Prevalence and genetic diversity of simian malaria in wild macaque populations across Thailand: Implications for human health.

Over the past year, P. falciparum infections have declined in Thailand, yet nonhuman primate malaria infections have correspondingly increased, including Plasmodium knowlesi and P. cynomolgi. Nevertheless, little is known about simian malaria in its natural macaque hosts, Macaca mulatta and Macaca fascicularis. This study aims to address several research questions, including the prevalence and distribution of simian malaria in these two Thai wild macaque species, variations in infection between different macaque species and between M. fascicularis subspecies, and the genetic composition of these pathogens. Blood samples were collected from 82 M. mulatta and 690 M. fascicularis across 15 locations in Thailand, as well as two locations in Vietnam and Myanmar. We employed quantitative real-time PCR targeting the Plasmodium genus-specific 18S ribosomal RNA (rRNA) gene to detect malaria infection, with a limit of detection set at 1,215.98 parasites per mL. We genotyped eight microsatellite markers, and the P. cynomolgi dihydrofolate reductase gene (DHFR) was sequenced (N = 29). In total, 100 of 772 samples (13 %) tested positive for malaria, including 45 (13 %) for P. cynomolgi, 37 (13 %) for P. inui, 16 (5 %) for P. coatneyi, and 2 (0.25 %) for Hepatocystis sp. in Saraburi, central and Ranong, southern Thailand. Notably, simian malaria infection was observed exclusively in M. fascicularis and not in M. mulatta (P = 0.0002). Particularly, P. cynomolgi was detected in 21.7 % (45/207) of M. f. fascicularis living in Wat Tham Phrapothisat, Saraburi Province. The infection with simian malaria was statistically different between M. fascicularis and M. mulatta (P = 0.0002) but not within M. fascicularis subspecies (P = 0.78). A haplotype network analysis revealed that P. cynomolgi shares a lineage with reference strains obtained from macaques. No mutation in the predicted binding pocket of PcyDHFR to pyrimethamine was observed. This study reveals a significant prevalence of simian malaria infection in M. fascicularis. The clonal genotypes of P. cynomolgi suggest in-reservoir breeding. These findings raise concerns about the potential spread of nonhuman primate malaria to humans and underscore the need for preventive measures.

Parasites and Viruses in Callithrix in Brazil.

PURPOSE: As a result of environmental imbalances of anthropogenic origin, the potential for transmission of parasites and viruses between different primates, including humans, might increase. Thus, parasitic studies have great relevance to primatology, which motivated us to conduct a literature review to synthesize the information available in American primates of the Callithrix genus. METHODS: We carried out the bibliographic search on the main groups of parasites (protozoa, helminths, arthropods, ectoparasites) and viruses found in Callithrix in Brazil in search platforms and consider all manuscript that appeared in search engines, published between the years 1910 and December 2022. In each selected article, the following information was recorded: the host species; parasite taxa; scientific classification of the parasite; host habitat (free-living, captive); diagnostic technique; state; and bibliographic reference. Data were tabulated and arranged in a parasite-host table. RESULTS: Some endemic genera, such as Callithrix, are widely distributed geographically across Brazil and have characteristics of adaptation to different habitats due to their flexibility in diet and behavior. These factors can make them subject to a greater diversity of parasites and viruses in the country. Here, we identified 68 parasitic taxa, belonging to the clades protozoa (n = 22), helminths (n = 34), ectoparasites (n = 7), and viruses (n = 5). Out of this total, 19 have zoonotic potential. Of the six existing marmoset species, Callithrix jacchus was the most frequent in studies, and Callithrix flaviceps did not have reports. All regions of the country had occurrences, mainly the Southeast, where 54% of the cases were reported. In 46% of the reported parasites and viruses, it was not possible to identify the corresponding species. CONCLUSION: We conclude that in part of the works the identification methods are not being specific, which makes it difficult to identify the species that affects Callithrix spp. Furthermore, the studies present geographic disparities, being concentrated in the southeast of the country, making it impossible to have a more uniform analysis of the findings. Thus, it is observed that information about parasites and viruses is incipient in the genus Callithrix in Brazil.

Detection of herpesviruses in neotropical primates from São Paulo, Brazil.

Transmission of herpesvirus between humans and non-human primates represents a serious potential threat to human health and endangered species conservation. This study aimed to identify herpesvirus genomes in samples of neotropical primates (NTPs) in the state of São Paulo, Brazil. A total of 242 NTPs, including Callithrix sp., Alouatta sp., Sapajus sp., and Callicebus sp., were evaluated by pan-herpesvirus polymerase chain reaction (PCR) and sequencing. Sixty-two (25.6%) samples containing genome segments representative of members of the family Herpesviridae, including 16.1% for Callitrichine gammaherpesvirus 3, 6.1% for Human alphaherpesvirus 1, 2.1% for Alouatta macconnelli cytomegalovirus, and 0.83% for Cebus albifrons lymphocryptovirus 1. No co-infections were detected. The detection of herpesvirus genomes was significantly higher among adult animals (p = 0.033) and those kept under human care (p = 0.008671). These findings confirm the importance of monitoring the occurrence of herpesviruses in NTP populations in epizootic events.

Gastrointestinal parasites of Leontopithecus chrysomelas in the Atlantic Forest, Brazil.

We performed coproparasitological testing of free-living golden-headed lion tamarins, Leontopithecus chrysomelas, using the Hoffmann-Pons-Janner method. In total, we collected 118 samples from ten groups: four living in Federal Protected Area and six living in Non-Protected Areas of cocoa farms. Eggs from parasites of the Acanthocephala phylum and Spiruridae, Ancylostomatidae, Ascarididae and Oxyuridae families were identified, as well as the genus Strongyloides (Nematode: Strongyloididae) and phylum Apicomplexa. This is the first description of infection with coccidian, Trichuridae family and Strongyloides spp. in L. chrysomelas. A total of 48% (n= 57) of the animals were infected and the highest prevalence (37.2±SD 8.72, n = 44) was for Acanthocephalidae, followed by Spiruridae (8.5±SD 5.03, n = 10). There was no difference in parasite prevalence by age classes or sex. However, we found higher diversity and prevalence of parasites in animals living in the Federal Protected Area. These results suggest that intestinal parasites may be influenced by environmental factors, such as the management of the areas where the animals live, in addition to the feeding behavior of L. chrysomelas and distinct transmission strategies of parasites. The combination of ecological and demographic data combined with parasitological studies may contribute to conservation programs for this species.

Non-thrombotic pulmonary embolism of brain, liver, or bone marrow tissues associated with traumatic injuries in free-ranging neotropical primates.

From 2016 to 2019, Southeastern Brazil faced an outbreak of yellow fever (YF) affecting both humans and New World primates (NWP). The outbreak was associated with a marked increase in traumatic lesions in NWP in the affected regions. Non-thrombotic pulmonary embolization (NTPE) can be a consequence of massive traumatic events, and it is rarely reported in human and veterinary medicine. Here, we describe NTPE of the brain, liver, and bone marrow in free-ranging NWP, highlighting the epidemiological aspects of these findings and the lesions associated with this condition, including data on traumatic injuries in wild NWP populations during the course of a recent YF outbreak. A total of 1078 NWP were necropsied from January 2017 to July 2019. Gross traumatic injuries were observed in 444 marmosets (44.3%), 10 howler monkeys (23.2%), 9 capuchins (31.0%), 1 titi-monkey (50.0%), and 1 golden lion tamarin (33.3%). NTPE was observed in 10 animals, including 9 marmosets (2.0%) and 1 howler monkey (10.0%). NTPE was identified in the lung and comprised hepatic tissue in 1 case, brain tissue in 1 case, and bone marrow tissue in 8 cases. Although uncommon, it is important to consider NTPE with pulmonary vascular occlusion during the critical care of traumatized NWP. In addition, this study highlights the importance of conservational strategies and environmental education focusing on One Health, not only to protect these free-ranging NWP populations but also to maintain the efficacy of epidemiological surveillance programs.

[Prevalence of laboratory markers of human respiratory viruses in monkeys of Adler primate center].

INTRODUCTION: The relevance of studying the circulation of human respiratory viruses among laboratory primates is associated with the need to test vaccines and antiviral drugs against these infections on monkeys.The aim of this work was to study the prevalence of serological and molecular markers of human respiratory viral infections in laboratory primates born at the Adler Primate Center and in imported monkeys. MATERIAL AND METHODS: Blood serum samples (n = 1971) and lung autopsy material (n = 26) were obtained from different monkey species. These samples were tested for the presence of serological markers of measles, parainfluenza (PI) types 1, 2, 3, influenza A and B, respiratory syncytial (RS) and adenovirus infections using enzyme immunoassay (ELISA). Detection of RS virus, metapneumovirus, PI virus types 1-4, rhinovirus, coronavirus, and adenoviruses B, C, E and bocavirus nucleic acids in this material was performed by reverse transcription polymerase chain reaction (RT-PCR). RESULTS AND DISCUSSION: The overall prevalence of antibodies (Abs) among all monkeys was low and amounted 11.3% (95% CI: 9.2-13.7%, n = 811) for measles virus, 8.9% (95% CI: 6.2-12.2%, n = 381) for PI type 3 virus, 2.5% (95% CI: 0.8-5.6%, n = 204) for PI type 1 virus, and 7.7% (95% CI: 3.8-13.7%, n = 130) for adenoviruses. When testing 26 autopsy lung samples from monkeys of different species that died from pneumonia, 2 samples from Anubis baboons (Papio аnubis) were positive for of parainfluenza virus type 3 RNA. CONCLUSION: Our data suggest the importance of the strict adherence to the terms of quarantine and mandatory testing of monkey sera for the presence of IgM antibodies to the measles virus that indicate the recent infection. The role of PI virus type 3 in the pathology of the respiratory tract in Anubis baboons has been established.

Association of human disturbance and gastrointestinal parasite infection of yellow baboons in western Tanzania.

Human disturbance is an ongoing threat to many wildlife species, manifesting as habitat destruction, resource overuse, or increased disease exposure, among others. With increasing human: non-human primate (NHP) encounters, NHPs are increasingly susceptible to human-introduced diseases, including those with parasitic origins. As such, epidemiology of parasitic disease is becoming an important consideration for NHP conservation strategies. To investigate the relationship between parasite infections and human disturbance we studied yellow baboons (Papio cynocephalus) living outside of national park boundaries in western Tanzania, collecting 135 fresh faecal samples from nine troops occupying areas with varying levels of human disturbance. We fixed all samples in 10% formalin and later evaluated parasite prevalence and abundance (of isotrichid ciliates and Strongylida). We identified seven protozoan and four helminth taxa. Taxa showed varied relationships with human disturbance, baboon troop size and host age. In four taxa, we found a positive association between prevalence and troop size. We also report a trend towards higher parasite prevalence of two taxa in less disturbed areas. To the contrary, high levels of human disturbance predicted increased abundance of isotrichid ciliates, although no relationship was found between disturbance and Strongylida abundance. Our results provide mixed evidence that human disturbance is associated with NHP parasite infections, highlighting the need to consider monitoring parasite infections when developing NHP conservation strategies.

Presence and potential distribution of malaria-infected New World primates of Costa Rica.

BACKGROUND: In South and Central America, Plasmodium malariae/Plasmodium brasilianum, Plasmodium vivax, Plasmodium simium, and Plasmodium falciparum has been reported in New World primates (NWP). Specifically in Costa Rica, the presence of monkeys positive to P. malariae/P brasilianum has been identified in both captivity and in the wild. The aim of the present study was to determine the presence of P. brasilianum, P. falciparum, and P. vivax, and the potential distribution of these parasites-infecting NWP from Costa Rica. METHODS: The locations with PCR (Polymerase Chain Reaction) positive results and bioclimatic predictors were used to construct ecological niche models based on a modelling environment that uses the Maxent algorithm, named kuenm, capable to manage diverse settings to better estimate the potential distributions and uncertainty indices of the potential distribution. RESULTS: PCR analysis for the Plasmodium presence was conducted in 384 samples of four primates (Howler monkey [n = 130], White-face monkey [n = 132], Squirrel monkey [n = 50], and red spider monkey [n = 72]), from across Costa Rica. Three Plasmodium species were detected in all primate species (P. falciparum, P. malariae/P. brasilianum, and P. vivax). Overall, the infection prevalence was 8.9%, but each Plasmodium species ranged 2.1-3.4%. The niche model approach showed that the Pacific and the Atlantic coastal regions of Costa Rica presented suitable climatic conditions for parasite infections. However, the central pacific coast has a more trustable prediction for malaria in primates. CONCLUSIONS: The results indicate that the regions with higher suitability for Plasmodium transmission in NWP coincide with regions where most human cases have been reported. These regions were also previously identified as areas with high suitability for vector species, suggesting that enzootic and epizootic cycles occur.

Gastrointestinal parasites of Leontopithecus chrysomelas in the Atlantic Forest, Brazil / Parasitas gastrintestinais de Leontopithecus chrysomelas na Floresta Atlântica, Brasil

Abstract We performed coproparasitological testing of free-living golden-headed lion tamarins, Leontopithecus chrysomelas, using the Hoffmann-Pons-Janner method. In total, we collected 118 samples from ten groups: four living in Federal Protected Area and six living in Non-Protected Areas of cocoa farms. Eggs from parasites of the Acanthocephala phylum and Spiruridae, Ancylostomatidae, Ascarididae and Oxyuridae families were identified, as well as the genus Strongyloides (Nematode: Strongyloididae) and phylum Apicomplexa. This is the first description of infection with coccidian, Trichuridae family and Strongyloides spp. in L. chrysomelas. A total of 48% (n= 57) of the animals were infected and the highest prevalence (37.2±SD 8.72, n = 44) was for Acanthocephalidae, followed by Spiruridae (8.5±SD 5.03, n = 10). There was no difference in parasite prevalence by age classes or sex. However, we found higher diversity and prevalence of parasites in animals living in the Federal Protected Area. These results suggest that intestinal parasites may be influenced by environmental factors, such as the management of the areas where the animals live, in addition to the feeding behavior of L. chrysomelas and distinct transmission strategies of parasites. The combination of ecological and demographic data combined with parasitological studies may contribute to conservation programs for this species.

Resumo Foram realizados testes coproparasitológicos de micos-leões-dourados de vida livre, Leontopithecus chrysomelas, usando-se o método de Hoffmann-Pons-Janner. No total, foram coletadas 118 amostras de dez grupos: quatro grupos residentes em Área de Conservação Federal e seis grupos em Área não protegida de fazendas de cacau. Ovos de parasitas do filo Acantocephala e das famílias Spiruridae, Ancylostomatidae, Ascarididae, Oxyuridae foram identificados, bem como o gênero Strongyloides (Nematoda: Strongyloididae) e o filo Apicomplexa. Esta é a primeira descrição de infecção de coccídeos, família Trichuridae e Strongyloides spp. em L. chrysomelas. Um total de 48% (n = 57) dos animais estavam parasitados e a maior prevalência (37,2 ±DP 8,72, n = 44) foi para Acanthocephalan, seguido por Spiruridae (8,5±DP 5,03, n = 10). Não houve diferença na prevalência do táxon de parasita por idade ou sexo. No entanto, foi encontrada maior diversidade e prevalência de parasitas em animais que vivem na Unidade de Conservação Federal. Esses resultados sugerem que os parasitas intestinais podem ser influenciados por fatores ambientais, como o manejo das áreas, além do comportamento alimentar de L. chrysomelas e distintas estratégias de transmissão dos parasitas. A combinação de dados ecológicos e demográficos com estudos parasitológicos podem contribuir para programas de conservação dessa espécie.

Epidemiological, clinical and pathological aspects of lethal acanthocephalosis in captive neotropical primates.

BACKGROUND: Acanthocephalosis is an important cause of death in captive New World primates (NWP). Once established in a colony, it is extremely difficult to treat and control, quickly spreading among NWP with a high mortality rate. This study aimed to characterize the disease associated with infection with acanthocephalans according to its epidemiological, clinical, and anatomopathological aspects in a captive NWP population. METHODS: From 2010 to 2020, a Brazilian zoo had recurrent deaths of NWP associated to acanthocephalan parasitism. Clinical and pathological profiles of these animals were analyzed considering the host species, sex, age, weight, clinical signs, therapeutic protocols, and pathological findings. RESULTS: A total of 27 deaths associated with acanthocephalosis were recorded, all lethal cases affected tamarins and lion tamarins, corresponding to 67.5% of total deaths during the course of this study. Ten animals died with no previously detected clinical signs, whereas cases with noticeable clinical signs often had apathy and progressive weight loss, resulting in cachexia. Symptomatic NWP were treated with anthelmintic protocols, antibiotics, and support therapy. However, all hospitalized animals died and had grossly detectable adult acanthocephalans in the intestinal lumen that were identified as Prosthenorchis sp., which were associated with transmural and ulcerative enteritis. CONCLUSIONS: This report revealed the impact of acanthocephalosis in a naturally infected captive colony of NWP, particularly affecting tamarins (Saguinus spp.) and lion tamarins (Leontopithecus spp.), with failed treatment and control strategies.

Dipetalonema graciliformis (Freitas, 1964) from the red-handed tamarins (Saguinus midas, Linnaeus, 1758) in French Guiana.

Six Dipetalonema species have been reported from Neotropical monkeys, Dipetalonema gracile, Dipetalonema graciliformis and Dipetalonema caudispina being the dominant species found in French Guiana primates. Adult filarioids isolated from the abdominal cavity of tamarins (Saguinus midas) in French Guiana were morphologically and molecularly identified as D. graciliformis. Phylogenetic analysis based on DNA and amino acid sequences of the cox1 gene as well as the concatenated sequences of the cox1 and the 18S genes indicated that D. graciliformis belongs to the clade 4 (ONC4) of Onchocercidae. Blast analysis of the 18S rDNA revealed that D. graciliformis in the studied tamarins is conspecific with the filarioid circulating in howler monkeys (Alouatta macconnelli) in French Guiana, previously referred to as unidentified Onchocercidae species.

Occurrence and potentially zoonotic genotypes of Enterocytozoon bieneusi in wild rhesus macaques (Macaca mulatta) living in Nanwan Monkey Island, Hainan, China: a public health concern.

BACKGROUND: Enterocytozoon bieneusi, a microsporidian species, is a zoonotic pathogen found in both humans and animals. Here, we determined the prevalence, explored the different genotypes of E. bieneusi in wild rhesus macaques (Macaca mulatta) (Hainan Island of China), and assessed their zoonotic potential. METHODS: We collected 173 fecal specimens from wild rhesus macaques living in Nanwan Monkey Island, Hainan, China. Subsequently, we identified and genotyped E. bieneusi using nested PCR analysis amplification of the internal transcribed spacer region (ITS) of the rRNA gene. Lastly, a neighbor-joining tree was built based on gene sequences from the ITS region of E. bieneusi. RESULTS: Of the 173 specimens from wild rhesus macaques, 26 (15%) were infected with E. bieneusi. We identified six genotypes of E. bieneusi, of which five were known: PigEBITS7 (n = 20), D (n = 2), Type IV (n = 1), Peru6 (n = 1), Henan-III (n = 1), and a novel genotype: HNM-IX (n = 1). From the phylogenetic analysis, the six genotypes identified here were all clustered into zoonotic group 1. CONCLUSION: This study is the first report to detect E. bieneusi infection in wild rhesus macaques from Hainan, China. Human-pathogenic genotypes D, Henan-III, Peru6, PigEbITS7, and Type IV in the wild rhesus macaques support these animals infected with E. bieneusi have a public health significance.

Gastrointestinal parasites of endemic and endangered free-ranging purple-faced leaf monkey (Semnopithecus vetulus) in Sri Lanka: effect of host group size and habitat type.

Similar infectious agents may be shared among human and nonhuman primates due to their close proximity. Gastrointestinal parasitism is one of the main diseases which can be transmitted between human and nonhuman primates. It is vital to understand the potential transmissions of gastrointestinal parasites (GIP) and monitor their prevalence in free-ranging populations. This study was carried out to determine the prevalence and diversity of the GIP of Semnopithecus vetulus in Sri Lanka from December 2017 to April 2019. Fresh fecal samples (N = 78) were collected and analyzed using fecal floatation technique and direct iodine mounts. Of these, 55% contained at least one species of GIP (helminths: N = 18 protozoans: N = 30). Multiple infections were recorded in 12% of the samples testing positive for parasites. The most prevalent helminth was Trichuris trichiura (15%). A significant relationship was found between the prevalence of T. trichiura and troop size. There were also significant differences in the prevalence of T. trichiura and Ascaris lumbricoides with habitat type. Compared to the forest dwelling populations sampled, those dwelling in urban and suburban habitats receive higher solar radiation, daytime temperatures and disturbance from humans. These conditions can be expected to influence GIP infection rates. S. vetulus living in continuously degrading habitats face a significant threat from GIP infections. Continuous and improved parasitological surveillance is needed to help monitor the conservation status of wildlife and to secure human health.

Historical contingency, geography and anthropogenic patterns of exposure drive the evolution of host switching in the Blastocystis species-complex.

Parasites have the power to impose significant regulatory pressures on host populations, making evolutionary patterns of host switching by parasites salient to a range of contemporary ecological issues. However, relatively little is known about the colonization of new hosts by parasitic, commensal and mutualistic eukaryotes of metazoans. As ubiquitous symbionts of coelomate animals, Blastocystis spp. represent excellent candidate organisms for the study of evolutionary patterns of host switching by protists. Here, we apply a big-data phylogenetic approach using archival sequence data to assess the relative roles of several host-associated traits in shaping the evolutionary history of the Blastocystis species-complex within an ecological framework. Patterns of host usage were principally determined by geographic location and shared environments of hosts, suggesting that weight of exposure (i.e. propagule pressure) represents the primary force for colonization of new hosts within the Blastocystis species-complex. While Blastocystis lineages showed a propensity to recolonize the same host taxa, these taxa were often evolutionarily unrelated, suggesting that historical contingency and retention of previous adaptions by the parasite were more important to host switching than host phylogeny. Ultimately, our findings highlight the ability of ecological theory (i.e. 'ecological fitting') to explain host switching and host specificity within the Blastocystis species-complex.

West Nile Virus Seroprevalence in an Outdoor Nonhuman Primate Breeding Colony in South Florida.

West Nile virus (WNV) was first detected in Florida in July 2001, with 404 human cases reported to the Centers for Disease Control and Prevention as of February 2020. The subtropical climate of Florida is ideal for the mosquitoes that transmit WNV. We investigated the WNV seroprevalence in 3 NHP species housed outdoors at The Mannheimer Foundation in South Florida. From January to December 2016, 520 3 to 30 y old NHP were sampled at our 2 closed sites in Homestead and LaBelle: 200 rhesus macaques (Macaca mulatta), 212 cynomolgus macaques (Macaca fascicularis), and 108 hamadryas baboons (Papio hamadryas hamadryas). The presence of WNV IgG antibodies in these animals was determined by serum neutralization assays, which found a total seroprevalence of 14%. Seroprevalence was significantly higher in the baboons (29%) than the rhesus (11%) and cynomolgus (9%) macaques. The probability of seropositivity significantly increased with age, but sex and site did not significantly affect seroprevalence. The frequency of WNV seropositivity detected in these outdoor-housed NHP suggests that screening for WNV and other vector-borne diseases may be necessary prior to experimental use, particularly for infectious disease studies in which viremia or viral antibodies could confound results, and especially for populations housed outdoors in warm, wet climates. As no seropositive subjects demonstrated clinical signs of WNV and WNV exposure did not appear to significantly impact colony health, routine testing is likely unnecessary for most NHP colonies. However, WNV infection should still be considered as a differential diagnosis for any NHP presenting with nonspecific neurologic signs. Mosquito abatement plans and vigilant sanitation practices to further decrease mosquito and avian interaction with research NHP should also be considered.

Prenatal disorders and congenital Zika syndrome in squirrel monkeys.

During the Zika virus (ZIKV) outbreak in Brazil (2015-2016), the clinical manifestations associated with its infection were complex and included miscarriage and congenital malformations, not previously described. In this study, we evaluated the prenatal conditions of pregnant female squirrel monkeys (Saimiri collinsi) infected during different gestational thirds (GTs) and assessed all clinical aspects, diagnostic imaging, viremia and the immune response. In our study, 75% of the infected animals in the 1st GT group had significant clinical manifestations, such as miscarriage and prolonged viremia associated with a late immune response. Consequently, their neonates showed fetal neuropathology, such as cerebral hemorrhage, lissencephaly or malformations of the brain grooves, ventriculomegaly, and craniofacial malformations. Thus, our study demonstrated the relevance of pregnant squirrel monkeys as a model for the study of ZIKV infection in neonates due to the broad clinical manifestations presented, including the typical congenital Zika syndrome manifestations described in humans.

Prevalence of simian malaria parasites in macaques of Singapore.

Plasmodium knowlesi is a simian malaria parasite currently recognized as the fifth causative agent of human malaria. Recently, naturally acquired P. cynomolgi infection in humans was also detected in Southeast Asia. The main reservoir of both parasites is the long-tailed and pig-tailed macaques, which are indigenous in this region. Due to increased urbanization and changes in land use, there has been greater proximity and interaction between the long-tailed macaques and the general population in Singapore. As such, this study aims to determine the prevalence of simian malaria parasites in local macaques to assess the risk of zoonosis to the general human population. Screening for the presence of malaria parasites was conducted on blood samples from 660 peridomestic macaques collected between Jan 2008 and Mar 2017, and 379 wild macaques collected between Mar 2009 and Mar 2017, using a Pan-Plasmodium-genus specific PCR. Positive samples were then screened using a simian Plasmodium species-specific nested PCR assay to identify the species of parasites (P. knowlesi, P. coatneyi, P. fieldi, P. cynomolgi, and P. inui) present. All the peridomestic macaques sampled were tested negative for malaria, while 80.5% of the 379 wild macaques were infected. All five simian Plasmodium species were detected; P. cynomolgi being the most prevalent (71.5%), followed by P. knowlesi (47.5%), P. inui (42.0%), P. fieldi (32.5%), and P. coatneyi (28.5%). Co-infection with multiple species of Plasmodium parasites was also observed. The study revealed that Singapore's wild long-tailed macaques are natural hosts of the five simian malaria parasite species, while no malaria was detected in all peridomestic macaques tested. Therefore, the risk of simian malaria transmission to the general human population is concluded to be low. However, this can be better demonstrated with the incrimination of the vectors of simian malaria parasites in Singapore.

Potentially zoonotic gastrointestinal nematodes co-infecting free ranging non-human primates in Kenyan urban centres.

BACKGROUND: Natural infections with soil-transmitted nematodes occur in non-human primates (NHPs) and have the potential to cross primate-species boundaries and cause diseases of significant public health concern. Despite the presence of NHPs in most urban centres in Kenya, comprehensive studies on their gastrointestinal parasites are scant. OBJECTIVE: Conduct a cross-sectional survey to identify zoonotic nematodes in free-ranging NHPs found within four selected urban and peri-urban centres in Kenya. METHODS: A total of 86 NHPs: 41 African green monkeys [AGMs] (Chlorocebus aethiops), 30 olive baboons (Papio anubis), 5 blue monkeys (Cercopithecus mitis stuhlmanni) and 10 red-tailed monkeys (Cercopithecus ascanius) were sampled once in situ and released back to their habitat. Microscopy was used to identify nematodes egg and larvae stages in the samples. Subsequently, PCR coupled with high-resolution melting (PCR-HRM) analysis and sequencing were used to identify nodule worms. RESULTS: NHPs inhabiting densely populated urban environs in Kenya were found infected with a rich diversity of nematodes including three potentially zoonotic nematodes including Oesophagostomum stephanostomum, Oesophagostomum bifurcum and Trichostrongylus colubriformis and co-infections were common. CONCLUSION: Phylogenetic analysis showed that O. stephanostomum from red-tailed and blue monkeys have a close evolutionary relatedness to human isolates suggesting the zoonotic potential of this parasite. Moreover, we also report the first natural co-infection of O. bifurcum and O. stephanostomum in free-ranging AGMs.

Distribution of intestinal parasites of baboons (Papio anubis) and warthogs (Phacochoerus aethiopicus) at the Mole National Park, Ghana.

The identification of intestinal parasite of baboons (Papio anubis) and warthogs (Phacochoerus aethiopicus) was undertaken at the Mole National Park, Ghana. The main objective of the study was to determine the types and prevalence of intestinal parasites in baboons and warthogs in the Mole National Park. A total of nineteen (19) and twenty-three (23) samples were collected from the baboons and warthogs, respectively, and examined using the direct saline smear and formol-ether concentration technique for the identification of cysts, eggs and larvae of parasites. The survey showed that 94.74% of the baboon samples examined was infected with at least one parasite, whereas that of the warthogs showed 95.65% prevalence. A total of seven (7) and eight (8) different parasites were identified in baboon and warthog faecal samples, respectively. Strongyloides sp. had the highest prevalence in baboons (84.21%) and warthogs (78.26%). The second prevalent parasite identified was Ascaris sp. in the baboons (31.58%) and warthogs (30.43%). The results showed a high level of multiparasitism in these wild animals and an increased risk of zoonotic transmission which may result from interaction with inhabitants of the park community.

Serological survey and DNA screening of Leptospira spp. in free-living adult tufted capuchin monkeys (Cebus apella nigritus) in a forest reserve Southeast São Paulo State, Brazil.

BACKGROUND: Leptospirosis is an important anthropozoonosis. The study investigated the presence of anti-Leptospira antibodies and detection of Leptospira spp DNA in the urine as well as the biochemical profile in Neotropical wild primates living in a forest reserve from Southeast São Paulo State, Brazil. METHODS: Blood samples were obtained from 50 adult tufted capuchin monkeys (Cebus apella nigritus). Urine samples were obtained only from male primates. The screening for antibodies against Leptospira spp was evaluated by microscopic agglutination test (MAT). Leptospira DNA in the urine was evaluated by polymerase chain reaction (PCR) considering the target gene LipL32. Biochemical profile was evaluated by using a spectrophotometer. RESULTS: The MAT results included 39 (78%) serum reactive animals with the proportions of 28/39 males and 11/39 females. The most frequent reactive serogroups were Icterohemorrhagiae, Canicola, and Autumnalis. All urine samples were negative for leptospiral DNA. There were no significant differences between sexes for aspartate aminotransferase (AST) and alkaline phosphatase values, but alanine aminotransferase (ALT), creatinine, glucose, and urea were significantly higher in males. CONCLUSIONS: Tufted capuchin monkeys were sera reactive against leptospirosis. Prevalence was similar for the 2 sexes. Leptospiral DNA was not detected in the urine of sera reactive primates tested by the MAT method. ALT, creatinine, glucose, and urea values were higher in male animals.