Horizontal transmission of endemic viruses among rhesus macaques (Macaca mulatta): Implications for human cytomegalovirus vaccine/challenge design

Abstract

Introduction Rhesus macaques are natural hosts to multiple viruses including rhesus cytomegalovirus (RhCMV), rhesus rhadinovirus (RRV), and Simian Foamy Virus (SFV). While viral infections are ubiquitous, viral transmissions to uninfected animals are incompletely defined. Management procedures of macaque colonies include cohorts that are Specific Pathogen Free (SPF). Greater understanding of viral transmission would augment SPF protocols. Moreover, vaccine/challenge studies of human viruses would be enhanced by leveraging transmission of macaque viruses to recapitulate expected challenges of human vaccine trials. Materials and Methods This study characterizes viral transmissions to uninfected animals following inadvertent introduction of RhCMV/RRV/SFV‐infected adults to a cohort of uninfected juveniles. Following co‐housing with virus‐positive adults, juveniles were serially evaluated for viral infection. Results Horizontal viral transmission was rapid and absolute, reaching 100% penetrance between 19 and 78 weeks. Conclusions This study provides insights into viral natural histories with implications for colony management and modeling vaccine‐mediated immune protection studies.

An analysis of risk factors for spontaneously occurring type 2 diabetes mellitus in rhesus macaques (Macaca mulatta)

“…We found no evidence that CMV serostatus was associated with T2D. The reason for this may be that, unlike humans, the monkeys in our colony are virtually 100% positive for CMV by 1 year of age, the exception being those animals that were reared expressly to be negative for this virus 23 . Prevalence figures for humans range widely but typically do not reach 100% 29 .…”

“…This contrast was our first analysis of the possible effects of CMV in T2D. Because virtually 100% of animals born in a CMV+ cage are themselves positive by approximately 1 year of age, 23 however, we performed a second analysis, in which the missing data from our cohort were assumed to be CMV+ by the time of their T2D diagnosis. In this analysis, n = 154 were CMV‐ and n = 1067 were CMV+.…”

“…The reason for this may be that, unlike humans, the monkeys in our colony are virtually 100% positive for CMV by 1 year of age, the exception being those animals that were reared expressly to be negative for this virus. 23 Prevalence figures for humans range widely but typically do not reach 100%. 29 In our sample, we only had n = 3 animals (out of a total of n = 22) with T2D that were seronegative for CMV.…”