Accelerated diversification of nonhuman primate malarias in Southeast Asia: adaptive radiation or geographic speciation?

Although parasitic organisms are found worldwide, the relative importance of host specificity and geographic isolation for parasite speciation has been explored in only a few systems. Here, we study Plasmodium parasites known to infect Asian nonhuman primates, a monophyletic group that includes the lineage leading to the human parasite Plasmodium vivax and several species used as laboratory models in malaria research. We analyze the available data together with new samples from three sympatric primate species from Borneo: The Bornean orangutan and the long-tailed and the pig-tailed macaques. We find several species of malaria parasites, including three putatively new species in this biodiversity hotspot. Among those newly discovered lineages, we report two sympatric parasites in orangutans. We find no differences in the sets of malaria species infecting each macaque species indicating that these species show no host specificity. Finally, phylogenetic analysis of these data suggests that the malaria parasites infecting Southeast Asian macaques and their relatives are speciating three to four times more rapidly than those with other mammalian hosts such as lemurs and African apes. We estimate that these events took place in approximately a 3-4-Ma period. Based on the genetic and phenotypic diversity of the macaque malarias, we hypothesize that the diversification of this group of parasites has been facilitated by the diversity, geographic distributions, and demographic histories of their primate hosts.

Androgens and innate immunity in rehabilitated semi-captive orangutans (Pongo pygmaeus morio) from Malaysian Borneo.

Despite the implications for the development of life-history traits, endocrine-immune trade-offs in apes are not well studied. This is due, in part, to difficulty in sampling wild primates, and lack of methods available for immune measures using samples collected noninvasively. Evidence for androgen-mediated immune trade-offs in orangutans is virtually absent, and very little is known regarding their pattern of adrenal development and production of adrenal androgens. To remedy both of these deficiencies, sera were collected from orangutans (Pongo pygmaeus morio) (N = 38) at the Sepilok Orangutan Rehabilitation Centre, Sabah, Malaysia, during routine health screenings. Testosterone, dehydroepiandrosterone (DHEA), and dehydroepiandrosterone-sulfate (DHEA-S) were assayed, along with two measures of functional innate immunity. DHEA-S concentrations, but not DHEA, increased with age in this sample of 1-18 year old animals. DHEA concentrations were higher in animals with higher levels of serum bacteria killing ability, while DHEA-S and testosterone concentrations were higher in animals with reduced complement protein activity. Patterns of DHEA-S concentration in this sample are consistent with patterns of adrenarche observed in other apes. Results from this study suggest that in addition to testosterone, DHEA and DHEA-S may have potent effects on immunological activity in this species.

Unhealthy travelers present challenges to sustainable primate ecotourism.

BACKGROUND: Ecotourism can function as a powerful tool for species conservation. However, a significant proportion of travelers at wildlife sanctuaries may be ill and potentially infectious, creating unnecessary risk of pathogen transmission to wildlife. METHODS: A questionnaire was distributed to adult visitors at the Sepilok Orangutan Rehabilitation Centre, Sabah, Malaysia. The questionnaire recorded age, occupation, region of origin, history of recent travel, recent contact with livestock, domestic and wild animals, and diagnoses/symptoms of various infections. RESULTS: 15% of the 633 tourists self-reported at least one of the following current symptoms: cough, sore throat, congestion, fever, diarrhea and vomiting. Participants who reported recent animal contact were significantly more likely to report current respiratory symptoms compared to other participants. Likewise, participants with a medical-related occupation were more likely to report current respiratory symptoms while at Sepilok compared to other participants. CONCLUSIONS: Despite being ill and potentially infectious, these tourists were visiting a wildlife sanctuary to view endangered species. Many of these visitors had animal contact immediately prior to arriving, and many had at least some basic knowledge about infection transmission. While participants in nature-based tourism are generally concerned about environmental protection, present analyses suggest that a significant proportion of ecotourists are uninformed of the risks they may pose to non-human animal health.

Perceived vaccination status in ecotourists and risks of anthropozoonoses.

Anthropozoonotic (human to nonhuman animal) transmission of infectious disease poses a significant threat to wildlife. A large proportion of travelers to tropical regions are not protected against vaccine-preventable illnesses, and a majority of these travelers demonstrate poor recall of actual vaccination status. Here we characterize self-perceived vaccination status among a large sample of ecotourists at the Sepilok Orangutan Rehabilitation Centre, Sabah, Malaysia. Despite their recognized travel itinerary to view endangered animals, tourists at wildlife sanctuaries are not adequately protected against vaccine-preventable illnesses. Of 633 surveys, over half reported being currently vaccinated against tuberculosis, hepatitis A, hepatitis B, polio, and measles. Fewer participants reported current vaccination status for influenza, rabies, and chickenpox. Despite the fact that the majority of visitors to Sepilok are from temperate regions where influenza is relatively more prevalent, 67.1% of those surveyed with medical-related occupations reported not being currently vaccinated for influenza. Ecotourists concerned about environmental protection are themselves largely unaware of their potential contribution to the spread of diseases to animals. The risks of negatively affecting animal populations must be communicated to all concerned parties, and this may begin by urging travelers to examine their actual vaccination status, particularly as the ecotourism industry continues its rapid expansion, and is seen increasingly as a possible tool to save great ape populations from extinction.