Gastrointestinal parasites of the colobus monkeys of Uganda

Anoplocephalid tapeworms in mountain gorillas (Gorilla beringei beringei) inhabiting the Volcanoes National Park, Rwanda

Cestodes of the family Anoplocephalidae parasitize a wide range of usually herbivorous hosts including e.g. rodents, ungulates, primates, elephants and hyraxes. While in some hosts, the epidemiology of the infection is well studied, information is lacking in others. In this study of mountain gorillas in the Virunga Massif, an extensive sample set comprising adult cestodes collected via necropsies, proglottids shed in feces, and finally, fecal samples from both night nests and identified individuals were analysed. Anoplocephala gorillae was the dominant cestode species detected in night nest samples and individually known gorillas, of which only 1 individual hosted a Bertiella sp. It was shown that the 2 species can be distinguished through microscopy based on egg morphology and polymerase chain reaction (PCR) assays for diagnostics of both species were provided. Sequences of mitochondrial (cox 1) and nuclear (ITS1, 18S rDNA, 28S rDNA) markers were used to evaluate the phylogenetic position of the 2 cestodes detected in mountain gorillas. Both types of fecal samples, from night nests and from identified individuals, provided comparable information about the prevalence of anoplocephalid cestodes, although the analysis of samples collected from identified gorilla individuals showed significant intra-individual fluctuation of A. gorillae egg shedding within a short period. Therefore, multiple samples should be examined to obtain reliable data for wildlife health management programmes, especially when application of anthelmintic treatment is considered. However, while A. gorillae is apparently a common symbiont of mountain gorillas, it does not seem to impair the health of its host.

Prevalence of gastrointestinal helminth parasites in rhesus macaques and local residents in the central mid-hills of Nepal

Rhesus macaques (Macaca mulatta) are distributed across Nepal in close association with humans and with a high probability of sharing of soil-transmitted intestinal helminth parasites. This study was carried out to determine the prevalence, richness and risk factors of gastrointestinal (GI) helminth parasites among rhesus macaques and humans in the Daunne Forest area, a community managed forest in the central mid-hills of Nepal. A total of 190 fecal samples, including 120 samples from rhesus macaques residing around the Daunne Devi Temple and in the surrounding forest, and 70 from local people, were microscopically examined by direct wet mount, floatation and sedimentation methods. Seasonal and age-sex based variations in helminth parasite prevalence were analyzed. Among the rhesus macaques, the total parasite prevalence was 39.2 %. Strongyloides sp. accounted for the highest prevalence (19.17 %) followed by Ascaris sp. (13.33 %), hookworm (10.83 %) and Trichuris sp. (4.17 %). Among the humans, Ascaris lumbricoides (11.3 %) was the only parasite detected. The Sorenson's coefficient of similarity of GI parasites between the macaques and local people at the generic level was 0.4. Mean parasite richness for the macaques was 1.21 ± 0.41 (SD) per infected sample. Parasite prevalence in the summer season (41.4 %) was higher than in the winter season (36 %). Adult macaques (41.67 %) had higher GI parasite prevalence than the young (30.77 %) and infants (27.27 %). Among the adult macaques, the prevalence rate was significantly higher (P=0.005) in females (52.46 %) than in males (22.86 %). Our results indicate that the temple rhesus macaques have a high prevalence of GI helminth parasites and could pose a potential zoonotic risk. As such, the need for routine monitoring and an effective management strategy is essential.

Influence of landscape structure on previous exposure to Leptospira spp. and Brucella abortus in free-living neotropical primates from southern Brazil

The environments in which neotropical primates live have been undergoing an intense fragmentation process, constituting a major threat to the species' survival and causing resource scarcity, social isolation, and difficulty in dispersal, leaving populations increasingly vulnerable. Moreover, the proximity of wild environments to anthropized landscapes can change the dynamics of pathogens and the parasite-host-environment relationship, creating conditions that favor exposure to different pathogens. To investigate the previous exposure of free-living primates in Rio Grande do Sul State (RS), southern Brazil, to the bacterial agents Leptospira spp. and Brucella abortus, we investigated agglutinating antibodies against 23 serovars of Leptospira spp. using the microscopic agglutination test and B. abortus acidified antigen test in primate serum samples; 101 samples from primates captured between 2002 and 2016 in different forest fragments were used: 63 Alouatta caraya, 36 Alouatta guariba clamitans, and 02 Sapajus nigritus cucullatus. In addition, the forest remnants where the primates were sampled were characterized in a multiscale approach in radii ranging from 200 to 1400 m to investigate the potential relationship of previous exposure to the agent with the elements that make up the landscape structure. The serological investigation indicated the presence of antibodies for at least one of the 23 serovars of Leptospira spp. in 36.6% (37/101) of the samples analyzed, with titers ranging from 100 to 1600. The most observed serovars were Panama (17.8%), Ballum (5.9%), Butembo (5.9%), Canicola (5.9%), Hardjo (4.9%), and Tarassovi (3.9%); no samples were seropositive for Brucella abortus. Decreased forest cover and edge density were the landscape factors that had a significant relationship with Leptospira spp. exposure, indicating that habitat fragmentation may influence contact with the pathogen. The data generated in this study demonstrate the importance of understanding how changes in landscape structure affect exposure to pathogenic microorganisms of zoonotic relevance. Hence, improving epidemiological research and understanding primates' ecological role in these settings can help improve environmental surveillance and conservation strategies for primate populations in different landscapes.

Preliminary assessment of gastrointestinal parasites of the sun-tailed monkey (Allochrocebus solatus) in a semi-free-ranging colony

BACKGROUND

The occurrence of gastrointestinal parasites in the sun-tailed monkey (Allochrocebus solatus) at the CIRMF primatology center is unknown. We, therefore, assessed the presence and richness (number of different parasite taxa) of gastrointestinal parasites in a semi-free-ranging colony of A. solatus.

METHODS

A total of 46 fecal samples were screened using a modified McMaster technique for fecal egg counts.

RESULTS

In the 46 samples collected, seven taxa of gastrointestinal parasites, including protozoa and nematodes were identified. The most prevalent parasite was strongyles parasites (98%), followed by Trichuris spp. (72%), Strongyloides spp. (67%) and Entamoeba coli (65%). Balantioides coli (33%), Endolimax nana (25%), and Spirurid eggs (26%) were only found in a minority of the animals.

CONCLUSIONS

This study contributes new host records of gastrointestinal parasites in semi-free-ranging A. solatus and highlights the need to investigate the health of this species and implement proper precautions in the management of this colony.

Prevalence of intestinal parasites with molecular detection and identification of Giardia duodenalis in fecal samples of mammals, birds and zookeepers at Beni-Suef Zoo, Egypt

The current study aimed to investigate the prevalence of intestinal parasites from various species of mammals and birds housed in a zoological garden in Beni-Suef province, Egypt. A total of 77 fecal samples were collected from various primates (16), carnivores (7) and herbivores (54). Meanwhile, 123 fecal samples were collected from two Ostrichs (Struthio camelus), five Numida meleagris (Numida meleagris), twoIndian Peafowls (Pavo cristatus), two Emu (Dromaius novaehollandiae) 101 Pigeons (Columba livia domestica) and 11 Swan Goose (Anser sygnoides). In addition, seven stool samples from zookeepers who had been in close contact with animals and birds were examined. Salt flotation and formol ether sedimentation techniques were applied for parasitological examination. Positive samples of Giardia cysts were preserved in alcohol and kept at 4 °C until DNA extraction. Parasitological findings revealed that 48.05% of zoo animals were infected with intestinal parasites; 11.69% were positive with helminths and 27.27% with protozoa, however 9.09% had mixed infection. It was found that 75%, 57.14% and 38.89% of primates, carnivores and herbivores respectively were infected with intestinal parasites. In Primates the most prevalent parasites were Giardia spp. (43.75%) then Entamoeba histolytica/dispar (12.5%), Entamoeba coli (12.5%) and Trichuris spp. (6.25%). For carnivores, Ancylostomatidae had the highest prevalence (42.86%) followed by Spirometra spp. (14.29%). Meanwhile, Eimeria spp. (20.37%) was the most prevalent parasite in herbivores, followed by Blantidium coli (7.41%) and Tricuris spp. (7.41%), then Toxocara spp. (3.70%). Furthermore, the prevalence of infection in zoo birds was 21.95%. The identified parasites were Eimeria spp., Giardia spp., Capillaria spp., Ascaridia spp., Isospora spp. and Sublura brumpti. Stool examination of zookeepers revealed the presence of G. doudenalis and E. histolytica/ dispar cysts. The gdh gene of G. duodenalis was successfully amplified from fecal samples of zoo mammalsand zookeepers. In conclusion, the application of preventive and control measures against the propagation of infectious intestinal parasites is essential to prevent the spread of these parasites among zoo animals or to humans.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12639-020-01341-2.

Soil-transmitted helminth infections in free-ranging non-human primates from Cameroon and Gabon

BACKGROUND

Zoonotic diseases are a serious threat to both public health and animal conservation. Most non-human primates (NHP) are facing the threat of forest loss and fragmentation and are increasingly living in closer spatial proximity to humans. Humans are infected with soil-transmitted helminths (STH) at a high prevalence, and bidirectional infection with NHP has been observed. The aim of this study was to determine the prevalence, genetic diversity, distribution and presence of co-infections of STH in free-ranging gorillas, chimpanzees and other NHP species, and to determine the potential role of these NHP as reservoir hosts contributing to the environmental sustenance of zoonotic nematode infections in forested areas of Cameroon and Gabon.

METHODS

A total of 315 faecal samples from six species of NHPs were analysed. We performed PCR amplification, sequencing and maximum likelihood analysis of DNA fragments of the internal transcribed spacer 2 (ITS2) nuclear ribosomal DNA to detect the presence and determine the genetic diversity of Oesophagostomum spp., Necator spp. and Trichuris spp., and of targeted DNA fragments of the internal transcribed spacer 1 (ITS1) to detect the presence of Ascaris spp.

RESULTS

Necator spp. infections were most common in gorillas (35 of 65 individuals), but also present in chimpanzees (100 of 222 individuals) and in one of four samples from greater spot-nosed monkeys. These clustered with previously described type II and III Necator spp. Gorillas were also the most infected NHP with Oesophagostomum (51/65 individuals), followed by chimpanzees (157/222 individuals), mandrills (8/12 samples) and mangabeys (7/12 samples), with O. stephanostomum being the most prevalent species. Oesophagostomum bifurcum was detected in chimpanzees and a red-capped mangabey, and a non-classified Oesophagostomum species was detected in a mandrill and a red-capped mangabey. In addition, Ternidens deminutus was detected in samples from one chimpanzee and three greater spot-nosed monkeys. A significant relative overabundance of co-infections with Necator and Oesophagostomum was observed in chimpanzees and gorillas. Trichuris sp. was detected at low prevalence in a gorilla, a chimpanzee and a greater spot-nosed monkey. No Ascaris was observed in any of the samples analysed.

CONCLUSIONS

Our results on STH prevalence and genetic diversity in NHP from Cameroon and Gabon corroborate those obtained from other wild NHP populations in other African countries. Future research should focus on better identifying, at a molecular level, the species of Necator and Oesophagostomum infecting NHP and determining how human populations may be affected by increased proximity resulting from encroachment into sylvatic STH reservoir habitats.

The Gombe Ecosystem Health Project: 16 years of program evolution and lessons learned

Infectious disease outbreaks pose a significant threat to the conservation of chimpanzees (Pan troglodytes) and all threatened nonhuman primates. Characterizing and mitigating these threats to support the sustainability and welfare of wild populations is of the highest priority. In an attempt to understand and mitigate the risk of disease for the chimpanzees of Gombe National Park, Tanzania, we initiated a long-term health-monitoring program in 2004. While the initial focus was to expand the ongoing behavioral research on chimpanzees to include standardized data on clinical signs of health, it soon became evident that the scope of the project would ideally include diagnostic surveillance of pathogens for all primates (including people) and domestic animals, both within and surrounding the National Park. Integration of these data, along with in-depth post-mortem examinations, have allowed us to establish baseline health indicators to inform outbreak response. Here, we describe the development and expansion of the Gombe Ecosystem Health project, review major findings from the research and summarize the challenges and lessons learned over the past 16 years. We also highlight future directions and present the opportunities and challenges that remain when implementing studies of ecosystem health in a complex, multispecies environment.

Genetic characterization of nodular worm infections in Asian Apes

Parasitic nematodes of Oesophagostomum spp., commonly known, as 'nodular worms' are emerging as the most widely distributed and prevalent zoonotic nematodes. Oesophagostomum infections are well documented in African non-human primates; however, the taxonomy, distribution and transmission of Oesophagostomum in Asian non-human primates are not adequately studied. To better understand which Oesophagostomum species infect Asian non-human primates and determine their phylogeny we analysed 55 faecal samples from 50 orangutan and 5 gibbon individuals from Borneo and Sumatra. Both microscopy and molecular results revealed that semi-wild animals had higher Oesophagostomum infection prevalence than free ranging animals. Based on sequence genotyping analysis targeting the Internal transcribed spacer 2 of rDNA, we report for the first time the presence of O. aculeatum in Sumatran apes. Population genetic analysis shows that there is significant genetic differentiation between Bornean and Sumatran O. aculeatum populations. Our results clearly reveal that O. aculeatum in free-ranging animals have a higher genetic variation than those in semi-wild animals, demonstrating that O. aculeatum is circulating naturally in wildlife and zoonotic transmission is possible. Further studies should be conducted to better understand the epidemiology and dynamics of Oesophagostomum transmission between humans, non-human primates and other wild species and livestock in Southeast Asia.

Diversity and prevalence of gastrointestinal parasites with zoonotic potential of Green Monkeys in Bandia Reserve in Senegal

Background and Aim: Parasitic and infectious diseases are ubiquitous threats to primate and human populations. This study was carried out to study the diversity and frequency of gastrointestinal parasites with zoonotic potential in green monkeys in the Bandia Reserve located in Senegal. Materials and Methods: For this study, 164 stool samples of Chlorocebus aethiops sabaeus (green monkey) were collected from October to November 2018 from Bandia Reserve. Stool samples were processed using the merthiolate-iodine-formalin staining technique and the modified Ritchie method. The slides were examined under a microscope and the identification of parasites was based on the morphology of protozoan cysts and helminth eggs. The analysis of data was conducted using R version 3.4.3 with p=0.05. Results: A total of six species of parasites were found, including five protozoa (Entamoeba coli, Entamoeba histolytica/ dispar, Entamoeba hartmanni, Endolimax nana, and Iodamoeba butschlii) and one nematode (Strongyloides spp.). The overall prevalence of gastrointestinal parasite was 76.2% (95% CI: 69.7%-82.7%). Two parasites with zoonotic potential, mainly E. histolytica/dispar with a prevalence of 13.4% (95% CI: 8.2%-18.6%) and Strongyloides spp. with a prevalence of 6.7% (95% CI: 2.9%-10.5%), were found. Conclusion: This study indicated that the monkeys of the Bandia Reserve are infested by zoonotic parasites and can, therefore, ensure transmission to visitors to the Reserve. The parasitological data that we report are the first available for these species of monkeys in the Bandia Reserve.

Loss of protozoan and metazoan intestinal symbiont biodiversity in wild primates living in unprotected forests

In light of the current biodiversity crisis, investigating the human impact on non-human primate gut biology is important to understanding the ecological significance of gut community dynamics across changing habitats and its role in conservation. Using traditional coproscopic parasitological techniques, we compared the gastrointestinal protozoan and metazoan symbiont richness of two primates: the Udzungwa red colobus (Procolobus gordonorum) and the yellow baboon (Papio cynocephalus). These species live sympatrically in both protected and unprotected forests within the Udzungwa Mountains of Tanzania with distinct ecological adaptations and diets. Our results showed that terrestrial and omnivorous yellow baboons had 2 (95% CI 1.47–2.73) and 3.78 (2.62–5.46) times higher gut symbiont richness (both including and excluding rare protozoans) compared to the arboreal and leaf-eating Udzungwa red colobus in unprotected and protected forest, respectively. We also found a consistent depletion of symbiont richness in red colobus living in the unprotected forest fragment compared to the continuous protected forests [the latter having 1.97 times (95% CI 1.33–2.92) higher richness], but not in yellow baboons. Richness reduction was particularly evident in the Udzungwa red colobus monkeys, confirming the pattern we reported previously for gut bacterial communities. This study demonstrates the impact of human activities even on the microbiodiversity of the intestinal tract of this species. Against the background of rapid global change and habitat degradation, and given the health benefits of intact gut communities, the decrease in natural gut symbionts reported here is worrying. Further study of these communities should form an essential part of the conservation framework.

Altitude and human disturbance are associated with helminth diversity in an endangered primate, Procolobus gordonorum

Gastrointestinal parasites colonizing the mammalian gut influence the host immune system and health. Parasite infections, mainly helminths, have been studied intensively in both humans and non-human animals, but relatively rarely within a conservation framework. The Udzungwa red colobus monkey (Procolobus gordonorum) is an endangered endemic primate species living in the Udzungwa Mountains of Tanzania, a global biodiversity hotspot. Since this endemic primate species is highly sensitive to human disturbance, here we investigate whether habitat type (driven by natural and human-induced factors) is associated with helminth diversity. Using standard flotation and sedimentation techniques, we analyzed 251 fecal samples belonging to 25 social groups from four different forest blocks within the Udzungwa Mountains. Five parasitic helminth taxa were recovered from Udzungwa red colobus, including Trichuris sp., Strongyloides fulleborni, S. stercoralis, a strongylid nematode and Colobenterobius sp. We used Generalized Linear Mixed Models to explore the contribution of habitat type, altitude and fecal glucocorticoid levels (as biomarkers of stress) in predicting gut parasite variation. Although some parasites (e.g., Trichuris sp.) infected more than 50% of individuals, compared to others (e.g., Colobenterobius sp.) that infected less than 3%, both parasite richness and prevalence did not differ significantly across forests, even when controlling for seasonality. Stress hormone levels also did not predict variation in parasite richness, while altitude could explain it resulting in lower richness at lower altitudes. Because human activities causing disturbance are concentrated mainly at lower altitudes, we suggest that protection of primate forest habitat preserves natural diversity at both macro- and microscales, and that the importance of the latter should not be underestimated.

A Review of Strongyloides spp. Environmental Sources Worldwide

Strongyloides spp. are parasitic nematodes that are transmitted through the environment and are capable of causing disease. These nematodes affect an estimated 3–300 million humans worldwide. Identifying the environmental reservoirs of Strongyloides spp. is essential for the development of appropriate control strategies. This systematic literature review examined all published studies that identified Strongyloidesstercoralis, Strongyloidesfuelleborni, Strongyloidesfuellebornikellyi, and Strongyloides spp. from an environmental source. Most studies detected the nematode from dog and primate fecal samples. Other environmental sources identified were ruminants, cats, rodents, insects, water, soil, as well as fruit and vegetables. Most studies used microscopy-based identification techniques; however, several employed molecular-based techniques, which have become increasingly popular for the detection of Strongyloides spp. A limitation identified was a lack of studies that comprehensively screened all potential environmental samples in a region. Future research should undertake this holistic screening process to identify which environmental reservoirs pose the greatest significance to human health. Potential controls can be identified through the identification of environmental sources. Understanding where Strongyloides spp. is commonly found within the environment of endemic areas will inform environmental control strategies to reduce this neglected disease.

Molecular Characterization of Entamoeba spp. in Wild Taihangshan Macaques (Macaca mulatta tcheliensis) in China

BACKGROUND

Entamoeba spp. is one of the most common enteric parasites of humans and animals.

PURPOSE

However, little information is available regarding prevalence and genotypes of Entamoeba spp. in wild Taihangshan macaques (Macaca mulatta tcheliensis).

METHODS

In the present study, a total of 458 fecal samples from wild rhesus macaque in Taihangshan mountains area between September 2015 and November 2016, were collected and examined for the presence of six Entamoeba species by PCR amplification of the SSU rRNA gene.

RESULTS

The overall prevalence of Entamoeba spp. infection was 89.96% (412/458). Four species of Entamoeba detected in our survey were E. chattoni (88.43%), E. hartmanni (79.91%), E. coil (69.87%) and E. dispar (58.30%), and among these, 398 (84.93%) were mixed infections. Phylogenetic analysis revealed that isolates were clustered into four known genotypes.

CONCLUSION

The present study firstly provides important information about the prevalence and diversity of Entamoeba species infecting wild Taihangshan macaques in China. Enough attention should be paid to monitor the potential interspecies transmission in the region.

Occurrence of Selected Zoonotic Fecal Pathogens and First Molecular Identification of Hafnia paralvei in Wild Taihangshan Macaques (Macaca mulatta tcheliensis) in China

Rhesus macaques (Macaca mulatta) are hosts to a range of zoonotic and potentially zoonotic pathogens. The present study firstly provides a broader investigation of the presence and prevalence of zoonotic fecal pathogens in wild Taihangshan macaques, a subspecies of rhesus macaque in China. A total of 458 fecal samples were collected between September 2015 and November 2016. Fourteen genera of intestinal parasites (four genera of protozoans and ten genera of helminths) and twelve genera of bacteria were tested for using PCR amplification. The overall samples prevalence of parasitic infection was 98.25%. Entamoeba spp. (89.96%), Balantidium coli (70.09%), and Isospora spp. (28.38%) were the most prevalent protozoa, whereas the predominant prevalent helminths were Trichuris sp. (93.23%), Strongyloides spp. (73.36%), and Oesophagostomum sp. (31.66%). Ten genera of intestinal bacteria were detected in samples of rhesus macaques, including Shigella (31.66%), Escherichia coli (29.91%), Klebsiella pneumoniae (28.38%), Leptospira (26.64%), Campylobacter jejuni (18.34%), Salmonella (13.32%), etc. Eight samples (1.75%) were tested Hafnia-positive based on sequences analysis of 16S rRNA and ampC gene. This is the first molecular characterization of Hafnia infection in NHPs. Our cross-sectional prevalence study provides important information for monitoring the potential transmission of zoonotic infections from wild rhesus macaques.

Severe whipworm (Trichuris spp.) infection in the hamadryas baboon (Papio hamadryas)

A 3-year-old male hamadryas baboon (Papio hamadryas) at the Seoul Zoo, Korea, died without any previous symptoms. Necropsy revealed severe whipworm infection in the large intestine. The animal weighed 2.6 kg and had a blood clot at the anus. Numerous whipworms were found attached to the intestinal wall, with their anterior ends embedded in the mucosa. Fecal microscopy revealed typical barrel-shaped, brown eggs of Trichuris spp., with hyaline polar plugs at each end. Histopathological examination revealed the thin anterior part of Trichuris spp. embedded in the mucosal layer and the thick posterior part at the mucosal surface or hanging freely in the intestinal lumen. This case emphasizes the importance of parasitic infection management in zoo animals.

Prevalence of gastrointestinal parasites in bonnet macaque and possible consequences of their unmanaged relocations

Relocation is one of the mitigating measures taken by either local people or related officers to reduce the human-bonnet macaque Macaca radiata conflict in India. The review on relocations of primates in India indicates that monkeys are unscreened for diseases or gastrointestinal parasites (henceforth endoparasites) before relocation. We collected 161 spatial samples from 20 groups of bonnet macaque across their distribution range in south India and 205 temporal samples from a group in Chiksuli in the central Western Ghats. The isolation of endoparasite eggs/cysts from the fecal samples was by the centrifugation flotation and sedimentation method. All the sampled groups, except one, had an infection of at least one endoparasite taxa, and a total of 21 endoparasite taxon were recorded. The number of helminth taxon (16) were more than protozoan (5), further, among helminths, nematodes (11) were more common than cestodes (5). Although the prevalence of Ascaris sp. (26.0%), Strongyloides sp. (13.0%), and Coccidia sp. (13.0%) were greater, the load of Entamoeba coli, Giardia sp., Dipylidium caninum and Diphyllobothrium sp. were very high. Distant groups had more similarity in composition of endoparasites taxon than closely located groups. Among all the variables, the degree of provisioning was the topmost determinant factor for the endoparasite taxon richness and their load. Temporal sampling indicates that the endoparasite infection remains continuous throughout the year. Monthly rainfall and average maximum temperature in the month did not influence the endoparasite richness. A total of 17 taxon of helminths and four-taxon of protozoan were recorded. The prevalence of Oesophagostomum sp., and Strongyloides sp., and mean egg load of Spirurids and Trichuris sp. was higher than other endoparasite taxon. The overall endoparasite load and helminth load was higher in immatures than adults, where, adult females had the highest protozoan load in the monsoon. The findings indicate that relocation of commensal bonnet macaque to wild habitat can possible to lead transmission of novel endoparasites that can affect their population. Thus, we suggest avoidance of such relocations, however, if inevitable the captured animals need to be screened and treated for diseases and endoparasites before relocations.

Entamoeba histolytica infection in humans, chimpanzees and baboons in the Greater Gombe Ecosystem, Tanzania

Entamoeba histolytica is an enteric parasite that infects approximately 50 million people worldwide. Although E. histolytica is a zoonotic parasite that has the potential to infect nonhuman primates, such transmission is poorly understood. Consequently, this study examined whether E. histolytica is present among humans, chimpanzees and baboons living in the Greater Gombe Ecosystem (GGE), Tanzania. The primary aims were to determine patterns of E. histolytica infection in a system with human-nonhuman primate overlap and to test associations between infection status and potential risk factors of disease. Entamoeba spp. occurred in 60.3% of human, 65.6% of chimpanzee and 88.6% of baboon samples. Entamoeba histolytica occurred in 12.1% of human, 34.1% of chimpanzee and 10.9% of baboon samples. Human E. histolytica infection was associated with gastrointestinal symptoms. This was the first study to confirm the presence of E. histolytica in the GGE. The high sample prevalence of E. histolytica in three sympatric primates suggests that zoonotic transmission is possible and stresses the need for further phylogenetic studies. Interventions targeting better sanitation and hygiene practices for humans living in the GGE can help prevent E. histolytica infection in humans, while also protecting the endangered chimpanzees and other primates in this region.

Lurking in the dark: Cryptic Strongyloides in a Bornean slow loris

Within host communities, related species are more likely to share common parasitic agents, and as a result, morphological similarities have led researchers to conclude that parasites infecting closely related hosts within a community represent a single species. However, genetic diversity within parasite genera and host range remain poorly investigated in most systems. Strongyloides is a genus of soil-transmitted nematode that has been reported from several primate species in Africa and Asia, and has been estimated to infect hundreds of millions of people worldwide, although no precise estimates are available. Here we describe a case of infection with a cryptic species of Strongyloides in a Bornean (Philippine) slow loris (Nycticebus menagensis) living within a diverse community of several primate species in the Lower Kinabatangan Wildlife Sanctuary, Malaysian Borneo. Fresh fecal samples were collected from five primate species and nematode larvae cultured from these samples were selected for phylogenetic analyses. Sequences obtained for most larvae were identified as S. fuelleborni, grouping into three different clusters and showing no aggregation within specific hosts or geographic location. In contrast, a set of parasite sequences obtained from a slow loris clustered closely with S. stercoralis into a different group, being genetically distinct to sequences reported from other primate hosts, humans included. Our results suggest that although S. fuelleborni infects all haplorrhines sampled in this primate community, a different species might be infecting the slow loris, the only strepsirrhine in Borneo and one of the least studied primates in the region. Although more data are needed to support this conclusion, we propose that Strongyloides species in primates might be more diverse than previously thought, with potential implications for ecological and evolutionary host-parasite associations, as well as epidemiological dynamics.

Schistosoma mansoni and other intestinal parasitic infections in schoolchildren and vervet monkeys in Lake Ziway area, Ethiopia

Objective

To assess Schistosoma mansoni and other intestinal parasitic infections in schoolchildren and vervet monkeys (Chlorocebus aethiops) in Bochessa Village, Ziway, Ethiopia.

Results

Fecal specimens from selected schoolchildren and droppings of the vervet monkeys were collected and microscopically examined for intestinal parasites using the Kato-Katz thick smear and formol-ether concentration techniques. The prevalences of S. mansoni, Trichuris trichiura, Ascaris lumbricoides, Enterobius vermicularis, hookworms, Hymenolepis nana and Taenia species among the children were 35.7, 26.9, 24.1, 2.1, 2.1, 1.07 and 2.1%, respectively (by Kato-Katz) and 39.3, 36.1, 35.6, 2.9, 10.0, 4.3, and 2.9%, respectively (by formol-ether concentration). Prevalence of S. mansoni in vervet monkeys ranged from 10 to 20%. B. pfeifferi snails were exposed to S. mansoni miracidia from vervet origin, shed cercariae were then used to infect lab-bred albino mice. Adult worms were harvested from the mice 5 weeks post-exposure to cercariae to establish the schistosome life cycle and confirm the infection in the vervet monkeys. The natural infection of S. mansoni in vervet monkeys suggests that the non-human primate is likely to be implicated in the local transmission of schistosomiasis. Further epidemiological and molecular studies are needed to fully elucidate zoonotic role of non-human primate in the area.

Oesophagostomiasis in non-human primates of Gombe National Park, Tanzania

Oesophagostomum sp. is a parasitic nematode that frequently infects wild chimpanzees. Although nodular lesions are commonly associated with infection, some wild chimpanzee populations seem to tolerate Oesophagostomum nodular lesions while those at Gombe and other sites suffer from associated morbidity and mortality. From August 2004 to December 2013, we examined demographic (i.e., age, sex) and individual correlates (i.e., fecal consistency, Oesophagostomum egg production) to Oesophagostomum-associated pathology in 14 individually recognized chimpanzees at Gombe Stream National Park, Tanzania. In addition, we characterized Oesophagostomum-associated pathology in 14 individual sympatric primates including baboons, colobus, and cercopithecid monkeys. In five chimpanzees, there was no evidence of any significant underlying disease aside from oesophagostomiasis to explain the thin condition or diarrhea. All five of these chimpanzees had moderate to numerous parasitic nodules. In general, nodules were more numerous in older chimpanzees. Three of four chimpanzees with the highest average Oesophagostomum egg counts in feces collected during the year prior to their death had numerous parasitic nodules at necropsy. In contrast, the four chimpanzees with the lowest egg counts had only moderate numbers of nodules. No association (P = 0.74) was noted between frequency of diarrhea in the year prior to death and the number of nodules noted at necropsy. Nodules were also present in all baboons examined documenting pathology associated with Oesophagostomum infection in wild baboons. In contrast, no lesions were noted in colobus or cercopithecid monkeys, although it is uncertain if they are infected as no fecal studies have been completed in these species to date at Gombe. Sequence of DNA isolated from nodules in chimpanzees matched (99%) Oesophagostomum stephanostomum. Further research is needed to identify the types of Oesophagostomum causing lesions in baboons and to determine if baboons suffer from these infections. Am. J. Primatol. 80:e22572, 2018. © 2016 Wiley Periodicals, Inc.

Gastrointestinal parasites in captive and free-ranging Cebus albifrons in the Western Amazon, Ecuador

Currently, there is a lack of surveys that report the occurrence of gastrointestinal parasites in the white-headed capuchin monkey (Cebus albifrons). We therefore assessed the presence and richness (= number of different parasite genera) of parasites in C. albifrons in wildlife refuges (n = 11) and in a free-ranging group near a human village (n = 15) in the Ecuadorian Amazon. In the 78 samples collected (median of 3 samples per animal), we identified a total of 6 genera of gastrointestinal parasites, representing protozoa, nematodes, acanthocephalans and cestodes. We observed a high prevalence (84%) across the 26 individuals, with the most prevalent parasite being Strongyloides sp. (76.9%), followed by Hymenolepis sp. (38.5%) and Prosthenorchis elegans (11.5%). We found Entamoeba histolytica/dispar/moskovskii/nuttalli and Capillaria sp. in only a minority of the animals (3.8%). In addition, we observed unidentified strongyles in approximately one-third of the animals (34.6%). We found a total of 6 parasite genera for the adult age group, which showed higher parasite richness than the subadult age group (5) and the juvenile age group (3). Faecal egg/cyst counts were not significantly different between captive and free-ranging individuals or between sexes or age groups. The free-ranging group had a higher prevalence than the captive group; however, this difference was not significant. The only genus common to captive and free-ranging individuals was Strongyloides sp. The high prevalence of gastrointestinal parasites and the presence of Strongyloides in both populations support results from previous studies in Cebus species. This high prevalence could be related to the high degree of humidity in the region. For the free-ranging group, additional studies are required to gain insights into the differences in parasite prevalence and intensity between age and sex groups. Additionally, our study demonstrated that a serial sampling of each individual increases the test sensitivity.

Co-infection patterns of intestinal parasites in arboreal primates (proboscis monkeys, Nasalis larvatus) in Borneo

Non-human primates of South-East Asia remain under-studied concerning parasite epidemiology and co-infection patterns. Simultaneously, efforts in conservation demand knowledge of parasite abundance and biodiversity in threatened species. The Endangered proboscis monkey, Nasalis larvatus, a primate flagship species for conservation in Borneo, was investigated in the present study. Habitat loss and fragmentation are among the greatest threats to bachelor and harem groups of this folivorous colobine. Designed as a follow-up study, prevalence and co-infection status of intestinal parasites from N. larvatus in a protected area in Malaysian Borneo were analyzed from fecal samples using a flotation method. For the first time, the intestinal parasite co-infection patterns were examined using quantitative analyses. Overall, 92.3% of fecal samples (N = 652) were positive for helminth eggs. Five helminth groups were detected: (1) trichurids (82.7% prevalence) including Trichuris spp. (82.1%) and Anatrichosoma spp. (1.4%), (2) strongyles (58.9%) including Trichostrongylus spp. (48.5%) and Oesophagostomum/Ternidens spp. (22.8%), (3) Strongyloides fuelleborni (32.7%), (4) Ascaris lumbricoides (8.6%), and (5) Enterobius spp. (5.5%). On average, an individual was co-infected with two different groups. Significant positive associations were found for co-infections of trichurids with strongyles and S. fuelleborni as well as S. fuelleborni with A. lumbricoides and strongyles. This study shows a high prevalence of various gastrointestinal helminths with potential transmission pathways primarily related to soil and with zoonotic relevance in wild proboscis monkeys in their remaining natural habitats. Observed positive associations of trichurids with strongyles and Strongyloides spp. may result from the high prevalence of trichurids. Similarly, positive associations between Strongyloides and Ascaris were found, both of which typically occur predominantly in juvenile hosts. These findings should be considered when proposing conservation actions in altered habitats nearby human settlements and when managing captive populations.

Cis-regulatory evolution in a wild primate: Infection-associated genetic variation drives differential expression of MHC-DQA1 in vitro

Few studies have combined genetic association analyses with functional characterization of infection-associated SNPs in natural populations of nonhuman primates. Here, we investigate the relationship between host genetic variation, parasitism and natural selection in a population of red colobus (Procolobus rufomitratus tephrosceles) in Kibale National Park, Uganda. We collected parasitological, cellular and genomic data to test the following hypotheses: (i) MHC-DQA1 regulatory genetic variation is associated with control of whipworm (Trichuris) infection in a natural population of red colobus; (ii) infection-associated SNPs are functional in driving differential gene expression in vitro; and (iii) balancing selection has shaped patterns of variation in the MHC-DQA1 promoter. We identified two SNPs in the MHC-DQA1 promoter, both in transcription factor binding sites, and both of which are associated with decreased control of Trichuris infection. We characterized the function of both SNPs by testing differences in gene expression between the two alleles of each SNP in two mammalian cell lines. Alleles of one of the SNPs drove differential gene expression in both cell lines, while the other SNP drove differences in expression in one of the cell lines. Additionally, we found evidence of balancing selection acting on the MHC-DQA1 promoter, including extensive trans-species polymorphisms between red colobus and other primates, and an excess of intermediate-frequency alleles relative to genome-wide, coding and noncoding RADseq data. Our data suggest that balancing selection provides adaptive regulatory flexibility that outweighs the consequences of increased parasite infection intensity in heterozygotes.

Prevalence, molecular epidemiology, and zoonotic potential of Entamoeba spp. in nonhuman primates in China

Amebiasis is a major public-health concern. It has a global distribution, and is listed as the third leading parasitic cause of human mortality. To survey the prevalence and assess the potential zoonotic transmission of Entamoeba spp. in nonhuman primates (NHPs) in China, 2688 fresh fecal specimens were collected from NHPs reared in farms or zoos/parks or free ranging in 13 districts. The overall prevalence of Entamoeba spp. infection determined with microscopy analysis was 39.4% (1059/2688). Higher infection rates were detected in the free ranging group (41.1%, 169/411) and in animals <1year old (58.7%, 556/947). Gene fragments were successfully amplified 463 (87.2%) out of the 531 selected specimens (approximately half of the total microscopy-positive specimens). Polymerase chain reaction (PCR) amplification identified 386 (83.4%) Entamoeba dispar and 287 (62.0%) E. coli infections, and among these, 210 (45.4%) were mixed infections. And that the E. dispar and E. coli had also been detected in humans. In phylogenetic analysis, the E. dispar and E. coli sequences clustered with reference E. dispar and E. coli, respectively. In conclusion, nonhuman primates infected with Entamoeba species, with high prevalence and zoonotic potential, should be considered when evaluating the maintenance of Entamoeba spp. and its transmission between animal reservoirs and humans.

An investigation of parasitic infections and review of molecular characterization of the intestinal protozoa in nonhuman primates in China from 2009 to 2015

Parasites are a well-known threat to nonhuman primate (NHP) populations, and potentially cause zoonotic diseases in humans. In this study, the basic data was provided of the parasites in NHPs and the molecular characterization of the Enterocytozoon bieneusi, Giardia duodenalis, Cryptosporidium spp., and Entamoeba spp. were reviewed, which were found in these samples. A total of 3349 fecal samples were collected from 34 species reared at 17 districts in zoos, farms, free-range, or research laboratories, and examined microscopically. Eleven genera of intestinal parasites were detected: five genera of protozoans (Isospora spp., Entamoeba spp., Giardia sp., Cryptosporidium spp., and Cyclospora spp.) and six genera of helminths (Trichuris spp., Strongyloides spp., Ascaris spp., Physaloptera spp., Ancylostoma spp., and Enterobius spp.). The overall sample prevalence of parasitic infection was 54.1% (1811/3349). Entamoeba spp. was the most prevalent (36.4%, 1218/3349). The infection rate was the highest in free-range animals (73.0%, 670/918) (P < 0.01) and Guangxi Zhuang autonomous region (64.8%, 566/873). Mixed infections were mostly detected for Entamoeba spp., Trichuris spp., and Strongyloides spp.. Molecular characterization was reviewed of Enterocytozoon bieneusi, Giardia duodenalis, Cryptosporidium spp., and Entamoeba spp., as these are zoonotic species or genotypes. This parasitological data for NHPs in China, provides important information for veterinarians and public health authorities for the elimination of such parasites and monitor the potential transmission of zoonotic infections from NHPs.

Social Behaviours and Networks of Vervet Monkeys Are Influenced by Gastrointestinal Parasites

Substantial research has shown that while some parasite infections can be fatal to hosts, most infections are sub-clinical and non-lethal. Such sub-clinical infections can nonetheless have negative consequences for the long-term fitness of the host such as reducing juvenile growth and the host's ability to compete for food and mates. With such effects, infected individuals are expected to exhibit behavioural changes. Here we use a parasite removal experiment to quantify how gastrointestinal parasite infections affect the behaviour of vervet monkeys (Chlorocebus aethiops) at Lake Nabugabo, Uganda. Behavioural profiles and the structure of nearest neighbour relationships varied significantly. As predicted, after deworming the duration of the resting events decreased, which is consistent with the idea that parasite infections are energetically costly. In contrast to what was predicted, we could not reject the null hypothesis and we observed no change in either the frequency or duration of grooming, but we found that the duration of travel events increased. A network analysis revealed that after deworming, individuals tended to have more nearest neighbours and hence probably more frequent interactions, with this effect being particularly marked for juveniles. The heightened response by juveniles may indicate that they are avoiding infected individuals more than other age classes because it is too costly to move energy away from growth. We consider that populations with high parasite burden may have difficulties developing social networks and behaviours that could have cascading effects that impact the population in general.

Sickness behaviour associated with non-lethal infections in wild primates

Non-lethal parasite infections are common in wildlife, but there is little information on their clinical consequences. Here, we pair infection data from a ubiquitous soil-transmitted helminth, the whipworm (genus Trichuris), with activity data from a habituated group of wild red colobus monkeys (Procolobus rufomitratus tephrosceles) in Kibale National Park, Uganda. We use mixed-effect models to examine the relationship between non-lethal parasitism and red colobus behaviour. Our results indicate that red colobus increased resting and decreased more energetically costly behaviours when shedding whipworm eggs in faeces. Temporal patterns of behaviour also changed, with individuals switching behaviour less frequently when whipworm-positive. Feeding frequency did not differ, but red colobus consumption of bark and two plant species from the genus Albizia, which are used locally in traditional medicines, significantly increased when animals were shedding whipworm eggs. These results suggest self-medicative plant use, although additional work is needed to verify this conclusion. Our results indicate sickness behaviours, which are considered an adaptive response by hosts during infection. Induction of sickness behaviour in turn suggests that these primates are clinically sensitive to non-lethal parasite infections.

Competing pressures on populations: long-term dynamics of food availability, food quality, disease, stress and animal abundance

Despite strong links between sociality and fitness that ultimately affect the size of animal populations, the particular social and ecological factors that lead to endangerment are not well understood. Here, we synthesize approximately 25 years of data and present new analyses that highlight dynamics in forest composition, food availability, the nutritional quality of food, disease, physiological stress and population size of endangered folivorous red colobus monkeys (Procolobus rufomitratus). There is a decline in the quality of leaves 15 and 30 years following two previous studies in an undisturbed area of forest. The consumption of a low-quality diet in one month was associated with higher glucocorticoid levels in the subsequent month and stress levels in groups living in degraded forest fragments where diet was poor was more than twice those in forest groups. In contrast, forest composition has changed and when red colobus food availability was weighted by the protein-to-fibre ratio, which we have shown positively predicts folivore biomass, there was an increase in the availability of high-quality trees. Despite these changing social and ecological factors, the abundance of red colobus has remained stable, possibly through a combination of increasing group size and behavioural flexibility.

Nodular Worm Infections in Wild Non-human Primates and Humans Living in the Sebitoli Area (Kibale National Park, Uganda): Do High Spatial Proximity Favor Zoonotic Transmission?

BACKGROUND

Nodular Oesophagostomum genus nematodes are a major public health concern in some African regions because they can be lethal to humans. Their relatively high prevalence in people has been described in Uganda recently. While non-human primates also harbor Oesophagostomum spp., the epidemiology of this oesophagostomosis and the role of these animals as reservoirs of the infection in Eastern Africa are not yet well documented.

METHODOLOGY/PRINCIPAL FINDINGS

The present study aimed to investigate Oesophagostomum infection in terms of parasite species diversity, prevalence and load in three non-human primates (Pan troglodytes, Papio anubis, Colobus guereza) and humans living in close proximity in a forested area of Sebitoli, Kibale National Park (KNP), Uganda. The molecular phylogenetic analyses provided the first evidence that humans living in the Sebitoli area harbored O. stephanostomum, a common species in free-ranging chimpanzees. Chimpanzees were also infected by O. bifurcum, a common species described in human populations throughout Africa. The recently described Oesophagostomum sp. found in colobine monkeys and humans and which was absent from baboons in the neighboring site of Kanyawara in KNP (10 km from Sebitoli), was only found in baboons. Microscopic analyses revealed that the infection prevalence and parasite load in chimpanzees were significantly lower in Kanyawara than in Sebitoli, an area more impacted by human activities at its borders.

CONCLUSIONS/SIGNIFICANCE

Three different Oesophagostomum species circulate in humans and non-human primates in the Sebitoli area and our results confirm the presence of a new genotype of Oesophagostomum recently described in Uganda. The high spatiotemporal overlap between humans and chimpanzees in the studied area coupled with the high infection prevalence among chimpanzees represent factors that could increase the risk of transmission for O. stephanostomum between the two primate species. Finally, the importance of local-scale research for zoonosis risk management is important because environmental disturbance and species contact can differ, leading to different parasitological profiles between sites that are close together within the same forest patches.

Prevalence of gastrointestinal parasites in captive non-human primates of twenty-four zoological gardens in China

Captive primates are susceptible to gastrointestinal (GIT) parasitic infections, which are often zoonotic and can contribute to morbidity and mortality. Fecal samples were examined by the means of direct smear, fecal flotation, fecal sedimentation, and fecal cultures. Of 26.51% (317/1196) of the captive primates were diagnosed gastrointestinal parasitic infections. Trichuris spp. were the most predominant in the primates, while Entamoeba spp. were the most prevalent in Old World monkeys (P < 0.05). These preliminary data will improve the management of captive primates and the safety of animal keepers and visitors.

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.

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.

Prevalence of Entamoeba species in captive primates in zoological gardens in the UK

The aim of this study was to determine the prevalence of amoebic infection in non-human primates (NHPs) from six Zoological gardens in the United Kingdom. Initially, 126 faecal samples were collected from 37 individually identified NHPs at Twycross Zoo, UK, and were subjected to microscopic examination. A subsequent, nationwide experiment included 350 faecal samples from 89 individually identified NHPs and 73 unidentified NHPs from a number of UK captive wildlife facilities: Twycross Zoo (n = 60), Colchester Zoo (n = 3), Edinburgh Zoo (n = 6), Port Lympne Wild Animal Park (n = 58), Howletts Wild Animal Park (n = 31), and Cotswold Wildlife Park (n = 4). Samples were examined by PCR and sequencing using four specific primer sets designed to differentiate between the pathogenic E. histolytica, the non-pathogenic E. dispar, and non-pathogenic uninucleate cyst-producing Entamoeba species. In the first experiment, Entamoeba was detected in 30 primates (81.1%). Six (16.2%) primates were infected with E. histolytica species complex. The highest carriage of Entamoeba species was found in Old World Colobinae primates. In the nationwide experiment, molecular analysis of faecal samples revealed notable rates of Entamoeba infection (101 samples, 28.9%), including one sample infected with E. histolytica, 14 samples with E. dispar, and 86 samples with uninucleated-cyst producing Entamoeba species. Sequences of positive uninucleated-cyst producing Entamoeba samples from Twycross Zoo clustered with the E. polecki reference sequences ST4 reported in Homo sapiens, and are widely separated from other Entamoeba species. These findings suggest a low prevalence of the pathogenic Entamoeba infection, but notable prevalence of non-pathogenic E. polecki infection in NHPs in the UK.

Epidemiology of pathogenic enterobacteria in humans, livestock, and peridomestic rodents in rural Madagascar

BACKGROUND

Among the families of enteric bacteria are globally important diarrheal agents. Despite their potential for zoonotic and environmental transmission, few studies have examined the epidemiology of these pathogens in rural systems characterized by extensive overlap among humans, domesticated and peridomestic animals. We investigated patterns of infection with Enterotoxigenic Escherichia coli, Shigella spp., Salmonella enterica, Vibrio cholerae, and Yersinia spp. (enterocolitica, and pseudotuberculosis) in Southeastern Madagascar where the potential for the aforementioned interactions is high. In this pilot project we conducted surveys to examine behaviors potentially associated with risk of infection and if infection with specific enterobacteria species was associated with diarrheal disease.

METHODOLOGY/PRINCIPAL FINDINGS

PCR was conducted on DNA from human, livestock, and rodent fecal samples from three villages. Overall, human prevalence was highest (77%), followed by rodents (51%) and livestock (18%). Rodents were ∼2.8 times more likely than livestock to carry one of the bacteria. The incidence of individual species varied between villages, with the observation that, E. coli and Shigella spp. were consistently associated with co-infections. As an aggregate, there was a significant risk of infection linked to a water source in one village. Individually, different pathogens were associated with certain behaviors, including: those who had used medication, experienced diarrhea in the past four weeks, or do not use toilets.

CONCLUSIONS/SIGNIFICANCE

Different bacteria were associated with an elevated risk of infection for various human activities or characteristics. Certain bacteria may also predispose people to co-infections. These data suggest that a high potential for transmission among these groups, either directly or via contaminated water sources. As these bacteria were most prevalent in humans, it is possible that they are maintained in humans and that transmission to other species is infrequent. Further studies are needed to understand bacterial persistence, transmission dynamics, and associated consequences in this and similar systems.

Patterns of infection by intestinal parasites in sympatric howler monkey (Alouatta palliata) and spider monkey (Ateles geoffroyi) populations in a tropical dry forest in Costa Rica

In primate populations, endoparasite species richness and prevalence are associated with host traits such as reproductive and social status, age, sex, host population density, and environmental factors such as humidity. We analyzed the species richness and prevalence of intestinal parasites in two sympatric primate populations, one of Alouatta palliata and one of Ateles geoffroyi, found in a tropical dry forest in Costa Rica. We identified three species of intestinal parasites (Controrchis sp., Trypanoxyuris sp., and Strongyloides sp.) in these two primate species. We did not find any differences in species richness between the primate species. However, the prevalences of Controrchis sp. and Trypanoxyuris sp. were higher in Alouatta palliata. Similarly, males and lactating females of Alouatta palliata showed higher Controrchis sp. prevalences. We did not observe any differences in parasite richness and prevalence between seasons. Infectious diseases in endangered primate populations must be considered in conservation strategies, especially when defining protected areas.

Nodule worm infection in humans and wild primates in Uganda: cryptic species in a newly identified region of human transmission

INTRODUCTION

Soil-transmitted helminths (STHs) are a major health concern in tropical and sub-tropical countries. Oesophagostomum infection is considered endemic to West Africa but has also been identified in Uganda, East Africa, among primates (including humans). However, the taxonomy and ecology of Oesophagostomum in Uganda have not been studied, except for in chimpanzees (Pan troglodytes), which are infected by both O. bifurcum and O. stephanostomum.

METHODS AND FINDINGS

We studied Oesophagostomum in Uganda in a community of non-human primates that live in close proximity to humans. Prevalence estimates based on microscopy were lower than those based on polymerase chain reaction (PCR), indicating greater sensitivity of PCR. Prevalence varied among host species, with humans and red colobus (Procolobus rufomitratus) infected at lowest prevalence (25% and 41% by PCR, respectively), and chimpanzees, olive baboons (Papio anubis), and l'hoest monkeys (Cercopithecus lhoesti) infected at highest prevalence (100% by PCR in all three species). Phylogenetic regression showed that primates travelling further and in smaller groups are at greatest risk of infection. Molecular phylogenetic analyses revealed three cryptic clades of Oesophagostomum that were not distinguishable based on morphological characteristics of their eggs. Of these, the clade with the greatest host range had not previously been described genetically. This novel clade infects humans, as well as five other species of primates.

CONCLUSIONS

Multiple cryptic forms of Oesophagostomum circulate in the people and primates of western Uganda, and parasite clades differ in host range and cross-species transmission potential. Our results expand knowledge about human Oesophagostomum infection beyond the West African countries of Togo and Ghana, where the parasite is a known public health concern. Oesophagostomum infection in humans may be common throughout Sub-Saharan Africa, and the transmission of this neglected STH among primates, including zoonotic transmission, may vary among host communities depending on their location and ecology.

Human contact influences the foraging behaviour and parasite community in long-tailed macaques

Human–wildlife interactions have reached unprecedented levels, and humans are influencing the earth’s ecosystems more rapidly and extensively than ever before. This situation is cause for serious concern, especially since disease interactions between wildlife and humans have been recognized as major conservation threats. In this study, long-tailed macaques, Macaca fascicularis, from 2 forest parks located in north-eastern Thailand were investigated to determine the influence of habitat modification by humans on helminth parasite associations in non-human primates. Macaque populations with contact to anthropogenically modified environments were compared with sylvatic groups in nearby natural environments. In order to test for human–non-human primate transmission of parasites, the local human populations were also examined. Humans were infected with a number of potentially pathogenic parasites, including Opisthorchis viverrini and Strongyloides stercoralis. However, eggs of these helminths were not detected in macaque feces. Thus, no direct parasite transfer from humans to non-human primates could be confirmed. However, macaque groups with more frequent contact with human modified habitats, and a higher portion of human-provided food in their diet, had significantly higher prevalences and intensities of Strongyloides fuelleborni and of an intestinal fluke (probably Haplorchis sp.) than sylvatic groups. Positive correlations were found between the time foraging on the ground and infection with S. fuelleborni, and the amount of human-provided food and intestinal fluke infection. Human alteration of habitat and associated modifications in nonhuman primate behaviour are likely to play a role in determining the occurrence, prevalence and intensity of zoonotic helminth infection of wild non-human primates.

Seasonal effects on great ape health: a case study of wild chimpanzees and Western gorillas

Among factors affecting animal health, environmental influences may directly or indirectly impact host nutritional condition, fecundity, and their degree of parasitism. Our closest relatives, the great apes, are all endangered and particularly sensitive to infectious diseases. Both chimpanzees and western gorillas experience large seasonal variations in fruit availability but only western gorillas accordingly show large changes in their degree of frugivory. The aim of this study is to investigate and compare factors affecting health (through records of clinical signs, urine, and faecal samples) of habituated wild ape populations: a community (N = 46 individuals) of chimpanzees (Pan troglodytes) in Kanyawara, Kibale National Park (Uganda), and a western gorilla (G. gorilla) group (N = 13) in Bai Hokou in the Dzanga-Ndoki National Park (Central African Republic). Ape health monitoring was carried out in the wet and dry seasons (chimpanzees: July-December 2006; gorillas: April-July 2008 and December 2008-February 2009). Compared to chimpanzees, western gorillas were shown to have marginally greater parasite diversity, higher prevalence and intensity of both parasite and urine infections, and lower occurrence of diarrhea and wounds. Parasite infections (prevalence and load), but not abnormal urine parameters, were significantly higher during the dry season of the study period for western gorillas, who thus appeared more affected by the large temporal changes in the environment in comparison to chimpanzees. Infant gorillas were the most susceptible among all the age/sex classes (of both apes) having much more intense infections and urine blood concentrations, again during the dry season. Long term studies are needed to confirm the influence of seasonal factors on health and parasitism of these great apes. However, this study suggest climate change and forest fragmentation leading to potentially larger seasonal fluctuations of the environment may affect patterns of ape parasitism and further exacerbate health impacts on great ape populations that live in highly seasonal habitats.

Parasitology of five primates in Mahale Mountains National Park, Tanzania

Parasitological surveillance in primates has been performed using coprological observation and identification of specimens from chimpanzees (Pan troglodytes schweinfurthii) in Mahale Mountains National Park, Tanzania (Mahale). In this study, we conducted coprological surveillance to identify the fauna of parasite infection in five primate species in Mahale: red colobus (Procolobus badius tephrosceles), red-tailed monkeys (Cercopithecus ascanius schmidti), vervet monkeys (Cercopithecus aethiops pygerythrus), yellow baboons (Papio cynocephalus), and chimpanzees. Fecal samples were examined microscopically, and parasite identification was based on the morphology of cysts, eggs, larvae, and adult worms. Three nematodes (Oesophagostomum spp., Strongyloides sp., and Trichuris sp.), Entamoeba coli, and Entamoeba spp. were found in all five primate species. The following infections were identified: Bertiella studeri was found in chimpanzees and yellow baboons; Balantidium coli was found in yellow baboons; three nematodes (Streptopharagus, Primasubulura, an undetermined genus of Spirurina) and Dicrocoeliidae gen. sp. were found in red-tailed monkeys, vervet monkeys, and yellow baboons; Chitwoodspirura sp. was newly identified in red colobus and red-tailed monkeys; Probstmayria gombensis and Troglocorys cava were newly identified in chimpanzees, together with Troglodytella abrassarti; and Enterobius sp. was newly identified in red colobus. The parasitological data reported for red colobus, vervet monkeys, and yellow baboons in Mahale are the first reports for these species.