A recombinant VSV-vectored vaccine rapidly protects nonhuman primates against lethal Nipah virus disease.

SignificanceConcern has increased about the pandemic potential of Nipah virus (NiV). Similar to SARS-CoV-2, NiV is an RNA virus that is transmitted by respiratory droplets. There are currently no NiV vaccines licensed for human use. While several preventive vaccines have shown promise in protecting animals against lethal NiV disease, most studies have assessed protection 1 mo after vaccination. However, in order to contain and control outbreaks, vaccines that can rapidly confer protection in days rather than months are needed. Here, we show that a recombinant vesicular stomatitis virus vector expressing the NiV glycoprotein can completely protect monkeys vaccinated 7 d prior to NiV exposure and 67% of animals vaccinated 3 d before NiV challenge.

Reemergence of yellow fever virus in southeastern Brazil, 2017-2018: What sparked the spread?

BACKGROUND: The 2017-2018 yellow fever virus (YFV) outbreak in southeastern Brazil marked a reemergence of YFV in urban states that had been YFV-free for nearly a century. Unlike earlier urban YFV transmission, this epidemic was driven by forest mosquitoes. The objective of this study was to evaluate environmental drivers of this outbreak. METHODOLOGY/PRINCIPAL FINDINGS: Using surveillance data from the Brazilian Ministry of Health on human and non-human primate (NHP) cases of YFV, we traced the spatiotemporal progression of the outbreak. We then assessed the epidemic timing in relation to drought using a monthly Standardized Precipitation Evapotranspiration Index (SPEI) and evaluated demographic risk factors for rural or outdoor exposure amongst YFV cases. Finally, we developed a mechanistic framework to map the relationship between drought and YFV. Both human and NHP cases were first identified in a hot, dry, rural area in northern Minas Gerais before spreading southeast into the more cool, wet urban states. Outbreaks coincided with drought in all four southeastern states of Brazil and an extreme drought in Minas Gerais. Confirmed YFV cases had an increased odds of being male (OR 2.6; 95% CI 2.2-3.0), working age (OR: 1.8; 95% CI: 1.5-2.1), and reporting any recent travel (OR: 2.8; 95% CI: 2.3-3.3). Based on this data as well as mosquito and non-human primate biology, we created the "Mono-DrY" mechanistic framework showing how an unusual drought in this region could have amplified YFV transmission at the rural-urban interface and sparked the spread of this epidemic. CONCLUSIONS/SIGNIFICANCE: The 2017-2018 YFV epidemic in Brazil originated in hot, dry rural areas of Minas Gerais before expanding south into urban centers. An unusually severe drought in this region may have created environmental pressures that sparked the reemergence of YFV in Brazil's southeastern cities.

Primate malarias as a model for cross-species parasite transmission.

Parasites regularly switch into new host species, representing a disease burden and conservation risk to the hosts. The distribution of these parasites also gives insight into characteristics of ecological networks and genetic mechanisms of host-parasite interactions. Some parasites are shared across many species, whereas others tend to be restricted to hosts from a single species. Understanding the mechanisms producing this distribution of host specificity can enable more effective interventions and potentially identify genetic targets for vaccines or therapies. As ecological connections between human and local animal populations increase, the risk to human and wildlife health from novel parasites also increases. Which of these parasites will fizzle out and which have the potential to become widespread in humans? We consider the case of primate malarias, caused by Plasmodium parasites, to investigate the interacting ecological and evolutionary mechanisms that put human and nonhuman primates at risk for infection. Plasmodium host switching from nonhuman primates to humans led to ancient introductions of the most common malaria-causing agents in humans today, and new parasite switching is a growing threat, especially in Asia and South America. Based on a wild host-Plasmodium occurrence database, we highlight geographic areas of concern and potential areas to target further sampling. We also discuss methodological developments that will facilitate clinical and field-based interventions to improve human and wildlife health based on this eco-evolutionary perspective.

Molecular evidence of Anaplasma phagocytophilum in olive baboons and vervet monkeys in Kenya.

BACKGROUND: Nonhuman primates (NHPs) play a significant role in zoonotic spill-overs, serving as either reservoirs, or amplifiers, of multiple neglected tropical diseases, including tick-borne infections. Anaplasma phagocytophilum are obligate intracellular bacteria of the family Anaplasmatacae, transmitted by Ixodid ticks and cause granulocytic anaplasmosis (formerly known as Human Granulocytic Ehrlichiosis (HGE)) in a wide range of wild and domestic mammals and humans too. The aim of this study was to determine whether Anaplasma phagocytophilum was circulating in olive baboons and vervet monkeys in Laikipia County, Kenya. RESULTS: Some 146 blood samples collected from olive baboons and 18 from vervet monkeys from Mpala Research Center and Ol jogi Conservancy in Laikipia County were screened for the presence of Anaplasma species using conventional Polymerase Chain Reaction (PCR), and then A. phagocytophilum was confirmed by sequencing using conventional PCR targeting 16S rRNA. This study found an overall prevalence of 18.3% for Anaplasma species. DNA sequences confirmed Anaplasma phagocytophilum in olive baboons for the first time in Kenya. CONCLUSION: This study provides valuable information on the endemicity of A. phagocytophilum bacteria in olive baboons in Kenya. Future research is needed to establish the prevalence and public health implications of zoonotic A. phagocytophilum isolates and the role of nonhuman primates as reservoirs in the region.

Marburg Virus Persistence on Fruit as a Plausible Route of Bat to Primate Filovirus Transmission.

Marburg virus (MARV), the causative agent of Marburg virus disease, emerges sporadically in sub-Saharan Africa and is often fatal in humas. The natural reservoir for this zoonotic virus is the frugivorous Egyptian rousette bat (Rousettus aegyptiacus) that when infected, sheds virus in the highest amounts in oral secretions and urine. Being fruit bats, these animals forage nightly for ripened fruit throughout the year, including those types often preferred by humans. During feeding, they continually discard partially eaten fruit on the ground that could then be consumed by other Marburg virus susceptible animals or humans. In this study, using qRT-PCR and virus isolation, we tested fruit discarded by Egyptian rousette bats experimentally infected with a natural bat isolate of Marburg virus. We then separately tested viral persistence on fruit varieties commonly cultivated in sub-Saharan Africa using a recombinant Marburg virus expressing the fluorescent ZsGreen1. Marburg virus RNA was repeatedly detected on fruit in the food bowls of the infected bats and viable MARV was recovered from inoculated fruit for up to 6 h.

COVID-19 cynomolgus macaque model reflecting human COVID-19 pathological conditions.

The pandemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a global threat to human health and life. A useful pathological animal model accurately reflecting human pathology is needed to overcome the COVID-19 crisis. In the present study, COVID-19 cynomolgus monkey models including monkeys with underlying diseases causing severe pathogenicity such as metabolic disease and elderly monkeys were examined. Cynomolgus macaques with various clinical conditions were intranasally and/or intratracheally inoculated with SARS-CoV-2. Infection with SARS-CoV-2 was found in mucosal swab samples, and a higher level and longer period of viral RNA was detected in elderly monkeys than in young monkeys. Pneumonia was confirmed in all of the monkeys by computed tomography images. When monkeys were readministrated SARS-CoV-2 at 56 d or later after initial infection all of the animals showed inflammatory responses without virus detection in swab samples. Surprisingly, in elderly monkeys reinfection showed transient severe pneumonia with increased levels of various serum cytokines and chemokines compared with those in primary infection. The results of this study indicated that the COVID-19 cynomolgus monkey model reflects the pathophysiology of humans and would be useful for elucidating the pathophysiology and developing therapeutic agents and vaccines.

Pet primates for sale in the United States.

Our research goal was to investigate the primate pet trade in the United States. While dogs and cats are the most common type of pet, there are an estimated 15,000 pet primates in the United States and the demand for exotic pets in general has been rising. Most research on pet primates occurs in habitat countries and little is known about these pets in the United States. We collected data from six exotic pet-trade websites twice a month for 12 months. We recorded the type of primate for sale, sex, age, location, and price. We used Chi-Square Goodness-of-Fit tests to compare whether the number of male and female pet primates for sale and the number of different age categories of pet primates for sale differed from equality and Spearman Correlation to examine associations between price and size and price and supply. We recorded 551 pet primates for sale between June 2019-June 2020, with 69.1% platyrrhines, 21.6% strepsirrhines, and 8.9% catarrhines. Marmosets were sold most often (36.7%, N = 202) followed by lemurs (21.6%, N = 119), capuchins (11.3%, N = 62), and squirrel monkeys (10.5%, N = 58). Almost two-thirds of the pet primates for sale were male (Chi-Square = 16.056, df = 1, P = 0. 00006) and 78.7% were under one year old (Chi-Square = 440.264, df = 2, P<0.00001). The median price was $3,800 though price was highly variable, even for the same taxa. There are several potential drivers for the primate pet trade, including media influence, fashion/status, and profitable breeding though these are not mutually exclusive. Primates do not make good pets and even when captive-bred, pet primates impact the conservation of their wild counterparts. Advertisement campaigns focusing on disease transmission and legal consequences and a federal ban on pet primate ownership are two avenues to pursue to end the ownership of pet primates in the United States.

PREVALENCE OF LAWSONIA INTRACELLULARIS INFECTION IN NONHUMAN PRIMATES AND PEST RODENTS IN A ZOOLOGICAL COLLECTION.

In 2016 and 2017, Lawsonia intracellularis was isolated from several pileated gibbons (Hylobates pileatus) presenting with diarrhea in Mulhouse Zoo (eastern France). To this day, infection with this bacterium has rarely been described in nonhuman primates (NHP) in captivity or in the wild and there are no data about the prevalence or transmission of the disease. This study focuses on finding the prevalence of this infection amongst Mulhouse Zoo's NHP collection and trying to identify a source of contamination responsible for this epizooty. Forty-eight real-time PCR were conducted on feces from all NHP species in the zoo and on small mammals trapped in the NHP housing structures. No NHP was experiencing symptoms at the time of the study, however test results showed that Lawsonia intracellularis can be found in 61.76% (21/34) of the group total (n = 34) and the prevalence even increases to 92.3% (12/13) in the Lemuriform infraorder (n = 13). In small mammals (n = 14), prevalence of the bacterium is 57.17% (8/14) including 77.78% in rodents (7/9). The results of this study show that several NHP species are healthy carriers and some species of small mammals can be considered as a potential source of contamination. Because of the difficulty encountered trying to isolate the bacterium, it is plausible that infections caused by Lawsonia intracellularis have been underdiagnosed to this day, and that it could be an emerging disease in Europe. Therefore, using real-time PCR to search for this bacterium seems essential in case of diarrhea occurring in nonhuman primates. Moreover, even though further studies on contamination sources need to be conducted, the issue of the presence of rodents in NHP housing structures has to be taken very seriously and tackled with the utmost care.

Recent epidemiologic, clinical, and genetic diversity of Toxoplasma gondii infections in non-human primates.

Toxoplasma gondii infections are common in humans and animals worldwide. The present review summarizes worldwide information on the prevalence of clinical and subclinical infections, epidemiology, diagnosis, and genetic diversity of T. gondii in non-human primates (NHP) for the past decade. Seroprevalence estimates of T. gondii worldwide were tabulated for each host. Risk factors associated with T. gondii infections are evaluated. New World NHP in captivity are highly susceptible to T. gondii infection with high mortality associated with disseminated toxoplasmosis. T. gondii can be transmitted to NHP in contact with symptomatic NHP. Therefore, precautions should be taken to prevent transmission of T. gondii to humans while handling symptomatic NHP. There were no reports of clinical toxoplasmosis in Old World NHP. Among the different genera of New World NHP, susceptibility to clinical toxoplasmosis varies a great deal; however, factors affecting this susceptibility are not fully understood. Genetic characteristics of T. gondii strains from monkeys is summarized.

Variation in predicted COVID-19 risk among lemurs and lorises.

The novel coronavirus SARS-CoV-2, which in humans leads to the disease COVID-19, has caused global disruption and more than 2 million fatalities since it first emerged in late 2019. As we write, infection rates are at their highest point globally and are rising extremely rapidly in some areas due to more infectious variants. The primary target of SARS-CoV-2 is the cellular receptor angiotensin-converting enzyme-2 (ACE2). Recent sequence analyses of the ACE2 gene predict that many nonhuman primates are also likely to be highly susceptible to infection. However, the anticipated risk is not equal across the Order. Furthermore, some taxonomic groups show high ACE2 amino acid conservation, while others exhibit high variability at this locus. As an example of the latter, analyses of strepsirrhine primate ACE2 sequences to date indicate large variation among lemurs and lorises compared to other primate clades despite low sampling effort. Here, we report ACE2 gene and protein sequences for 71 individual strepsirrhines, spanning 51 species and 19 genera. Our study reinforces previous results while finding additional variability in other strepsirrhine species, and suggests several clades of lemurs have high potential susceptibility to SARS-CoV-2 infection. Troublingly, some species, including the rare and endangered aye-aye (Daubentonia madagascariensis), as well as those in the genera Avahi and Propithecus, may be at high risk. Given that lemurs are endemic to Madagascar and among the primates at highest risk of extinction globally, further understanding of the potential threat of COVID-19 to their health should be a conservation priority. All feasible actions should be taken to limit their exposure to SARS-CoV-2.

Use of convalescent serum reduces severity of COVID-19 in nonhuman primates.

Passive transfer of convalescent plasma or serum is a time-honored strategy for treating infectious diseases. Human convalescent plasma containing antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is currently being used to treat patients with coronavirus disease 2019 where clinical efficacy trials are ongoing. Here, we assess therapeutic passive transfer in groups of SARS-CoV-2-infected African green monkeys with convalescent sera containing either high or low anti-SARS-CoV-2 neutralizing antibody titers. Differences in viral load and pathology are minimal between monkeys that receive the lower titer convalescent sera and untreated controls. However, lower levels of SARS-CoV-2 in respiratory compartments, reduced severity of virus-associated lung pathology, and reductions in coagulopathy and inflammatory processes are observed in monkeys that receive high titer sera versus untreated controls. Our data indicate that convalescent plasma therapy in humans may be an effective strategy provided that donor sera contain high anti-SARS-CoV-2 neutralizing titers given in early stages of the disease.

Host Associations of Ectoparasites of the Gray Mouse Lemur, Microcebus murinus, in Northwestern Madagascar.

Eight species of ectoparasites were collected during 225 gray mouse lemur, Microcebus murinus (J. F. Miller), captures, in Ankarafantsika National Park, Madagascar, in 2010-2011. The ixodid tick, Haemaphysalis lemuris Hoogstraal, was the most common ectoparasite and was mostly represented by nymphs. Other ectoparasites recorded include the polyplacid sucking louse, Lemurpediculus madagascariensis Durden, Kessler, Radespiel, Zimmermann, Hasiniaina, and Zohdy; the ixodid tick, Haemaphysalis simplex Neumann; an undescribed laelapid mite in the genus Aetholaelaps; another laelapid belonging to the genus Androlaelaps; the chigger mite Schoutedenichia microcebi Stekolnikov; an undescribed species of atopomelid mite in the genus Listrophoroides; and an undescribed species of psoroptid mite in the genus Cheirogalalges. Except for the 2 species of ticks and 1 species of chigger, these ectoparasites may be host-specific to M. murinus. Total tick (H. lemuris and H. simplex) infestation was significantly greater in August than October, whereas louse (L. madagascariensis) infestation was significantly greater in October. There was no significant difference in tick infestations between male and female lemurs, but male lemurs had significantly more lice than female lemurs. Reproductive status was not a significant predictor of tick infestation in males and females.

Climate change: how it impacts the emergence, transmission, resistance and consequences of viral infections in animals and plants.

The ongoing COVID-19 pandemic has made us wonder what led to its occurrence and what can be done to avoid such events in the future. As we document, one changing circumstance that is resulting in the emergence and changing the expression of viral diseases in both plants and animals is climate change. Of note, the rapidly changing environment and weather conditions such as excessive flooding, droughts, and forest fires have raised concerns about the global ecosystem's security, sustainability, and balance. In this review, we discuss the main consequences of climate change and link these to how they impact the appearance of new viral pathogens, how they may facilitate transmission between usual and novel hosts, and how they may also affect the host's ability to manage the infection. We emphasize how changes in temperature and humidity and other events associated with climate change influence the reservoirs of viral infections, their transmission by insects and other intermediates, their survival outside the host as well the success of infection in plants and animals. We conclude that climate change has mainly detrimental consequences for the emergence, transmission, and outcome of viral infections and plead the case for halting and hopefully reversing this dangerous event.

A mathematical model for zoonotic transmission of malaria in the Atlantic Forest: Exploring the effects of variations in vector abundance and acrodendrophily.

Transmission foci of autochthonous malaria caused by Plasmodium vivax-like parasites have frequently been reported in the Atlantic Forest in Southeastern and Southern Brazil. Evidence suggests that malaria is a zoonosis in these areas as human infections by simian Plasmodium species have been detected, and the main vector of malaria in the Atlantic Forest, Anopheles (Kerteszia) cruzii, can blood feed on human and simian hosts. In view of the lack of models that seek to predict the dynamics of zoonotic transmission in this part of the Atlantic Forest, the present study proposes a new deterministic mathematical model that includes a transmission compartment for non-human primates and parameters that take into account vector displacement between the upper and lower forest strata. The effects of variations in the abundance and acrodendrophily of An. cruzii on the prevalence of infected humans in the study area and the basic reproduction number (R0) for malaria were analyzed. The model parameters are based on the literature and fitting of the empirical data. Simulations performed with the model indicate that (1) an increase in the abundance of the vector in relation to the total number of blood-seeking mosquitoes leads to an asymptotic increase in both the proportion of infected individuals at steady state and R0; (2) the proportion of infected humans at steady state is higher when displacement of the vector mosquito between the forest strata increases; and (3) in most scenarios, Plasmodium transmission cannot be sustained only between mosquitoes and humans, which implies that non-human primates play an important role in maintaining the transmission cycle. The proposed model contributes to a better understanding of the dynamics of malaria transmission in the Atlantic Forest.

LEPTOSPIRA SPECIES STATUS OF CAPTIVE NONHUMAN PRIMATES AND FREE-RANGING RODENTS AT THE BARRANQUILLA ZOO, COLOMBIA, 2013.

Leptospirosis is a zoonotic disease with worldwide distribution caused by pathogenic Leptospira spp. Pathogenic Leptospira spp. are shed in urine of infected hosts and transmitted via ingestion of contaminated food or water, inoculation, inhalation of aerosolized urine, and absorption through mucous membranes. Leptospirosis is of particular concern in tropical and subtropical regions such as Barranquilla, Colombia. Recent reports indicate that in Barranquilla, rodents, dogs, and humans have a high leptospiral seroprevalence; and amongst zoo mammals, nonhuman primates have a high prevalence of Leptospira spp. infection. We therefore sought to determine whether primates in captivity at the Barranquilla Zoo were exposed to Leptospira spp. and whether there was a probable causal transmission link between the primates and peridomestic rodents. Samples were collected from 29 captive nonhuman primates, 15 free-ranging rats (Rattus rattus), and 10 free-ranging squirrels (Sciurus granatensis). Serum samples from primates, rats, and squirrels were evaluated via microagglutination test (MAT) vs 24 reference Leptospira serovars. Blood and urine from the primates and kidney tissue from the rats and squirrels were cultured in Ellinghausen-McCullough-Johnson-Harris (EMJH) medium and polymerase chain reaction (PCR) of lipL32 was performed to determine whether active infection was present. Leptospiral seroprevalence was found to be 66.7% (10/15) in rats, 60% (6/10) in squirrels, and 6.9% (2/29) in neotropical primates. Ateles hybridus and Ateles fusciceps had positive titers to serogroups Cynopteri and Ictohaemorrhagiae, respectively. Of the rodents that had antibodies against Leptospira spp., 90% of the rats and 66.7% of the squirrels corresponded to the serovar australis. Interestingly, all animals were culture and PCR negative, indicating Leptospira spp. exposure in the absence of current infection. While their status as maintenance hosts needs to be investigated further, this is the first study to show leptospiral seropositivity in red-tailed squirrels (S. granatensis).

Diagnostic evaluation of fatal Balamuthia mandrillaris meningoencephalitis in a captive Bornean orangutan (Pongo pygmaeus) with identification of potential environmental source and evidence of chronic exposure.

A female Bornean orangutan (Pongo pygmaeus) aged 11 years and 6 months was examined by veterinarians after caretakers observed lethargy and facial grimacing. Within 72 h the primate had left-sided hemiparesis that worsened over the next week. An MRI revealed a focal right-sided cerebral mass suspected to be a neoplasm. Ten days after onset of clinical signs, the orangutan died. On postmortem exam, the medial right parietal lobe was replaced by a 7 × 4 × 3.5 cm focus of neuromalacia and hemorrhage that displaced the lateral ventricle and abutted the corpus callosum. Histopathology of the cerebral lesion revealed pyogranulomatous meningoencephalitis with intralesional amoeba trophozoites and rare cysts. Fresh parietal lobe was submitted to the Centers for Disease Control and Prevention lab for multiplex free-living amoebae real-time PCR and detected Balamuthia mandrillaris DNA at a high burden. Mitochondrial DNA was sequenced, and a 760-bp locus 19443F/20251R was compared to several human infections of B. mandrillaris and shown to be identical to the isolates from four human cases of encephalitis: 1998 in Australia, 1999 in California, 2000 in New York, and 2010 in Arizona. Indirect immunofluorescent antibody testing of stored serum samples indicated exposure to B. mandrillaris for at least 2 years prior to death. Within 1 week of the orangutan's death, water from the exhibit was analyzed and identified the presence of B. mandrillaris DNA, elucidating a possible source of exposure. B. mandrillaris, first reported in a mandrill in 1986, has since occurred in humans and animals and is now considered an important emerging pathogen.

Trichuris trichiura isolated from Macaca sylvanus: morphological, biometrical, and molecular study.

BACKGROUND: Recent studies have reported the existence of a Trichuris species complex parasitizing primate. Nevertheless, the genetic and evolutionary relationship between Trichuris spp. parasitizing humans and Non-Human Primates (NHP) is poorly understood. The hypothesised existence of different species of Trichuris in primates opens the possibility to evaluate these primates as reservoir hosts of human trichuriasis and other putative new species of whipworms. RESULTS: In this paper, we carried out a morphological, biometrical and molecular study of Trichuris population parasitizing Macaca sylvanus from Spain based on traditional morpho-biometrical methods, PCA analysis and ribosomal (ITS2) and mitochondrial (cox1 and cob) DNA sequencing. Morphological results revealed that Trichuris sp. from M. sylvanus is Trichuris trichiura. Ribosomal datasets revealed that phylogenetic relationships of populations of Trichuris sp. from M. sylvanus were unresolved. The phylogeny inferred on mitochondrial datasets (partitioned and concatenated) revealed similar topologies; Thus, phylogenetic trees supported the existence of clear molecular differentiation between individuals of Trichuris sp. from M. sylvanus appearing in two different subclades. CONCLUSIONS: Based on morphological parameters, biometrical measurements, and molecular sequence analysis, we conclude that the whipworms isolated from M. sylvanus were T. trichiura. Further, the evolutionary relationship showed that these worms belonged to two genotypes within the T. trichiura lineage. Since T. trichiura is of public health importance, it is important to carry out further studies to improve the understanding of its hosts range, evolution and phylogeography.

Detection of a Larva of Armillifer armillatus in a Potto (Perodicticus potto) from the Republic of the Congo.

We determined the complete sequence of the mitochondrial DNA (mtDNA) of a parasite discovered between the subcutaneous tissue and the peritoneum of an African nocturnal non-human primate (NHP). The parasite and host sequences were obtained by a combination of Sanger sequencing and nanopore MinION techniques. Analyses of mtDNA gene arrangements and sequences unambiguously showed that the parasite investigated was the pentastomid Armillifer armillatus, also commonly named the tongue worm. The full-length mitochondrial genome of A. armillatus, measuring 16,706 bp in length, contains 13 protein-coding genes, 2 ribosomal RNA genes, and 22 transfer RNA genes, an arrangement identical to that of previously described pentastomid mitochondrial genomes. We describe here the second full mitochondrial genome of A. armillatus to date. To identify the NHP host, maximum likelihood phylogenetic analyses of a 441-bp fragment on the 12S rDNA gene and of a 1,140-bp fragment of the mitochondrial cytochrome b strongly support clustering with the African lorisid Perodicticus potto, a species that has rarely been reported as an intermediate host of this parasite.

Comparative ACE2 variation and primate COVID-19 risk.

The emergence of SARS-CoV-2 has caused over a million human deaths and massive global disruption. The viral infection may also represent a threat to our closest living relatives, nonhuman primates. The contact surface of the host cell receptor, ACE2, displays amino acid residues that are critical for virus recognition, and variations at these critical residues modulate infection susceptibility. Infection studies have shown that some primate species develop COVID-19-like symptoms; however, the susceptibility of most primates is unknown. Here, we show that all apes and African and Asian monkeys (catarrhines), exhibit the same set of twelve key amino acid residues as human ACE2. Monkeys in the Americas, and some tarsiers, lemurs and lorisoids, differ at critical contact residues, and protein modeling predicts that these differences should greatly reduce SARS-CoV-2 binding affinity. Other lemurs are predicted to be closer to catarrhines in their susceptibility. Our study suggests that apes and African and Asian monkeys, and some lemurs, are likely to be highly susceptible to SARS-CoV-2. Urgent actions have been undertaken to limit the exposure of great apes to humans, and similar efforts may be necessary for many other primate species.

Genetic evidence for the role of non-human primates as reservoir hosts for human schistosomiasis.

BACKGROUND: Schistosomiasis is a chronic parasitic disease, that affects over 207 million people and causes over 200,000 deaths annually, mainly in sub-Saharan Africa. Although many health measures have been carried out to limit parasite transmission, significant numbers of non-human primates such as Chlorocebus aethiops (Ch. aethiops) (vervet) and Papio anubis (baboon) are infected with S. mansoni, notably in Ethiopia, where they are expected to have potentially significant implications for transmission and control efforts. OBJECTIVE: The objective of this study was to assess and compare the genetic diversity and population structure of S. mansoni isolates from human and non-human primates free-ranging in close proximity to villages in selected endemic areas of Ethiopia. METHODS: A cross-sectional study was conducted in three transmission sites: Bochesa, Kime and Fincha. A total of 2,356 S. mansoni miracidia were directly isolated from fecal specimens of 104 hosts (i.e. 60 human hosts and 44 non-human primates). We performed DNA extraction and PCR amplification using fourteen microsatellite loci. RESULTS: At population scale we showed strong genetic structure between the three sample sites. At the definitive host scale, we observed that host factors can shape the genetic composition of parasite infra-populations. First, in male patients, we observed a positive link between parasite genetic diversity and the age of the patients. Second, we observed a difference in genetic diversity which was high in human males, medium in human females and low in non-human primates (NHPs). Finally, whatever the transmission site no genetic structure was observed between human and non-human primates, however, there appears to be little barriers, if any, host specificity of the S. mansoni populations with cross-host infections. CONCLUSION: Occurrence of infection of a single host with multiple S. mansoni strains and inter- and intra-host genetic variations was observed. Substantial genetic diversity and gene flow across the S. mansoni population occurred at each site and non-human primates likely play a role in local transmission and maintenance of infection. Therefore, public health and wildlife professionals should work together to improve disease control and elimination strategies.