What killed Knut the polar bear? Study offers 'closure'

Berlin zoo employee Thomas Doerflein plays with polar bear cub Knut during the bear's first presentation in Berlin zoo, in this March 23, 2007 file picture.
PHOTO: Reuters

Thrust into the spotlight during his short life, Knut the polar bear's celebrity has outlived his dramatic drowning in 2011 - as has the medical mystery surrounding his demise.

On Thursday, animal and disease experts said they finally have the answer; the seizure that caused Knut to drown in the pool in his zoo pen, before hundreds of shocked visitors, was triggered by a type of auto-immune disease which causes brain inflammation.

"Everyone remembers how he was born, how he was presented to the public, how he lived and then the movement of death, and now... there is some closure. We can actually say this is why he died," said study co-author Alex Greenwood of the Leibniz Institute for Zoo and Wildlife Research in Berlin.

Reported in the journal Scientific Reports, this is the first-ever diagnosis in an animal of NMDAR encephalitis, a condition that affects about one in 200,000 people each year.

After his birth in December 2006, Knut soon shot to fame with TV crews and adoring crowds flocking to witness his cuddly cuteness.

A series of tragedies further captured the public imagination: Knut's was abandoned by his mother, his twin died a few days after birth, and the zookeeper who raised him by hand, died in 2008.

Knut was reportedly bullied by other bears and thought to suffer from a behavioural disorder that caused him to seek out human attention, throwing tantrums when he was denied an audience.

The bear earned the zoo millions of euros, drawing over two million zoo visitors, graced the cover of Vanity Fair magazine and even appeared on German postage stamps.

Knut was just four years old when he died.

Mourners flocked to his cage, leaving flowers, candles and cards, and a bronze statue dubbed "Knut the Dreamer" was erected in his memory.

The cause of death was suspected to have been a brain seizure, likely from encephalitis, but the exact trigger has remained a mystery.

The brain inflammation can be caused by viral or bacterial infections, or a faulty immune system reaction which causes antibodies, meant to attack intruder microbes, turn on the body instead.

The most common non-infectious form of the disease is NMDAR encephalitis.

After years of head-scratching, investigators had a breakthrough inspiration to test for NMDAR antibodies, and found "high concentrations" in Knut's cerebrospinal fluid, they said.

In humans, the treatable disease only discovered in 2007, affects mainly young women.

Symptoms generally start with headaches and a high temperature, followed by psychotic episodes like hallucinations and aggression, and finally epileptic seizures.

It is often diagnosed in the late stages but patients react well to treatment - a combination of steroids, blood transfusions and therapy to destroy the errant antibodies.

Knut's diagnosis should open a new field of research into animal encephalitis, said the team.

"Because treatment options are available in humans that could easily be transferred to animals, the death of many animals, particularly of conservation concern, from encephalitis in the future may be preventable," Greenwood said in a telephone conference.

Co-author Harald Pruess said he hoped Knut's high profile would raise awareness of NMDAR encephalitis in humans too - presented with initial symptoms, doctors and patients often do not think of testing for the disease.

In animals, it would be much more difficult to diagnose.

Predators like polar bears tend to hide disease-caused discomfort or weakness from rivals.

"With, for example, Knut's case ... you only saw that there was something wrong when he started to seize," said Greenwood.

Berlin Zoo director Andreas Knierim welcomed the findings.

The research team, he said in a statement, "have made it possible that in the future, diseases in animals similar to Knut's could be diagnosed earlier and treated."

 

Purchase this article for republication.

VIDEOS YOU SHOULD WATCH

  • #Joeyjios: We try bubble tea mala hotpot and bubble tea toast

    Full story: http://www.asiaone.com/food/we-try-bubble-tea-mala-hotpot-and-bubble-tea-toast-guess-which-ones-got-us-hooked Mala and bubble milk tea within the same hotpot? What about bubble tea on toast? Who even comes up with these ideas?! This week on #Joeyjios, we give these dubious food creations a taste-test to see if they're worth your time, money and calories. #bubbletea #bbt #boba --- Read more: http://www.asiaone.com/ FOLLOW us on - Facebook: https://www.facebook.com/asiaonecom - Twitter: https://twitter.com/asiaonecom - Instagram: https://www.instagram.com/asiaonecom/ EMAIL: For story leads, business enquiries, contact asiaone@mm2entertainment.com
  • Thirstdays: Where we talk weird dates and wild fantasies

    Full story: https://www.asiaone.com/entertainment/thirstdays-where-we-talk-weird-dates-and-wild-fantasies Ooo, it's been a hot week and the thirst is real at AsiaOne. Join Le En and Bryan as they chat about weird dates, constant 'cravings', and Beyonce's thigh gap! And they are quenching that thirst with a cup of root beer float to celebrate the return of a certain fast food restaurant. Thirstdays is a fortnightly AsiaOne #entertainment series where our hosts Le En and Bryan give you a peek into their personal lives while they satisfy their thirst over a drink, have a no-holds-barred chat, and do fun things. #gossip #confessions #realness --- Read more: http://www.asiaone.com/ FOLLOW us on - Facebook: https://www.facebook.com/asiaonecom - Twitter: https://twitter.com/asiaonecom - Instagram: https://www.instagram.com/asiaonecom/ EMAIL: For story leads, business enquiries, contact asiaone@mm2entertainment.com
  • Don't Say Cannot Ep4: He beats people up, but for the country

    Full story: http://www.asiaone.com/singapore/dont-say-cannot-delinquent-national-wrestler He used to beat people up, simply because he had "too much energy" to expend. Now, he still beats people up - but for the country. Meet 24-year-old #Singapore national wrestler Toh Xin Ran. Seeing the number of medals that he has been awarded and the respectful manner in which he now interacts with his wrestling coach, it is hard to imagine that Xin Ran used to be a troubled kid in his younger days. #wrestling #sportsman --- Read more: http://www.asiaone.com/ FOLLOW us on - Facebook: https://www.facebook.com/asiaonecom - Twitter: https://twitter.com/asiaonecom - Instagram: https://www.instagram.com/asiaonecom/ EMAIL: For story leads, business enquiries, contact asiaone@mm2entertainment.com
  • #Joeyjios: Taste-testing The Alley Luxe and CHICHA San Chen

    Full story: https://www.asiaone.com/food/alley-luxe-and-chicha-san-chen-opens-week-heres-what-try A Michelin-standard bubble tea for $4.70? A drink that looks like the Northern Lights? This week, #Joeyjios her colleague Le En to check out two new bubble tea (BBT) stores that are opening along Orchard Road. Which will they prefer? Watch to find out. #Thedeerishere #TheAlley #Chichasanchen #Boba --- Read more: http://www.asiaone.com/ FOLLOW us on - Facebook: https://www.facebook.com/asiaonecom - Twitter: https://twitter.com/asiaonecom - Instagram: https://www.instagram.com/asiaonecom/ EMAIL: For story leads, business enquiries, contact asiaone@mm2entertainment.com
  • Office Tea Episode 5: Bosses and Things

    It’s been a few weeks - let’s find out if the higher-ups of AsiaOne have any regrets about hiring Le En. Efforts were made to make nice, charity is involved and work is never-ending still. Follow and subscribe so you won't miss a single episode of our new series, Office Tea! To catch more of her antics, follow her @goofy_feline! --- Read more: http://www.asiaone.com/ FOLLOW us on - Facebook: https://www.facebook.com/asiaonecom - Twitter: https://twitter.com/asiaonecom - Instagram: https://www.instagram.com/asiaonecom/ EMAIL: For story leads, business enquiries, contact asiaone@mm2entertainment.com
  • #Joeyjios: DIY your way into mum's heart this Mother's Day

    Full story: https://www.asiaone.com/women/joeyjios-diy-your-way-mums-heart-mothers-day Mother’s Day is this Sunday! Have you gotten mum a gift yet? This week on #Joeyjios, Joey tries her hand at DIY projects that’s thoughtful, useful and inexpensive. #Mothersday #DIY --- Read more: http://www.asiaone.com/ FOLLOW us on - Facebook: https://www.facebook.com/asiaonecom - Twitter: https://twitter.com/asiaonecom - Instagram: https://www.instagram.com/asiaonecom/ EMAIL: For story leads, business enquiries, contact asiaone@mm2entertainment.com
  • Don't Say Cannot Ep3: He 'sees' the world with the help of tech

    Full story: https://www.asiaone.com/singapore/dont-say-cannot-he-may-be-blind-he-can-text-faster-you Edwin Khoo, 43, surprises friends with the speed at which he types on his phone. The reason? He's been blind since birth. But #technology has been the game-changer for Edwin in navigating the world around him despite his #disability, allowing him to #travel and even host his own online #podcast. --- Read more: http://www.asiaone.com/ FOLLOW us on - Facebook: https://www.facebook.com/asiaonecom - Twitter: https://twitter.com/asiaonecom - Instagram: https://www.instagram.com/asiaonecom/ EMAIL: For story leads, business enquiries, contact asiaone@mm2entertainment.com
  • Office Tea Episode 4: The Dress Code

    It’s in the employee handbook - but does ANYONE actually read and follow the dress code? Are calves too scandalous? Le En puts on Athleisure and tries to get away with it! Follow and subscribe so you won't miss a single episode of our new series, Office Tea! To catch more of her antics, follow her @goofy_feline! --- Read more: http://www.asiaone.com/ FOLLOW us on - Facebook: https://www.facebook.com/asiaonecom - Twitter: https://twitter.com/asiaonecom - Instagram: https://www.instagram.com/asiaonecom/ EMAIL: For story leads, business enquiries, contact asiaone@mm2entertainment.com
  • Caryn Cheng finds the best deals at IMM's Greater Savings Home and Furnishing Sale

    Full story: https://www.asiaone.com/singapore/5-couples-share-most-expensive-items-they-have-ever-bought-their-home AsiaOne challenges Caryn Cheng to find the best deals at the upcoming #IMM Greater Savings Home and Furnishing #Sale. IMM's Greater Savings Home & Furnishing Sale will start May 13 to 19. With 20 per cent off storewide at Best Denki and discounts of up to 50 per cent at stores such as INKAGU Outlet by Picket & Rail, Linen Gallery Outlet and Red Apple from May 17 to 19, this epic sale is not to be missed. Address: 2 Jurong East Street 21, Singapore 609601 Opening hours: 10am to 10pm #brandedcontent --- Read more: http://www.asiaone.com/ FOLLOW us on - Facebook: https://www.facebook.com/asiaonecom - Twitter: https://twitter.com/asiaonecom - Instagram: https://www.instagram.com/asiaonecom/ EMAIL: For story leads, business enquiries, contact asiaone@mm2entertainment.com
  • #Joeyjios: I try a ballet-inspired workout despite my two left feet

    Full story: https://www.asiaone.com/singapore/joeyjios-i-try-ballet-inspired-workout-despite-my-two-left-feet Tendu, Arabesque and Grand Pliés? This week on #Joeyjios, I found out that these are in fact, not edible food dishes, but dance moves in ballet.  Watch as former professional ballerinas and co-founders of #BalletBody, Lisha Chin and Alison Carroll, take me through a snippet of their hour-long ballet-inspired workout while I try my best to keep up.  #Ballet #Barre #Fitness --- Read more: http://www.asiaone.com/ FOLLOW us on - Facebook: https://www.facebook.com/asiaonecom - Twitter: https://twitter.com/asiaonecom - Instagram: https://www.instagram.com/asiaonecom/ EMAIL: For story leads, business enquiries, contact asiaone@mm2entertainment.com

SERVICES