Laboratory Animal Science Vol 47, No 5 Copyright 1997 October 1997 by the American Association for Laboratory Animal Science Viral Infections of Nonhuman Primates Seymour S. Kalter,* Richard L. Heberling, Anthony W. Cooke, John D. Barry, Pei Y. Tian, and William J. Northam Abstract Approximately 53,000 serologic tests and viral isolation studies were performed on 1,700 nonhu- man primate specimens for evidence of past and/or current viral infection. Information, other than the re- quested test, generally was not provided with the specimen. This lack of information does not permit any attempt at interpretation of results. Requested testing included a large number of diverse viral agents in approximately 40 primate species. The resulting data are in keeping with those of previous studies and offer an insight into the needs of colony management, as well as some general information on the overall frequency of infection with the indicated viruses. Inasmuch as the results represent testing of single specimens, they are not to be construed as “diagnostic,” and simply indicate past infection as represented by the presence of antibody in the test animal. Viral isolation results are listed, and the number of positive results versus the number of animals tested emphasizes the limitations of the procedure. Investigations such as these continue to assist in the maintenance of healthy nonhuman primate colonies. This information also supports contin- ued use of nonhuman primates for research in human viral infections and may be helpful in terms of animal selection for use in xenotransplants. Continued study of nonhuman primates has clearly in- than the requested test(s), clinical or other information did dicated that these animals have a microflora not only of not accompany each specimen. This lack of additional in- unique simian agents, but of human and other animal or- formation prohibited any correlation of data: health stud- ganisms as well (1–5). Although many organisms appear ies, environment, origin, or age. to be highly specific for their primate hosts, others are able to induce infection or disease in widely diverse animal spe- Materials and Methods cies. In certain instances, the same organism (e.g., measles Specimens were submitted to our laboratory for serologic virus) is capable of infecting human and nonhuman pri- detection of antibody and/or for the isolation of an agent mates. Human infection and the infection of other animals from one or another body specimen. At the time of this study, (zoonoses) are major concerns associated with nonhuman presence of an infective agent was determined by use of primates. Prevention of colony disease outbreaks requires standard isolation procedures (4). All specimens were un- periodic monitoring as well as recognition of clinical infec- solicited, and only the requested tests were performed. In tion within the colony to maintain colony health and con- a number of instances, consultation with the investigator trol possible spread to human and other nonhuman pri- suggested a particular test course to follow, but in general, mates (6). Individuals responsible for such endeavors rou- all tests were those selected by the investigator. Most tinely survey their colonies, including personnel, for the samples for serologic testing were received unfrozen the presence or absence of infective agents. day after acquisition and were placed on test the day of We present an overview of test results obtained at our arrival in the laboratory. Serum samples from outside the laboratory in accordance with requests by individuals in- United States, also unfrozen, generally were received volved with nonhuman primates (e.g., from primate cen- within 2 to 3 days of acquisition. Specimens for virus isola- ters, zoos, biomedical research laboratories, importers, and tion studies, regardless of organ source, also were usually veterinarians with pet-owner clients). In this study, ap- unfrozen on receipt, but ice packs (-20 ) were included in proximately 53,000 tests on sera obtained from approxi- the package. Most specimens for isolation studies were re- mately 40 nonhuman primate species during a selected ceived in an acceptable transport medium within 24 to 48 period in 1994 were performed along with miscellaneous h of acquisition. If a delay in sending specimens for insola- testing of 475 human sera. In addition, 1,700 specimens tion studies was anticipated, it was recommended that the were submitted for virus isolation studies during this same specimens be shipped on dry ice. Delays due to Customs or time. Unfortunately, many of the specimens for isolation other contingencies were infrequent. studies were not collated with the serum samples, thus not In developing these data, the year 1994 was chosen to allowing any diagnostic interpretation. In general, other provide sufficient numbers of test results from a wide as- sortment of nonhuman primate species. In certain in- Virus Reference Laboratory, Inc. (VRL), San Antonio, Texas stances, a small number of additional randomized sera from *Address correspondence to Dr. S. S. Kalter, Virus Reference Labora- tory, Inc. (VRL), 7540 Louis Pasteur, San Antonio, TX 78229. another time interval were tested for those infrequently 461 Vol 47, No 5 Laboratory Animal Science October 1997 used species to provide meaningful numbers. Because the In other instances, a positive serum from a different spe- number of tests requested for each serum sample varied cies was used when it was known that a virus did not in- from one to several, the precise number of tests per animal fect a particular species (e.g., hepatitis B in macaques). is not indicated. Specimens were submitted from the fol- The following assay methods were used with the indi- lowing species. cated antigens. Apes: Chimpanzee (Pan troglodytes, P. paniscus); gorilla (i) Dot immunobinding assay (7, 8). Herpesvirus (Gorilla gorilla); orangutan (Pongo pygmaeus); gibbon simiae (B virus); Herpesvirus hominis type 1 (HSV-1) and (Hylobates lar, type species); siamang (Symphalangus type 2 (HSV-2); African green monkey herpesvirus (SA8); syndactylus). Herpesvirus tamarinus; Herpesvirus saimiri; simian vari- Old World monkeys: Baboon (Papio cynocephalus, in- cella (Delta herpesvirus); human varicella-zoster (V-Z) vi- cluding P. anubis, P. papio, P. ursinus, P. hamadryus); colo- rus; rhesus cytomegalovirus (rhCMV); SA6 (African green bus (Colobus polykomos, C. guerezas); guenon (Cercopith- monkey CMV); chimpanzee CMV; squirrel monkey CMV; ecus pygerythrus [vervet], C. sabaeus [African green], C. simian retroviruses (SRV 1–5); Simian T-cell leukemia vi- aethiops [grivet], C. diana [Diana], C. albogularis [Sykes], rus (STLV-1); simian immunodeficiency viruses (SIV); C. mona [Mona], C. neglectus [De Brazza’s], C. nictitans measles (rubeola); rubella; mumps; adenovirus (adenovi- [spot-nose guenon]); macaque (the most frequently submit- rus group-specific antibody); influenza A and B (Influ A and ted test serum, Macaca fascicularis or M. irus [cynomol- B); parainfluenza types 1 to 3 (Paraflu 1–3); respiratory gus], M. mulatta [rhesus], M. nemestrina [pig-tail], M. syncytial virus (RSV); SV40; encephalomyocarditis virus speciosa [stump-tail], M. fuscata [Japanese or snow mon- (EMC); monkeypox; simian hemorrhagic fever (SHF); key], M. silenus [lion tail]); mandrill (Mandrillus sphinx, filoviruses (Ebola-Reston and Marburg); foamyvirus (group- M. leucophaeus); mangabey (Cercocebus atys [sooty specific antibody); rabies; rotavirus (SA11). mangebey], C. torquatus); patas (Erythrocebus patas); pro- (ii) Commercial antibody assay kits (EIA). Hepati- boscis (Nasalis larvatus). tis A (Hep A); total antibody (Abbott HAVAB); Hep A IgM New World monkeys: Capuchin (Cebus capucinus, C. antibody (Abbott HAVAB-M); hepatitis B surface antibody albifrons, C. nigrivitattus, C. apella); howler (Alouatta (HBsAb, Abbott AUSAB); hepatitis B surface antigen belzebul); owl (Aotus trivirgatus); spider (Ateles paniscus, (HBsAg, Abbott AUSZYME); hepatitis B core antibody A. geoffroyi, A. fusciceps, A. belzebuth); squirrel (Saimiri (HBcAb, Abbott CORZYME); hepatitis B Delta antibody sciureus, S. oerstedii); titi (Callicebus personatus); woolly (Hep Delta, Abbott Anti-DELTA); hepatitis C antibody (Hep (Lagothrix lagothricha). C, Abbott HCV 2.0). Serologic testing: Sera were not treated prior to test- (iii) Commercial antibody assay kits (IFA). ing, but were diluted either 1:5 (monkeys) or 1:10 (apes) in Epstein-Barr virus (Gull Laboratories, Salt Lake City, phosphate-buffered saline (pH 7.4). When titer was desired, Utah, EBV-IgG); human herpesvirus type 6 (Advanced sera were serially diluted twofold. Titers are not provided Biotechnologies, Inc., Bethesda, Md., HHV6 IgG IFA); herein, but results are indicated as positive or negative. lymphocytic choriomeningitis (LCM; slides for IFA test- With the exception of hepatitis testing, results were ob- ing were prepared in house, using LCM strain tained by use of dot-immunobinding assay, a modified en- Armstrong-infected Vero E6 cells). zyme immunoassay (EIA) developed in this laboratory (7, Most sera were tested by use of panels of up to five viral 8). Hepatitis testing was performed according to insert di- antigens in the dot immunobinding assay format. rections accompanying manufacturer’s (Abbott Laborato- Virus isolations: Swab specimens submitted for isola- ries, Abbott Park, Ill.) test kits. Immunofluorescent anti- tion studies were placed in approximately 3 ml of cell cul- body (IFA) assays and serum neutralization