December 15, 2009
Recent Hepatitis C Study Challenges Chimpanzee Use
Review of decade of research shows lack of impact on human health
The Humane Society of the United States questions the use of chimpanzees in hepatitis C testing despite a recent announcement claiming effective treatment of hepatitis C in chimpanzees with a new experimental drug. A recently published report, Chimpanzees in hepatitis C virus research: 1998-2007, initiated by The Humane Society of the United States, found that hepatitis C research on chimpanzees was not as useful as is claimed and urged a commitment to other approaches that show more promise for developing effective therapies for hepatitis C.
The HSUS-initiated report, in the Nov. 9 online edition of the Journal of Medical Primatology, identifies many scientific problems with the chimpanzee studies including a lack of biological relevance, questions regarding the statistical validity of the studies, and incompleteness in the reporting of methods and experimental data. While many of the published chimpanzee studies, including the recent study mentioned above (published in the Dec. 3 issue of Science Express), claim to produce important results for the treatment of human hepatitis C infections, closer scrutiny reveals the claims are exaggerated.
"The cost of using chimpanzees in research is enormous — both financially and in terms of chimpanzee suffering," says Andrew Rowan, Ph.D., chief scientific officer for The HSUS. "If you look collectively at their use, as our recent review does, the benefits for human health have been meager at best. For the most part, studies of hepatitis C in chimpanzees, such as the one most recently touted, do little more than confirm what is already suspected from research that does not involve chimpanzee use."
Experimental hepatitis C vaccines, usually developed and tested using chimpanzees, have been disappointing when tested in human patients, and the results from chimpanzees have not reliably predicted the human clinical experience. Among the many differences between chimpanzees and humans, chimpanzees do not develop active chronic hepatitis, cirrhosis or liver cancer and often spontaneously clear hepatitis C infection. More detailed scientific analysis and arguments regarding The HSUS' concerns related to the recent drug study and other data are available here.
Chimpanzees in hepatitis research suffer from isolation and confinement in small cages, as shown in The HSUS' 2009 undercover investigation, and must endure invasive procedures from repeated liver punches and wedge biopsies to remove liver tissue. Very few of the more than 100 published papers report the use of anesthetics or pain-relieving drugs in chimpanzee studies, although liver biopsy usually requires sedation and painkillers when done in human patients.
In vitro and other technological developments in conjunction with human studies hold more promise for the development of effective vaccines to prevent hepatitis C infections and treat the estimated 170 million people currently infected with this virus.
- The study Chimpanzees in hepatitis C virus research: 1998-2007 by Raija Bettauer, M.S., reviewed 109 articles, the total number of articles in the PubMed database published in English between January 1998 and December 2007 involving live chimpanzees.
- Although results of hepatitis C studies using chimpanzees have questionable application to humans regardless of the number of chimpanzees used, nearly 50 percent of the studies used only one to three chimpanzees — leading to major questions regarding the statistical significance of any findings reported.
- More than 50 percent of the chimpanzees were used in multiple studies but papers typically failed to mention previous health history or its potential impact.
- The Great Ape Protection Act (H.R. 1326) would phase out the use of chimpanzees in invasive research, retire the 500 federally owned chimpanzees to sanctuary, and prohibit the breeding of chimpanzees for invasive research.
To learn more about chimps in research, visit humanesociety.org/chimps.
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The Humane Society of the United States is the nation's largest animal protection organization — backed by 11 million Americans, or one of every 28. For more than a half-century, The HSUS has been fighting for the protection of all animals through advocacy, education and hands-on programs. Celebrating animals and confronting cruelty — On the Web at humanesociety.org.