Further Assessment of Monkeypox Virus Infection in Gambian Pouched Rats (Cricetomys gambianus) Using In Vivo Bioluminescent Imaging

Clinical manifestations and pathogenicity of Clade IIb monkeypox virus in rabbits

The 2022 monkeypox outbreak involved rapid global dissemination, prompting research into animal models for the monkeypox virus (MPXV), including non-human primates and mice. However, studies utilizing rabbits as models remain limited. In this study, we established three rabbit models using the current epidemic MPXV strain. Following intravenous MPXV injection, adult rabbits exhibited characteristic clinical manifestations, including widespread rash and fever, with viral replication in the skin, lungs, and testes, resulting in severe pathological damage by 6 days post-infection (dpi). Intradermal injection of MPXV into the dorsal skin of adult rabbits produced red lesions with central necrosis and hemorrhage accompanied by dense inflammatory infiltrates. Abundant viral particles were observed in epidermal cells at 6 dpi. Additionally, a fatal MPXV model was developed in 10-day-old rabbits using intranasal virus administration. These young rabbits exhibited lethargy and diarrhea beginning at 2 dpi, significant weight loss, and a 50% mortality rate by 15 dpi. Viral dissemination was detected in multiple organs, leading to extensive multi-organ damage. This study highlights the utility of rabbit models for MPXV, displaying typical clinical features and pathogenic mechanisms.

An overview of the progress made in research into the Mpox virus

Mpox is a zoonotic illness caused by the Mpox virus (MPXV), a member of the Orthopoxvirus family. Although a few cases have been reported outside Africa, it was originally regarded as an endemic disease limited to African countries. However, the Mpox outbreak of 2022 was remarkable in that the infection spread to more than 123 countries worldwide, causing thousands of infections and deaths. The ongoing Mpox outbreak has been declared as a public health emergency of international concern by the World Health Organization. For a better management and control of the epidemic, this review summarizes the research advances and important scientific findings on MPXV by reviewing the current literature on epidemiology, clinical characteristics, diagnostic methods, prevention and treatment measures, and animal models of MPXV. This review provides useful information to raise awareness about the transmission, symptoms, and protective measures of MPXV, serving as a theoretical guide for relevant institutions to control MPXV.

Establishment of an animal model for monkeypox virus infection in dormice

This study aims to establish an animal model of monkeypox virus (MPXV) infection in dormice through intranasal inoculation. Male dormice aged 4-5 months were selected as experimental subjects and administered different titers of MPXV (103.5 PFU, 104.5 PFU, and 105.5 PFU, respectively) via nasal instillation. Within 14 days post-infection, clinical indicators such as survival rate, body weight changes, respiratory status, and mental state were continuously monitored. Additionally, tissue samples from the lungs, liver, spleen, and trachea of dormice from each group were collected on the 5th and 10th days for virus titer detection, and histopathological analysis was performed on lung samples collected on the 5th and 10th days. Dormice infected with MPXV exhibited typical symptoms such as appetite loss, continuous body weight reduction, aggravated respiratory difficulties, accompanied by lethargy, chills, and other clinical manifestations similar to human monkeypox infection. Virological tests further confirmed the distribution of MPXV in multiple vital organs of dormice, including the lungs, liver, spleen, and trachea, with particularly significant pathological damage observed in lung tissue. An MPXV infection model in dormice was successfully established through intranasal inoculation with a titer of 105.5 PFU MPXV, which can be used for studying the infection mechanism and pharmacology of MPXV.

Monkeypox: A comprehensive review on mutation, transmission, pathophysiology, and therapeutics

Monkeypox virus (MPXV) is the causative agent of the monkeypox (Mpox) disease, belongs to the Orthopoxvirus genus of the Poxviridae family. Due to the recent re-emergence of Mpox in 2024, this is the second time when the World Health Organization (WHO) declared Mpox as a Public Health Emergency of International Concern (PHEIC). This review intends to offer an in-depth analysis of Mpox, including its key characteristics, epidemiological, mutation, pathophysiology, transmission, and therapeutics. The infection of MPXV is a lethal threat to children, pregnant women, and immunocompromised individuals. However, we can prevent the infection by proper precautions including hygiene practices and minimizing exposure to infected individuals or animals. Multivalent mRNA vaccines, antibody-based immunotherapy, and combination drug therapies have all shown significant effectiveness in treating Mpox infection. In addition to addressing antivirals and drug resistance, the review also explores potential targets for vaccine and drug development, as well as the use of animal models for studying MPXV. Because of multiple mutational events, Mpox began exhibiting drug resistance. Overall, this review will contribute significantly to advancing the development of new vaccines and drug options for combating emerging Mpox.

Experimental inoculation of pigs with monkeypox virus results in productive infection and transmission to sentinels

Monkeypox virus (MPXV) is a re-emerging zoonotic poxvirus responsible for producing skin lesions in humans. Endemic in sub-Saharan Africa, the 2022 outbreak with a clade IIb strain has resulted in ongoing sustained transmission of the virus worldwide. MPXV has a relatively wide host range, with infections reported in rodent and non-human primate species. However, the susceptibility of many domestic livestock species remains unknown. Here, we report on a susceptibility/transmission study in domestic pigs that were experimentally inoculated with a 2022 MPXV clade IIb isolate or served as sentinel contact control animals. Several principal-infected and sentinel contact control pigs developed minor lesions near the lips and nose starting at 12 through 18 days post-challenge (DPC). No virus was isolated and no viral DNA was detected from the lesions; however, MPXV antigen was detected by IHC in tissue from a pustule of a principal infected pig. Viral DNA and infectious virus were detected in nasal and oral swabs up to 14 DPC, with peak titers observed at 7 DPC. Viral DNA was also detected in nasal tissues or skin collected from two principal-infected animals at 7 DPC post-mortem. Furthermore, all principal-infected and sentinel control animals enrolled in the study seroconverted. In conclusion, we provide the first evidence that domestic pigs are susceptible to experimental MPXV infection and can transmit the virus to contact animals.

Mpox Resurgence: A Multifaceted Analysis for Global Preparedness

This study provides an in-depth analysis of mpox, encompassing its history, characteristics, epidemiology, diagnostics, treatment options, and the ongoing evolution of the virus and its transmission dynamics. Mpox, though once successfully eradicated, has re-emerged with new modes of transmission and a broader host range. Genomic analyses have revealed the virus's adaptability, posing challenges for diagnostics and vaccine efficacy. The epidemiology has shifted from sporadic zoonotic transmission in rural Africa to a significant presence in urban areas, particularly impacting high-risk populations. Advancements in diagnostics and therapeutics offer hope, but challenges persist. This work underscores the critical need for enhanced surveillance, vaccination strategies, and continued research to bolster global health systems and preparedness for future outbreaks.

Mpox infection in animals: A systematic review and meta-analysis

Mpox is a zoonotic disease that became epidemic in multiple countries in 2022. There is a lack of published systematic reviews on natural animal infection due to Mpox. We performed a systematic literature review with meta-analysis to assess animal Mpox prevalence. We performed a random-effects model meta-analysis to calculate the pooled prevalence and 95% confidence interval (95%CI) for prevalence studies. After the screening, 15 reports were selected for full-text assessment and included in qualitative and quantitative analyses. Ten reports assessed Mpox infection by molecular or serological tests (n = 2680), yielding a pooled prevalence of 16.0% (95%CI: 3.0-29.0%) for non-human primates; 8.0% (95%CI: 4.0-12.0%) for rodents and 1.0% (95%CI: 0.0-3.0%) for shrews. Further studies in other animals are required to define the extent and importance of natural infection due to Mpox. These findings have implications for public human and animal health. OneHealth approach is critical for prevention and control.

Understanding the biology of monkeypox virus to prevent future outbreaks

Historically, monkeypox (mpox) was a zoonotic disease endemic in Africa. However, in 2022, a global outbreak occurred following a substantial increase in cases in Africa, coupled with spread by international travellers to other continents. Between January 2022 and October 2023, about 91,000 confirmed cases from 115 countries were reported, leading the World Health Organization to declare a public health emergency. The basic biology of monkeypox virus (MPXV) can be inferred from other poxviruses, such as vaccinia virus, and confirmed by genome sequencing. Here the biology of MPXV is reviewed, together with a discussion of adaptive changes during MPXV evolution and implications for transmission. Studying MPXV biology is important to inform specific host interactions, to aid in ongoing outbreaks and to predict those in the future.

Infection with mpox virus via the genital mucosae increases shedding and transmission in the multimammate rat (Mastomys natalensis)

The 2022 mpox virus (MPXV) outbreak was sustained by human-to-human transmission; however, it is currently unclear which factors lead to sustained transmission of MPXV. Here we present Mastomys natalensis as a model for MPXV transmission after intraperitoneal, rectal, vaginal, aerosol and transdermal inoculation with an early 2022 human outbreak isolate (Clade IIb). Virus shedding and tissue replication were route dependent and occurred in the presence of self-resolving localized skin, lung, reproductive tract or rectal lesions. Mucosal inoculation via the rectal, vaginal and aerosol routes led to increased shedding, replication and a pro-inflammatory T cell profile compared with skin inoculation. Contact transmission was higher from rectally inoculated animals. This suggests that transmission might be sustained by increased susceptibility of the anal and genital mucosae for infection and subsequent virus release.

Ophthalmic Manifestations of Monkeypox Virus Infection: A Cases Series

This retrospective case series aims to describe the ophthalmic manifestations of the Monkeypox virus infection in seven patients evaluated in two countries of South America (Colombia and Brazil). Two had skin lesions in the eyelid, and five had conjunctivitis. None had intraocular involvement. Three of seven patients had a history of Human Immunodeficiency Virus infection, and all patients had lesions in the genital region, suggesting sexual-contact transmission. In 6 of 7 cases, conjunctival RT-PCR was positive for the Monkeypox virus, including one case without conjunctival vesicles. In all cases, lesions resolved without complications, and just two required antiviral treatment. All patients demonstrated improvement without complications. RT-PCR positivity in conjunctiva demonstrated the presence of the Monkeypox virus, suggesting that ocular-mediated transmission could be plausible. Ophthalmologists should be aware of this ophthalmic manifestation.

Dynamics of Mpox infection in Nigeria: a systematic review and meta-analysis

The seasonal outbreaks of Mpox continue in most parts of West and Central Africa. In the past year, Nigeria had the highest number of reported cases. Here, we used the PRISMA guidelines to carry out a systematic review and meta-analysis of available evidence on Mpox in Nigeria to assess the prevalence, transmission pattern, diagnostic approach, and other associated factors useful for mitigating the transmission of the disease. All relevant observational studies in PubMed/MEDLINE, Embase, AJOL, Web of Science, Scopus and Google Scholar on Mpox in Nigeria were assessed within the last fifty years (1972 to 2022). In all, 92 relevant articles were retrieved, out of which 23 were included in the final qualitative analysis. Notably, most of the cases of Mpox in Nigeria were from the southern part of the country. Our findings showed a progressive spread from the southern to the northern region of the country. We identified the following factors as important in the transmission of Mpox in Nigeria; poverty, lack of basic healthcare facilities, and risk of exposure through unsafe sexual practices. Our findings reiterate the need to strengthen and expand existing efforts as well as establish robust multi-sectoral collaboration to understand the dynamics of Mpox Nigeria.

Monkeypox: Past, Present, and Future

Monkeypox (Mpox) is a zoonotic disease caused by a virus (monkeypox virus-MPV) belonging to the Poxviridae family. In humans, the disease has an incubation period of 5-21 days and then progresses in two phases, the prodromal phase and the rash phase. The prodromal phase is characterized by non-specific symptoms such as fever, muscle pain, malaise, lymphadenopathy, headache, and chills. Skin lesions appear in the rash phase of the disease. These lesions progress through different stages (macules, papules, vesicles, and pustules). In May 2022, WHO reported an outbreak of human Mpox in several countries which were previously Mpox-free. As per the CDC report of March 01, 2023, a total of 86,231 confirmed cases of Mpox and 105 deaths have been reported from 110 countries and territories across the globe. Notably, more than 90% of these countries were reporting Mpox for the first time. The phylogenetic analysis revealed that this outbreak was associated with the virus from the West African clade. However, most of the cases in this outbreak had no evidence of travel histories to MPV-endemic countries in Central or West Africa. This outbreak was primarily driven by the transmission of the virus via intimate contact in men who have sex with men (MSM). The changing epidemiology of Mpox raised concerns about the increasing spread of the disease in non-endemic countries and the urgent need to control and prevent it. In this chapter, we present all the documented cases of Mpox from 1970 to 2023 and discuss the past, present, and future of MPV.

Mapping the Landscape of Health Research Priorities for Effective Pandemic Preparedness in Human Mpox Virus Disease

The global re-emergence of monkeypox (Mpox) in non-endemic regions in 2022 has highlighted the critical importance of timely virus detection and robust public health surveillance in assessing outbreaks and their impact. Despite significant Mpox research being conducted worldwide, there is an urgent need to identify knowledge gaps and prioritize key research areas in order to create a roadmap that maximizes the utilization of available resources. The present research article provides a comprehensive mapping of health research priorities aimed at advancing our understanding of Mpox and developing effective interventions for managing its outbreaks, and, as evidenced by the fact that achieving this objective requires close interdisciplinary collaboration. The key research priorities observed were identifying variants responsible for outbreaks; discovering novel biomarkers for diagnostics; establishing suitable animal models; investigating reservoirs and transmission routes; promoting the One Health approach; identifying targets for vaccination; gaining insight into the attitudes, experiences, and practices of key communities, including stigma; and ensuring equity during public health emergencies. The findings of this study hold significant implications for decision making by multilateral partners, including research funders, public health practitioners, policy makers, clinicians, and civil society, which will facilitate the development of a comprehensive plan not only for Mpox but also for other similar life-threatening viral infections.

Animal models of mpox virus infection and disease

Mpox (monkeypox) virus (MPXV), which causes a mild smallpox-like disease, has been endemic in Africa for several decades, with sporadic cases occurring in other parts of the world. However, the most recent outbreak of mpox mainly among men that have sex with men has affected several continents, posing serious global public health concerns. The infections exhibit a wide spectrum of clinical presentation, ranging from asymptomatic infection to mild, severe disease, especially in immunocompromised individuals, young children, and pregnant women. Some therapeutics and vaccines developed for smallpox have partial protective and therapeutic effects against MPXV historic isolates in animal models. However, the continued evolution of MPXV has produced multiple lineages, leading to significant gaps in the knowledge of their pathogenesis that constrain the development of targeted antiviral therapies and vaccines. MPXV infections in various animal models have provided a central platform for identification and comparison of diseased pathogenesis between the contemporary and historic isolates. In this review, we discuss the susceptibility of various animals to MPXV, and describe the key pathologic features of rodent, rabbit and nonhuman primate models. We also provide application examples of animal models in elucidating viral pathogenesis and evaluating effectiveness of vaccine and antiviral drugs. These animal models are essential to understand the biology of MPXV contemporary isolates and to rapidly test potential countermeasures. Finally, we list some remaining scientific questions of MPXV that can be resolved by animal models.

Mapping global zoonotic niche and interregional transmission risk of monkeypox: a retrospective observational study

BACKGROUND

Outbreaks of monkeypox have been ongoing in non-endemic countries since May 2022. A thorough assessment of its global zoonotic niche and potential transmission risk is lacking.

METHODS

We established an integrated database on global monkeypox virus (MPXV) occurrence during 1958 - 2022. Phylogenetic analysis was performed to examine the evolution of MPXV and effective reproductive number (Rt) was estimated over time to examine the dynamic of MPXV transmissibility. The potential ecological drivers of zoonotic transmission and inter-regional transmission risks of MPXV were examined.

RESULTS

As of 24 July 2022, a total of 49 432 human patients with MPXV infections have been reported in 78 countries. Based on 525 whole genome sequences, two main clades of MPXV were formed, of which Congo Basin clade has a higher transmissibility than West African clade before the 2022-monkeypox, estimated by the overall Rt (0.81 vs. 0.56), and the latter significantly increased in the recent decade. Rt of 2022-monkeypox varied from 1.14 to 4.24 among the 15 continuously epidemic countries outside Africa, with the top three as Peru (4.24, 95% CI: 2.89-6.71), Brazil (3.45, 95% CI: 1.62-7.00) and the United States (2.44, 95% CI: 1.62-3.60). The zoonotic niche of MPXV was associated with the distributions of Graphiurus lorraineus and Graphiurus crassicaudatus, the richness of Rodentia, and four ecoclimatic indicators. Besides endemic areas in Africa, more areas of South America, the Caribbean States, and Southeast and South Asia are ecologically suitable for the occurrence of MPXV once the virus has invaded. Most of Western Europe has a high-imported risk of monkeypox from Western Africa, whereas France and the United Kingdom have a potential imported risk of Congo Basin clade MPXV from Central Africa. Eleven of the top 15 countries with a high risk of MPXV importation from the main countries of 2022-monkeypox outbreaks are located at Europe with the highest risk in Italy, Ireland and Poland.

CONCLUSIONS

The suitable ecological niche for MPXV is not limited to Africa, and the transmissibility of MPXV was significantly increased during the 2022-monkeypox outbreaks. The imported risk is higher in Europe, both from endemic areas and currently epidemic countries. Future surveillance and targeted intervention programs are needed in its high-risk areas informed by updated prediction.

Human Monkeypox: A Comprehensive Overview of Epidemiology, Pathogenesis, Diagnosis, Treatment, and Prevention Strategies

Monkeypox virus (MPXV) is an emerging zoonotic virus that belongs to the Orthopoxvirus genus and presents clinical symptoms similar to those of smallpox, such as fever and vesicular-pustular skin lesions. However, the differential diagnosis between smallpox and monkeypox is that smallpox does not cause lymphadenopathy but monkeypox generates swelling in the lymph nodes. Since the eradication of smallpox, MPXV has been identified as the most common Orthopoxvirus to cause human disease. Despite MPXV being endemic to certain regions of Africa, the current MPXV outbreak, which began in early 2022, has spread to numerous countries worldwide, raising global concern. As of the end of May 2023, over 87,545 cases and 141 deaths have been reported, with most cases identified in non-endemic countries, primarily due to human-to-human transmission. To better understand this emerging threat, this review presents an overview of key aspects of MPXV infection, including its animal reservoirs, modes of transmission, animal models, epidemiology, clinical and immunological features, diagnosis, treatments, vaccines, and prevention strategies. The material presented here provides a comprehensive understanding of MPXV as a disease, while emphasizing the significance and unique characteristics of the 2022 outbreak. This offers valuable information that can inform future research and aid in the development of effective interventions.

Selective events at individual sites underlie the evolution of monkeypox virus clades

In endemic regions (West Africa and the Congo Basin), the genetic diversity of monkeypox virus (MPXV) is geographically structured into two major clades (Clades I and II) that differ in virulence and host associations. Clade IIb is closely related to the B.1 lineage, which is dominating a worldwide outbreak initiated in 2022. Lineage B.1 has however accumulated mutations of unknown significance that most likely result from apolipoprotein B mRNA editing catalytic polypeptide-like 3 (APOBEC3) editing. We applied a population genetics-phylogenetics approach to investigate the evolution of MPXV during historical viral spread in Africa and to infer the distribution of fitness effects. We observed a high preponderance of codons evolving under strong purifying selection, particularly in viral genes involved in morphogenesis and replication or transcription. However, signals of positive selection were also detected and were enriched in genes involved in immunomodulation and/or virulence. In particular, several genes showing evidence of positive selection were found to hijack different steps of the cellular pathway that senses cytosolic DNA. Also, a few selected sites in genes that are not directly involved in immunomodulation are suggestive of antibody escape or other immune-mediated pressures. Because orthopoxvirus host range is primarily determined by the interaction with the host immune system, we suggest that the positive selection signals represent signatures of host adaptation and contribute to the different virulence of Clade I and II MPXVs. We also used the calculated selection coefficients to infer the effects of mutations that define the predominant human MPXV1 (hMPXV1) lineage B.1, as well as the changes that have been accumulating during the worldwide outbreak. Results indicated that a proportion of deleterious mutations were purged from the predominant outbreak lineage, whose spread was not driven by the presence of beneficial changes. Polymorphic mutations with a predicted beneficial effect on fitness are few and have a low frequency. It remains to be determined whether they have any significance for ongoing virus evolution.

Ophthalmic manifestations of monkeypox infection

After the global COVID-19 pandemic, there has been an alarming concern with the monkeypox (mpox) outbreak, which has affected more than 110 countries worldwide. Monkeypox virus is a doublestranded DNA virus of the genus Orthopox of the Poxviridae family, which causes this zoonotic disease. Recently, the mpox outbreak was declared by the World Health Organization (WHO) as a public health emergency of international concern (PHEIC). Monkeypox patients can present with ophthalmic manifestation and ophthalmologists have a role to play in managing this rare entity. Apart from causing systemic involvement such as skin lesions, respiratory infection and involvement of body fluids, Monkeypox related ophthalmic disease (MPXROD) causes varied ocular manifestations such as lid and adnexal involvement, periorbital and lid lesion, periorbital rash, conjunctivitis, blepharocounctivitis and keratitis. A detailed literature review shows few reports on MPXROD infections with limited overview on management strategies. The current review article is aimed to provide the ophthalmologist with an overview of the disease with a spotlight on ophthalmic features. We briefly discuss the morphology of the MPX, various modes of transmission, an infectious pathway of the virus, and the host immune response. A brief overview of the systemic manifestations and complications has also been elucidated. We especially highlight the detailed ophthalmic manifestations of mpox, their management, and prevention of vision threatening sequelae.

Monkeypox Virus in Animals: Current Knowledge of Viral Transmission and Pathogenesis in Wild Animal Reservoirs and Captive Animal Models

Mpox, formerly called monkeypox, is now the most serious orthopoxvirus (OPXV) infection in humans. This zoonotic disease has been gradually re-emerging in humans with an increasing frequency of cases found in endemic areas, as well as an escalating frequency and size of epidemics outside of endemic areas in Africa. Currently, the largest known mpox epidemic is spreading throughout the world, with over 85,650 cases to date, mostly in Europe and North America. These increased endemic cases and epidemics are likely driven primarily by decreasing global immunity to OPXVs, along with other possible causes. The current unprecedented global outbreak of mpox has demonstrated higher numbers of human cases and greater human-to-human transmission than previously documented, necessitating an urgent need to better understand this disease in humans and animals. Monkeypox virus (MPXV) infections in animals, both naturally occurring and experimental, have provided critical information about the routes of transmission; the viral pathogenicity factors; the methods of control, such as vaccination and antivirals; the disease ecology in reservoir host species; and the conservation impacts on wildlife species. This review briefly described the epidemiology and transmission of MPXV between animals and humans and summarizes past studies on the ecology of MPXV in wild animals and experimental studies in captive animal models, with a focus on how animal infections have informed knowledge concerning various aspects of this pathogen. Knowledge gaps were highlighted in areas where future research, both in captive and free-ranging animals, could inform efforts to understand and control this disease in both humans and animals.

Insights into monkeypox pathophysiology, global prevalence, clinical manifestation and treatments

On 23rd July 2022, the World Health Organization (WHO) recognized the ongoing monkeypox outbreak as a public medical crisis. Monkeypox virus (MPV), the etiological agent of monkeypox, is a zoonotic, linear, double-stranded DNA virus. In 1970, the Democratic Republic of the Congo reported the first case of MPV infection. Human-to-human transmission can happen through sexual contact, inhaled droplets, or skin-to-skin contact. Once inoculated, the viruses multiply rapidly and spread into the bloodstream to cause viremia, which then affect multiple organs, including the skin, gastrointestinal tract, genitals, lungs, and liver. By September 9, 2022, more than 57,000 cases had been reported in 103 locations, especially in Europe and the United States. Infected patients are characterized by physical symptoms such as red rash, fatigue, backache, muscle aches, headache, and fever. A variety of medical strategies are available for orthopoxviruses, including monkeypox. Monkeypox prevention following the smallpox vaccine has shown up to 85% efficacy, and several antiviral drugs, such as Cidofovir and Brincidofovir, may slow the viral spread. In this article, we review the origin, pathophysiology, global epidemiology, clinical manifestation, and possible treatments of MPV to prevent the propagation of the virus and provide cues to generate specific drugs.

A brief review of the monkeypox virus and emerging concerns for neuroinvasiveness

Background:

Amidst the ongoing COVID-19 pandemic, monkeypox virus (MPXV) disease has been recognized as another disease of pandemic nature by the World Health Organization. Nearly four decades after the eradication of smallpox, as half of the world population is naïve to ortho-pox viruses (supposedly due to lack of immunity by vaccination), MPXV remains the most pathogenic species of the family of poxviruses.

Methods:

The articles on MPXV were searched on PubMed/Medline and data were retrieved and analyzed.

Results:

Although reported as a disease of milder exanthem and lower mortality as compared to smallpox, the MPXV disease tends to be neuroinvasive. This article highlights the neurological signs and symptoms of MPXV disease and discusses, in brief, the management strategies.

Conclusion:

Neuroinvasive properties of the virus as demonstrated in in vitro studies, and further verified by neurological illnesses in patients, present a special threat to mankind. Clinicians must be prepared to recognize and treat these neurological complications and start treatment to limit long-lasting brain injury as seen in patients with COVID-19.

Orthopoxvirus Zoonoses—Do We Still Remember and Are Ready to Fight?

The eradication of smallpox was an enormous achievement due to the global vaccination program launched by World Health Organization. The cessation of the vaccination program led to steadily declining herd immunity against smallpox, causing a health emergency of global concern. The smallpox vaccines induced strong, humoral, and cell-mediated immune responses, protecting for decades after immunization, not only against smallpox but also against other zoonotic orthopoxviruses that now represent a significant threat to public health. Here we review the major aspects regarding orthopoxviruses’ zoonotic infections, factors responsible for viral transmissions, as well as the emerging problem of the increased number of monkeypox cases recently reported. The development of prophylactic measures against poxvirus infections, especially the current threat caused by the monkeypox virus, requires a profound understanding of poxvirus immunobiology. The utilization of animal and cell line models has provided good insight into host antiviral defenses as well as orthopoxvirus evasion mechanisms. To survive within a host, orthopoxviruses encode a large number of proteins that subvert inflammatory and immune pathways. The circumvention of viral evasion strategies and the enhancement of major host defenses are key in designing novel, safer vaccines, and should become the targets of antiviral therapies in treating poxvirus infections.

A Review of Monkeypox Ocular Manifestations and Complications: Insights for the 2022 Outbreak

Monkeypox (MPVX) infection has been associated with multiorgan presentations. Thus, monkeypox infection's early and late complications are of particular concern, prompting health systems to decipher threatening sequels and their possible countermeasures. The current article will review the clinical signs and symptoms of the present and former outbreaks, differential diagnoses, workup and treatment of the ocular manifestations of MPXV infection in detail. One of the uncommon yet considerable MPXV complications is ocular involvement. These injuries are classified as (1) more frequent and benign lesions and (2) less common and vision-threatening sequels. Conjunctivitis, blepharitis and photophobia are the most uncomplicated reported presentations. Moreover, MPXV can manifest as eye redness, frontal headache, orbital and peri-ocular rashes, lacrimation and ocular discharge, subconjunctival nodules and, less frequently, as keratitis, corneal ulceration, opacification, perforation and blindness. The ocular manifestations have been less frequent and arguably less severe within the current outbreak. Despite the possibility of underestimation, the emerging evidence from observational investigations documented rates of around 1% for ocular involvement in the current outbreak compared to a 9-23% incidence in previous outbreaks in the endemic countries. The history of smallpox immunization is a protective factor against these complications. Despite a lack of definite and established treatment, simple therapies like regular lubrication and prophylactic use of topical antibiotics may be considered for MPXV ocular complications. Timely administration of specific antivirals may also be effective in severe cases. Monkeypox usually has mild to moderate severity and a self-limited course. However, timely recognition and proper management of the disease could reduce the risk of permanent ocular sequelae and disease morbidity.

Monkeypox virus from neurological complications to neuroinvasive properties: current status and future perspectives

Cases of monkeypox (MPV) are sharply rising around the world. While most efforts are being focused on the management of the first symptoms of monkeypox, such as cutaneous lesions and flu-like symptoms, the effect of the monkeypox virus (MPXV) on multiple organs still remains unclear. Recently, several neurological manifestations, such as headache, myalgia, malaise, fatigue, altered consciousness, agitation, anorexia, nausea, and vomiting, have been reported in patients with MPV. In addition, data from experimental studies have indicated that MPXV can gain access to the central nervous system (CNS) through the olfactory epithelium and infected circulatory monocytes/macrophages as two probable neuroinvasive mechanisms. Therefore, there are growing concerns about the long-term effect of MPXV on the CNS and subsequent neurological complications. This paper highlights the importance of the neuroinvasive potential of MPXV, coupled with neurological manifestations.

Monkeypox Virus and Ophthalmology-A Primer on the 2022 Monkeypox Outbreak and Monkeypox-Related Ophthalmic Disease

Importance

An ongoing global monkeypox virus outbreak in 2022 includes the US and other nonendemic countries. Monkeypox ophthalmic manifestations may present to the ophthalmologist, or the ophthalmologist may be involved in comanagement. This narrative review creates a primer for the ophthalmologist of clinically relevant information regarding monkeypox, its ophthalmic manifestations, and the 2022 outbreak.

Observations

Monkeypox virus is an Orthopoxvirus (genus includes variola [smallpox] and vaccinia [smallpox vaccine]). The 2022 outbreak is of clade II (historically named West African clade), specifically subclade IIb. In addition to historic transmission patterns (skin lesions, bodily fluids, respiratory droplets), sexual transmission has also been theorized in the current outbreak due to disproportionate occurrence in men who have sex with men. Monkeypox causes a characteristic skin eruption and mucosal lesions and may cause ophthalmic disease. Monkeypox-related ophthalmic disease (MPXROD) includes a spectrum of ocular pathologies including eyelid/periorbital skin lesions, blepharoconjunctivitis, and keratitis). Smallpox vaccination may reduce MPXROD occurrence. MPXROD seems to be rarer in the 2022 outbreaks than in historical outbreaks. MPXROD may result in corneal scarring and blindness. Historical management strategies for MPXROD include lubrication and prevention/management of bacterial superinfection in monkeypox keratitis. Case reports and in vitro data for trifluridine suggest a possible role in MPXROD. Tecovirimat, cidofovoir, brincidofovir and vaccinia immune globulin intravenous may be used for systemic infection. There is a theoretical risk for monkeypox transmission by corneal transplantation, and the Eye Bank Association of America has provided guidance. Smallpox vaccines (JYNNEOS [Bavarian Nordic] and ACAM2000 [Emergent Product Development Gaithersburg Inc]) provide immunity against monkeypox.

Conclusions and Relevance

The ophthalmologist may play an important role in the diagnosis and management of monkeypox. MPXROD may be associated with severe ocular and visual morbidity. As the current outbreak evolves, up-to-date guidance from public health organizations and professional societies are critical.

Ophthalmic Features and Implications of Poxviruses: Lessons from Clinical and Basic Research

Amidst the ongoing monkeypox outbreak, global awareness has been directed towards the prevention of viral transmission and case management, with the World Health Organization declaring the outbreak a public health emergency of international concern. Monkeypox virus is one of several species in the Orthopoxvirus genus, with other species of the genus including the variola, cowpox, mousepox, camelpox, raccoonpox, skunkpox, and volepox viruses. Although the nomenclature of these species is based on the animal host from which they were originally isolated, transmission from animals to humans has been reported with several species. The progression of disease, following an incubation period, typically consists of a prodromal phase with systemic flu-like symptoms. Various organ systems may be affected in addition to the formation of pathognomonic skin lesions. As monkeypox poses a continued public health concern, the ophthalmic sequelae of monkeypox virus, especially those leading to vision loss, warrant consideration as well. This review provides a comprehensive summary of the ophthalmic implications of poxviruses in clinical and laboratory settings reported in the literature, as well as areas of unmet need and future research.

Monkeypox: An Unfamiliar Virus-Clinical and Epidemiological Characteristics, Diagnosis, and Treatment with Special Emphasis on Oral Health

With the recent increased prevalence of human outbreaks, monkeypox has been recognized for decades as an infectious disease with substantial pandemic potential. The majority of cases of this virus have been observed in the European region (11,865), with few cases in the Western Pacific (54). Various governing health agencies are striving to restrain the fatal monkeypox virus (MPXV). Health practitioners around the world are learning about the many clinical manifestations of this infection, and its potential therapies. Despite the plethora of new evidence and rising cases, the essential questions remain unsolved. Thus, in this review, we have modernized the outlook for monkeypox, which will be helpful for various medical practitioners. In the light of continuing outbreaks around the world, we have also presented our assessment of the readiness of India against this outbreak, with a special focus on its effects on oral health.

Animal Models Used in Monkeypox Research

Monkeypox is an emerging zoonotic disease with a growing prevalence outside of its endemic area, posing a significant threat to public health. Despite the epidemiological and field investigations of monkeypox, little is known about its maintenance in natural reservoirs, biological implications or disease management. African rodents are considered possible reservoirs, although many mammalian species have been naturally infected with the monkeypox virus (MPXV). The involvement of domestic livestock and pets in spillover events cannot be ruled out, which may facilitate secondary virus transmission to humans. Investigation of MPXV infection in putative reservoir species and non-human primates experimentally uncovered novel findings relevant to the course of pathogenesis, virulence factors and transmission of MPXV that provided valuable information for designing appropriate prevention measures and effective vaccines.

Monkeypox: epidemiology, pathogenesis, treatment and prevention

Monkeypox is a zoonotic disease that was once endemic in west and central Africa caused by monkeypox virus. However, cases recently have been confirmed in many nonendemic countries outside of Africa. WHO declared the ongoing monkeypox outbreak to be a public health emergency of international concern on July 23, 2022, in the context of the COVID-19 pandemic. The rapidly increasing number of confirmed cases could pose a threat to the international community. Here, we review the epidemiology of monkeypox, monkeypox virus reservoirs, novel transmission patterns, mutations and mechanisms of viral infection, clinical characteristics, laboratory diagnosis and treatment measures. In addition, strategies for the prevention, such as vaccination of smallpox vaccine, is also included. Current epidemiological data indicate that high frequency of human-to-human transmission could lead to further outbreaks, especially among men who have sex with men. The development of antiviral drugs and vaccines against monkeypox virus is urgently needed, despite some therapeutic effects of currently used drugs in the clinic. We provide useful information to improve the understanding of monkeypox virus and give guidance for the government and relative agency to prevent and control the further spread of monkeypox virus.

Monkeypox virus: The changing facets of a zoonotic pathogen

In the last five years, the prevalence of monkeypox has been increasing both in the regions considered endemic for the disease (West and Central Africa) and worldwide. Indeed, in July 2022, the World Health Organization declared the ongoing global outbreak of monkeypox a public health emergency of international concern. The disease is caused by monkeypox virus (MPXV), a member of the Orthopoxvirus genus, which also includes variola virus (the causative agent of smallpox) and vaccinia virus (used in the smallpox eradication campaign). Here, we review aspects of MPXV genetic diversity and epidemiology, with an emphasis on its genome structure, host range, and relationship with other orthopoxviruses. We also summarize the most recent findings deriving from the sequencing of outbreak MPXV genomes, and we discuss the apparent changing of MPXV evolutionary trajectory, which is characterized by the accumulation of point mutations rather than by gene gains/losses. Whereas the availability of a vaccine, the relatively mild presentation of the disease, and its relatively low transmissibility speak in favor of an efficient control of the global outbreak, the wide host range of MPXV raises concerns about the possible establishment of novel reservoirs. We also call for the deployment of field surveys and genomic surveillance programs to identify and control the MPXV reservoirs in West and Central Africa.

An Overview of Monkeypox Virus and Its Neuroinvasive Potential

Monkeypox virus (MPV) is an orthopox virus in the Poxviridae family that is currently of international concern. It is endemic to Central and Western Africa with two known viral clades. Various African rodents and primates are likely the natural reservoirs. Zoonotic transmission occurs by direct contact with infected animals (e.g., bites, scratches, slaughtering). Human to human transmission occurs through close contact with infected persons (e.g., respiratory droplets, skin-on-skin, or sexual contact) or fomites. Classically, human MPV disease first has a febrile prodrome with lymphadenopathy followed by a diffuse maculopapular to vesiculopustular skin/mucosal lesion eruption. In the current 2022 outbreak, which is primarily affecting men who have sex with men (MSM) currently, the febrile prodrome may be absent and skin/mucosal lesions may be isolated to the genital and anal regions. Rarely, MPV likely has the potential to be neuroinvasive based on animal models, previous case series, and preliminary reports currently under investigation. Even though neurologic manifestations of human MPV infection are rare, given the sheer numbers of increasing cases throughout the world, neurologists should be prepared to recognize, diagnose, and treat potential neuroinvasive disease or other neurologic symptoms. ANN NEUROL 2022;92:527-531.

Ocular manifestations of recent viral pandemics: A literature review

Viral pandemics often take the world by storm, urging the medical community to prioritize the most evident systemic manifestations, often causing ocular manifestations to go unnoticed. This literature review highlights the ocular complications of the Monkeypox, SARS-CoV-2, MERS, Ebola, H1N1, and Zika viruses as the most recent viral pandemics. Research into the effects of these pandemics began immediately. Moreover, it also discusses the ocular complications of the vaccines and treatments that were used in the scope of the viral pandemics. Additionally, this review discusses the role of the eye as an important route of viral transmission, and thereafter, the International recommendations to reduce the incidence of viral transmission were mentioned. Lastly, this paper wants to lay out a platform for researchers who want to learn more about how viruses show up in the eye.

Monkeypox: The consequences of neglecting a disease, anywhere

A disease anywhere can spread everywhere, if neglected

Atypical and Unique Transmission of Monkeypox Virus during the 2022 Outbreak: An Overview of the Current State of Knowledge

An ongoing monkeypox outbreak in non-endemic countries has resulted in the declaration of a public health emergency of international concern by the World Health Organization (WHO). Though monkeypox has long been endemic in regions of sub-Saharan Africa, relatively little is known about its ecology, epidemiology, and transmission. Here, we consider the relevant research on both monkeypox and smallpox, a close relative, to make inferences about the current outbreak. Undetected circulation combined with atypical transmission and case presentation, including mild and asymptomatic disease, have facilitated the spread of monkeypox in non-endemic regions. A broader availability of diagnostics, enhanced surveillance, and targeted education, combined with a better understanding of the routes of transmission, are critical to identify at-risk populations and design science-based countermeasures to control the current outbreak.

Comparative Pathology of Zoonotic Orthopoxviruses

This review provides a brief history of the impacts that a human-specific Orthopoxvirus (OPXV), Variola virus, had on mankind, recalls how critical vaccination was for the eradication of this disease, and discusses the consequences of discontinuing vaccination against OPXV. One of these consequences is the emergence of zoonotic OPXV diseases, including Monkeypox virus (MPXV). The focus of this manuscript is to compare pathology associated with zoonotic OPXV infection in veterinary species and in humans. Efficient recognition of poxvirus lesions and other, more subtle signs of disease in multiple species is critical to prevent further spread of poxvirus infections. Additionally included are a synopsis of the pathology observed in animal models of MPXV infection, the recent spread of MPXV among humans, and a discussion of the potential for this virus to persist in Europe and the Americas.

IMVAMUNE® and ACAM2000® Provide Different Protection against Disease When Administered Postexposure in an Intranasal Monkeypox Challenge Prairie Dog Model

The protection provided by smallpox vaccines when used after exposure to Orthopoxviruses is poorly understood. Postexposu re administration of 1st generation smallpox vaccines was effective during eradication. However, historical epidemiological reports and animal studies on postexposure vaccination are difficult to extrapolate to today’s populations, and 2nd and 3rd generation vaccines, developed after eradication, have not been widely tested in postexposure vaccination scenarios. In addition to concerns about preparedness for a potential malevolent reintroduction of variola virus, humans are becoming increasingly exposed to naturally occurring zoonotic orthopoxviruses and, following these exposures, disease severity is worse in individuals who never received smallpox vaccination. This study investigated whether postexposure vaccination of prairie dogs with 2nd and 3rd generation smallpox vaccines was protective against monkeypox disease in four exposure scenarios. We infected animals with monkeypox virus at doses of 10⁴ pfu (2× LD₅₀) or 10⁶ pfu (170× LD₅₀) and vaccinated the animals with IMVAMUNE^® or ACAM2000^® either 1 or 3 days after challenge. Our results indicated that postexposure vaccination protected the animals to some degree from the 2× LD₅₀, but not the 170× LD₅ challenge. In the 2× LD₅₀ challenge, we also observed that administration of vaccine at 1 day was more effective than administration at 3 days postexposure for IMVAMUNE^®, but ACAM2000^® was similarly effective at either postexposure vaccination time-point. The effects of postexposure vaccination and correlations with survival of total and neutralizing antibody responses, protein targets, take formation, weight loss, rash burden, and viral DNA are also presented.

Human monkeypox - After 40 years, an unintended consequence of smallpox eradication

Smallpox eradication, coordinated by the WHO and certified 40 years ago, led to the cessation of routine smallpox vaccination in most countries. It is estimated that over 70% of the world's population is no longer protected against smallpox, and through cross-immunity, to closely related orthopox viruses such as monkeypox. Monkeypox is now a re-emerging disease. Monkeypox is endemic in as yet unconfirmed animal reservoirs in sub-Saharan Africa, while its human epidemiology appears to be changing. Monkeypox in small animals imported from Ghana as exotic pets was at the origin of an outbreak of human monkeypox in the USA in 2003. Travellers infected in Nigeria were at the origin of monkeypox cases in the UK in 2018 and 2019, Israel in 2018 and Singapore in2019. Together with sporadic reports of human infections with other orthopox viruses, these facts invite speculation that emergent or re-emergent human monkeypox might fill the epidemiological niche vacated by smallpox. An ad-hoc and unofficial group of interested experts met to consider these issues at Chatham House, London in June 2019, in order to review available data and identify monkeypox-related research gaps. Gaps identified by the experts included:The experts further agreed on the need for a better understanding of the genomic evolution and changing epidemiology of orthopox viruses, the usefulness of in-field genomic diagnostics, and the best disease control strategies, including the possibility of vaccination with new generation non-replicating smallpox vaccines and treatment with recently developed antivirals.

Asymptomatic Orthopoxvirus Circulation in Humans in the Wake of a Monkeypox Outbreak among Chimpanzees in Cameroon

Monkeypox virus is a zoonotic Orthopoxvirus (OPXV) that causes smallpox-like illness in humans. In Cameroon, human monkeypox cases were confirmed in 2018, and outbreaks in captive chimpanzees occurred in 2014 and 2016. We investigated the OPXV serological status among staff at a primate sanctuary (where the 2016 chimpanzee outbreak occurred) and residents from nearby villages, and describe contact with possible monkeypox reservoirs. We focused specifically on Gambian rats (Cricetomys spp.) because they are recognized possible reservoirs and because contact with Gambian rats was common enough to render sufficient statistical power. We collected one 5-mL whole blood specimen from each participant to perform a generic anti-OPXV ELISA test for IgG and IgM antibodies and administered a questionnaire about prior symptoms of monkeypox-like illness and contact with possible reservoirs. Our results showed evidence of OPXV exposures (IgG positive, 6.3%; IgM positive, 1.6%) among some of those too young to have received smallpox vaccination (born after 1980, n = 63). No participants reported prior symptoms consistent with monkeypox. After adjusting for education level, participants who frequently visited the forest were more likely to have recently eaten Gambian rats (OR: 3.36, 95% CI: 1.91-5.92, P < 0.001) and primate sanctuary staff were less likely to have touched or sold Gambian rats (OR: 0.23, 95% CI: 0.19-0.28, P < 0.001). The asymptomatic or undetected circulation of OPXVs in humans in Cameroon is likely, and contact with monkeypox reservoirs is common, raising the need for continued surveillance for human and animal disease.

Characterization of Monkeypox virus dissemination in the black-tailed prairie dog (Cynomys ludovicianus) through in vivo bioluminescent imaging

Monkeypox virus (MPXV) is a member of the genus Orthopoxvirus, endemic in Central and West Africa. This viral zoonosis was introduced into the United States in 2003 via African rodents imported for the pet trade and caused 37 human cases, all linked to exposure to MPXV-infected black-tailed prairie dogs (Cynomys ludovicianus). Prairie dogs have since become a useful model of MPXV disease, utilized for testing of potential medical countermeasures. In this study, we used recombinant MPXV containing the firefly luciferase gene (luc) and in vivo imaging technology to characterize MPXV pathogenesis in the black-tailed prairie dog in real time. West African (WA) MPXV could be visualized using in vivo imaging in the nose, lymph nodes, intestines, heart, lung, kidneys, and liver as early as day 6 post infection (p.i.). By day 9 p.i., lesions became visible on the skin and in some cases in the spleen. After day 9 p.i., luminescent signal representing MPXV replication either increased, indicating a progression to what would be a fatal infection, or decreased as infection was resolved. Use of recombinant luc+ MPXV allowed for a greater understanding of how MPXV disseminates throughout the body in prairie dogs during the course of infection. This technology will be used to reduce the number of animals required in future pathogenesis studies as well as aid in determining the effectiveness of potential medical countermeasures.

Recombinase polymerase amplification assay for rapid detection of Monkeypox virus

In this study, a rapid method for the detection of Central and West Africa clades of Monkeypox virus (MPXV) using recombinase polymerase amplification (RPA) assay targeting the G2R gene was developed. MPXV, an Orthopoxvirus, is a zoonotic dsDNA virus, which is listed as a biothreat agent. RPA was operated at a single constant temperature of 42°C and produced results within 3 to 10 minutes. The MPXV-RPA-assay was highly sensitive with a limit of detection of 16 DNA molecules/μl. The clinical performance of the MPXV-RPA-assay was tested using 47 sera and whole blood samples from humans collected during the recent MPXV outbreak in Nigeria as well as 48 plasma samples from monkeys some of which were experimentally infected with MPXV. The specificity of the MPXV-RPA-assay was 100% (50/50), while the sensitivity was 95% (43/45). This new MPXV-RPA-assay is fast and can be easily utilised at low resource settings using a solar powered mobile suitcase laboratory.

Monkeypox re-emergence in Africa: a call to expand the concept and practice of One Health

INTRODUCTION

Monkeypox is a re-emerging viral zoonosis that occurs naturally in heavily forested regions of West and Central Africa. Inter-human transmission of monkeypox virus, although limited, drives outbreaks, particularly in household and health-care settings. But the available evidence suggests that without repeated zoonotic introductions, human infections would eventually cease to occur. Therefore, interrupting virus transmission from animals to humans is key to combating this disease. Areas covered: Herein we review laboratory and field studies examining the susceptibility of various animal taxa to monkeypox virus infection, and note the competence of various species to serve as reservoirs or transmission hosts. In addition, we discuss early socio-ecologic theories of monkeypox virus transmission in rural settings and review current modes of ecologic investigation - including ecologic niche modeling, and ecologic sampling - in light of their potential to identify specific animal species and features of the environment that are associated with heightened risk for human disease. Expert opinion: The role of disease ecology and scientific research in ongoing disease prevention efforts should be reinforced, particularly for wildlife-associated zoonoses such as monkeypox. Such efforts alongside those aimed at nurturing 'One Health' collaborations may ultimately hold the greatest promise for reducing human infections with this pathogen.

Challenges and Achievements in Prevention and Treatment of Smallpox

Declaration of smallpox eradication by the WHO in 1980 led to discontinuation of the worldwide vaccination campaign. The increasing percentage of unvaccinated individuals, the existence of its causative infectious agent variola virus (VARV), and the recent synthetic achievements increase the threat of intentional or accidental release and reemergence of smallpox. Control of smallpox would require an emergency vaccination campaign, as no other protective measure has been approved to achieve eradication and ensure worldwide protection. Experimental data in surrogate animal models support the assumption, based on anecdotal, uncontrolled historical data, that vaccination up to 4 days postexposure confers effective protection. The long incubation period, and the uncertainty of the exposure status in the surrounding population, call for the development and evaluation of safe and effective methods enabling extension of the therapeutic window, and to reduce the disease manifestations and vaccine adverse reactions. To achieve these goals, we need to evaluate the efficacy of novel and already licensed vaccines as a sole treatment, or in conjunction with immune modulators and antiviral drugs. In this review, we address the available data, recent achievements, and open questions.

Ophthalmic examination findings and intraocular pressures in wild-caught African giant pouched rats (Cricetomys spp.)

PURPOSE

To report ophthalmic examination findings and intraocular pressures (IOPs) in wild-caught African giant pouched rats (Cricetomys ansorgei and gambianus) from Tanzania and Ghana.

PROCEDURES

After being placed under general anesthesia for examination, slit-lamp biomicroscopy before and after pharmacologic mydriasis and indirect ophthalmoscopy was performed. Eyes were fluorescein stained and IOPs measured by rebound tonometry using the TonoVet^® .

RESULTS

Thirty-two sexually mature pouched rats (64 eyes) were examined, including 16 males and 16 females. The mean IOP (± standard deviation) was 7.7 (±2.9) mmHg. Fluorescein staining was negative in all eyes. One or more ocular abnormalities were detected in 21 pouched rats (35 eyes). These ocular lesions included the following: lens opacities (n = 23 eyes), persistent pupillary membranes (n = 5), chorioretinal scarring (n = 3), corneal vascularization (n = 2), palpebral margin defect with focal trichiasis (n = 2), phthisis bulbi (n = 1), and posterior synechiae (n = 1). Lens opacities included incipient anterior cortical opacities (n = 7), immature cataract (n = 6), incipient nuclear opacities (n = 5), punctate pigment on anterior lens capsule (n = 2 eyes), incipient suture tip opacities (n = 2), and hypermature cataract (n = 1).

CONCLUSIONS

Ocular abnormalities were common in the evaluated population of giant pouched rats; however, most of the detected lesions were mild and believed to have minimal impact on vision. Rebound tonometry with the TonoVet^® was a reliable and simple technique to measure IOPs in the anesthetized pouched rats.

Serological Survey of Zoonotic Viruses in Invasive and Native Commensal Rodents in Senegal, West Africa

Increasing studies on rodent-borne diseases still highlight the major role of rodents as reservoirs of numerous zoonoses of which the frequency is likely to increase worldwide as a result of accelerated anthropogenic changes, including biological invasions. Such a situation makes pathogen detection in rodent populations important, especially in the context of developing countries characterized by high infectious disease burden. Here, we used indirect fluorescent antibody tests to describe the circulation of potentially zoonotic viruses in both invasive (Mus musculus domesticus and Rattus rattus) and native (Mastomys erythroleucus and Mastomys natalensis) murine rodent populations in Senegal (West Africa). Of the 672 rodents tested, we reported 22 seropositive tests for Hantavirus, Orthopoxvirus, and Mammarenavirus genera, and no evidence of viral coinfection. This study is the first to report serological detection of Orthopoxvirus in rodents from Senegal, Mammarenavirus in R. rattus from Africa, and Hantavirus in M. m. domesticus and in M. erythroleucus. Further specific identification of the viral agents highlighted here is urgently needed for crucial public health concerns.

Characterization of Monkeypox virus infection in African rope squirrels (Funisciurus sp.)

Monkeypox (MPX) is a zoonotic disease endemic in Central and West Africa and is caused by Monkeypox virus (MPXV), the most virulent Orthopoxvirus affecting humans since the eradication of Variola virus (VARV). Many aspects of the MPXV transmission cycle, including the natural host of the virus, remain unknown. African rope squirrels (Funisciurus spp.) are considered potential reservoirs of MPXV, as serosurveillance data in Central Africa has confirmed the circulation of the virus in these rodent species [1,2]. In order to understand the tissue tropism and clinical signs associated with infection with MPXV in these species, wild-caught rope squirrels were experimentally infected via intranasal and intradermal exposure with a recombinant MPXV strain from Central Africa engineered to express the luciferase gene. After infection, we monitored viral replication and shedding via in vivo bioluminescent imaging, viral culture and real time PCR. MPXV infection in African rope squirrels caused mortality and moderate to severe morbidity, with clinical signs including pox lesions in the skin, eyes, mouth and nose, dyspnea, and profuse nasal discharge. Both intranasal and intradermal exposures induced high levels of viremia, fast systemic spread, and long periods of viral shedding. Shedding and luminescence peaked at day 6 post infection and was still detectable after 15 days. Interestingly, one sentinel animal, housed in the same room but in a separate cage, also developed severe MPX disease and was euthanized. This study indicates that MPXV causes significant pathology in African rope squirrels and infected rope squirrels shed large quantities of virus, supporting their role as a potential source of MPXV transmission to humans and other animals in endemic MPX regions.