INTRODUCTION

Infectious agents affect population dynamics, ecology, behaviour and individual reproductive success, and disease and health issues are widely recognised as important factors in wildlife conservation (Daszak et al., 2000; Deem et al., 2001). Non-human primates (NHPs) deserve special attention for general health issues because of their close relatedness to humans and potential disease exchange between NHPs and humans (zoonosis) and vice versa (anthropozoonosis) (Chapter 1). However, there are very few published data on the health status and diseases of free-living NHPs, the interrelationships between diseases of wild NHPs and other biological parameters, and more generally on the baseline biological parameters of NHPs under natural conditions. This paucity of information hampers our understanding of natural epidemiological situations and especially the understanding of new emergent diseases (Wolfe et al., 1998), the impacts of habitat modification, the success of introduction, reintroduction or translocation programs (Tutin et al., 2001), interactions between domestic and wild animals, and interactions between humans and NHPs (Chapter 1).

Primatologists capture wild NHPs for a number of reasons other than medical screening, including sampling for endocrinology, genetics (Chapter 20) and physiology (Chapter 18), or for marking and radiotelemetry (Chapter 10). This provides a valuable opportunity to collect biological samples, and since the capture and handling of free-ranging NHPs is always accompanied by the risk of injury or mortality, it is ethically important to maximise the amount of information gathered during these procedures (Karesh et al., 1998). Biological samples should therefore be collected opportunistically every time wild NHPs are handled.