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Join the Fight Against Elephant Herpesvirus

Within the past seven years, the BioPark Zoo has lost three calves to elephant endotheliotropic herpesvirus (EEHV). These deaths bring to light the insidious nature of EEHV and how so much remains unknown about this virus. However, the ABQ BioPark Zoo and New Mexico BioPark Society, along with other Association of Zoos & Aquariums (AZA) facilities and a network of researchers, are making strides in combating the virus.


What is EEHV?

EEHV is a herpesvirus present – in some form – in all elephants, both wild and those in human care. It causes hemorrhagic disease that can be fatal in young elephants. There are several strains of the virus.

All elephants can carry the virus in a latent (dormant) state throughout their entire lives without negative effects. It is unknown why the virus sometimes comes out of latency, but it enters the bloodstream and circulates the body once it does so. A reliable test to detect a latent infection is not currently available.

EEHV is the largest single cause of death in Asian elephants in North America and Europe, and elephants are most susceptible to the virus from 18 months to 8 years of age. In some cases, the virus load reaches a fatal level within a matter of days, or in worse cases, hours.

The virus was first identified in the 1990s after researchers at the Smithsonian’s National Zoo identified the cause of their 16-month-old Asian elephant’s death. And while a lot is still unknown about this virus, the body of knowledge continues to grow thanks to a network of researchers and Association of Zoos and Aquariums (AZA)-accredited facilities. Detection methods have improved, and rapidly applied treatment is the best course of action. Several elephant calves have successfully recovered from EEHV infections in recent years. However, the course of medical care to minimize the effects of EEHV in 60-70% of young elephants can remain ineffective.

To read more about EEHV, visit the resource links listed near the bottom of this page.


Our Experience with EEHV

In September 2009, the ABQ BioPark welcomed Daizy, Rozie’s first calf. As more and more information was becoming available about EEHV, elephant programs, including the BioPark, began routinely testing blood samples for EEHV. In May 2015, the herpesvirus was detected in her bloodwork. The elephant care team worked round the clock to administer antivirals and supportive therapies, but despite everything, she succumbed to the virus. The BioPark collected samples from her birth and death that have continued to provide information for EEHV researchers.

Attention quickly turned to Jazmine, Rozie’s 19-month-old calf and Daizy’s little sister. There was less known about the herpesvirus during that time, and the mortality rate was 80% among elephant calves. It was then that the elephant care team decided that a more aggressive monitoring system needed to be implemented for the herd. This included blood samples for EEHV weekly or more frequently as needed.

Three years later, Jazmine’s brother Thorn was born in May 2018. Like Daizy and Jazmine, Thorn started training from a few days old to participate in his own healthcare. This included, but was not limited to, allowing blood draws from his ears, eye and mouth exams, baths, and more to complex procedures such as ultrasounds.

On December 15, 2021, 3-year-old Thorn’s bloodwork tested positive for EEHV at a very low level. The BioPark team immediately began treating the virus with antiviral medications and other supportive therapies. Thorn’s disease progressed rapidly, and staff shifted to twice-daily treatments to ensure he was getting everything he needed. This included plasma infusions, whole blood, stem cells, antibiotics, antivirals, and pain medicine. Despite staff working around the clock for Thorn, he succumbed to EEHV early morning on Christmas Day.

Just three days later, on December 28, 8-year-old Jazmine’s bloodwork detected the herpesvirus at a very high level, and the elephant care team, once more, began herculean efforts to treat her symptoms. Jazmine lost her battle to the virus six days later, on January 2, 2022.

As we mourn the devastating losses of these siblings, we know Jazmine, Thorn, and Daizy’s medical cases have already helped contribute to the overall knowledge of EEHV treatment efforts. The BioPark received help from medical and elephant experts and blood donations from other elephants from across the country, including specialists from the Houston Zoo, St. Louis Zoo, Oregon Zoo, Oklahoma City Zoo, Fort Worth Zoo, Denver Zoo, African Lion Safari, the Elephant Managers Association, and the National Elephant Herpesvirus Lab at the Smithsonian’s National Zoo in Washington, D.C.

For FAQs from our community, scroll to the bottom of this page.


How can we expand our fight against EEHV?

Testing blood samples for EEHV is quite specialized. Currently, our Zoo utilizes the services of the National Elephant Herpesvirus Laboratory at the Smithsonian National Zoo. This requires shipping blood samples overnight, and results can take up to 48 hours to receive or longer over holidays. Because of this fast-moving virus, it is crucial to receive test results as quickly as possible.

After assessing the welfare process and preventative measures already in place at the BioPark, the elephant team is determined to create an in-house, cutting-edge EEHV monitoring lab program that analyzes blood and trunk secretions for any DNA virus. This real-time testing would mean that if any of the adults are shedding the virus, we could increase our levels of surveillance in future calves, and even more importantly, prevent any test result delays.

In addition to reduced test time, An EEHV lab at the BioPark would allow our facility to be a regional resource for experts in the field and help other AZA facilities in surrounding states with quicker response times for emergency EEHV testing for their elephants.


How can you help?

The early blood work detection of EEHV and aggressive medical treatment are currently the best-known ways to help elephants overcome this naturally occurring virus.

EEHV testing is completed by polymerase chain reaction (PCR), which requires specialized equipment and staff training to look for DNA from EEHV in blood. Developing and running an EEHV PCR lab will require significant commitment.

A vaccine for EEHV is only a few years away from reality, and in honor of Jazmine, Thorn, and Daizy, we are committed to forging ahead in early detection and virus treatment.

We are committed to developing an EEHV monitoring lab at the BioPark while continuing to support herpesvirus research. If you would like to help us in our efforts by donating to this vital program, please donate below.




Resource Links

National Elephant Herpesvirus Laboratory: https://nationalzoo.si.edu/animals/national-elephant-herpesvirus-laboratory

EEHV Advisory Group: https://eehvinfo.org/



How are the other elephants doing, not just health-wise but emotionally?
The herd is doing well. Like us, they grieve the loss of Thorn and Jazmine. We give them all the time they need to mourn and heal from the loss. The herd continues to spend their day foraging together and playing. They also regularly seek out the attention of their human caretakers. The relationships that have been built over the years are evident every time you see how eagerly the elephants seek out the companionship of the staff each day. 

Is the mother the carrier of the herpesvirus since it has only been in Rozie’s family line so far?
Elephant endothelial herpesviruses have naturally evolved with elephants. Elephants carry the virus in a latent state. It is unclear why it activates. When it is active, the virus sheds through secretions. Rozie has been tested throughout her life, and no active viremia has been detected. 

Is it possible the illness was triggered by stress from habitat construction? Also, was there any construction happening when Daizy passed?
Construction has been ongoing around the elephant area for over six months. The elephants have all been naturally curious about the activity, often watching the workers and machinery. They have adapted well to the sights and sounds and have the option to move away from it if they prefer. No construction projects were occurring in 2015 when Daizy became sick with and succumbed to EEHV. 

What is being done to prevent further occurrences?
The ABQ BioPark funds and supports the leading researchers worldwide in fighting this virus and developing a vaccine to help eradicate EEHV. 

How is the staff doing? They must be heartbroken.
The staff are heartbroken and are taking time to heal and care for one another and the elephants. They are immensely grateful for the outpouring of support from their fellow staff, the New Mexico Bio Park Society, the local community, and the professional community. 

Will you stop breeding at the BioPark?
Elephants have evolved to live in a herd and raise young together. It is a core tenet of providing for their welfare and ensuring that they have the opportunity to thrive. The ABQ BioPark is committed to saving Asian Elephants from extinction and will continue to support and follow the recommendations of the Association of Zoos and Aquariums Species Survival Plan and Saving Animals From Extinction. 

Is all the EEHV research throughout the world being consolidated in one place, or are there separate leaders on each continent? Do they talk to each other? 
Many researchers are working across the globe. Even though they are spread abroad, it is a community working together and supporting one another for the best possible outcome for elephants. 

Does EEHV affect African elephants?
Yes, EEHV affects both African and Asian Elephants. Each species of elephant has specific strains of herpesviruses that cause illness. 

Would keeping young elephants isolated protect them more?
No, elephants live in herds. They live together, play together, learn together, and mourn together. To isolate young elephants would deny them the opportunity to live full and complete lives, and the stress that would come from separation would be detrimental to the physical and psychological well-being of the calves. The BioPark is committed to providing opportunities for all animals entrusted to our care to thrive.

Is EEHV related to COVID-19?
No. These viruses are not related.

Is EEHV always fatal?
No, but the animal care professionals at the ABQ BioPark did not take any chances and immediately began treatment as soon as we learned the virus was present. Over the past few years, the detection, medical care and treatment of EEHV has improved exponentially. An elephant diagnosed with EEHV has a better chance of survival now than at any point since it was first identified.

How many elephants call the ABQ BioPark home?
The herd at the ABQ BioPark consists of four elephants. Rozie, her mother Alice, Irene, and Albert, our current resident male.

Are the adult elephants at risk of also contracting EEHV?
Adult elephants have more developed immune systems, so it is rare for an adult to develop a fatal infection.