Giardia sp. and Cryptosporidium sp. Infections in Primates in Fragmented and Undisturbed Forest in Western Uganda

Metabarcoding of pathogenic parasites based on copro-DNA analysis of wild animals in South Korea

Four species of dominant wild animals, namely, Prionailurus bengalensis euptilurus, Nyctereutes procyonoides koreensis, Hydropotes inermis argyropus, and Sus scrofa coreanus, are hosts of potential infectious agents, including helminths and protozoa. Therefore, it is necessary to analyze the infectious agents present in these wild animals to monitor and control the spread of pathogens. In the present study, fecal samples from 51 wild animals were collected from the mountains of Yangpyeong, Hoengseong, and Cheongyang in South Korea and metabarcoding of the V9 region of the 18S rRNA gene was performed to identify various parasite species that infect these wild animals. Genes from nematodes, such as Metastrongylus sp., Strongyloides spp., Ancylostoma sp., and Toxocara sp., were detected in the fecal samples from wild animals. In addition, platyhelminthes, including Spirometra sp., Echinostomatidae gen. sp., Alaria sp., Neodiplostomum sp., and Clonorchis sp., and protozoa, including Entamoeba sp., Blastocystis sp., Isospora sp., Tritrichomonas sp., Pentatrichomonas sp., and Cryptosporidium sp., were detected. In the present study, various parasites infecting wild animals were successfully identified using metabarcoding. Our technique may play a crucial role in monitoring parasites within wild animals, especially those causing zoonoses.

Human-Borne Pathogens: Are They Threatening Wild Great Ape Populations?

Simple Summary

Human-driven activities, including agriculture, forestry, and mining, are destroying the natural habitats of wild great ape (bonobo, chimpanzee, gorilla, and orangutan) populations in Africa and Southeast Asia. The reduction in and fragmentation of wild great ape environments lead to (i) a decrease in population numbers, (ii) the isolation of current populations, and (iii) increased exposure to humans and their livestock. Consequently, the spatial overlap between humans and wild great apes might facilitate the transmission of infectious agents between them. Historically, animal-to-human pathogen transmission has attracted most of the attention of researchers and public health authorities. Only in recent years has the human-to-animal transmission pathway acquired notoriety, mainly due to conservation concerns. In this review, we examine and appraise literature-based evidence reporting wild great ape infections with viral, bacterial, parasitic, and fungal pathogens of potential anthropic nature. We select and further discuss two viral (Human Metapneumovirus and Respiratory Syncytial Virus), one bacterial (diarrhoeagenic Escherichia coli), and two parasitic (Cryptosporidium spp. and Giardia duodenalis) pathogens causing infections in wild great ape populations for which a human origin is most likely. Gaps in knowledge and future research directions are also identified.

Abstract

Climate change and anthropic activities are the two main factors explaining wild great ape habitat reduction and population decline. The extent to which human-borne infectious diseases are contributing to this trend is still poorly understood. This is due to insufficient or fragmented knowledge on the abundance and distribution of current wild great ape populations, the difficulty obtaining optimal biological samples for diagnostic testing, and the scarcity of pathogen typing data of sufficient quality. This review summarises current information on the most clinically relevant pathogens of viral, bacterial, parasitic, and fungal nature for which transmission from humans to wild great apes is suspected. After appraising the robustness of available epidemiological and/or molecular typing evidence, we attempt to categorise each pathogen according to its likelihood of truly being of human origin. We further discuss those agents for which anthroponotic transmission is more likely. These include two viral (Human Metapneumovirus and Respiratory Syncytial Virus), one bacterial (diarrhoeagenic Escherichia coli), and two parasitic (Cryptosporidium spp. and Giardia duodenalis) pathogens. Finally, we identify the main drawbacks impairing research on anthroponotic pathogen transmission in wild great apes and propose research lines that may contribute to bridging current knowledge gaps.

Parasites of Free-Ranging and Captive American Primates: A Systematic Review

The diversity, spread, and evolution of parasites in non-human primates (NHPs) is a relevant issue for human public health as well as for NHPs conservation. Although previous reviews have recorded information on parasites in NHPs (Platyrrhines) in the Americas, the increasing number of recent studies has made these inventories far from complete. Here, we summarize information about parasites recently reported in Platyrrhines, attempting to build on earlier reviews and identify information gaps. A systematic literature search was conducted in PubMed, ISI Web of Science, and Latin American and Caribbean Health Sciences Literature (LILACS), and following the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. Ninety-three studies were included after the screening process. Records for 20 genera of NHPs, including 90 species were found. Most of the studies were conducted on captive individuals (54.1%), and morphological approaches were the most used for parasite identification. The most commonly collected biological samples were blood and stool, and Protozoa was the most frequent parasite group found. There is still scarce (if any) information on the parasites associated to several Platyrrhine species, especially for free-ranging populations. The use of molecular identification methods can provide important contributions to the field of NHPs parasitology in the near future. Finally, the identification of parasites in NHPs populations will continue to provide relevant information in the context of pervasive habitat loss and fragmentation that should influence both human public health and wildlife conservation strategies.

Community health and human-animal contacts on the edges of Bwindi Impenetrable National Park, Uganda

Cross-species transmission of pathogens is intimately linked to human and environmental health. With limited healthcare and challenging living conditions, people living in poverty may be particularly susceptible to endemic and emerging diseases. Similarly, wildlife is impacted by human influences, including pathogen sharing, especially for species in close contact with people and domesticated animals. Here we investigate human and animal contacts and human health in a community living around the Bwindi Impenetrable National Park (BINP), Uganda. We used contact and health survey data to identify opportunities for cross-species pathogen transmission, focusing mostly on people and the endangered mountain gorilla. We conducted a survey with background questions and self-reported diaries to investigate 100 participants' health, such as symptoms and behaviours, and contact patterns, including direct contacts and sightings over a week. Contacts were revealed through networks, including humans, domestic, peri-domestic, and wild animal groups for 1) contacts seen in the week of background questionnaire completion, and 2) contacts seen during the diary week. Participants frequently felt unwell during the study, reporting from one to 10 disease symptoms at different intensity levels, with severe symptoms comprising 6.4% of the diary records and tiredness and headaches the most common symptoms. After human-human contacts, direct contact with livestock and peri-domestic animals were the most common. The contact networks were moderately connected and revealed a preference in contacts within the same taxon and within their taxa groups. Sightings of wildlife were much more common than touching. However, despite contact with wildlife being the rarest of all contact types, one direct contact with a gorilla with a timeline including concerning participant health symptoms was reported. When considering all interaction types, gorillas mostly exhibited intra-species contact, but were found to interact with five other species, including people and domestic animals. Our findings reveal a local human population with recurrent symptoms of illness in a location with intense exposure to factors that can increase pathogen transmission, such as direct contact with domestic and wild animals and proximity among animal species. Despite significant biases and study limitations, the information generated here can guide future studies, such as models for disease spread and One Health interventions.

Sparse Evidence for Giardia intestinalis, Cryptosporidium spp. and Microsporidia Infections in Humans, Domesticated Animals and Wild Nonhuman Primates Sharing a Farm-Forest Mosaic Landscape in Western Uganda

Zoonotic pathogen transmission is considered a leading threat to the survival of non-human primates and public health in shared landscapes. Giardia spp., Cryptosporidium spp. and Microsporidia are unicellular parasites spread by the fecal-oral route by environmentally resistant stages and can infect humans, livestock, and wildlife including non-human primates. Using immunoassay diagnostic kits and amplification/sequencing of the region of the triosephosphate isomerase, small ribosomal subunit rRNA and the internal transcribed spacer genes, we investigated Giardia, Cryptosporidium, and microsporidia infections, respectively, among humans, domesticated animals (livestock, poultry, and dogs), and wild nonhuman primates (eastern chimpanzees and black and white colobus monkeys) in Bulindi, Uganda, an area of remarkably high human-animal contact and spatial overlap. We analyzed 137 fecal samples and revealed the presence of G. intestinalis assemblage B in two human isolates, G. intestinalis assemblage E in one cow isolate, and Encephalitozoon cuniculi genotype II in two humans and one goat isolate. None of the chimpanzee and colobus monkey samples were positive for any of the screened parasites. Regular distribution of antiparasitic treatment in both humans and domestic animals in Bulindi could have reduced the occurrence of the screened parasites and decreased potential circulation of these pathogens among host species.

Molecular characterization of Giardia duodenalis and evidence for cross-species transmission in Northern Argentina

Anthropogenic activities, such as human population expansion and land-use change, create ecological overlap between humans, domesticated animals, and wildlife and can exacerbate the zoonotic transmission of parasites. To improve our understanding of this dynamic, we employed multi-locus genotyping to conduct a cross-sectional study of the potential for zoonotic transmission of the protozoan parasite Giardia duodenalis among humans, household associated livestock and dogs, and black and gold howler monkeys (Alouatta caraya) in the Corrientes Province of Argentina. We found Giardia prevalence to be highest in howler monkeys (90.3% (47/52)), followed by humans (61.1% (22/36)), dogs (44.4% (16/36)), and cattle (41.9% (18/43)). We further established that howler monkeys exclusively harbored strains of assemblage B (100%) while humans were infected with either assemblage A (13.3%) or B (80%) or A and B (6.7%), and cattle and dogs were infected with either assemblage A (cattle, 94.1%; dogs, 80%)), A and C (10%), or their host-adapted assemblage (cattle, 5.9%; dogs, 10%). Our finding of G. duodenalis in both humans and domesticated animals (assemblage A) and humans and wild primates (assemblage B) suggests that cross-species transmission of multiple assemblages of G. duodenalis may occur in rural complexes such as northern Argentina where people, domesticated animals, and wildlife overlap. We further highlight the need to investigate the implications of these results for human health, the economics of livestock production, and wildlife conservation in this and similar systems.

Biodiversity of the Coccidia (Apicomplexa: Conoidasida) in vertebrates: what we know, what we do not know, and what needs to be done

Over the last two decades my colleagues and I have assembled the literature on a good percentage of most of the coccidians (Conoidasida) known, to date, to parasitise: Amphibia, four major lineages of Reptilia (Amphisbaenia, Chelonia, Crocodylia, Serpentes), and seven major orders in the Mammalia (Carnivora, Chiroptera, Lagomorpha, Insectivora, Marsupialia, Primates, Scandentia). These vertebrates, combined, comprise about 15,225 species; only about 899 (5.8%) of them have been surveyed for coccidia and 1,946 apicomplexan valid species names or other forms are recorded in the literature. Based on these compilations and other factors, I extrapolated that there yet may be an additional 31,381 new apicomplexans still to be discovered in just these 12 vertebrate groups. Extending the concept to all of the other extant vertebrates on Earth; i.e. lizards (6,300 spp.), rodents plus 12 minor orders of mammals (3,180 spp.), birds (10,000 spp.), and fishes (33,000 spp.) and, conservatively assuming only two unique apicomplexan species per each vertebrate host species, I extrapolate and extend my prediction that we may eventually find 135,000 new apicomplexans that still need discovery and to be described in and from those vertebrates that have not yet been examined for them! Even doubling that number is a significant underestimation in my opinion.

Cryptosporidium and Giardia prevalence amongst lemurs, humans, domestic animals and black rats in Tsinjoarivo, Madagascar

Few studies have measured the prevalence of Cryptosporidium sp. and Giardia sp. infections in Madagascar. This project provides baseline data of these pathogens in humans and other mammals in Tsinjoarivo. Fecal samples were collected May–July 2014 from lemurs (Propithecus diadema and Hapalemur griseus), humans, domestic animals (cattle, pigs and dogs), and black rats (Rattus rattus). Samples were analyzed utilizing immunofluorescence assay. No lemurs were positive for either parasite. Cryptosporidium sp. was found in humans (10%), cattle (20%), pigs (20%), dogs (15%) and rats (38%), and Giardia sp. was found in humans (10%), pigs (40%), dogs (29%) and rats (53%). Coinfections were noted in humans (6%), pigs (20%), dogs (15%) and rats (33%). All human subjects reported daily contact with domestic animals and rats, and all infected humans were ≤13 years old. Human population growth and increasing human-wildlife encounters make it critical to understand the potential for zoonotic pathogen transmission.

Cryptosporidium hominis infections in non-human animal species: revisiting the concept of host specificity

Parasites in the genus Cryptosporidium, phylum Apicomplexa, are found worldwide in the intestinal tract of many vertebrate species and in the environment. Driven by sensitive PCR methods, and the availability of abundant sequence data and reference genomes, the taxonomic complexity of the genus has steadily increased; 38 species have been named to date. Due to its public health importance, Cryptosporidium hominis has long attracted the interest of the research community. This species was initially described as infectious to humans only. This perception has persisted in spite of an increasing number of observations of natural and experimental infections of animals with this species. Here we summarize and discuss this literature published since 2000 and conclude that the host range of C. hominis is broader than originally described. The evolving definition of the C. hominis host range raises interesting questions about host specificity and the evolution of Cryptosporidium parasites.

Intestinal Parasites and the Occurrence of Zoonotic Giardia duodenalis Genotype in Captive Gibbons at Krabokkoo Wildlife Breeding Center, Thailand

Intestinal parasitic infections can have an impact on health and growth of wildlife. The current study aims were to determine the prevalence of intestinal parasites and to molecular characterize Giardia duodenalis and Cryptosporidium spp. in captive gibbons at Krabokkoo Wildlife Breeding Center, Thailand. Fifty-five gibbons, 2 agile- (Hylobates agilis), 38 lar- (Hylobates lar) and 15 pileated gibbons (Hylobates pileatus) were included in this study. Fecal samples were collected individually at Krabokkoo Wildlife Breeding Center, Chachoengsao province, eastern Thailand, in November 2013. Intestinal parasitic infections were examined by zinc sulfate centrifugation flotation and by a commercially available immunofluorescent assay (IFA) for detection of G. duodenalis and Cryptosporidium spp.. Polymerase chain reaction targeting the Giardia glutamate dehydrogenase (gdh), beta- giardin (bg), triose phosphate isomerase (tpi) genes, and the Cryptosporidium small subunit-rRNA and heat-shock protein (hsp70) following by DNA sequencing were performed on the IFA positive samples. The overall prevalence of intestinal parasitic infection in gibbons at Krabokkoo Wildlife Breeding Center was 12.7% (95%CI: 5.3–24.5), Strongyloides spp. eggs or larvae were present in all positive samples. Co-infections with G. duodenalis were detected in 1.8% (95%CI: 0.1–9.7) of the samples. Based on the sequencing results of the three genes, the IFA Giardia positive isolate typed as the zoonotic genotype B. Since the data reveals the occurrence of zoonotic Giardia genotype, good hygiene management is suggested to prevent the transmission of this pathogen from gibbon to human, and vice versa.

A review of wildlife tourism and meta-analysis of parasitism in Africa's national parks and game reserves

The recent increase of parasitic diseases associated with wildlife tourism can be traced to human contact with wildlife and intense modification of wildlife habitat. The continental estimates of parasitic diseases among visited wildlife-tourists and mammalian wildlife present in conservation areas are lacking; therefore, a general review was necessary to provide insights into Africa's parasitic disease burden and transmission between humans and wildlife. A two-step analysis was conducted with searches in Ovid MEDLINE, EMBASE, PubMed, Web of Science and Global Health. All diseases reported without prevalence were grouped and analysed as categorical data while meta-analysis of prevalence rates of parasitic diseases in wildlife from national parks and reserves in Africa was conducted. Only 4.7% of the tourist centres reported routine wildlife diagnosis for parasitic diseases. Disease intensity shows that cryptosporidiosis and seven other parasitic diseases were observed in both human and wildlife; however, no significant difference in intensity between human and wildlife hosts was observed. Schistosomiasis intensity reports showed a significant increase (P < 0.05) while entamoebiasis showed a significant decrease (P < 0.05) in humans as compared to wildlife. Visiting tourists were more infected with malaria, while wildlife was more infected with parasitic gastroenteritis (PGE). The meta-analysis of wildlife revealed the highest prevalence of PGE with mixed parasites and lowest prevalence of Giardia spp. at 99.9 and 5.7%, respectively. The zoonotic and socioeconomic impact of some of these parasites could pose a severe public threat to tourism. Pre- and post-travel clinical examinations are important for tourists while routine examination, treatment and rational surveillance are important for these animals to improve wildlife tourism.

Association of Anthropogenic Disturbances and Intestinal Parasitism in Ecuadorian Mantled Howler Monkeys, Alouatta palliata aequatorialis

Forest disturbance and human encroachment have the potential to influence intestinal parasite communities in animal hosts by modifying nutritional health, physiological stress, host densities, contact rates, and ranging patterns. Anthropogenic disturbances also have the ability to affect the ecological landscape of parasitic disease, potentially impacting the health of both wildlife and people. Our research investigated the association of forest disturbance and human encroachment on intestinal parasite communities in mantled howler monkeys, Alouatta palliata aequatorialis. We found that individual parasite species prevalence was associated with group size and forest disturbance. Proximity to people was not a direct factor influencing intestinal parasitism; rather, several human proximity indices were related to group size, which was in turn related to overall species richness and the presence of specific parasite species. These results, coupled with previous findings, suggest that anthropogenic disturbances are likely influencing intestinal parasite communities. Though no single study has definitively explained all relationships between anthropogenic disturbances and intestinal parasitism, we propose that our models are appropriate for meta-analysis testing across other species and environments.

Immunologic detection of Giardia duodenalis in a specific pathogen–free captive olive baboon (Papio cynocephalus anubis) colony

Several commercial Giardia immunoassays were evaluated in baboons for sensitivity and specificity as well as ease of use in a large specific pathogen–free (SPF) colony. An additional objective was to identify the assemblage(s) of Giardia duodenalis present in this baboon colony. A direct immunofluorescent antibody test (IFAT) was used as the reference test. Tests evaluated were a patient-side rapid test for dogs and cats, a human rapid test, and a well-plate ELISA designed for use with humans. Test sensitivities and specificities were compared using the McNemar paired t-test and were further evaluated for agreement using an unweighted Cohen kappa statistic. When compared to the IFAT reference, both human tests were more sensitive than the veterinary test. Based on PCR and sequencing of the G. duodenalis small-subunit ribosomal RNA and glutamate dehydrogenase loci, assemblage AI was present in this baboon colony. We found that 10 of the 110 (9%) baboons in this SPF colony were infected with a zoonotic strain of G. duodenalis.

Spatial Overlap Between People and Non-human Primates in a Fragmented Landscape

In western Uganda, the landscape surrounding Kibale National Park (KNP) contains households, trading centers, roads, fields, and forest fragments. The mosaic arrangement of these landscape features is thought to enhance human-primate interaction, leading to primate population declines and increased bi-directional disease transmission. Using a social-ecological systems research framework that captures the complexity of interaction among people, wildlife, and environment, we studied five forest fragments near KNP and conducted intensive on-the-ground mapping to identify locations of human-primate spatial overlap. Primate locations and human activities were distributed within, on the edges, and far beyond fragment borders. Analysis of shared spaces indicated that 5.5% of human space overlapped with primate spaces, while 69.5% of primate spaces overlapped with human spaces. Nearest neighbor analysis indicated that human activities were significantly spatially clustered within and around individual fragments, as were primate locations. Getis-Ord statistics revealed statistically significant "hotspots" of human activity and primate activity, but only one location where spatial overlap between humans and primates was statistically significant. Human activities associated with collecting fuelwood and other forest products were the primary drivers of human-primate overlap; however, primates also spent time outside of forest fragments in agricultural spaces. These results demonstrate that fragmented landscapes are not uniform with respect to human-primate overlap, and that the implications of human-primate interaction, such as primate population declines and possible cross-species disease transmission, are spatially aggregated.

Occurrence of Giardia, Cryptosporidium, and Entamoeba in wild rhesus macaques (Macaca mulatta) living in urban and semi-rural North-West India

Giardia duodenalis, Cryptosporidium spp., and Entamoeba spp. are intestinal protozoa capable of infecting a range of host species, and are important causes of human morbidity and mortality. Understanding their epidemiology is important, both for public health and for the health of the animals they infect. This study investigated the occurrence of these protozoans in rhesus macaques (Macaca mulatta) in India, with the aim of providing preliminary information on the potential for transmission of these pathogens between macaques and humans. Faecal samples (n = 170) were collected from rhesus macaques from four districts of North-West India. Samples were analysed for Giardia/Cryptosporidium using a commercially available direct immunofluorescent antibody test after purification via immunomagnetic separation. Positive samples were characterised by sequencing of PCR products. Occurrence of Entamoeba was investigated first by using a genus-specific PCR, and positive samples further investigated via species-specific PCRs for Entamoeba coli, Entamoeba histolytica, Entamoeba dispar and Entamoeba moshkovskii. Giardia cysts were found in 31% of macaque samples, with all isolates belonging to Assemblage B. Cryptosporidium oocysts were found in 1 sample, however this sample did not result in amplification by PCR. Entamoeba spp. were found in 79% of samples, 49% of which were positive for E. coli. Multiplex PCR for E. histolytica, E. dispar and E. moshkovskii, did not result in amplification in any of the samples. Thus in 51% of the samples positive at the genus specific PCR, the Entamoeba species was not identified. This study provides baseline information on the potential for transmission of these zoonotic parasites at the wildlife-human interface.

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Intestinal protozoa in wild rhesus macaques (n = 170) in India investigated.

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Cryptosporidium oocysts identified in only one sample.

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No zoonotic Entamoeba detected, but Entamoeba coli and unknown Entamoeba spp.

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Giardia duodenalis cysts detected in approximately 30% samples.

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Only Assemblage B Giardia, even when exposure to Assemblages A and E in calves.

Occurrence and genetic characterisation of Acanthamoeba spp. from environmental and domestic water sources in Queen Elizabeth Protected Area, Uganda

Background

Acanthamoeba is an emerging potentially pathogenic amoeba that has been receiving increasing attention worldwide as a reservoir and potential vector for the transmission of pathogenic bacteria. It is also associated with brain cell damage, keratitis and skin irritation in humans. Its effects are more severe in immunocompromised individuals. This study provides for the first time in Uganda, information on the prevalence and genotypes of Acanthamoeba in environmental and domestic (tap) water.

Methods

A total of 324 environmental and 84 tap water samples were collected between November 2013 and September 2014. The samples were centrifuged, cultured (Non-Nutrient agar seeded with gram-negative bacteria) and observed under a microscope. After confirmation of Acanthamoeba, genomic DNA was extracted for PCR assays by chemical lysis and purification with phenol/chloroform/isoamyl alcohol. Samples that showed the strongest positive bands (400–600 bp) were subjected to cycle sequencing.

Results

Among environmental and tap water samples, 107 (33 %) and 36 (42.9 %) tested positive for Acanthamoeba spp., respectively. Prevalence of Acanthamoeba from specific environmental locations was as follows; Kazinga channel banks (60.7 %), Fish landing sites (50 %), River Kyambura (39.6 %) and Kazinga mid channel (5.3 %). There was a significant difference (p = 0.001) in the prevalence of Acanthamoeba between sampling sites. The mean (Mean ± SE) occurrence of the organism was higher in Kazinga channel banks (3.44 ± 0.49) and Fish landing sites (3.08 ± 0.53). Correlation between in situ parameters and Acanthamoeba was insignificant except for the Dissolved Oxygen (mg/ML) which was negatively correlated (r = −0.231, p = 0.001) to Acanthamoeba. Six distinct partial Acanthamoeba T-genotype groups T1, T2, T4, T5, T6 and T11 were obtained. Ultimately, Acanthamoeba spp., Acanthamoeba hatchetti and Acanthamoeba polyphaga were isolated in the current study.

Conclusions

There was a high prevalence of Acanthamoeba in communal piped tap and environmental water used by communities, indicating poor environmental and domestic water quality.

Bushmeat and Emerging Infectious Diseases: Lessons from Africa

Zoonotic diseases are the main contributor to emerging infectious diseases (EIDs) and present a major threat to global public health. Bushmeat is an important source of protein and income for many African people, but bushmeat-related activities have been linked to numerous EID outbreaks, such as Ebola, HIV, and SARS. Importantly, increasing demand and commercialization of bushmeat is exposing more people to pathogens and facilitating the geographic spread of diseases. To date, these linkages have not been systematically assessed. Here we review the literature on bushmeat and EIDs for sub-Saharan Africa, summarizing pathogens (viruses, fungi, bacteria, helminths, protozoan, and prions) by bushmeat taxonomic group to provide for the first time a comprehensive overview of the current state of knowledge concerning zoonotic disease transmission from bushmeat into humans. We conclude by drawing lessons that we believe are applicable to other developing and developed regions and highlight areas requiring further research to mitigate disease risk.

Identification of Giardia duodenalis and Enterocytozoon bieneusi in an epizoological investigation of a laboratory colony of prairie dogs, Cynomys ludovicianus

Since 2005, black-tailed prairie dogs (Cynomys ludovicianus) have been collected for use as research animals from field sites in Kansas, Colorado, and Texas. In January of 2012, Giardia trophozoites were identified by histology, thin-section electron microscopy, and immunofluorescent staining in the lumen of the small intestine and colon of a prairie dog euthanized because of extreme weight loss. With giardiasis suspected as the cause of weight loss, a survey of Giardia duodenalis in the laboratory colony of prairie dogs was initiated. Direct immunofluorescent testing of feces revealed active shedding of Giardia cysts in 40% (n=60) of animals held in the vivarium. All tested fecal samples (n=29) from animals in another holding facility where the index case originated were PCR positive for G. duodenalis with assemblages A and B identified from sequencing triosephosphate isomerase (tpi), glutamate dehydrogenase (gdh), and β-giardin (bg) genes. Both assemblages are considered zoonotic, thus the parasites in prairie dogs are potential human pathogens and indicate prairie dogs as a possible wildlife reservoir or the victims of pathogen spill-over. Molecular testing for other protozoan gastrointestinal parasites revealed no Cryptosporidium infections but identified a host-adapted Enterocytozoon bieneusi genotype group.

Epidemiology and molecular characterization of Cryptosporidium spp. in humans, wild primates, and domesticated animals in the Greater Gombe Ecosystem, Tanzania

Cryptosporidium is an important zoonotic parasite globally. Few studies have examined the ecology and epidemiology of this pathogen in rural tropical systems characterized by high rates of overlap among humans, domesticated animals, and wildlife. We investigated risk factors for Cryptosporidium infection and assessed cross-species transmission potential among people, non-human primates, and domestic animals in the Gombe Ecosystem, Kigoma District, Tanzania. A cross-sectional survey was designed to determine the occurrence and risk factors for Cryptosporidium infection in humans, domestic animals and wildlife living in and around Gombe National Park. Diagnostic PCR revealed Cryptosporidium infection rates of 4.3% in humans, 16.0% in non-human primates, and 9.6% in livestock. Local streams sampled were negative. DNA sequencing uncovered a complex epidemiology for Cryptosporidium in this system, with humans, baboons and a subset of chimpanzees infected with C. hominis subtype IfA12G2; another subset of chimpanzees infected with C. suis; and all positive goats and sheep infected with C. xiaoi. For humans, residence location was associated with increased risk of infection in Mwamgongo village compared to one camp (Kasekela), and there was an increased odds for infection when living in a household with another positive person. Fecal consistency and other gastrointestinal signs did not predict Cryptosporidium infection. Despite a high degree of habitat overlap between village people and livestock, our results suggest that there are distinct Cryptosporidium transmission dynamics for humans and livestock in this system. The dominance of C. hominis subtype IfA12G2 among humans and non-human primates suggest cross-species transmission. Interestingly, a subset of chimpanzees was infected with C. suis. We hypothesize that there is cross-species transmission from bush pigs (Potaochoerus larvatus) to chimpanzees in Gombe forest, since domesticated pigs are regionally absent. Our findings demonstrate a complex nature of Cryptosporidium in sympatric primates, including humans, and stress the need for further studies.

Cryptosporidium is a common zoonotic gastrointestinal parasite. In a cross-sectional survey of humans, non-human primates (chimpanzees and baboons) and livestock in the Greater Gombe Ecosystem, Tanzania, Cryptosporidium infection rate was 4.3%, 16.0% and 9.6% respectively. Infection was not associated with clinical disease in people; however, living in a household with an infected person increased one’s risk of infection. Phylogenetic analyses identified clusters of Cryptosporidium with a mixed host background. Surprisingly, the Mitumba chimpanzee community, which shares a natural boundary with a human community, had a lower occurrence of C. hominis compared to the Kasakela chimpanzee community, which resides in the forest interior (less human exposure). However, Kasakela chimpanzees were also infected with C. suis, suggesting a transmission cycle linked to sympatric bush pigs. Our findings highlight the complex nature of zoonotic parasite transmission and stress the need for further studies in similar systems.

Diversity and prevalence of gastrointestinal parasites in seven non-human primates of the Taï National Park, Côte d'Ivoire

Parasites and infectious diseases are well-known threats to primate populations. The main objective of this study was to provide baseline data on fecal parasites in the cercopithecid monkeys inhabiting Côte d'Ivoire's Taï National Park. Seven of eight cercopithecid species present in the park were sampled: Cercopithecus diana, Cercopithecus campbelli, Cercopithecus petaurista, Procolobus badius, Procolobus verus, Colobus polykomos, and Cercocebus atys. We collected 3142 monkey stool samples between November 2009 and December 2010. Stool samples were processed by direct wet mount examination, formalin-ethyl acetate concentration, and MIF (merthiolate, iodine, formalin) concentration methods. Slides were examined under microscope and parasite identification was based on the morphology of cysts, eggs, and adult worms. A total of 23 species of parasites was recovered including 9 protozoa (Entamoeba coli, Entamoeba histolytica/dispar, Entamoeba hartmanni, Endolimax nana, Iodamoeba butschlii, Chilomastix mesnili, Giardia sp., Balantidium coli, and Blastocystis sp.), 13 nematodes (Oesophagostomum sp., Ancylostoma sp., Anatrichosoma sp., Capillariidae Gen. sp. 1, Capillariidae Gen. sp. 2, Chitwoodspirura sp., Subulura sp., spirurids [cf Protospirura muricola], Ternidens sp., Strongyloides sp., Trichostrongylus sp., and Trichuris sp.), and 1 trematode (Dicrocoelium sp.). Diversity indices and parasite richness were high for all monkey taxa, but C. diana, C. petaurista, C. atys, and C. campbelli exhibited a greater diversity of parasite species and a more equitable distribution. The parasitological data reported are the first available for these cercopithecid species within Taï National Park.

Multi-locus analysis of Giardia duodenalis from nonhuman primates kept in zoos in China: geographical segregation and host-adaptation of assemblage B isolates

Only a few studies based on single locus characterization have been conducted on the molecular epidemiology of Giardia duodenalis in nonhuman primates (NHPs). The present study was conducted to examine the occurrence and genotype identity of G. duodenalis in NHPs based on multi-locus analysis of the small-subunit ribosomal RNA (SSU rRNA), triose phosphate isomerase (tpi), glutamate dehydrogenase (gdh), and beta-giardin (bg) genes. Fecal specimens were collected from 496 animals of 36 NHP species kept in seven zoos in China and screened for G. duodenalis by tpi-based PCR. G. duodenalis was detected in 92 (18.6%) specimens from 18 NHP species, belonging to assemblage A (n=4) and B (n=88). In positive NHP species, the infection rates ranged from 4.8% to 100%. In tpi sequence analysis, the assemblage A included subtypes A1, A2 and one novel subtype. Multi-locus analysis of the tpi, gdh, and bg genes detected 11 (8 known and 3 new), 6 (3 known and 3 new) and 9 (2 known and 7 new) subtypes in 88, 47 and 35 isolates in assemblage B, respectively. Thirty-two assemblage B isolates with data at all three loci yielded 15 multi-locus genotypes (MLGs), including 2 known and 13 new MLGs. Phylogenetic analysis of concatenated sequences of assemblage B showed that MLGs found here were genetically different from those of humans, NHPs, rabbit and guinea pig in Italy and Sweden. It further indicated that assemblage B isolates in ring-tailed lemurs and squirrel monkeys might be genetically different from those in other NHPs. These data suggest that NHPs are mainly infected with G. duodenalis assemblage B and there might be geographical segregation and host-adaptation in assemblage B in NHPs.

Beyond bushmeat: animal contact, injury, and zoonotic disease risk in Western Uganda

Zoonotic pathogens cause an estimated 70% of emerging and re-emerging infectious diseases in humans. In sub-Saharan Africa, bushmeat hunting and butchering is considered the primary risk factor for human-wildlife contact and zoonotic disease transmission, particularly for the transmission of simian retroviruses. However, hunting is only one of many activities in sub-Saharan Africa that bring people and wildlife into contact. Here, we examine human-animal interaction in western Uganda, identifying patterns of injuries from animals and contact with nonhuman primates. Additionally, we identify individual-level risk factors associated with contact. Nearly 20% (246/1,240) of participants reported either being injured by an animal or having contact with a primate over their lifetimes. The majority (51.7%) of injuries were dog bites that healed with no long-term medical consequences. The majority (76.8%) of 125 total primate contacts involved touching a carcass; however, butchering (20%), hunting (10%), and touching a live primate (10%) were also reported. Red colobus (Piliocolobus rufomitratus tephrosceles) accounted for most primate contact events. Multivariate logistic regression indicated that men who live adjacent to forest fragments are at elevated risk of animal contact and specifically primate contact. Our results provide a useful comparison to West and Central Africa where "bushmeat hunting" is the predominant paradigm for human-wildlife contact and zoonotic disease transmission.

Diversity of microsporidia, Cryptosporidium and Giardia in mountain gorillas (Gorilla beringei beringei) in Volcanoes National Park, Rwanda

BACKGROUND

Infectious diseases represent the greatest threats to endangered species, and transmission from humans to wildlife under increased anthropogenic pressure has been always stated as a major risk of habituation.

AIMS

To evaluate the impact of close contact with humans on the occurrence of potentially zoonotic protists in great apes, one hundred mountain gorillas (Gorilla beringei beringei) from seven groups habituated either for tourism or for research in Volcanoes National Park, Rwanda were screened for the presence of microsporidia, Cryptosporidium spp. and Giardia spp. using molecular diagnostics.

RESULTS

The most frequently detected parasites were Enterocytozoon bieneusi found in 18 samples (including genotype EbpA, D, C, gorilla 2 and five novel genotypes gorilla 4-8) and Encephalitozoon cuniculi with genotype II being more prevalent (10 cases) compared to genotype I (1 case). Cryptosporidium muris (2 cases) and C. meleagridis (2 cases) were documented in great apes for the first time. Cryptosporidium sp. infections were identified only in research groups and occurrence of E. cuniculi in research groups was significantly higher in comparison to tourist groups. No difference in prevalence of E. bieneusi was observed between research and tourist groups.

CONCLUSION

Although our data showed the presence and diversity of important opportunistic protists in Volcanoes gorillas, the source and the routes of the circulation remain unknown. Repeated individual sampling, broad sampling of other hosts sharing the habitat with gorillas and quantification of studied protists would be necessary to acquire more complex data.

Hidden population structure and cross-species transmission of whipworms (Trichuris sp.) in humans and non-human primates in Uganda

BACKGROUND

Whipworms (Trichuris sp.) are a globally distributed genus of parasitic helminths that infect a diversity of mammalian hosts. Molecular methods have successfully resolved porcine whipworm, Trichuris suis, from primate whipworm, T. trichiura. However, it remains unclear whether T. trichiura is a multi-host parasite capable of infecting a wide taxonomic breadth of primate hosts or a complex of host specific parasites that infect one or two closely related hosts.

METHODS AND FINDINGS

We examined the phylogenetic structure of whipworms in a multi-species community of non-human primates and humans in Western Uganda, using both traditional microscopy and molecular methods. A newly developed nested polymerase chain reaction (PCR) method applied to non-invasively collected fecal samples detected Trichuris with 100% sensitivity and 97% specificity relative to microscopy. Infection rates varied significantly among host species, from 13.3% in chimpanzees (Pan troglodytes) to 88.9% in olive baboons (Papio anubis). Phylogenetic analyses based on nucleotide sequences of the Trichuris internal transcribed spacer regions 1 and 2 of ribosomal DNA revealed three co-circulating Trichuris groups. Notably, one group was detected only in humans, while another infected all screened host species, indicating that whipworms from this group are transmitted among wild primates and humans.

CONCLUSIONS AND SIGNIFICANCE

Our results suggest that the host range of Trichuris varies by taxonomic group, with some groups showing host specificity, and others showing host generality. In particular, one Trichuris taxon should be considered a multi-host pathogen that is capable of infecting wild primates and humans. This challenges past assumptions about the host specificity of this and similar helminth parasites and raises concerns about animal and human health.

Effects of anthropogenic and demographic factors on patterns of parasitism in African small mammal communities

Habitat disturbance often results in alterations in community structure of small mammals. Additionally, the parasites harboured by these small mammals may be impacted by environmental changes or indirectly affected by changes in available hosts. To improve our understanding of this interplay, we examined the patterns of parasitism in small mammal communities from a variety of habitats in forested Uganda. Small mammals were collected from areas experiencing variable habitat disturbance, host density and species richness. The analysis focused on 3 most abundant rodent species, Lophuromys aquilus, Praomys jacksoni and Hylomyscus stella, and a diverse group of parasites they harbour. The impact of various habitat and host community factors on parasite prevalence was examined using linear regression and Spearman's rank-order correlation. We further investigated the parasite communities associated with each individual using correspondence analysis. We determined that, parasite prevalence and richness may be occasionally influenced by community and habitat factors, but taxonomy is a driving force in influencing the parasite community harboured by an individual host. Ultimately, applying general principles across a broad range of disturbance levels and diverse host communities needs to be approached with caution in complex communities.

Multilocus typing of Cryptosporidium spp. and Giardia duodenalis from non-human primates in China

Non-human primates (NHPs) are commonly infected with Cryptosporidium spp. and Giardia duodenalis. However, molecular characterisation of these pathogens from NHPs remains scarce. In this study, 2,660 specimens from 26 NHP species in China were examined and characterised by PCR amplification of 18S rRNA, 70kDa heat shock protein (hsp70) and 60kDa glycoprotein (gp60) gene loci for Cryptosporidium; and 1,386 of the specimens by ssrRNA, triosephosphate isomerase (tpi) and glutamate dehydrogenase (gdh) gene loci for Giardia. Cryptosporidium was detected in 0.7% (19/2660) specimens of four NHP species including rhesus macaques (0.7%), cynomolgus monkeys (1.0%), slow lorises (10.0%) and Francois' leaf monkeys (6.7%), belonging to Cryptosporidium hominis (14/19) and Cryptosporidium muris (5/19). Two C. hominis gp60 subtypes, IbA12G3 and IiA17 were observed. Based on the tpi locus, G. duodenalis was identified in 2.2% (30/1,386) of specimens including 2.1% in rhesus macaques, 33.3% in Japanese macaques, 16.7% in Assam macaques, 0.7% in white-headed langurs, 1.6% in cynomolgus monkeys and 16.7% in olive baboons. Sequence analysis of the three targets indicated that all of the Giardia-positive specimens belonged to the zoonotic assemblage B. Highest sequence polymorphism was observed at the tpi locus, including 11 subtypes: three known and eight new ones. Phylogenetic analysis of the subtypes showed that most of them were close to the so-called subtype BIV. Intragenotypic variations at the gdh locus revealed six types of sequences (three known and three new), all of which belonged to so-called subtype BIV. Three specimens had co-infection with C. hominis (IbA12G3) and G. duodenalis (BIV). The presence of zoonotic genotypes and subtypes of Cryptosporidium spp. and G. duodenalis in NHPs suggests that these animals can potentially contribute to the transmission of human cryptosporidiosis and giardiasis.

Biomedical evaluation of Verreaux's sifaka (Propithecus verreauxi) from Kirindy Mitea National Park in Madagascar

Evaluation of the health, prevalence, and incidence of diseases in wild populations is a critical component of wildlife management. In addition, the establishment of reference physiologic parameters can Verreaux's sifaka (Propithecus verreauxi) from Kirindy Mitea National Park, Madagascar, during two field captures incontribute to the assessment of population risks. Complete medical evaluations were performed on 33 wild June 2010 and June 2011. Each animal received a complete physical examination: weight, body temperature, heart rate, and respiratory rate were recorded, and ectoparasites collected. Blood samples were collected for complete blood cell count, differential white blood cell count, hemoparasite examination, serum biochemical profile, fat-soluble vitamin analysis, trace mineral analysis, and toxoplasmosis and viral serology. Fecal samples were collected for bacterial culture and endoparasite examination. Significant differences exist between age classes for neutrophil and lymphocyte count, alkaline phosphatase, and creatinine values. Parasites detected were Callistoura sp., Bertiella lemuriformis, and Dipetalonema petteri. This publication reports the first complete biomedical evaluation of the P. verreauxi and provides a basis for hematologic and biochemical comparisons of P. verreauxi in the wild.

Field immobilization for treatment of an unknown illness in a wild chimpanzee (Pan troglodytes schweinfurthii) at Gombe National Park, Tanzania: findings, challenges, and lessons learned

Infectious diseases are widely presumed to be one of the greatest threats to ape conservation in the wild. Human diseases are of particular concern, and the costs and benefits of human presence in protected areas with apes are regularly debated. While numerous syndromes with fatal outcomes have recently been described, precise identification of pathogens remains difficult. These diagnostic difficulties are compounded by the fact that direct veterinary intervention on wild apes is quite rare. Here we present the unique case of a wild chimpanzee at Gombe National Park that was observed with a severe illness and was subsequently examined and treated in the field. Multiple specimens were collected and tested with the aim of identifying the pathogen responsible for the illness. Our findings represent the first extensive screening of a living wild chimpanzee, yet despite our efforts, the cause and source of illness remain unknown. Nevertheless, our findings represent valuable baseline data for the ape conservation community and for comparison with other recent findings. In addition, we present the case here to demonstrate the planning required and multiple types of expertise necessary to maximize the amount of data obtained from such a rare intervention, and to provide lessons learned for future studies.

Fecal microbiomes of non-human primates in Western Uganda reveal species-specific communities largely resistant to habitat perturbation

Primate gastrointestinal microbial communities are becoming increasingly appreciated for their relevance to comparative medicine and conservation, but the factors that structure primate "microbiomes" remain controversial. This study examined a community of primates in Kibale National Park, Uganda, to assess the relative importance of host species and location in structuring gastrointestinal microbiomes. Fecal samples were collected from primates in intact forest and from primates in highly disturbed forest fragments. People and livestock living nearby were also included, as was a geographically distant population of related red colobus in Kenya. A culture-free microbial community fingerprinting technique was used to analyze fecal microbiomes from 124 individual red colobus (Procolobus rufomitratus), 100 individual black-and-white colobus (Colobus guereza), 111 individual red-tailed guenons (Cercopithecus ascanius), 578 human volunteers, and 364 domestic animals, including cattle (Bos indicus and B. indicus × B. taurus crosses), goats (Caprus hircus), sheep (Ovis aries), and pigs (Sus scrofa). Microbiomes sorted strongly by host species, and forest fragmentation did not alter this pattern. Microbiomes of Kenyan red colobus sorted distinctly from microbiomes of Ugandan red colobus, but microbiomes from these two red colobus populations clustered more closely with each other than with any other species. Microbiomes from red colobus and black-and-white colobus were more differentiated than would be predicted by the phylogenetic relatedness of these two species, perhaps reflecting heretofore underappreciated differences in digestive physiology between the species. Within Kibale, social group membership influenced intra-specific variation among microbiomes. However, intra-specific variation was higher among primates in forest fragments than among primates in intact forest, perhaps reflecting the physical separation of fragments. These results suggest that, in this system, species-specific processes such as gastrointestinal physiology strongly structure microbial communities, and that primate microbiomes are relatively resistant to perturbation, even across large geographic distances or in the face of habitat disturbance.

Long-term monitoring of microsporidia, Cryptosporidium and Giardia infections in western Lowland Gorillas (Gorilla gorilla gorilla) at different stages of habituation in Dzanga Sangha Protected Areas, Central African Republic

BACKGROUND

Infectious diseases pose one of the greatest threats to endangered species, and a risk of gastrointestinal parasite transmission from humans to wildlife has always been considered as a major concern of tourism. Increased anthropogenic impact on primate populations may result in general changes in communities of their parasites, and also in a direct exchange of parasites between humans and primates.

AIMS

To evaluate the impact of close contact with humans on the occurrence of potentially zoonotic protists in great apes, we conducted a long-term monitoring of microsporidia, Cryptosporidium and Giardia infections in western lowland gorillas at different stages of the habituation process, humans, and other wildlife in Dzanga-Sangha Protected Areas in the Central African Republic.

RESULTS

We detected Encephalitozoon cuniculi genotypes I and II (7.5%), Enterocytozoon bieneusi genotype D and three novel genotypes (gorilla 1-3) (4.0%), Giardia intestinalis subgroup A II (2.0%) and Cryptosporidium bovis (0.5%) in gorillas, whereas in humans we found only G. intestinalis subgroup A II (2.1%). In other wild and domestic animals we recorded E. cuniculi genotypes I and II (2.1%), G. intestinalis assemblage E (0.5%) and C. muris TS03 (0.5%).

CONCLUSION

Due to the non-specificity of E. cuniculi genotypes we conclude that detection of the exact source of E. cuniculi infection is problematic. As Giardia intestinalis was recorded primarily in gorilla groups with closer human contact, we suggest that human-gorilla transmission has occurred. We call attention to a potentially negative impact of habituation on selected pathogens which might occur as a result of the more frequent presence of humans in the vicinity of both gorillas under habituation and habituated gorillas, rather than as a consequence of the close contact with humans, which might be a more traditional assumption. We encourage to observe the sections concerning hygiene from the IUCN best practice guidelines for all sites where increased human-gorilla contact occurs.

Zoonotic potential of Giardia

Giardia duodenalis (syn. Giardia lamblia and Giardia intestinalis) is a common intestinal parasite of humans and mammals worldwide. Assessing the zoonotic transmission of the infection requires molecular characterization as there is considerable genetic variation within G. duodenalis. To date eight major genetic groups (assemblages) have been identified, two of which (A and B) are found in both humans and animals, whereas the remaining six (C to H) are host-specific and do not infect humans. Sequence-based surveys of single loci have identified a number of genetic variants (genotypes) within assemblages A and B in animal species, some of which may have zoonotic potential. Multi-locus typing data, however, has shown that in most cases, animals do not share identical multi-locus types with humans. Furthermore, interpretation of genotyping data is complicated by the presence of multiple alleles that generate "double peaks" in sequencing files from PCR products, and by the potential exchange of genetic material among isolates, which may account for the non-concordance in the assignment of isolates to specific assemblages. Therefore, a better understanding of the genetics of this parasite is required to allow the design of more sensitive and variable subtyping tools, that in turn may help unravel the complex epidemiology of this infection.

Gastrointestinal symbionts of chimpanzees in Cantanhez National Park, Guinea-Bissau with respect to habitat fragmentation

One of the major factors threatening chimpanzees (Pan troglodytes verus) in Guinea-Bissau is habitat fragmentation. Such fragmentation may cause changes in symbiont dynamics resulting in increased susceptibility to infection, changes in host specificity and virulence. We monitored gastrointestinal symbiotic fauna of three chimpanzee subpopulations living within Cantanhez National Park (CNP) in Guinea Bissau in the areas with different levels of anthropogenic fragmentation. Using standard coproscopical methods (merthiolate-iodine formalin concentration and Sheather's flotation) we examined 102 fecal samples and identified at least 13 different symbiotic genera (Troglodytella abrassarti, Troglocorys cava, Blastocystis spp., Entamoeba spp., Iodamoeba butschlii, Giardia intestinalis, Chilomastix mesnili, Bertiella sp., Probstmayria gombensis, unidentified strongylids, Strongyloides stercoralis, Strongyloides fuelleborni, and Trichuris sp.). The symbiotic fauna of the CNP chimpanzees is comparable to that reported for other wild chimpanzee populations, although CNP chimpanzees have a higher prevalence of Trichuris sp. Symbiont richness was higher in chimpanzee subpopulations living in fragmented forests compared to the community inhabiting continuous forest area. We reported significantly higher prevalence of G. intestinalis in chimpanzees from fragmented areas, which could be attributed to increased contact with humans and livestock.

Wildlife disease prevalence in human-modified landscapes

Human-induced landscape change associated with habitat loss and fragmentation places wildlife populations at risk. One issue in these landscapes is a change in the prevalence of disease which may result in increased mortality and reduced fecundity. Our understanding of the influence of habitat loss and fragmentation on the prevalence of wildlife diseases is still in its infancy. What is evident is that changes in disease prevalence as a result of human-induced landscape modification are highly variable. The importance of infectious diseases for the conservation of wildlife will increase as the amount and quality of suitable habitat decreases due to human land-use pressures. We review the experimental and observational literature of the influence of human-induced landscape change on wildlife disease prevalence, and discuss disease transmission types and host responses as mechanisms that are likely to determine the extent of change in disease prevalence. It is likely that transmission dynamics will be the key process in determining a pathogen's impact on a host population, while the host response may ultimately determine the extent of disease prevalence. Finally, we conceptualize mechanisms and identify future research directions to increase our understanding of the relationship between human-modified landscapes and wildlife disease prevalence. This review highlights that there are rarely consistent relationships between wildlife diseases and human-modified landscapes. In addition, variation is evident between transmission types and landscape types, with the greatest positive influence on disease prevalence being in urban landscapes and directly transmitted disease systems. While we have a limited understanding of the potential influence of habitat loss and fragmentation on wildlife disease, there are a number of important areas to address in future research, particularly to account for the variability in increased and decreased disease prevalence. Previous studies have been based on a one-dimensional comparison between unmodified and modified sites. What is lacking are spatially and temporally explicit quantitative approaches which are required to enable an understanding of the range of key causal mechanisms and the reasons for variability. This is particularly important for replicated studies across different host-pathogen systems. Furthermore, there are few studies that have attempted to separate the independent effects of habitat loss and fragmentation on wildlife disease, which are the major determinants of wildlife population dynamics in human-modified landscapes. There is an urgent need to understand better the potential causal links between the processes of human-induced landscape change and the associated influences of habitat fragmentation, matrix hostility and loss of connectivity on an animal's physiological stress, immune response and disease susceptibility. This review identified no study that had assessed the influence of human-induced landscape change on the prevalence of a wildlife sexually transmitted disease. A better understanding of the various mechanisms linking human-induced landscape change and the prevalence of wildlife disease will lead to more successful conservation management outcomes.

Epidemiology and molecular relationships of Cryptosporidium spp. in people, primates, and livestock from Western Uganda

Background

Cryptosporidium is one of the most common parasitic diarrheal agents in the world and is a known zoonosis. We studied Cryptosporidium in people, livestock, and non-human primates in the region of Kibale National Park, Uganda. Land use change near the park has resulted in fragmented forest patches containing small, remnant populations of wild primates that interact intensively with local people and livestock. Our goal was to investigate risk factors for Cryptosporidium infection and to assess cross-species transmission using molecular methods.

Methodology/Principal Findings

Diagnostic PCR revealed a prevalence of Cryptosporidium of 32.4% in humans, 11.1% in non-human primates, and 2.2% in livestock. In the case of humans, residence in one particular community was associated with increased risk of infection, as was fetching water from an open water source. Although 48.5% of infected people reported gastrointestinal symptoms, this frequency was not significantly different in people who tested negative (44.7%) for Cryptosporidium, nor was co-infection with Giardia duodenalis associated with increased reporting of gastrointestinal symptoms. Fecal consistency was no different in infected versus uninfected people or animals. DNA sequences of the Cryptosporidium oocyst wall protein gene placed all infections within a well-supported C. parvum/C. hominis clade. However, the only two sequences recovered from primates in the core of the park's protected area fell into a divergent sub-clade and were identical to published sequences from C. parvum, C. hominis, and C. cuniculus, suggesting the possibility of a separate sylvatic transmission cycle.

Conclusions/Significance

Cryptosporidium may be transmitted frequently among species in western Uganda where people, livestock, and wildlife interact intensively as a result of anthropogenic changes to forests, but the parasite may undergo more host-specific transmission where such interactions do not occur. The parasite does not appear to have strong effects on human or animal health, perhaps because of persistent low-level shedding and immunity.

Cryptosporidium is a common gastrointestinal parasite known for its zoonotic potential. We found Cryptosporidium in 32.4% of people, 11.1% of non-human primates, and 2.2% of livestock in the region of Kibale National Park, Uganda. In people, infection rates were higher in one community than elsewhere, and fetching water from an open water source increased the probability of infection. Phylogenetic analyses identified clusters of Cryptosporidium with mixed host origins in people, primates, and livestock outside the park; however, parasites from primates inside the park were genetically divergent, suggesting a separate sylvatic transmission cycle. Infection was not associated with clinical disease in people, even in the case of co-infection with the gastrointestinal parasite Giardia duodenalis. Parasites such as Cryptosporidium may be maintained through frequent cross-species transmission in tropical settings where people, livestock, and wildlife interact frequently, but the parasite may undergo more host-specific transmission where such interactions do not occur. Persistent low-level shedding and immunity may limit the clinical effects of infection in such settings.

Microbiological quality of drinking rainwater in the inland region of Pajeú, Pernambuco, Northeast Brazil

Despite all efforts to store and reduce its consumption, water is becoming less inexhaustible and its quality is falling faster. Considering that water is essential to animal life, it is necessary to adopt measures to ensure its sanitary conditions in order to be fit for consumption. The aim of this study was to analyze the microbiological quality of drinking rainwater used by rural communities of Tuparetama, a small town located in Northeast Brazil. The study covered seven rural communities, totaling 66 households. In each household two samples were collected, one from a tank and the other from a clay pot located inside the home, resulting in 132 samples (tank plus clay pot). Approximately 90% of samples were below the standard recommended by the current legislation, being considered unfit for human consumption. Part of this high microbiological contamination of drinking rainwater could be related to the lack of sanitary education and of an adequate sewerage sanitation system.

The anthropogenic environment lessens the intensity and prevalence of gastrointestinal parasites in Balinese long-tailed macaques (Macaca fascicularis)

The distribution of wildlife parasites in a landscape is intimately tied to the spatial distribution of hosts. In parasite species, including many gastrointestinal parasites, with obligate or common environmental life stages, the dynamics of the parasite can also be strongly affected by geophysical components of the environment. This is especially salient in host species, for example humans and macaques, which thrive across a wide variety of habitat types and quality and so are exposed to a wealth of environmentally resilient parasites. Here, we examine the effect of environmental and anthropogenic components of the landscape on the prevalence, intensity, and species diversity of gastrointestinal parasites across a metapopulation of long-tailed macaques on the island of Bali, Indonesia. Using principal-components analysis, we identified significant interaction effects between specific environmental and anthropogenic components of the landscape, parsing the Balinese landscape into anthropogenic (PC1), mixed environment (PC2), and non-anthropogenic (PC3) components. Further, we determined that the anthropogenic environment can mitigate the prevalence and intensity of specific gut parasites and the intensity of the overall community of gut parasites, but that non-anthropogenically driven landscape components have no significant effect in increasing or reducing the intensity or prevalence of the community of gut parasites in Balinese macaques.

Molecular epidemiology of cross-species Giardia duodenalis transmission in western Uganda

Background

Giardia duodenalis is prevalent in tropical settings where diverse opportunities exist for transmission between people and animals. We conducted a cross-sectional study of G. duodenalis in people, livestock, and wild primates near Kibale National Park, Uganda, where human-livestock-wildlife interaction is high due to habitat disturbance. Our goal was to infer the cross-species transmission potential of G. duodenalis using molecular methods and to investigate clinical consequences of infection.

Methodology/Principal Findings

Real-time PCR on DNA extracted from fecal samples revealed a combined prevalence of G. duodenalis in people from three villages of 44/108 (40.7%), with prevalence reaching 67.5% in one village. Prevalence rates in livestock and primates were 12.4% and 11.1%, respectively. Age was associated with G. duodenalis infection in people (higher prevalence in individuals ≤15 years) and livestock (higher prevalence in subadult versus adult animals), but other potential risk factors in people (gender, contact with domestic animals, working in fields, working in forests, source of drinking water, and medication use) were not. G. duodenalis infection was not associated with gastrointestinal symptoms in people, nor was clinical disease noted in livestock or primates. Sequence analysis of four G. duodenalis genes identified assemblage AII in humans, assemblage BIV in humans and endangered red colobus monkeys, and assemblage E in livestock and red colobus, representing the first documentation of assemblage E in a non-human primate. In addition, genetic relationships within the BIV assemblage revealed sub-clades of identical G. duodenalis sequences from humans and red colobus.

Conclusions/Significance

Our finding of G. duodenalis in people and primates (assemblage BIV) and livestock and primates (assemblage E) underscores that cross-species transmission of multiple G. duodenalis assemblages may occur in locations such as western Uganda where people, livestock, and primates overlap in their use of habitat. Our data also demonstrate a high but locally variable prevalence of G. duodenalis in people from western Uganda, but little evidence of associated clinical disease. Reverse zoonotic G. duodenalis transmission may be particularly frequent in tropical settings where anthropogenic habitat disturbance forces people and livestock to interact at high rates with wildlife, and this could have negative consequences for wildlife conservation.

Giardia duodenalis is a common protozoan parasite that infects multiple mammalian species, including humans. We analyzed G. duodenalis from people, livestock, and wild non-human primates in forest fragments near Kibale National Park, western Uganda, where habitat disturbance and human-animal interaction are high. Molecular analyses indicated that endangered red colobus monkeys were infected with G. duodenalis assemblages BIV and E, which characteristically infect humans and livestock, respectively. G. duodenalis infected people at rates of up to 67.5% in one village, and people age 15 years or younger were especially likely to be infected. G. duodenalis infection in people was not associated with other factors related to behavior and hygiene, and infected people were no more likely to have reported gastrointestinal symptoms than were uninfected people. These results demonstrate that G. duodenalis transmission from humans and domestic animals to wildlife may occur with ease in locations such as western Uganda, where habitat disturbance causes ecological overlap among people, livestock, and primates. This conclusion has conservation implications for wildlife such as red colobus, which are already endangered by habitat loss.

Ecology of the gastrointestinal parasites of Colobus vellerosus at Boabeng-Fiema, Ghana: possible anthropozoonotic transmission

Parasite richness and prevalence in wild animals can be used as indicators of population and ecosystem health. In this study, the gastrointestinal parasites of ursine colobus monkeys (Colobus vellerosus) at the Boabeng-Fiema Monkey Sanctuary (BFMS), Ghana, were investigated. BFMS is a sacred grove where monkeys and humans have long lived in relatively peaceful proximity. Fecal samples (n = 109) were collected opportunistically from >27 adult and subadult males in six bisexual groups and one all-male band from July 2004 to August 2005. Using fecal floatation, we detected three protozoans (two Entamoeba sp., Isospora sp.), five nematodes (Ascaris sp., Enterobius sp., Trichuris sp., two strongyle sp.), and one digenean trematode. Using fluorescein labeled antibodies, we detected an additional protozoan (Giardia sp.), and with PCR techniques, we characterized this as G. duodenalis Assemblage B and also identified a protistan (Blastocystis sp., subtype 2). The most prevalent parasite species were G. duodenalis and Trichuris sp. Parasites were more prevalent in the long wet season than the long dry. Parasite prevalence did not vary by age, and average parasite richness did not differ by rank for males whose status remained unchanged. However, males that changed rank tended to show higher average parasite richness when they were lower ranked. Individuals that spent more time near human settlements had a higher prevalence of Isospora sp. that morphologically resembled the human species I. belli. The presence of this parasite and G. duodenalis Assemblage B indicates possible anthropozoonotic and/or zoonotic transmission between humans and colobus monkeys at this site.

A legacy of low-impact logging does not elevate prevalence of potentially pathogenic protozoa in free-ranging gorillas and chimpanzees in the Republic of Congo: logging and parasitism in African apes

Many studies have examined the long-term effects of selective logging on the abundance and diversity of free-ranging primates. Logging is known to reduce the abundance of some primate species through associated hunting and the loss of food trees for frugivores; however, the potential role of pathogens in such primate population declines is largely unexplored. Selective logging results in a suite of alterations in host ecology and forest structure that may alter pathogen dynamics in resident wildlife populations. In addition, environmental pollution with human fecal material may present a risk for wildlife infections with zoonotic protozoa, such as Cryptosporidium and Giardia. To better understand this interplay, we compared patterns of infection with these potentially pathogenic protozoa in sympatric western lowland gorillas (Gorilla gorilla gorilla) and chimpanzees (Pan troglodytes troglodytes) in the undisturbed Goualougo Triangle of Nouabalé-Ndoki National Park and the adjacent previously logged Kabo Concession in northern Republic of Congo. No Cryptosporidium infections were detected in any of the apes examined and prevalence of infection with Giardia was low (3.73% overall) and did not differ between logged and undisturbed forest for chimpanzees or gorillas. These results provide a baseline for prevalence of these protozoa in forest-dwelling African apes and suggest that low-intensity logging may not result in long-term elevated prevalence of potentially pathogenic protozoa.

Habitat fragmentation and haemoparasites in the common fruit bat, Artibeus jamaicensis (Phyllostomidae) in a tropical lowland forest in Panamá

Anthropogenic influence on ecosystems, such as habitat fragmentation, impacts species diversity and interactions. There is growing evidence that degradation of habitats favours disease and hence affects ecosystem health. The prevalence of haemoparasites in the Common Fruit Bat (Artibeus jamaicensis) in a tropical lowland forest in Panamá was studied. We assessed the relation of haemoparasite to the general condition of the animals and tested for possible association of haemoparasite prevalence to habitat fragmentation, with special focus on trypanosomes. Overall, a total of 250 A. jamaicensis sampled from fragmented sites, here man-made, forested islands in Lake Gatùn, and sites in the adjacent, continuous forest in and around the Barro Colorado Nature Monument were examined. Using microscopy and DNA-sequencing 2 dominant types of haemoparasite infections, trypanosomes and Litomosoides (Nematoda) were identified. Trypanosome prevalence was significantly higher in bats from forest fragments, than in bats captured in continuous forest. We attribute this to the loss of species richness in forest fragments and specific characteristics of the fragments favouring trypanosome transmission, in particular changes in vegetation cover. Interestingly, the effect of habitat fragmentation on the prevalence of trypanosomes as multi-host parasites could not be observed in Litomosoides which probably has a higher host specificity and might be affected less by overall diversity loss.

Molecular characterisation of Giardiaduodenalis in captive non-human primates reveals mixed assemblage A and B infections and novel polymorphisms

Giardia is frequently detected in stools of non-human primates (NHP). However, a molecular identification has been rarely applied to Giardia isolates from NHP, and the distribution of the zoonotic assemblages A and B remains unclear. Moreover, little is known about the genetic variability among the isolates, although this may contribute to the elucidation of the different transmission pathways, including the role of NHP as a reservoir for human giardiasis. Therefore, 258 Giardia samples from 31 NHP species housed in nine zoological gardens and one sanctuary in Belgium and The Netherlands were characterised based on an assemblage-specific PCR targeting the triose phosphate isomerase (tpi) gene to identify both assemblage A and B infections. In addition, a multi-locus sequencing approach based on the glutamate dehydrogenase, the tpi and the beta-giardin genes was used to examine both the genetic variability and the ability to allocate these isolates to different NHP groups. Overall, assemblage B was the most prevalent (78.6%), but mixed assemblage A and B infections occurred in 32.7% of the samples. Sequencing of the isolates revealed the presence of new polymorphisms for both assemblages and at the three loci examined. The majority of the assemblage B isolates could not be grouped into recently described sub-assemblages, particularly at the tpi gene. Isolates could only be allocated to a specific group when polymorphisms of the three loci were combined. The results confirm that NHP are a potential reservoir for zoonotic transmission and advocate the use of assemblage-specific primers in molecular epidemiological surveys, as mixed infections are likely to be underestimated. The high level of heterogeneity within assemblages indicates that a revised nomenclature of these sub-assemblages is needed, but points out the potency of a multi-locus sequencing approach to unravel the complex epidemiology of Giardia duodenalis.

Integrative approaches to the study of primate infectious disease: implications for biodiversity conservation and global health

The close phylogenetic relationship between humans and nonhuman primates, coupled with the exponential expansion of human populations and human activities within primate habitats, has resulted in exceptionally high potential for pathogen exchange. Emerging infectious diseases are a consequence of this process that has the capacity to threaten global health and drive primate population declines. Integration of standardized empirical data collection, state-of-the-art diagnostics, and the comparative approach offers the opportunity to create a baseline for patterns of infection in wild primate populations; to better understand the role of disease in primate ecology, behavior, and evolution; and to examine how anthropogenic effects alter the zoonotic potential of various pathogenic organisms. We review these technologies and approaches, including noninvasive sampling in field conditions, and we identify ways in which integrative research activities are likely to fuel future discoveries in primate disease ecology. In addition to considering applied aspects of disease research in primate health and conservation, we review how these approaches are shedding light on parasite biodiversity and the drivers of disease risk across primate species.

Forest fragmentation, the decline of an endangered primate, and changes in host-parasite interactions relative to an unfragmented forest

Forest fragmentation may alter host-parasite interactions in ways that contribute to host population declines. We tested this prediction by examining parasite infections and the abundance of infective helminths in 20 forest fragments and in unfragmented forest in Kibale National Park, Uganda. Over 4 years, the endangered red colobus (Procolobus rufomitratus) declined by 20% in fragments, whereas the black-and-white colobus (Colobus guereza) in fragments and populations of both colobines in unfragmented forest remained relatively stable. Seven nematodes (Strongyloides fulleborni, Strongyloides stercoralis, Oesophagostomum sp., an unidentified strongyle, Trichuris sp., Ascaris sp., and Colobenterobius sp.), one cestode (Bertiella sp.), and three protozoans (Entamoeba coli, Entamoeba histolytica/dispar, and Giardia sp.) were detected. Infection prevalence and the magnitude of multiple infections were greater for red colobus in fragmented than in unfragmented forest, but these parameters did not differ between forests for black-and-white colobus. Infective-stage colobus parasites occurred at higher densities in fragmented compared with unfragmented forest, demonstrating greater infection risk for fragmented populations. There was little evidence that the nature of the infection was related to the size of the fragment, the density of the host, or the nature of the infection in the other colobine, despite the fact that many of the parasites are considered generalists. This study suggests that forest fragmentation can alter host-parasite dynamics and demonstrates that such changes can correspond with changes in host population size in forest fragments.