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Giving Elephants a Fighting Chanceby Graciela Gutierrez "Our newly developed test looks specifically for the most common deadly strain and its subtypes."
Development of the testLittle is known about elephant herpes. There are many strains, but this one in particular is deadly. Because researchers cannot grow the virus in culture, they cannot develop a vaccine or effective treatment. In fact, they do not know how elephants become infected with the virus. Prior to the development of the current test, the diagnostic screening process looked for all types of viral infections that an elephant might have. "Our newly developed test looks specifically for the most common deadly strain and its subtypes," said Dr. Jeff Stanton, postdoctoral fellow in the department of molecular virology and microbiology at BCM. "While both tests are important, when it comes to this particular strain, a more sensitive screening process was needed." 
Dr. Jeff Stanton of BCM has helped develop a test for the virus. Since a virus has yet to be grown in a lab, researchers used archival DNA samples from historical cases of elephant herpesvirus given to them by the National Elephant Herpesvirus Laboratory at the Smithsonian National Zoo in Washington, D.C. Using those samples along with samples from the Houston Zoo, researchers analyzed the validity of the new test. Stanton, who worked as a veterinarian in St. Louis before coming to BCM, helped develop the new test while working in the lab of Dr. Paul Ling, an associate professor of molecular virology and microbiology at BCM. His lab focuses on the human herpes virus. Time is of the essenceNot only is the new test more specific toward the deadly elephant herpes virus, it also produces a faster result—in as little as a day if necessary. Because the disease can kill within a week, the sooner a diagnosis is established, the sooner treatment can begin. In fatal cases, symptoms do not show up in elephants until it is too late. "Right now we receive fluid samples from the zoo once a week for testing. We want to catch the virus as soon as possible so treatment can begin immediately," Stanton said. The virus can potentially appear in a number of bodily fluids. The current test can be used on blood, urine, trunk washes and even tears. Being able to screen a number of sources will also help to pinpoint how an elephant becomes infected. So far during the screening program, no elephant at the Houston Zoo has tested positive for the virus, but researchers are keeping their eyes on 4-year old Tucker, who is at the age when elephant herpes is most likely to become active. Diagnosis, then what?Now that the experts can diagnose the herpesvirus, they need better treatment. The only treatments currently available are antiviral medications effective for other herpes strains. "Only about 15 percent of infected elephants survive when treated. However, we aren't sure if the antivirals actually made the difference," Stanton said. "We also aren't certain current treatments will be more effective if started sooner rather than later. By the time the elephants were diagnosed, it was already too late." 
Daryl Hoffman, curator of large mammals at the Houston Zoo, and Martina Stevens, elephant supervisor, examine one of the animals. One way Stanton is hoping to understand the mechanisms of the virus is to have its genome sequenced. The Human Genome Sequencing Center at BCM is sequencing DNA from tissues of infected elephants to try and fish out the herpesvirus genome. The HGSC has been successful in sequencing many types of animal genomes. "In some sense, it will be like finding a needle in a haystack, given the relative amounts of viral and elephant DNA present," said Dr. Joseph Petrosino, BCM assistant professor of virology and microbiology. "However, we know there is a lot of virus in these infected tissues, and we know a lot about the herpesvirus genome sequence already, so we are hopeful that we will be able to fish out this particular virus genome from these samples." Stanton added, "A complete sequence of the virus genome could help in making a vaccine. We would be able to identify glycoproteins (proteins that contain carbohydrates and are essential in many cellular processes) that would give us more information about how the virus works." Understanding the virusThe elephant endotheliotropic herpesviruses affects both Asian and African elephants but is more often fatal in the Asian type. It occurs in elephants in zoos and in those who live in the wild. The elephant herpesvirus was identified by the National Zoo in 1995. Herpes viruses are usually species-specific but share common features. Once inside a host, whether human or animal, the virus can go into a latent phase after causing only mild symptoms or no signs of the disease. How it began
Dr. Alan Herron of BCM began the collaboration with the Houston Zoo. BCM and the Houston Zoo began collaborating during a conversation between Dr. Alan Herron, director of the Comparative Pathology Laboratory in the Center for Comparative Medicine at BCM, and Dr. Joseph Flanagan, the Houston Zoo's director of veterinary services. Herron called Flanagan to express sympathy after 2-year-old elephant Mac died Nov. 9, 2008. The talk quickly turned to how beneficial it would be to be able to test appropriately and effectively for the disease. They also talked about whether such work could lead to development of a vaccine. Herron, a professor of pathology and a veterinarian, brought in two of BCM's leading virologists and vaccine experts, Dr. Wendy Keitel, professor of molecular virology and microbiology, and Dr. Robert Atmar, professor of medicine and molecular virology and microbiology. How will it end?
It affects the breeding rate of elephants in zoos. Stanton said that without further research toward a vaccine and treatment for elephant herpes, the number of zoo elephants will be depleted. In the wild, Asian elephants are already endangered. As their habitats are taken over, their packs get separated, reducing options for mating. "The research being done now, as well as the new testing method, will also be used to look for ways to establish a screening program for elephant herds in the wild," Stanton said. "If researchers can develop a vaccine, then we have the potential to save an entire species." |
FeaturesGiving Elephants a Fighting Chance Facilitating a Vision for Research Integrating Care Around the Patient Baylor Flu Fighters Take On the Wily "Novel H1N1" (Swine) Flu Virus NewsNew Board Chair has High Hopes for BCM Lynch: A Physician-Teacher with a Humanitarian Twist SpotlightDr. Sean McGuire: Translating Early Lessons into Tomorrow's Treatment Simulated Patient Program Important Part of Medical Training Adding Value to Medical School Training Catalyzing Innovative Research is Mantra for BCM Diabetes Center A Coordinated Effort to Improve Health Care BriefsBCM Researchers Top Texas List of Stimulus Funds Recipients Wang Recognized for Contributions to Genetic Research Dr. Brendan Lee Receives Director's Transformative R01 'Pioneer' Studies Bacteria to Understand Cancer Dr. Mark Kline Selected Chair of Pediatrics Herding DNA to a New Understanding of Cows Development/AlumniBaylor Alumni Help Ease the Financial Burdens of Current Students Development BriefsAlkek Eye Center Celebrates 20th Year Partnership Gala To Fund DeBakey Heart Center® of Baylor College of Medicine Breast Center Advisory Council Funds Imaging Fellow Bra Art Displayed as Fundraiser Promise of Research Solid in Baylor's Future Understanding Animal GenomesWhile collaboration with the Houston Zoo is a first for Baylor College of Medicine, researching illnesses and understanding animal genomes is nothing new here. The Human Genome Sequencing Center at BCM has successfully sequenced a number of genomes since it was established in 1996. Most recently, the bovine genome was sequenced, providing a look at the evolutionary process of mammals, including humans. This project took more than 300 scientists from 25 countries to complete. Other genomes sequenced in cooperation with the BCM sequencing center include the mouse, fly, sea urchin and human. Currently the HGSC is working on sequencing the genome of the wasp and wallaby, among many others. The Center recently received additional funding from the National Institutes of Health to support the Human Microbiome Project, which seeks to understand how the trillions of microscopic organisms that live in and on the human body affect human health and lives. (A story on this project ran in Solutions.) Most notably, the DNA sequence of Nobel laureate Dr. James Watson, co-discoverer of the DNA double helix and developer of the Human Genome Project, was annotated and verified by researchers at BCM. Dr. Richard Gibbs, director of the BCM Human Genome Sequencing Center, was a part of the group that presented Watson with his DNA sequence and annotation. The BCM Human Genome Sequencing Center is currently one of three large-scale sequencing centers funded by the National Institutes of Health. |
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Volume 5, Issue 1, Winter 2009 |
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| Last modified: July 23, 2010 |
The fight against a deadly virus killing elephants across the globe is gaining strength with an unlikely pairing between Baylor College of Medicine and the Houston Zoo. Less than a year after the two institutions began working together, a new test has been developed that specifically diagnoses elephant endotheliotropic herpesviruses, or what is commonly called elephant herpes.
"This virus is killing off elephants in zoos and in the wild," Stanton said.