Shields on Electric Posts Prevent Primate Deaths: A Case Study at Polonnaruwa, Sri Lanka.

When monkeys, such as the toque macaques (Macaca sinica) of Sri Lanka, seek food on the ground near human habitation, they may use electrical posts to escape aggression from conspecifics, dogs, or humans. Shields mounted on electrical posts prevented monkeys from reaching the electrical wires, thereby averting their electrocution: the frequency of electrocutions (n = 0) was significantly less (p < 0.001) in the 12 years after installation of the shields than in the 12 years before (n = 18). Electric shocks were either fatal (n = 14) or caused permanent injury (n = 4) (collectively referred to as electrocutions hereafter). The shields may find broader applications in other primate species and environments wherever monkeys are attracted by human food near electrical posts. Primates and other arboreal mammals also accessed live wires from trees; at known electrocution hotspots, short spans of exposed wires were insulated by encapsulating them in PVC water pipes. It was impossible, however, to prevent electrocutions from all electric supply infrastructures that put monkeys at risk. A wider use of insulated electric conductors in planning power distribution in habitats frequented by wild animals would be desirable in preventing electric shocks to wildlife.

Retrospective analysis of wound characteristics and tetanus development in captive macaques.

Traumatic wounds and access to outdoor enclosures containing soil contribute to development of tetanus in nonhuman primates. A retrospective, matched case-control study was conducted at a primate center to evaluate these factors by analysis of medical records of animals sustaining traumatic injuries during a 3-yr study period. Thirty-one macaques with traumatic injuries and a clinical diagnosis of tetanus were selected as cases, and 62 macaques with traumatic injuries and no diagnosis of tetanus were selected as controls. For an animal with injuries to the digits, the odds of developing tetanus were 9.6 times those of a similar animal without injuries to the digits (Odds Ratio [OR] = 9.55, 95% CI = 1.56-58.59); with injuries to the tail, the odds of developing tetanus were 8.0 times those of a similar animal without injuries to the tail (OR = 7.95, 95% CI = 0.82-77.04); and with injuries in more than one location, the odds of developing tetanus were 8.5 times those for a similar animal with injuries in just one location (OR = 8.45, 95% CI = 1.01-70.46). A nonhuman primate with injuries to the leg was less likely to develop tetanus than a similar nonhuman primate without injuries to the leg (OR = 0.19, 95% CI = 0.03-1.2). Results indicated that wound location is associated with development of tetanus infection in rhesus macaques. Identification of high-risk trauma cases will allow better allocation of wound management and tetanus prophylaxis in institutions, especially in those housing nonhuman primates outdoors.

Modes of transmission and genetic diversity of foamy viruses in a Macaca tonkeana colony.

BACKGROUND: Foamy viruses are exogenous complex retroviruses that are highly endemic in several animal species, including monkeys and apes, where they cause persistent infection. Simian foamy viral (SFV) infection has been reported in few persons occupationally exposed to non-human primates (NHP) in zoos, primate centers and laboratories, and recently in few hunters from central Africa. Most of the epidemiological works performed among NHP populations concern cross-sectional studies without long-term follow-up. Therefore, the exact timing and the modes of transmission of SFVs remain not well known, although sexual and oral transmissions have been suspected. We have conducted a longitudinal study in a free-breeding colony of Macaca tonkeana in order (1) to determine the prevalence of the infection by foamy viruses, (2) to characterize molecularly the viruses infecting such animals, (3) to study their genetic variability overtime by long-term follow-up of several DNA samples in a series of specific animals, and (4) to get new insights concerning the timing and the modes of SFVs primary infection in these monkeys by combining serology and molecular means, as well as studies of familial structures and long-term behavioral observations. RESULTS/CONCLUSION: We first demonstrated that this colony was highly endemic for SFVs, with a clear increase of seroprevalence with age. Only 4.7% of immatures, and 43,7% of sub-adults were found seropositive, while 89.5% of adults exhibited antibodies directed against SFV. We further showed that 6 different strains of foamy viruses (exhibiting a very low intra-strain and overtime genetic variability in the integrase gene) are circulating within this group. This suggests a possible infection by different strains within an animal. Lastly, we provide strong evidence that foamy viruses are mostly acquired through severe bites, mainly in sub-adults or young adults. Most cases of seroconversion occur after 7 years of age; from this age individuals competed for access to sexual partners, thus increasing the likelihood of being wounded. Furthermore, all the serological and molecular data, obtained in this free-breeding colony, argue against a significant transmission of SFVs from mother or father to infants as well as between siblings.

The use of honey as a topical dressing to treat a large, devitalized wound in a stumptail macaque (Macaca arctoides).

There are many reasons wounds are managed as open wounds rather than by primary closure. Indications include gross contamination, infection, and skin loss leading to insufficient adjacent tissue for wound closure. The most common method of managing an open wound is with wet-to-dry dressings. Wet-to-dry dressings provide mechanical debridement and promote the movement of viscous exudates away from the wound. Wet-to-dry bandages ideally are changed every 12 to 24 h. For nonhuman primates, it is desirable to develop wound management techniques that limit animal handling for bandage changes and thus the frequency of sedation. Anecdotal reports on the use of honey to treat wounds date back to 2000 B.C. Recently, scientific inquiries have found merit to these reports. Honey accelerates healing because of its direct effects on tissue and antibacterial properties. In addition, dressings with honey can be changed relatively infrequently. Honey decreases inflammatory edema, hastens sloughing of devitalized tissue, attracts macrophages which cleanse the wound, provides a local cellular energy source, and protectively covers the wound. A high osmolarity, acidity, and hydrogen peroxide content confer honey with antibacterial properties. Here we describe the use of honey to manage a bite wound in a stumptail macaque (Macaca arctoides). The wound healed rapidly: after 2 weeks of treatment, there was markedly less exudate and no necrotic tissue. This report describes how honey may be helpful in the management of open wounds in nonhuman primates by minimizing the need for sedation for bandage changes.

Differential density of blood vessels in the mesencephalon of Macaque brain stem

The blood vessels (BV) of the brain stem show different patterns of development, and nutrient requeriments, metabolism and the activity of the different nuclei of the mesencephalon differ from one nucleus to another. The density of BV indirectly explains the blood flow intensity and physiological activity of the nuclei, and may explain the varying degrees of vulnerability of neurons to pathologies. To ascertain the different vascular densities of the mesencephalic nuclei, in the present work we used stereological methods to measure BV density in the Ventral Tegmental Area (VTA), the Substantia Nigra pars compacta (SNpc), the A8 Catecholaminergic Cell group (A8), the Periaqueductal Grey Matter (PAG) and the Locus Coeruleus (LC) of two intact macaques. The results pointed to a high density of BV in the LC; a low density in the SNpc, and an intermediate density in the VTA, A8 and PAG. These results confirm the high blood metabolism of the LC and suggest that the vulnerability of SNpc neurons may be related to the observed low density of BV (AU)

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Detection and discrimination of chromatic targets in hemianopic macaque monkeys and humans.

We measured the ability of three macaque monkeys with unilateral removal of primary visual cortex to detect 9 degrees, 200-ms targets presented at random in the upper or lower quadrants of the normal and hemianopic visual fields. The white or variously coloured target could differ from the background in both colour and luminance, or in either of them. Blue and red targets were detectable at any luminance contrast, but green and white targets were barely or not at all detectable at and near isoluminance in the hemianopic field. Blue and red targets were better detected than white targets at the same luminance difference. However, when both the target and the background were dynamically luminance-masked, detection in the hemianopic field failed at isoluminance whatever the colour. In addition, the monkeys were unable to discriminate between simultaneously presented red and green or blue and green targets in the hemianopic field when both targets had similar luminance contrast with the background. Two hemianopic patients tested on a subset of the tasks performed similarly to the monkeys. Together, the results indicate that the residual colour-opponent system that survives damage to V1 is involved in the detection of chromatic changes but cannot sustain simultaneous discrimination between pairs of colours.

Experimental thromboembolic stroke in cynomolgus monkey.

To develop an experimental model of thromboembolic stroke without intracranial surgery, an autologous blood clot was delivered to the middle cerebral artery (MCA) via the internal carotid artery in cynomolgus monkeys. Male cynomolgus monkeys, in which a chronic catheter had been earlier implanted in the left internal carotid artery, were used. The clot was flushed into the internal carotid artery under sevofluorane anesthesia. A neurologic deficit score was assigned after MCA embolization. After 24 h, cerebral infarct size and location were determined by the TTC staining method. Cerebral blood flow (CBF) was measured prior to and after MCA embolization, using positron emission tomography (PET). After embolization, long-lasting and profound extensor hypotonia of the contralateral upper and lower limbs, and mild to severe incoordination were observed. Contralateral hemiplegia was observed over the following 24 h. In gross morphologic observation of the brain, the lesions involved mostly the caudate nucleus, putamen, globus pallidus and insular cortex. CBF was maximally reduced in the left MCA territory, but not in the right MCA territory. This model is relevant to thromboembolic stroke in human in neurologic dysfunction and histopathologic brain damage.

Rhesus macaque (Macaca mulatta) group formation and housing: wounding and reproduction in a specific pathogen free (SPF) colony.

In the present report, we examined the effects of group formation strategy and corral design on wounding and reproduction rates in rhesus macaques. Specifically, we examined group formation using a staged strategy, in which small groups of animals were introduced incrementally over a period of weeks, and a rapid formation strategy, in which all animals were introduced in 1 day. We also examined group formation using a divided corral design that facilitated visual and social separation of individuals, and an undivided corral design that did not facilitate visual or social separation. Dependent measures were wounding and reproductive rates over each of the 2 years that followed group formation. Results indicate that incrementally releasing subgroups of animals, and using a corral design that provides for visual and social separation of individuals, are effective strategies for reducing rates of traumatic wounding when forming multimale-multifemale rhesus macaque breeding groups. However, it must be noted that differences in formation strategy and corral design did not lead to higher reproductive rates. We conclude that incrementally releasing animals in hierarchical subgroups, and using a divided vs. undivided housing design, reduced intra-group wounding and associated demands on veterinary and animal management resources following formation of rhesus macaque breeding groups.