Comparison of three rhesus groups for antibody patterns to some viruses: Absence of activesimian virus 40 transmission in the free-ranging rhesus of cayo santiago

The free-ranging rhesus population of Cayo Santiago, Puerto Rico, was established in 1938 and has since remained completely isolated from other rhesus and relatively isolated from human contact. Approximately 10% of the over 700 rhesuson the island were bled for a viral antibody survey. Their antibody pattern was compared with that of free-living rhesus in India and of a laboratory colony at San Juan, Puerto Rico. The Cayo Santiago rhesus were free of antibodies to human myxoviruses parainfluenza 3 and measles, to simian myxovirus SV5 and, with the exception of a single animal, to SV40. In contrast, a high proportion of laboratory rhesus had antibodies to these viruses, reaching 98-100% for antibodies to SV5 and parainfluenza 3. The free-living rhesus in India had intermediate prevalence rates for measles, parainfluenza 3 and SV40, but were completely free of antibodies to SV5. In contrast to the virtual absence of activity of the above viruses, infection withHerpesvirut simiaewas very common in the Cayo Santiago rhesus; age-adjusted antibody prevalence rate of this population was almost twice as high as that of the free-living rhesus. Laboratory rhesus raised in individual cages had a low prevalence of antibodies toHerpesvirvs simiae. Antibodies to simian adenoviruses SV20 and SA7 were detected in sera from all three groups.