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The establishment of a sylvatic reservoir of Zika virus (ZIKV) in the Americas is dependent on the susceptibility of primates of sufficient population density, the duration and magnitude of viremia, and their exposure to the human mosquito-borne transmission cycle. To assess the susceptibility of squirrel ( Saimiri sp.) and owl monkeys ( Aotus sp.) to infection, we inoculated four animals of each species with ZIKV from the current epidemic. Viremia in the absence of detectible disease was observed in both species and seroconversion occurred by day 28. ZIKV was detected in the spleen of three owl monkeys: one at 7 days postinoculation (dpi) and two at 14 dpi. This study confirms the susceptibility to ZIKV infection of two Neotropical primate species that live in close proximity to humans in South America, suggesting that they could support a widespread sylvatic ZIKV cycle there. Collectively, establishment of a ZIKV sylvatic transmission cycle in South America would imperil eradication efforts and could provide a mechanism for continued exposure of humans to ZIKV infection and disease.

Owl monkeys are New World primates frequently used in biomedical research. Despite the historical difficulty of breeding owl monkeys in captivity, several productive owl monkey breeding colonies exist currently. The animals in the colony we describe here are not timed-pregnant, and determination of gestational age is an important factor in prenatal care. Gestational age of human fetuses is often determined by using transabdominal measurements of fetal biparietal diameter. The purpose of this study was to correlate biparietal diameter measurements with gestational age in owl monkeys. We found that biparietal diameter can be used to accurately predict gestational age in owl monkeys.

Lesions consistent with heart failure were found in 23 of 88 adult squirrel monkeys that died between 1995 and 1999 at the Squirrel Monkey Breeding and Research Resource (SMBRR). This provided a rationale for a study surveying aged animals in the SMBRR for normal cardiac characteristics, using echocardiography (ECHO) and electro-cardiogram. In the pilot study, ECHO and electrocardiography were performed on 59 healthy female squirrel monkeys aged 10 years or older and 39 five-year-old monkeys. Parameters were heart rate, P-wave duration and amplitude, and PR, QRS, and QT intervals (electrocardiography), and ejection fraction. Two animals with cardiomyopathy were identified and received similar testing. Advanced-study animals had the same measurements, plus left ventricular internal diameter-systole (LVIDs) and -diastole (LVIDd), left atrial diameter-diastole (LADd) and aortic root diameter-diastole (AoRDd) by use of ECHO. Significant differences were found between groups in LADd, and P-wave and QRS interval durations. In a clinical context, these differences were not considered to be substantial. Normal aged female squirrel monkeys had significant increases in heart dimension and longer P- and QRS-wave durations than did monkeys of a five-year-old control group, although the increases were not considered clinically relevant. This study documents myocardial dynamics in healthy saimiri and those with cardiomyopathy.

Purpose: To explore the possibility that inoculation of the eyes of African green monkeys with simian varicella virus (SVV) induces the symptoms of herpes zoster ophthalmicus (HZO), as seen in humans, and to develop a realistic and reproducible animal model of herpes zoster ophthalmicus for experimental studies., Methods: In the first experiment, the right eyes of three African green monkeys were inoculated by intrastromal and subconjunctival injections with a suspension of SVV-infected Vero cells. In the second experiment, three additional monkeys were pretreated with intramuscular injections of methylprednisolone (41 mg/kg) for 7 days before ocular inoculation with SVV and for 3 weeks at 14 mg/kg after virus inoculation. The eyes were examined by slit-lamp biomicroscopy. Histologic, immunohistochemical, and electron microscopic studies were performed., Results: In the first experiment, all three animals developed high titers of anti-SVV antibodies (IgG). Diffuse stromal opacity, with keratitic precipitates, stromal edema, and mild vascularization of the cornea, appeared 12 to 14 days after inoculation. The onset of ocular disease was correlated with the rise in serum antibody levels. There was no clinical evidence of a systemic viral infection resulting from the corneal inoculations in these monkeys. In the second experiment, all three animals treated with methylprednisolone developed severe ocular pathology within 1 week of inoculation. The clinical appearance of the diseased eyes strongly indicated that local viral infection had occurred. Dendritiform keratitis, corneal erosion, and stromal necrosis with vascularization of the cornea was seen in all the eyes. The disease resolved within 4 to 5 weeks of inoculation, leaving opaque, vascularized corneas. Histologic studies showed that inflammatory cells and viral antigens were widespread throughout the diseased corneas. A high titer of anti-SVV antibody (IgG) was detected in the immunosuppressed monkeys, but no evidence of systemic viral infection was observed., Conclusions: The authors propose that inoculation of the eyes of methylprednisolone-treated African green monkeys with simian varicella virus provides an appropriate animal model for studies of the virology and immunopathology of ocular varicella virus infection.

The squirrel monkey (Saimiri sciureus) has been proposed as a model for urogenital trichomoniasis in man, but has not been accepted as such because of the purported presence of naturally occurring vaginal trichomonads in this animal. The study published here shows that these are easily eradicated organisms of intestinal origin, which eliminates the potential confusion created by them. In addition, our experiments have shown that the hormonal status of primates seems to be a determinant in successfully establishing experimental trichomoniasis. This experimental infection recapitulates the clinical observations sufficiently to warrant the use of this model for studies of vaginal trichomoniasis.

Periapical abscesses of canine teeth in a group of 47 male cynomolgus macaques are found to be associated with a procedure, involving cutting the canine teeth, used to make non-human primates less hazardous. Examination of 150 canine teeth in dry specimens revealed 30 cut teeth with no exposure of the pulpal chamber and 107 cut teeth where the dental pulp had been exposed. Of those teeth which had the pulpal chamber exposed by the cutting procedure, 85 (79.4%) showed clear evidence of osseous changes consistent with abscess formation in the apical regions.

The Whittier Narrows earthquake sequence (local magnitude, M(L) = 5.9), which caused over $358-million damage, indicates that assessments of earthquake hazards in the Los Angeles metropolitan area may be underestimated. The sequence ruptured a previously unidentified thrust fault that may be part of a large system of thrust faults that extends across the entire east-west length of the northern margin of the Los Angeles basin. Peak horizontal accelerations from the main shock, which were measured at ground level and in structures, were as high as 0.6g (where g is the acceleration of gravity at sea level) within 50 kilometers of the epicenter. The distribution of the modified Mercalli intensity VII reflects a broad north-south elongated zone of damage that is approximately centered on the main shock epicenter.