Abstract

A survey was sent via the American Association of Zoo Veterinarians (AAZV) list serve (AAZV-L) to American Zoo and Aquarium Association (AZA) institutions housing old world nonhuman primates (OWP), asking what retroviral testing was done on these animals, and if testing was done, would the institutions like to share results with the survey author and old-world monkey Taxonomic Advisory Group (TAG). Forty-nine percent of zoos housing OWP responded to the initial survey asking if they tested for retroviruses and 27% said they do no testing, while 73% tested for at least one retrovirus. A follow-up survey was sent to responders and via the AAZV-L asking which species were tested for simian immunodeficiency virus (SIV), simian foamy virus (SFV), simian retrovirus (SRV), and simian T-cell lymphotropic virus (STLV) and what the results were. Thirty-three institutions responded to the follow-up survey (37% of zoos housing OWP) and some of these institutions also were testing prosimians, new world primates, and apes for the specified retroviruses. A total of 621 individuals representing 43 taxa (genus, species/subspecies) were tested for SIV with a positive percentage of 3.1% (19 individuals). Four hundred and forty-two individuals representing 44 taxa (genus, species/subspecies) were tested for SFV with a positive percentage of 50.9% (225 individuals). Three hundred and fifty-seven individuals representing 35 taxa (genus, species/subspecies) were tested for SRV (types 1–3) and six individuals were positive (1.6%). Four hundred and fifty animals representing 35 taxa (genus, species/subspecies) were tested for STLV with 31 individuals (6.8%) testing positive.

Results

Results ranked by suborder/family are as follows.

Prosimians

• 19 individuals tested for SIV, 0 positives
• 43 individuals tested for SFV, 0 positives
• 6 individuals tested for SRV, 0 positives
• 4 individuals tested for STLV, 0 positives

New World Primates

• 1 individual tested for SIV, 0 positive
• 3 individuals tested for SFV, 3 positives (100%)
• 1 individual tested for SRV, 0 positives
• 0 individuals tested for STLV

Old World Monkeys

• 432 individuals tested for SIV, 18 positives (4.2%)
• 277 individuals tested for SFV, 166 positives (60%)
• 249 individuals tested for SRV, 2 positives (0.8%)
• 305 Individuals tested for STLV, 26 positives (8.5%)

Apes

• 143 individuals tested for SIV, 0 positives
• 102 individuals tested for SFV, 45 positives (44%)
• 78 individuals tested for SRV, 0 positives
• 123 individuals tested for STLV, 5 positives (4%)

Discussion

Results included new world primates, prosimians, old world monkeys, and apes. Several confounders to this data are: small sample size compared to overall population in AZA accredited institutions, individuals were only counted once even if they had been tested numerous times, and if they ever tested positive, that was recorded; indeterminate results were not counted unless confirmed on a later date. There was no standardization of laboratories used. Some animals were listed by common names, with no species/subspecies listed. Those individuals were counted under genus only. Even though the survey was originally intended to just look at retroviral status in old world monkeys, the inclusion by some zoos of results for prosimians, new world primates and apes lent some interesting data to the survey.

Conclusions

In recent years, concern over the prevalence and zoonotic risk potential of retroviruses in captive nonhuman primate collections at zoos has grown.^1-4 In addition to the zoonotic risk potential, there has also been concern over the potential impact these viruses may make on TAG recommendations for breeding, moving animals, etc. While the infectious disease committee (IDC) of the AAZV and animal health committee (AHC) of the AZA has been working on occupational primate disease safety guidelines for zoological institutions to protect zoo workers, as well as zoo nonhuman primates, from zoonotic risks, sound advice about species management has been difficult because the retroviral prevalence in the captive monkey populations is largely unknown. There have been no coordinated efforts to pull all of this data together and develop standardized testing and reporting. These preliminary results point out the need for such research to be done. Once a complete analysis of morbidity, mortality and viral prevalence is accomplished, sound recommendations on both health screening, zoonotic risks, as well as species management, can be made.

Acknowledgments

The authors would like to thank all responding institutions, who shall remain anonymous.

Literature Cited

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