SINCE THE middle of August, a rare disease has killed five elephants in Odisha. Four calves between the ages of six and 10 have died in Nandan Kanan Zoo in Bhubaneswar, followed by the fifth elephant that died in Chandaka forest this week.
The disease is caused by a virus called EEHV, or elephant endotheliotropic herpesvirus. The four deaths in Nandan Kanan Zoo are the first reported cases of EEHV-related deaths in an Indian zoo, state government and Central Zoo Authority (CZA) officials said, while the death in the forest too is the first known such case in the wild in India.
How the virus works
An EEHV information website, a resource conceived in 2011 at the the 7th Annual International EEHV Workshop in Houston, describes EEHVs as a type of herpesvirus that can cause a highly fatal haemorrhagic disease in young Asian elephants.
“Most elephants carry just as most humans carry a cold virus. When EEHV is triggered, the elephant dies of massive internal bleeding and symptoms which are hardly visible,” said Dr S P Yadav, CZA member-secretary. Some elephants show symptoms such as reduced appetite, nasal discharge and swollen glands, researchers say.
The disease is usually fatal, with a short course of 28-35 hours.
No true cure yet
There is no true cure for herpesviruses in animals or in humans, the Washington-based Smithsonian’s National Zoo and Conservation Biology Institute says on its website. “Because herpes viruses go latent, we won’t be able to find a ‘cure’ but we hope to collaborate in refining effective treatments and help in the development of a vaccine to prevent EEHV.”
Because the disease has a short course, “this means we have to take a very quick call on a suspected EEHV case and kick off treatment protocols. This treatment is a combination of anti-viral therapy, aggressive fluid therapy (to counter haemorrhaging), immuno-stimulant drugs (selenium and Vitamins C, E), anti-pyretics and analgesics (to bring down fever),” said senior veterinarian Alok Kumar Das, who treated the four sick elephants at Nandan Kanan.
The diagnostic detection of active EEHV infections in Nandan Kanan was carried out at the Indian Veterinary Research Institute (IVRI) in Bareilly.
Why it is a concern
The death of the Chandaka forest elephant has worried officials in Odisha. “If elephants in the wild start falling prey to the virus, then treatment will be very difficult,” H S Upadhyay, Principal Chief Conservator of Forests and Chief Wildlife Warden, told The Indian Express. It will be extremely hard to track down every wild elephant in the state and test whether they are positive for EEHV, and the state government cannot afford the manpower, he said.
EEHV is lethal for young elephants between the ages of one and 12. If a young elephant dies before reproducing, it affects the population of the species as a whole in the concerned geography.
The way forward
An Asian elephant calf’s recovery after falling ill due to EEHV in Chester Zoo, UK, has raised new hope. In June, the BBC reported that two-year-old Indali Hi Way’s recovery has been hailed as a “momentous step”. This was after a treatment regimen including nine anaesthetic procedures, blood plasma transfusions, interferon therapy, anti-viral medications and immune boosting treatments, as well as very large amounts of intravenous fluids. The BBC quoted researchers as saying that the case would help “find answers” to the virus.
In India, the CZA will set up a national committee of scientists from Guwahati, Kerala, IVRI and Nandan Kanan to develop protocols for the country lest an EEHV outbreak occurs elsewhere in the future. “The timeline may be around two months. One of the aims will be to develop a detection centre in Odisha. Currently it can only be done in Guwahati and IVRI,” Yadav said.