The HSUS has compiled this concise yet informative summary of various aspects of primate research in the United States, including the species and number of non-human primates (NHPs) used, types of research, levels of invasiveness associated with research on chimpanzees, housing, and government support for primate research.

Species Used

The term "nonhuman primate" includes monkeys, apes and prosimians, but certain species are more commonly used in research while some are not used in research at all. An analysis of NHP research grants* for 2000 through mid-2002, conducted by The HSUS, revealed that macaques (primarily the rhesus macaque) are the most commonly used monkeys; this category includes crab-eating macaques, pig-tailed macaques and others. Additional species used are marmosets, squirrel monkeys and tamarins; with the use of marmosets in research becoming increasingly more common.

The chimpanzee is the only great ape species used in research and it is estimated that there are approximately 1,300 remaining in research laboratories in the United States. Although chimpanzees are listed as endangered under the Endangered Species Act, they have been "split-listed" so that they can continue to be used in research. The chimpanzee is the only species with such a split-listed status.

Number of NHPs Used in Research

According to statistics provided by the U.S. Department of Agriculture, 52,279 NHPs were used in research during 2002. The number of NHPs used in research ranged from 50,000 to 58,000 between 1995 and 2001. These USDA statistics do not include NHPs who are breeders or being held for research.

Recent events and publications indicate that the use of NHPs in research is expected to rise, particularly in the near future. For example, a number of institutions have expanded their primate facilities, including the Oregon and California National Primate Research Centers, and the New Iberia Research Center. A privately-owned breeding colony expected to house approximately 3,000 NHPs is being established in Florida. The National Institutes of Health is seeking applications for the establishment of additional breeding colonies. Finally, China is greatly increasing primate use and is establishing itself as a global force in nonhuman primate biomedical research.  The low cost of conducting research in China is one aspect that is appealing to other countries, such as the United States.

Types of Research and Level of Invasiveness

NHPs are used in numerous types of research, including HIV, behavior, cognition, reproduction, genetics, malaria, respiratory viruses, infectious disease and drug testing. Chimpanzees are most commonly used in hepatitis research, while monkeys are most commonly used in HIV research. Other areas include vaccine and drug testing, neurology, human pathologies/diseases, drug abuse, and xenotransplantation.

With regard to the level of invasiveness of chimpanzee research, The HSUS's analysis revealed that 23% of grant projects were characterized as noninvasive (e.g., the animal received no physical or psychological insult), 9% as minimally invasive (e.g., a minor procedure, such as venipuncture), 59% as invasive (e.g., inoculation with an infectious agent, surgery, or biopsy conducted for the purpose of research and not for the health of the chimpanzee), and the remaining 9% could not be categorized from the information provided. An analysis of monkey research revealed that 8% of the grant projects were noninvasive, 12% were minimally invasive, 77% were invasive and 3% could not be categorized. Overall, the majority of research conducted on nonhuman primates is invasive.

Housing

Nonhuman primates are social animals; whether or not they are housed with other animals is important to their well-being. The HSUS has tried to determine from grants and publications how NHPs are housed, but this information is often not readily available. According to the APHIS [Animal & Plant Health Inspection Service] Animal Care Report of Winter 2001, "65% of primates in research are pair/group housed, with only 13% having no contact with other primates." But these numbers are somewhat misleading because the survey included breeders, so the percentages do not convey the housing conditions of the NHPs actually used in research.

But given the type of research being conducted—particularly HIV and malaria research—it is likely that monkeys used in active protocols are often housed in isolation (single housing). Single housing can lead to depression, withdrawal, frustration, self-biting, hair pulling, rocking and other psychotic behaviors.

Government Support for Primate Research

The amount of federal funding devoted to NHP research is estimated by The HSUS to be $25–30 million for chimpanzee research and $575–800 million for monkey research annually. A large portion of federal funding for monkey research is devoted to the National Primate Research Centers (NPRCs), formerly known as the Regional Primate Research Centers. The NPRCs were established by Congress in 1960 to provide an infrastructure and resources to investigators conducting primate research. Supported by the National Institute of Health, the centers have more than 20,000 individuals of 20 different primate species (NCRR, 2002). There are currently eight NPRCs:

• California (Davis, Calif.)
• New England (Southborough, Mass.)
• Oregon (Beaverton, Ore.)
• Southwest (San Antonio, Texas)
• Tulane (Covington, La.)
• Washington (Seattle, Wash.)
• Wisconsin (Madison, Wis.)
• Yerkes (Atlanta, Ga.)

Additional government-funded primate resources include the Caribbean Primate Research Center, a squirrel monkey colony at the University of South Alabama, a baboon research resource at the University of Oklahoma, and chimpanzee centers at the University of Texas MD Anderson Cancer Center and University of Louisiana at Lafayette New Iberia Research Center. Other resources in the U.S. include private breeding facilities, some of which receive federal funding. Although there is some importation of NHPs for research purposes, the majority of NHPs used in research are currently bred at facilities in the United States.

References

National Center for Research Resources (NCRR) (2002). Survey of NIH-funded investigators who use nonhuman primates: Report of survey findings. Bethesda, Maryland.

* The HSUS retrieved this information from the National Institutes of Health (NIH) Office of Extramural Research's Computer Retrieval of Information on Scientific Projects (CRISP).