders.” Yet another report said that the tiger was infected with feline immunodeficiency virus (FIV - the feline equivalent of HIV).
Facts to keep in mind:
- Glanders is an highly contagious disease, and highly fatal (B. mallei is even classified as a Class B bioterrorism agent).
- Animals that do recover from the disease can become long-term carriers of B. mallei, and are a risk to other animals (and people). Prompt euthanasia of affected animals is therefore often the primary means of controlling outbreaks (but the bacterium is susceptible to antibiotics).
- The infection can be transmitted to other animals (and people), usually through close direct contact or contact with oral and nasal secretions and discharge from skin ulcers. It can also be transmitted by eating tissues from infected animals.
- The bacterium is killed by most disinfectants, and UV radiation (sunlight).
Glanders can affect species other than equids, including people and cats, however there is very little information available about glanders in any felids, let alone lions and tigers. Theoretically it might be possible for the disease to spread from the zoo animals to feral cats and then to people, but I don’t know how many feral cats are brave (or stupid) enough to wander into a lion enclosure. There’s also a possibility that a glanders-positive feral cat may have infected the zoo cats (but again, it would have to be very brave, or very stupid). It is also unclear what tests were used to confirm that the big cats were infected with glanders, and it is unknown if other animals at the zoo have been tested. Since this is typically a disease of equids (and has also been found in goats and camels), I would certainly be checking these animals first.
The big question is, where did the glanders come from in the first place? It seems unlikely that the tigers brought it from Russia, when the disease is actually endemic in Iran (even though they’d had no diagnosed cases at the zoo for many years). Is there a carrier animal in the zoo? Were the animals infected by eating contaminated meat? Was it brought in by feral cats? The source needs to be identified and addressed or animals will continue to be infected, which is particularly bad news for the kinds of rare species that may be found in a zoological collection. Some more details about the testing would also be appreciated – given the severity of this disease, and the severity of the consequences for positive animals (euthanasia), one needs to be as sure as possible that these animals are infected with B. mallei and not something else.
Photo: Amur Tiger (Panthera tigris ssp. altaica) (click image for source)
Cause of Bahraini horse outbreak identified
A recently reported outbreak affecting horses in Bahrain has been diagnosed as glanders, a very serious bacterial infection caused by the highly contagious bacterium Burkholderia mallei. So far, it has been reported that 8 horses were euthanized over the past 3 weeks because of the infection.
Bahrain's cabinet has allocated BD150 000 to fight the outbreak. Authorities have apparently stated that the outbreak can be "easily" managed, "We have sent samples from nearly 400 horses to a specialist laboratory in the UAE and the 10 results we have got so far give us the all-clear. We now know we can manage this quite easily and are taking appropriate action."
That's a pretty dangerous sentiment to be expressing (and believing) early in an outbreak, but hopefully it's true. "Easily" and "outbreak" aren't often uttered in the same sentence, and it's far from unusual to be fooled by an allegedly contained or controlled outbreak. I'd be very surprised if all of the positive horses have already been identified. Control of glanders involves widespread testing of horses, typically with euthanasia of any infected animals. It sounds like testing is underway and results of this will give a good indication of the extent of the problem. Ten negative samples don't mean that much to me. As more results come in (and if they continue to be negative), more confidence can be had in the assessment that this outbreak is truly contained. Glanders is not solely a concern for horses. It's a zoonotic disease that can cause rare but serious infection in humans, with a high mortality rate (almost 100% if proper treatment is not administered). People can become infected by direct contact with infected horses, with the bacterium gaining entry through skin abrasions, inhalation or contact with tissues of the mouth and nose. Pneumonia, bloodstream infections and other problems can develop. Burkholderia mallei is a Class B bioterrorism agent. Hopefully, people working around infected horses are using appropriate infection control precautions to reduce the risk of infection. Hopefully, more information will be available soon about this outbreak and results of ongoing testing. Image: A horse with glanders (Burkholderia mallei infection), exhibiting the characteristic infectious nasal discharge. Glanders is a reportable disease which has been eradicated from North America, Australia and most of Europe.
This Worms & Germs blog entry was originally posted on equIDblog on 26-Apr-10.
