Naturally occurring fatal herpes simplex virus 1 infection in a family of white-faced saki monkeys (Pithecia pithecia pithecia)

Fatal Simplexvirus humanalpha1 infection in howler-monkeys (Alouatta sp.) under human care: Clinical, molecular, and pathological findings

BACKGROUND

Simplexvirus humanalpha1 (HuAHV-1) are common anthropozoonosis reported in marmosets but rare in howler monkeys (Alouatta sp.).

METHODS

Necropsy of two brown-howler monkeys (A. caraya) and one red-howler monkey (A. guariba clamitans) from different zoo collections were performed. Fragments of all organs were examined through microscopy. Samples were submitted to IHC for Simplexvirus humanalpha 2 (HuAHV-2) [sin. Herpesvirus simplex type 2] and PCR.

RESULTS

Grossly, only the A. guariba showed liver lesions characterized by multifocal, pinpoint white areas corresponding microscopically as random necrotizing herpetic hepatitis and ulcerative glossitis. Both A. caraya showed necrotizing meningoencephalitis with Cowdry A-type body inclusions within neurons and astrocytes. Immunolabeling for HuAHV-1/2 was observed in the tongue, liver, and brain. HuAHV-1 was confirmed in all samples by PCR, Sanger sequencing, and phylogenetic analyses.

CONCLUSION

Necrotizing meningoencephalitis was appreciated in 2/3 of animals, and it is associated with neurologic signs. Along with ulcerative glossitis, a hallmark lesion in marmosets, it was present in one animal. Regarding herpetic hepatitis, it is not frequent in monkeys and occurs mainly in immunocompromised animals. HuAHV-1 infection was confirmed corroborating with a human source. This is the second report on captive black-howler monkeys and the first gross, histologic, immunohistochemical, and molecular description of herpetic hepatitis and ulcerative glossitis in red-howler monkeys (A. guariba).

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.

Simian homologues of human herpesviruses and implications for novel viral introduction to free-living mountain gorillas

The endangered mountain gorilla (Gorilla beringei beringei) in Rwanda, Uganda, and the Democratic Republic of Congo is frequently in contact with humans through tourism, research activities, and illegal entry of people into protected gorilla habitat. Herpesviruses, which are ubiquitous in primates, have the potential to be shared in any setting where humans and gorillas share habitat. Based on serological findings and clinical observations of orofacial ulcerated lesions resembling herpetic lesions, an alpha-herpesvirus resembling human herpes simplex virus type 1 (HSV-1) has long been suspected to be present in human-habituated mountain gorillas in the wild. While the etiology of orofacial lesions in the wild has not been confirmed, HSV-1 has been suspected in captively-housed mountain gorillas and confirmed in a co-housed confiscated Grauer's gorilla (Gorilla beringei graueri). To better characterize herpesviruses infecting mountain gorillas and to determine the presence/absence of HSV-1 in the free-living population, we conducted a population-wide survey to test for the presence of orally shed herpesviruses. DNA was extracted from discarded chewed plants collected from 294 individuals from 26 groups, and samples were screened by polymerase chain reaction using pan-herpesvirus and HSV-1-specific assays. We found no evidence that human herpesviruses had infected free-ranging mountain gorillas. However, we found gorilla-specific homologs to human herpesviruses, including cytomegaloviruses (GbbCMV-1 and 2), a lymphocryptovirus (GbbLCV-1), and a new rhadinovirus (GbbRHV-1) with similar characteristics (i.e., timing of primary infection, shedding in multiple age groups, and potential modes of transmission) to their human counterparts, human cytomegalovirus, Epstein-Barr virus and Kaposi's sarcoma-associated herpesvirus, respectively.

First report on herpesvirus in black-fronted titi (Callicebus nigrifrons) kept under human care

Keeping Neotropical primates in captivity puts them at great risk of illness because of their susceptibility to human herpesvirus. This is the first report on herpesvirus in Callicebus nigrifrons that developed clinical disease and was confirmed by immunohistochemical and RT-PCR. Diagnosis and prevention are essential for the conservation of species.

Callitrichine gammaherpesvirus 3 and Human alphaherpesvirus 1 in New World Primate negative for yellow fever virus in Rio de Janeiro, Brazil

BACKGROUND

Herpesvirus transmission between humans and non-human primate (NHP) can occur through contact scratches with lesions, infected saliva, and mainly through contaminated food. Therefore, cross-infection can lead to severe illness or even death for both the animal and human. In 2017, during the yellow fever (YF) outbreak in Brazil, species of the New World Primates (NWP) from Rio de Janeiro state, tested negative for yellow fever virus (YFV) detection.

OBJECTIVES

To evaluate herpesvirus in the population NWP in Rio de Janeiro.

METHODS

To investigate, liver samples of 283 NWP, from several regions of the state of Rio de Janeiro, were tested for the herpesvirus family using a Pan-polymerase chain reaction (Pan-PCR) and sequencing.

FINDINGS

34.6% (98/283) tested positive for at least one herpesvirus; 29.3% (83/283) tested positive to Human alphaherpesvirus 1 (HSV-1), this virus from humans can be lethal to New World monkey; 13% (37/283) were detected Callitrichine gammaherpesvirus 3 (CalHV-3), responsible for lymphoproliferative disease that can be fatal in NWP. In addition, CalHV-3 / HSV-1 co-infection was in 11.6% (33/283) of the samples.

MAIN CONCLUSIONS

Pan-herpesvirus was useful to identify species-specific herpesviruses and virus from human that can infect animals. Furthermore, during an outbreak of YF other infections should be monitored.

Fatal Human Alphaherpesvirus 1 Infection in Free-Ranging Black-Tufted Marmosets in Anthropized Environments, Brazil, 2012–2019

Human alphaherpesvirus 1 (HuAHV1) causes fatal neurologic infections in captive New World primates. To determine risks for interspecies transmission, we examined data for 13 free-ranging, black-tufted marmosets (Callithrix penicillata) that died of HuAHV1 infection and had been in close contact with humans in anthropized areas in Brazil during 2012–2019. We evaluated pathologic changes in the marmosets, localized virus and antigen, and assessed epidemiologic features. The main clinical findings were neurologic signs, necrotizing meningoencephalitis, and ulcerative glossitis; 1 animal had necrotizing hepatitis. Transmission electron microscopy revealed intranuclear herpetic inclusions, and immunostaining revealed HuAHV1 and herpesvirus particles in neurons, glial cells, tongue mucosal epithelium, and hepatocytes. PCR confirmed HuAHV1 infection. These findings illustrate how disruption of the One Health equilibrium in anthropized environments poses risks for interspecies virus transmission with potential spillover not only from animals to humans but also from humans to free-ranging nonhuman primates or other animals.

Herpesvirus Infection in Lumholtz's Tree-Kangaroo (Dendrolagus lumholtzi)

Herpesvirus infections associated with a range of clinical findings are widespread in free-ranging and captive Australian marsupials. We report on herpesviruses identified by virus neutralization and PCR in free-ranging and captive Lumholtz's tree-kangaroos (Dendrolagus lumholtzi). Herpesvirus has not been confirmed previously by DNA testing in tree kangaroos. Virus neutralization testing for alphaherpesviruses MaHV1 and MaHV2 was positive on 4/10 captive and 0/35 free-ranging tree-kangaroo samples tested. A novel gammaherpesvirus was found on PCR in 17/20 apparently healthy individuals (11/12 free-ranging, 5/6 wild-caught, captive, and 1/2 captive-bred). One captive-bred animal that died following an acute illness was positive on PCR only for MaHV4, an alphaherpesvirus previously identified from an eastern grey kangaroo (Macropus giganteus). The detection of MaHV4, associated with morbidity and mortality in captive tree-kangaroos, raises biosecurity concerns about introducing a non-endemic alphaherpesvirus into naive wild populations through release of captive animals. We propose that: 1) further work on herpesviruses in marsupials be carried out to determine whether herpesviruses from captive individuals represent a potential threat to wild populations, particularly for endangered species in which there are captive breeding and cross-fostering programs; and 2) that captive tree kangaroos be kept in such a way that prevents cross-species transmission of herpesviruses, in particular eliminating close direct or indirect contact with other species of macropods.

Evolution and Genetic Diversity of Primate Cytomegaloviruses

Cytomegaloviruses (CMVs) infect many mammals, including humans and non-human primates (NHPs). Human cytomegalovirus (HCMV) is an important opportunistic pathogen among immunocompromised patients and represents the most common infectious cause of birth defects. HCMV possesses a large genome and very high genetic diversity. NHP-infecting CMVs share with HCMV a similar genomic organization and coding content, as well as the course of viral infection. Recent technological advances have allowed the sequencing of several HCMV strains from clinical samples and provided insight into the diversity of NHP-infecting CMVs. The emerging picture indicates that, with the exclusion of core genes (genes that have orthologs in all herpesviruses), CMV genomes are relatively plastic and diverse in terms of gene content, both at the inter- and at the intra-species level. Such variability most likely underlies the strict species-specificity of these viruses, as well as their ability to persist lifelong and with relatively little damage to their hosts. However, core genes, despite their strong conservation, also represented a target of adaptive evolution and subtle changes in their coding sequence contributed to CMV adaptation to different hosts. Indubitably, important knowledge gaps remain, the most relevant of which concerns the role of viral genetics in HCMV-associated human disease.

Cytomegalovirus distribution and evolution in hominines

Herpesviruses are thought to have evolved in very close association with their hosts. This is notably the case for cytomegaloviruses (CMVs; genus Cytomegalovirus) infecting primates, which exhibit a strong signal of co-divergence with their hosts. Some herpesviruses are however known to have crossed species barriers. Based on a limited sampling of CMV diversity in the hominine (African great ape and human) lineage, we hypothesized that chimpanzees and gorillas might have mutually exchanged CMVs in the past. Here, we performed a comprehensive molecular screening of all 9 African great ape species/subspecies, using 675 fecal samples collected from wild animals. We identified CMVs in eight species/subspecies, notably generating the first CMV sequences from bonobos. We used this extended dataset to test competing hypotheses with various degrees of co-divergence/number of host switches while simultaneously estimating the dates of these events in a Bayesian framework. The model best supported by the data involved the transmission of a gorilla CMV to the panine (chimpanzee and bonobo) lineage and the transmission of a panine CMV to the gorilla lineage prior to the divergence of chimpanzees and bonobos, more than 800,000 years ago. Panine CMVs then co-diverged with their hosts. These results add to a growing body of evidence suggesting that viruses with a double-stranded DNA genome (including other herpesviruses, adenoviruses, and papillomaviruses) often jumped between hominine lineages over the last few million years.

Management of Ocular Human herpesvirus 1 Infection in a White-faced Saki Monkey (Pithecia pithecia)

A 20-y-old male intact white-faced saki monkey (Pithecia pithecia) presented with an acute ocular disease of the right eye. Clinical signs included periocular swelling, conjunctivitis, and anisocoria with a miotic right pupil. Conjunctival swabs were positive for Human herpesvirus 1 (HHV1) according to PCR amplification with sequencing. Initial clinical signs resolved with supportive treatment, and the animal was managed chronically by using acyclovir (5 mg/kg PO twice daily) during flare-ups. After more than 2 y, the progression of clinical disease led to enucleation of the right eye. At 2 mo after surgery, acute presentation of severe neurologic signs, including ataxia and blindness, resulted in euthanasia. Histopathology, PCR analysis, and sequencing results were consistent with viral encephalitis due to HHV1; coinfection with Pithecia pithecia lymphocryptovirus 1 was identified. This report describes the first case of managed HHV1 infection in a platyrrhine primate and the first case of HHV1 in a white-faced saki monkey that was not rapidly fatal.

LONG-TERM SURVEILLANCE OF LANGUR ALPHAHERPESVIRUS IN A ZOO POPULATION OF SILVERED LANGURS ( TRACHYPITHECUS CRISTATUS)

  Langur alphaherpesvirus (HVL), a provisionally named alphaherpesvirus in the Simplexvirus genus, was first identified in 1991 at the Bronx Zoo in wild-origin silvered langurs ( Trachypithecus cristatus) and their descendants. HVL is closely related to B virus ( Macacine alphaherpesvirus 1) based on serologic and genetic data, but its natural history and zoonotic potential remain unknown. A cohort study was undertaken to describe the epidemiology, clinical impact, and potential management implications of this virus in a naturally infected, zoo-based population of silvered langurs. Opportunistic surveillance sampling from 1991 through 2015 resulted in 235 serum samples and 225 mucosal swabs from 75 individuals. A total of 43 individuals (57.3%) were seropositive for HVL within this period. Seroprevalence increased significantly with age, and indirect evidence suggested a peak in transmission at the onset of sexual maturity. These findings were similar to the behavior of other simplexviruses in their adapted hosts. Yearly cumulative incidence declined significantly through the study period, with zero or one new case detected each year from 2007 through 2015. The density of this population decreased within the study period for management reasons unrelated to HVL infection, and a change in age distribution or less-frequent contacts may have contributed to low transmission. In addition, clinical signs of simplexvirus infection were rare, and virus isolation was negative on all mucosal swabs, suggesting that viral shedding was infrequent. Yearly period seroprevalence remained relatively constant with a median of 45.8%, likely because of the extended survival of infected individuals within the population. Maintenance of a naturally occurring, novel virus with unknown zoonotic potential in a zoo population for over 25 yr highlights the importance of biosecurity and biosafety for management of silvered langurs and all primate species.

An Intrinsically Disordered Region of the DNA Repair Protein Nbs1 Is a Species-Specific Barrier to Herpes Simplex Virus 1 in Primates

Humans occasionally transmit herpes simplex virus 1 (HSV-1) to captive primates, who reciprocally harbor alphaherpesviruses poised for zoonotic transmission to humans. To understand the basis for the species-specific restriction of HSV-1 in primates, we simulated what might happen during the cross-species transmission of HSV-1 and found that the DNA repair protein Nbs1 from only some primate species is able to promote HSV-1 infection. The Nbs1 homologs that promote HSV-1 infection also interact with the HSV-1 ICP0 protein. ICP0 interaction mapped to a region of structural disorder in the Nbs1 protein. Chimeras reversing patterns of disorder in Nbs1 reversed titers of HSV-1 produced in the cell. By extending this analysis to 1,237 virus-interacting mammalian proteins, we show that proteins that interact with viruses are highly enriched in disorder, suggesting that viruses commonly interact with host proteins through intrinsically disordered domains.

A model of genital herpes simplex virus Type 1 infection in Rhesus Macaques

BACKGROUND

Although HSV-2 is the major cause of genital lesions, HSV-1 accounts for half of new cases in developed countries.

METHODS

Three healthy SHIV-SF162P3-infected Indian rhesus macaques were inoculated with 4×108 pfu of HSV-1 twice, with the second inoculation performed after the vaginal mucosa was gently abraded with a cytobrush.

RESULTS

HSV-1 DNA was detected in vaginal swabs 5 days after the second but not the first inoculation in all three macaques. An increase in inflammatory cytokines was detected in the vaginal fluids of the animals with no or intermittent shedding. Higher frequency of blood α4 β7high CD4+ T cells was measured in the animals with consistent and intermitted shedding, while a decrease in the frequency of CD69+ CD4+ T cells was present in all animals.

CONCLUSIONS

This macaque model of genital HSV-1 could be useful to study the impact of the growing epidemic of genital HSV-1 on HIV infection.

Primates on display: Potential disease consequences beyond bushmeat

Human interactions with nonhuman primates vary tremendously, from daily cultural engagements and food commodities, to pet ownership and tourist encounters. These interactions provide opportunities for the exchange of pathogenic organisms (both zoonoses and anthroponoses). As exposures are not limited to areas where bushmeat usage continues to be a major problem, we must work to understand better our motivations for engaging in activities like owning primates as pets and having direct physical contact with wild primates within the context of nature-based tourism. These topics, and the theoretical potential for pathogen transmission, are reviewed in the present manuscript. This is followed by a case study utilizing 3845 survey responses collected from four international locations known for primate-based tourism, with results indicating that while a majority of people understand that they can give/get diseases to/from wild primates, a surprising percentage would still touch or feed these animals if given the opportunity. Many people still choose to touch and/or own primates, as their drive to bond with animals outweighs some basic health behaviors. Desires to tame, control, or otherwise establish emotional connections with other species, combined with the central role of touch for exploring our environment, necessitate the development of better communication and educational campaigns to minimize risks of emerging infectious diseases.

Understanding Primate Herpesviruses

Viruses related to the herpes simplex viruses of humans are present in all nonhuman primate (NHP) species tested and cross species transmission has been documented. The herpesvirus present in macaques, Herpes B virus (BV) rarely causes disease in its natural macaque host. However, when transmitted to a nonnative host, BV has occasionally caused severe and even fatal disease if not treated immediately. Here we present a comprehensive review of the taxonomy, molecular biology, physiology, epidemiology, diagnosis and treatment of BV. We also summarizes what is known about related herpesviruses of other NHP species and the zoonotic potential of these viruses.

Fatal Human herpesvirus 1 (HHV-1) infection in captive marmosets (Callithrix jacchus and Callithrix penicillata) in Brazil: clinical and pathological characterization

Fatal Human herpesvirus 1 (HHV-1) was diagnosed in 12 captive marmosets (Callithrix jacchus and Callithrix penicillata) from metropolitan region of São Paulo, São Paulo State. Clinical signs were variable among the cases, but most affected marmosets presented signs associated with viral epithelial replication: oral, lingual and facial skin ulcers and hypersalivation, and viral replication in the central nervous system: prostration, seizure and aggressive behavior. Consistent microscopic findings were diffuse mild to severe nonsuppurative necrotizing meningoencephalitis with gliosis, vasculitis and neuronal necrosis. Additionally, in the brain, oral cavity, skin, adrenal gland and myoenteric plexus intranuclear inclusion bodies were present. Immunohistochemistry confirmed the presence of the HHV-1 antigen in association with lesions in the brain, oral and lingual mucosa, facial skin, adrenal gland and myoenteric plexus. HHV-1-specific polymerase chain reaction (PCR) analysis of the brain was carried out and the virus was detected in 7/8 infected marmosets. It is concluded that HHV-1 causes widespread fatal infection in marmosets.

Herpes simplex virus type 1 infection in two pet marmosets in Japan

An 8-month-old common marmoset (Callithrix jacchus) was presented with tic-like symptoms, and a 2-year-old pigmy marmoset (Callithrix pygmaea) was presented with dyspnea and hypersalivation. Both monkeys died within a few days, and necropsies were performed. Histopathological examinations revealed ulcerative stomatitis with epithelial cell swelling and eosinophilic intranuclear inclusion bodies in the oral epithelium of both cases. In the central and peripheral nervous systems, neuronal cell degeneration with intranuclear inclusion bodies was observed. Immunohistochemical examination using anti-herpes simplex virus type 1 antibody revealed virus antigens in both cases. Both animals had been kept as pets with limited exposure to the ambient environment except via their owners. Therefore, herpes simplex virus type-1 was probably acquired from close contact with their owners.

Ulcerative cheilitis in a rhesus macaque

A 2-year-old, female, simian immunodeficiency virus E543-infected rhesus macaque (Macaca mulatta) was presented for necropsy following euthanasia due to a history of diarrhea, weight loss, and a small, round ulcer along the left labial commissure. Histopathologic examination of the ulcer revealed infiltration by large numbers of degenerate and nondegenerate neutrophils and macrophages admixed with syncytial epithelial cells. Rare epithelial cells contained herpetic inclusion bodies. These cells stained positive for Human herpesvirus 1 via immunohistochemistry, and DNA sequencing confirmed the presence of closely related Macacine herpesvirus 1 (B virus).

The significant but understudied impact of pathogen transmission from humans to animals

Zooanthroponotic pathogens, which are transmitted from humans to nonhuman animals, are an understudied aspect of global health, despite their potential to cause significant disease burden in wild and domestic animal populations and affect global economies. Some key human-borne pathogens that have been shown to infect animals and cause morbidity and mortality include measles virus (paramyxoviruses), influenza A virus (orthomyxoviruses), herpes simplex 1 virus (herpesviruses), protozoal and helminthic parasites, and bacteria such as methicillin-resistant Staphylococcus aureus and Mycobacterium tuberculosis. However, zooanthroponotic pathogens are most commonly reported in captive animals or domestic livestock with close human contact; there, the potential for economic loss and human reinfection is most apparent. There is also the potential for infection in wild animal populations, which may threaten endangered species and decrease biodiversity. The emergence and reemergence of human-borne pathogens in wildlife may also have negative consequences for human health if these pathogens cycle back into humans. Many of the anthropogenic drivers of zoonotic disease emergence also facilitate zooanthroponotic transmission. Increasing research to better understand the occurrence of and the potential for bidirectional pathogen transmission between humans and animals is essential for improving global health. Mt Sinai J Med 76:448-455, 2009. (c) 2009 Mount Sinai School of Medicine.

Fatal human herpesvirus type 1 infection in a white-handed gibbon (Hylobates lar)

This report documents a case of spontaneous, fatal, and likely recrudescent human herpesvirus type 1 (HHV-1) infection in a captive white-handed gibbon (Hylobates lar) confirmed by polymerase chain reaction (PCR). An approximately 44-year-old, captive, female, white-handed gibbon with a history of recurrent conjunctivitis and occasional seizures became acutely weak, disoriented, and ataxic. A postictal state was suspected by caretakers and veterinary staff, and euthanasia was ultimately elected because of lack of clinical improvement with supportive care. No significant abnormalities were detected at necropsy. Histologically, sections of cerebrum and midbrain contained minimal to mild, multifocal lymphoplasmacytic meningoencephalitis with numerous intranuclear viral inclusions within astrocytes and some neurons. The presumptive diagnosis of HHV-1-induced encephalitis was strengthened by nested PCR amplification of a segment of the herpesvirus DNA polymerase gene. Sequences from this region have been found to be unique to each herpesvirus species, thus identifying HHV-1 as the likely etiologic agent in this case. Positive HHV-1 serology from several years before the terminal episode suggested that the disease was most likely due to recrudescence of latent HHV-1 infection.

Specific detection and identification of herpes B virus by a PCR-microplate hybridization assay

Herpes B virus DNA was specifically amplified by PCR, targeting the regions that did not cross-react with herpes simplex virus (HSV). The amplified products, which were shown to be highly genetic polymorphisms among herpes B virus isolates, were identified by microplate hybridization with probes generated by PCR. The products immobilized in microplate wells were hybridized with the biotin-labeled probes derived from the SMHV strain of herpes B virus. The amplified products derived from the SMHV and E2490 strains of herpes B virus were identified by microplate hybridization. PCR products amplified from the trigeminal ganglia of seropositive cynomolgus macaques were identified as herpes B virus DNA. The utility of the PCR-microplate hybridization assay for genetic detection and identification of the polymorphic region of herpes B virus was determined.