Gastrointestinal Parasites of Indigenous and Introduced Primate Species of Rubondo Island National Park, Tanzania

Fatal coinfection of blastocystosis and intestinal trichomoniasis in a rhesus macaque (Macaca mulatta)

A 3-year-old male rhesus macaque was presented at Referral Veterinary Polyclinic-Teaching Veterinary Clinical Complex, with a chief complaint of chronic diarrhoea and swelling of dependent body parts. The patient's history indicates that the monkey had been experiencing diarrhoea for the past month, with 2-3 episodes of vomiting in the last 2 days. Additionally, oedema has developed within the last 2 weeks. The clinical examination findings revealed dullness and depression, the mucus membrane appeared pale, with a temperature-102.1 °F, a respiration rate-28/min, and a heart rate-92/min. The capillary refill time was 4 s. During the physical examination, the animal exhibited oedema on the dependent part of the body and faecal staining around the perineum along with loose yellow stool. Direct saline and iodine mount faecal smear examination revealed the presence of many motile pear-shaped flagellated protozoa and round vacuolated Blastocystis organisms. Giemsa-stained faecal smear cytology confirmed the presence of Pentatrichomonas sp. and Blastocystis sp. along with many microbes. The faecal culture was negative for all pathogenic microbes. The case was diagnosed as co-infection Blastocystosis and intestinal trichomoniasis. The treatment was initiated with a combination of sulfamethoxazole + trimethoprim @ 35 mg/kg body weight and metronidazole @25 mg/kg administered orally once daily for 7 days. Supportive therapy includes hematinic injection (iron sorbitol, folic acid and vitamin B12) @ 1 ml total dose, administered intramuscularly on alternate days for four occasions as well as intravenous infusion of crystalline amino acid @ 5 ml total dose on alternate days for four occasions. To manage vomition, injection ondansetron was administered@0.5 mg/kg intramuscularly, twice daily for 3 days and H2 blockers, including injection ranitidine@2 mg/kg intramuscularly twice daily for 3 days. Electrolyte and probiotic supplementation were administered orally. After 7 days of therapy, the oedema had significantly improved and episodes of vomition were stopped but there was no significant improvement in the episode of diarrhoea and consistency of faeces. Unfortunately, on the 10th day of therapy, the animal suddenly collapsed. Understanding the virulence pattern of opportunistic protozoa in primates is crucial, and identifying suitable therapeutic candidates to prevent fatal outcomes is the need of the hour, especially considering protozoal infections as an important differential diagnosis in gastrointestinal tract-related ailments. Our study successfully demonstrated the co-occurrence of blastocystosis and intestinal trichomoniasis, both uncommon infections with potential zoonotic implications.

Molecular Detection and Characterization of Intestinal and Blood Parasites in Wild Chimpanzees (Pan troglodytes verus) in Senegal

Simple Summary

Western chimpanzees are currently listed as a Critically Endangered subspecies. Human encroachment has taken a toll on this great ape due to fragmented habitat and the exchange of pathogens. This epidemiological study investigated the occurrence and genetic diversity of intestinal and blood parasites in faecal samples from wild chimpanzees living in the Dindefelo Community Nature Reserve, Senegal. We paid special attention to potential human-driven sources of infection and transmission pathways. Potential diarrhoea-causing protist parasites (e.g., Cryptosporidium spp., Giardia duodenalis, Entamoeba histolytica) were detected at low infection rates (and densities) or absent, whereas commensals (Entamoeba dispar) or protist of uncertain pathogenicity (Blastocystis sp.) were far more abundant. We detected Sarcocystis spp. in chimpanzee faeces. Blood protist parasites such as Plasmodium spp. and Trypanosoma brucei spp. (the etiological agents of malaria and sleeping sickness, respectively, in humans) were also found at low prevalences, but microfilariae of the nematode Mansonella perstans were frequently found. Molecular analyses primarily revealed host-adapted species/genotypes and an apparent absence of gastrointestinal clinical manifestations in infected chimpanzees. Zoonotic events of still unknown frequency and directionality may have taken part between wild chimpanzees and humans sharing natural habitats and resources.

Abstract

Wild chimpanzee populations in West Africa (Pan troglodytes verus) have dramatically decreased as a direct consequence of anthropogenic activities and infectious diseases. Little information is currently available on the epidemiology, pathogenic significance, and zoonotic potential of protist species in wild chimpanzees. This study investigates the occurrence and genetic diversity of intestinal and blood protists as well as filariae in faecal samples (n = 234) from wild chimpanzees in the Dindefelo Community Nature Reserve, Senegal. PCR-based results revealed the presence of intestinal potential pathogens (Sarcocystis spp.: 11.5%; Giardia duodenalis: 2.1%; Cryptosporidium hominis: 0.9%), protist of uncertain pathogenicity (Blastocystis sp.: 5.6%), and commensal species (Entamoeba dispar: 18.4%; Troglodytella abrassarti: 5.6%). Entamoeba histolytica, Enterocytozoon bieneusi, and Balantioides coli were undetected. Blood protists including Plasmodium malariae (0.4%), Trypanosoma brucei (1.3%), and Mansonella perstans (9.8%) were also identified. Sanger sequencing analyses revealed host-adapted genetic variants within Blastocystis, but other parasitic pathogens (C. hominis, P. malariae, T. brucei, M. perstans) have zoonotic potential, suggesting that cross-species transmission between wild chimpanzees and humans is possible in areas where both species overlap. Additionally, we explored potential interactions between intestinal/blood protist species and seasonality and climate variables. Chimpanzees seem to play a more complex role on the epidemiology of pathogenic and commensal protist and nematode species than initially anticipated.

PATHOLOGY OF SPIRURID INFECTION IN VERVET MONKEYS (CHLOROCEBUS PYGERYTHRUS) HOUSED IN A PRIMATE REHABILITATION CENTER

Spirurids, specifically the Rictularia, Chitwoodspirura, Streptopharagus, and Protospirura genera, have been reported to parasitize all nonhuman primate taxa. Spirurid pathogenesis in nonhuman primates has not been reported frequently; however, Protospirura muricola has been associated with serious gastric pathologies, including gastric perforation. This study was a retrospective study of 38 vervet monkey (Chlorocebus pygerythrus) necropsies performed in a primate sanctuary that houses captive orphaned or injured wild-born vervet monkeys. Individuals were categorized according to their age, sex, and body condition score to investigate the relationships between these factors and parasite presence. This study identified P. muricola in 47.37% of the necropsied carcasses. Regarding individual factors associated with P. muricola infection, no significant differences between males and females were observed; however, relationships between parasite presence and poor body condition and advanced host age were observed. Furthermore, one monkey death was potentially directly related to spirurid pathogenic action, because the individual showed gastric perforation.

Gastro-intestinal parasites in two subspecies of toque macaque (Macaca sinica) in Sri Lanka and their zoonotic potential

Gastro-intestinal (GI) parasites of primates have a greater potential of becoming zoonotic. This potential may vary in different primates based on multiple factors such as proximity to human settlements and the climate of their habitat. We examined the GI parasites in two subspecies of toque macaque: Macaca sinica sinica (confined to the dry zone) and Macaca sinica aurifrons (confined to the wet zone) of Sri Lanka. Fresh faecal samples were collected and analysed following a modified Sheather's sucrose floatation method. A total of 90.8% (89/98) macaques were infected with one or more parasite species. There was no difference in the overall prevalence of GI parasites between the two subspecies, M. s. aurifrons (95.9%) and M. s. sinica (85.7%; χ²;χ = 3.059, p = 0.080). Sixteen parasite species were recorded including, 15 species in the M. s. sinica and 12 species in the M. s. aurifrons. Among the helminths identified, Anatrichosoma sp., Ancylostoma spp., Capillaria spp., Oesophagostomum /Bunostomum spp. and Physaloptera spp. are known to be zoonotic while Ascaris spp., Enterobius sp., Strongyloides spp. and Trichuris spp. have both zoonotic and anthroponotic potential. Among the protozoans, Balantidium coli and Buxtonella sp. are known to be zoonotic, while Entamoeba spp. and Cryptosporidium spp. have both anthroponotic and zoonotic potential. This study provides the first record of Anatrichosoma sp. and Buxtonella sp. in Sri Lanka and the first record of Cryptosporidium spp. in M. s. aurifrons. The molecular data allowed further identification and differentiation of Entamoeba nuttalli and E. coli that are known to be zoonotic and anthroponotic, respectively. The two subspecies of macaques have close interactions with humans; hence, in-depth epidemiological studies are required to understand the potential public-health risks to humans and conservation implications for macaque populations.

Diversity of parasites in two captive chimpanzee populations in southern Gabon

Captive chimpanzees living in confined environments like sanctuaries or primatology centers are frequently affected by gastrointestinal parasites. Some of these are likely to be transmitted to humans and may seriously affect public health. However little information is currently available on the gastrointestinal parasites of primates living in such environments. Here, we characterize the diversity and prevalence of gastrointestinal parasites in two populations of captive chimpanzees living in south-eastern Gabon. Our study reveals that at least nine parasite species infect the chimpanzees with high prevalence, including several helminths (Ascaris spp., Enterobius spp., Strongyloides spp., Trichuris spp., Hymenolepis spp., Mammomonogamus spp), three protozoa (Balantioides spp., Entamoeba spp. and Troglodytella spp) and several unidentified parasites. All the parasite taxa we identified had previously been identified in other primates, including humans. Age, sex and site type may influence infection rates and/or parasite diversity found in a particular host.

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.

Population history of chimpanzees introduced to Lake Victoria's Rubondo Island

Between 1966 to 1969, Bernhard Grzimek (Frankfurt Zoological Society, FZS) introduced chimpanzees (Pan troglodytes) previously held in European institutions to Rubondo Island in Lake Victoria in Tanzania. Earlier publications report various numbers of released animals and that all founders originated from West Africa. We revise these assumptions through consultation of archived FZS records and genetic analyses of surviving descendants. Accordingly, 17 chimpanzees were transported to Africa in four waves, with male-female ratios of 3:8, 1:0, 1:0 and 2:2; one female died in transit. Thus, 16 chimpanzees were released in total. FZS and studbook records allocate a West African provenance to only 19% of the founders and a generic "Africa" origin to 56%. Still, studbook records render it unlikely that any of the founders were captive-born. In addition, our genetic analyses based on biological samples from the current descendants trace the geographical origin of their ancestors back to West Africa (P. t. verus) and Central Africa (P. t. troglodytes). Based on counts of individuals and night nests, we estimate that the population, since 1969, grew to around 35 individuals in 2014 (annual increase 3.3%). Thus, chimpanzees released onto a large forested island free from predators or hunting pressure, habitat destruction and conspecific competition can form a self-sustaining island population without human support.

Primate Infectious Disease Ecology: Insights and Future Directions at the Human-Macaque Interface

Global population expansion has increased interactions and conflicts between humans and nonhuman primates over shared ecological space and resources. Such ecological overlap, along with our shared evolutionary histories, makes human-nonhuman primate interfaces hot spots for the acquisition and transmission of parasites. In this chapter, we bring to light the importance of human-macaque interfaces in particular as hot spots for infectious disease ecological and epidemiological assessments. We first outline the significance and broader objectives behind research related to the subfield of primate infectious disease ecology and epidemiology. We then reveal how members of the genus Macaca, being among the most socioecologically flexible and invasive of all primate taxa, live under varying degrees of overlap with humans in anthropogenic landscapes. Thus, human-macaque interfaces may favor the bidirectional exchange of parasites. We then review studies that have isolated various types of parasites at human-macaque interfaces, using information from the Global Mammal Parasite Database (GMPD: http://www.mammalparasites.org/). Finally, we elaborate on avenues through which the implementation of both novel conceptual frameworks (e.g., Coupled Systems, One Health) and quantitative network-based approaches (e.g., social and bipartite networks, agent-based modeling) may potentially address some of the critical gaps in our current knowledge of infectious disease ecology at human-primate interfaces.

The changing ecology of primate parasites: Insights from wild-captive comparisons

Host movements, including migrations or range expansions, are known to influence parasite communities. Transitions to captivity-a rarely studied yet widespread human-driven host movement-can also change parasite communities, in some cases leading to pathogen spillover among wildlife species, or between wildlife and human hosts. We compared parasite species richness between wild and captive populations of 22 primate species, including macro- (helminths and arthropods) and micro-parasites (viruses, protozoa, bacteria, and fungi). We predicted that captive primates would have only a subset of their native parasite community, and would possess fewer parasites with complex life cycles requiring intermediate hosts or vectors. We further predicted that captive primates would have parasites transmitted by close contact and environmentally-including those shared with humans and other animals, such as commensals and pests. We found that the composition of primate parasite communities shifted in captive populations, especially because of turnover (parasites detected in captivity but not reported in the wild), but with some evidence of nestedness (holdovers from the wild). Because of the high degree of turnover, we found no significant difference in overall parasite richness between captive and wild primates. Vector-borne parasites were less likely to be found in captivity, whereas parasites transmitted through either close or non-close contact, including through fecal-oral transmission, were more likely to be newly detected in captivity. These findings identify parasites that require monitoring in captivity and raise concerns about the introduction of novel parasites to potentially susceptible wildlife populations during reintroduction programs.

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.

Diversity of Entamoeba spp. in African great apes and humans: an insight from Illumina MiSeq high-throughput sequencing

Understanding the complex Entamoeba communities in the mammalian intestine has been, to date, complicated by the lack of a suitable approach for molecular detection of multiple variants co-occurring in mixed infections. Here, we report on the application of a high throughput sequencing approach based on partial 18S rDNA using the Illumina MiSeq platform. We describe, to our knowledge, for the first time, the Entamoeba communities in humans, free-ranging western lowland gorillas and central chimpanzees living in the Dja Faunal Reserve in Cameroon. We detected 36 Entamoeba haplotypes belonging to six haplotype clusters, containing haplotypes possessing high and low host specificity. Most of the detected haplotypes belonged to commensal Entamoeba, however, the pathogenic species (Entamoeba histolytica and Entamoeba nuttalli) were also detected. We observed that some Entamoeba haplotypes are shared between humans and other hosts, indicating their zoonotic potential. The findings are important not only for understanding the epidemiology of amoebiasis in humans in rural African localities, but also in the context of wild great ape conservation.

Comparison of gastrointestinal parasite communities in vervet monkeys

Globally, habitat degradation is accelerating, especially in the tropics. Changes to interface habitats can increase environmental overlap among nonhuman primates, people, and domestic animals and change stress levels in wildlife, leading to changes in their risk of parasite infections. However, the direction and consequences of these changes are unclear, since animals may benefit by exploiting human resources (e.g., improving nutritional health by eating nutritious crops) and decreasing susceptibility to infection, or interactions with humans may lead to chronic stress and increased susceptibility to infection. Vervet monkeys are an excellent model to understand parasitic disease transmission because of their tolerance to anthropogenic disturbance. Here we quantify the gastrointestinal parasites of a group of vervet monkeys (Chlorocebus aethiops) near Lake Nabugabo, Uganda, that frequently overlaps with people in their use of a highly modified environment. We compare the parasites found in this population to seven other sites where vervet monkey gastrointestinal parasites have been identified. The vervets of Lake Nabugabo have the greatest richness of parasites documented to date. We discuss how this may reflect differences in sampling intensity or differences in the types of habitat where vervet parasites have been sampled.

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.

Differences between chimpanzee and baboon gastrointestinal parasite communities

Cross-species infection among humans, chimpanzees (Pan troglodytes) and baboons (Papio spp.) is potentially a significant public health issue in Africa, and of concern in the conservation of P. troglodytes. However, to date, no statistical comparisons have been made between the prevalence, richness and composition of parasite communities in sympatric populations of baboons and P. troglodytes. We compared parasite communities in sympatric P. troglodytes and Papio papio living in a wilderness site, in the Republic of Senegal, West Africa. We asked whether, in the absence of humans, there are significant differences between these hosts in their interactions with gastrointestinal parasites. We tested whether host, location, or time of collection accounted for variation in prevalence, richness and community composition, and compared prevalence across six studies. We concluded that, despite being closely related, there are significant differences between these two hosts with respect to their parasite communities. At our study site, prevalence of Balantidium, Trichuris and Watsonius was higher in P. papio. Papio papio harboured more parasites per host, and we found evidence of a positive association between Trichuris and Balantidium in P. troglodytes but not P. papio.

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.

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.

Assessment of gastrointestinal parasites in wild chimpanzees (Pan troglodytes troglodytes) in southeast Cameroon

We tested 114 faecal samples from wild simian immunodeficiency virus (SIV)-positive (n = 43) and SIV-negative (n = 71) chimpanzees (Pan troglodytes troglodytes) in southeast Cameroon for the presence of gastrointestinal parasites by direct smear. We observed cysts from different protozoa (Entamoeba coli and Entamoeba histolytica / Entamoeba dispar, Endolimax nana, Iodamoeba butschlii, Chilomastix mesnili, Balantidium coli and Blastocystis cells) and trophozoites from Troglodytella abrassarti and Balantidium coli. Eggs from different helminths (strongylids, Ascaris lumbricoides, Abbreviata caucasica, Trichuris sp., Capillaria sp., Enterobius anthropopeci, Bertiella sp., Hymenolepis diminuta and an undetermined fluke) were also observed. Finally, we observed eggs that could not be properly identified and classified. We did not observe any differences between the SIV+ and SIV- samples except for the unidentified eggs. The studied chimpanzees were highly parasitised by strongylid (85.1% of prevalence), Troglodytella (43.8%) and Blastocystis (2.9%), and the frequency of the other parasites ranged from 0.9 to 8.8%. These high levels of parasite infections could represent an additional burden in a population where there is a high rate of the SIV virus in circulation.

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.

Zoonotic schistosomiasis in non-human primates: past, present and future activities at the human–wildlife interface in Africa

Schistosomiasis is one of the world's most widely distributed and prevalent parasitic diseases. Less widely recognized is that some species of Schistosoma, including several that commonly affect humans, also cause disease in other mammalian species; in particular, infections in non-human primates are known. With interest increasing in emerging zoonotic diseases, the status of schistosomiasis as a zoonotic infection is in need of re-appraisal, especially in light of advances in application of molecular screening and epidemiological tools where newly reported infections raise general animal welfare and conservation concerns. Focusing on Africa, this review provides a summary of the occurrence of schistosomiasis in non-human primates and discusses new ways in which surveillance for schistosomiasis should be integrated into more effective conservation management and disease control strategies. Emphasis is on the more common forms of human schistosomiasis, their clinical manifestations and epidemiological significance in terms of infection reservoir potential.