Monkeypox virus diagnosis and laboratory testing

Rapid identification of A29L antibodies based on mRNA immunization and high-throughput single B cell sequencing to detect Monkeypox virus

With the large number of atypical cases in the mpox outbreak, which was classified as a global health emergency by the World Health Organization (WHO) on 23 July 2022, rapid diagnosis of mpox and diseases with similar symptoms to mpox such as chickenpox and respiratory infectious diseases in the early stages of viral infection is key to controlling the spread of the outbreak. In this study, antibodies against the monkeypox virus A29L protein were efficiently and rapidly identified by combining rapid mRNA immunization with high-throughput sequencing of individual B cells. We obtained eight antibodies with a high affinity for A29L validated by ELISA, which were was used as the basis for developing an ultrasensitive fluorescent immunochromatographic assay based on multilayer quantum dot nanobeads (SiTQD-ICA). The SiTQD-ICA biosensor utilizing M53 and M78 antibodies showed high sensitivity and stability of detection: A29L was detected within 20 min, with a minimum detection limit of 5 pg/mL. A specificity test showed that the method was non-cross-reactive with chickenpox or common respiratory pathogens and can be used for early and rapid diagnosis of monkeypox virus infection by antigen detection. This antibody identification method can also be used for rapid acquisition of monoclonal antibodies in early outbreaks of other infectious diseases for various studies.

Sensitive Dual-Signal ELISA Based on Specific Phage-Displayed Double Peptide Probes with Internal Filtering Effect to Assay Monkeypox Virus Antigen

The global spread of monkeypox has become a worldwide public healthcare issue. Therefore, there is an urgent need for accurate and sensitive detection methods to effectively control its spreading. Herein, we screened by phage display two peptides M4 (sequence: DPCGERICSIAL) and M6 (sequence: SCSSFLCSLKVG) with good affinity and specificity to monkeypox virus (MPXV) B21R protein. To simulate the state of the peptide in the phage and to avoid spatial obstacles of the peptide, GGGSK was added at the C terminus of M4 and named as M4a. Molecular docking shows that peptide M4a and peptide M6 are bound to different epitopes of B21R by hydrogen bonds and salt-bridge interactions, respectively. Then, peptide M4a was selected as the capture probe, phage M6 as the detection probe, and carbonized polymer dots (CPDs) as the fluorescent probe, and a colorimetric and fluorescent double-signal capture peptide/antigen/signal peptide-displayed phage sandwich ELISA triggered by horseradish peroxidase (HRP) through a simple internal filtration effect (IFE) was constructed. HRP catalyzes H2O2 to oxidize 3,3',5,5'-tetramethylbenzidine (TMB) to generate blue oxidized TMB, which can further quench the fluorescence of CPDs through IFE, enabling to detect MPXV B21R in colorimetric and fluorescent modes. The proposed simple immunoassay platform shows good sensitivity and reliability in MPXV B21R detection. The limit of detection for colorimetric and fluorescent modes was 27.8 and 9.14 pg/mL MPXV B21R, respectively. Thus, the established double-peptide sandwich-based dual-signal immunoassay provides guidance for the development of reliable and sensitive antigen detection capable of mutual confirmation, which also has great potential for exploring various analytical strategies for other respiratory virus surveillance.

Longitudinal viral shedding and antibody response characteristics of men with acute infection of monkeypox virus: a prospective cohort study

Understanding of infection dynamics is important for public health measures against monkeypox virus (MPXV) infection. Herein, samples from multiple body sites and environmental fomites of 77 acute MPXV infections (HIV co-infection: N = 42) were collected every two to three days and used for detection of MPXV DNA, surface protein specific antibodies and neutralizing titers. Skin lesions show 100% positivity rate of MPXV DNA, followed by rectum (88.16%), saliva (83.78%) and oropharynx (78.95%). Positivity rate of oropharynx decreases rapidly after 7 days post symptom onset (d.p.o), while the rectum and saliva maintain a positivity rate similar to skin lesions. Viral dynamics are similar among skin lesions, saliva and oropharynx, with a peak at about 6 d.p.o. In contrast, viral levels in the rectum peak at the beginning of symptom onset and decrease rapidly thereafter. 52.66% of environmental fomite swabs are positive for MPXV DNA, with highest positivity rate (69.89%) from air-conditioning air outlets. High seropositivity against A29L (100%) and H3L (94.74%) are detected, while a correlation between IgG endpoint titers and neutralizing titers is only found for A29L. Most indexes are similar between HIV and Non-HIV participants, while HIV and rectitis are associated with higher viral loads in rectum.

Rapid detection of monkeypox virus and differentiation of West African and Congo Basin strains using endonuclease restriction-mediated real-time PCR-based testing

The ongoing multi-country outbreak of monkeypox virus (MPXV) has continuously attracted global attention, highlighting the critical need for timely and accurate methods to detect MPXV and differentiate its clades. Herein, we devised a novel multiplex ET-PCR (endonuclease restriction-mediated real-time PCR) assay that integrates PCR amplification, restriction endonuclease cleavage and real-time fluorescence detection to diagnose MPXV infection and distinguish the Congo Basin and West African MPXV strains. In the MPXV ET-PCR system, three sets of specific primers were designed for MPXV, Congo Basin and West African strains. A short sequence, which could be recognized by restriction endonuclease enzyme BstUI, was added to the 5'end of amplification primers. Then, the modified primers were assigned different reporter dyes and corresponding quenching dyes to each of the three targets, enabling real-time fluorescence reporting of the results and multiplex detection. The designed assay enabled the detection of single or three targets in a single tube, with excellent specificity and analytical sensitivity in terms of plasmid and pseudotyped virus. Moreover, the clinical feasibility of our assay was validated using artificially simulated plasma, nasopharyngeal swab and skin swab samples. In conclusion, the multiplex ET-PCR assay devised here had the advantages of simple primer design, cost-effectiveness, low contamination risk, excellent sensitivity, high specificity and multiplex detection, making it a valuable and dependable tool for curbing the extensive spread of MPXV.

Human monkeypox virus: Epidemiologic review and research progress in diagnosis and treatment

Monkeypox virus (MPXV) is responsible for causing a zoonotic disease called monkeypox (mpox), which sporadically infects humans in West and Central Africa. It first infected humans in 1970 and, along with the variola virus, belongs to the genus Orthopoxvirus in the poxvirus family. Since the World Health Organization declared the MPXV outbreak a "Public Health Emergency of International Concern" on July 23, 2022, the number of infected patients has increased dramatically. To control this epidemic and address this previously neglected disease, MPXV needs to be better understood and reevaluated. In this review, we cover recent research on MPXV, including its genomic and pathogenic characteristics, transmission, mutations and mechanisms, clinical characteristics, epidemiology, laboratory diagnosis, and treatment measures, as well as prevention of MPXV infection in light of the 2022 and 2023 global outbreaks. The 2022 MPXV outbreak has been primarily associated with close intimate contact, including sexual activity, with most cases diagnosed among men who have sex with men. The incubation period of MPXV infection usually lasts from 6 to 13 days, and symptoms include fever, muscle pains, headache, swollen lymph nodes, and a characteristic painful rash, including several stages, such as macules, papules, blisters, pustules, scabs, and scab shedding involving the genitals and anus. Polymerase chain reaction (PCR) is usually used to detect MPXV in skin lesion material. Treatment includes supportive care, antivirals, and intravenous vaccinia immune globulin. Smallpox vaccines have been designed with four givens emergency approval for use against MPXV infection.

A comprehensive review of monkeypox virus and mpox characteristics

Monkeypox virus (MPXV) is the etiological agent of monkeypox (mpox), a zoonotic disease. MPXV is endemic in the forested regions of West and Central Africa, but the virus has recently spread globally, causing outbreaks in multiple non-endemic countries. In this paper, we review the characteristics of the virus, including its ecology, genomics, infection biology, and evolution. We estimate by phylogenomic molecular clock that the B.1 lineage responsible for the 2022 mpox outbreaks has been in circulation since 2016. We interrogate the host-virus interactions that modulate the virus infection biology, signal transduction, pathogenesis, and host immune responses. We highlight the changing pathophysiology and epidemiology of MPXV and summarize recent advances in the prevention and treatment of mpox. In addition, this review identifies knowledge gaps with respect to the virus and the disease, suggests future research directions to address the knowledge gaps, and proposes a One Health approach as an effective strategy to prevent current and future epidemics of mpox.

Role of the Laboratory in the Diagnosis of Poxvirus Infections

Although WHO-led global efforts led to eradication of smallpox over four decades ago, other poxviruses, especially monkeypox, have re-emerged to occupy the ecological niche vacated by smallpox. Many of these viruses produce similar lesions thus mandating a prompt laboratory confirmation. There has been considerable evolution in the techniques available to diagnose these infections and differentiate between them. With the 2022 multi-country outbreak of monkeypox, significant efforts were made to apprise the laboratory diagnosis of the virus and numerous real-time-PCR-based assays were made commercially available. This chapter discusses the sample collection and biosafety aspects along with the repertoire of diagnostic modalities, both traditional and emerging, for poxviruses which a special focus on monkeypox. The advantages and disadvantages of each technique have been illustrated. We have also reflected upon the newer advances and the existing lacunae.

Screening, Expression and Identification of Nanobody Against Monkeypox Virus A35R

Introduction

The monkeypox (Mpox) virus epidemic presents a significant risk to global public health security. A35R, a crucial constituent of EEV, plays a pivotal role in virus transmission, serves as a vital target for vaccine development, and has potential for serological detection. Currently, there is a dearth of research on nanobodies targeting A35R. The purpose of this study is to identify specific nanobodies target A35R, so as to provide new antibody candidates for Mpox vaccine development and diagnostic kit development.

Methods

Three nanobodies specific to the monkeypox virus protein A35R were screened from a naïve phage display library. After four rounds of panning, positive phage clones were identified by enzyme-linked immunosorbent assay (ELISA). Further, the nanobody fusion protein was constructed in pNFCG1-IgG1-Fc vector and expressed in HEK293F cells and purified by affinity chromatography. The specificity and affinity of the nanobodies were identified by ELISA. The binding kinetics of the VHH antibody to A35R were assessed via employment of a bio-layer interferometry (BLI) apparatus, thereby determining the nanobodies affinity.

Results

The three purified nanobodies showed specific high-affinity binding MPXV A35R, of them, VHH-1 had the best antigen binding affinity (EC50 = 0.010 ug/mL). In addition, VHH-1 on Protein A biosensor can bind Mpox virus A35R, with an affinity constant of 54 nM as determined in BLI assay.

Conclusion

In sum, we has obtained three nanobody strains against Mpox virus A35R with significant affinity and specificity, therefore laying an essential foundation for further research as well as the applications of diagnostic and therapeutic tools of Mpox virus.

Molybdenum disulfide-loaded multilayer AuNPs with colorimetric-SERS dual-signal enhancement activities for flexible immunochromatographic diagnosis of monkeypox virus

The sudden outbreak of monkeypox in 2022 suggests the importance of developing a rapid but sensitive virus detection technology. Herein, we report a colorimetric/surface-enhanced Raman scattering (SERS) dual-signal co-enhanced immunochromatographic assay (ICA) for the flexible, ultrasensitive, and accurate detection of monkeypox virus (MPXV) in various complex samples. A thickness-controlled polyethyleneimine interlayer (1 nm) is coated onto two-dimensional molybdenum disulfide (MoS2) nanosheet to enable the electrostatic adsorption of two layers of dense 30 nm AuNPs, which not only improves colorimetric ability but also creates numerous efficient SERS hotspots. Moreover, the SERS activity of film-like dual-signal tag (MoS2@Au-Au) is drastically enhanced by combining the chemical enhancement effect of MoS2 sheets and the electromagnetic enhancement effect of Au-Au hotspots. The introduction of MoS2@Au-Au greatly broadens the application range of existing ICA methods, in which the colorimetric signal supports the quick identification of the target virus and the SERS signal allows the quantitative detection of MPXV with detection limits of as low as 0.2 and 0.002 ng/mL. Given its rapid detection ability (< 20 min), high accuracy in real samples (RSD < 9.89 %), and superior sensitivity than traditional AuNP-based colorimetric ICA (> 500 times), the proposed assay has great potential for field application.

Monkeypox: Virology, laboratory diagnosis and therapeutic approach

Monkeypox infection outbreaks have been observed sporadically in Africa, usually as a result of interaction with wildlife reservoirs. The genomes of the new strain range in size from 184.7 to 198.0 kb and are identified with 143-214 open reading frames. Viral cores are rapidly carried on microtubules away from the cell's perimeter and deeper into the cytoplasm once the virus and cell membranes fuse. Depending on the kind of exposure, patients with monkeypox may experience a febrile prodrome 5-13 days after exposure, which frequently includes lymphadenopathy, malaise, headaches, and muscle aches. A different diagnostic approach is available for monkeypox, including histopathological analysis, electron microscopy, immunoassays, polymerase chain reaction, genome sequencing, microarrays, loop-mediated isothermal amplification technology and CRISPR (i.e., "clustered regularly interspaced short palindromic repeats"). There are currently no particular, clinically effective treatments available for the monkeypox virus. An initial treatment is cidofovir. As a monophosphate nucleotide analog, cidofovir is transformed into an inhibitor of viral DNA polymerase by cellular kinases, which is analogous to cidofovir's function in inhibiting viral DNA synthesis. The European Medicine Agency and the Food and Drug Administration have both granted permission for IMVAMUNE, a replication-deficient, attenuated third-generation modified vaccinia Ankara vaccine, to be used for the prevention of smallpox and monkeypox in adults.

Beyond skin deep: shedding light on the neuropsychiatric consequences of Monkeypox (Mpox)

This review is attempted in view of World Health Organization (WHO) warning on Monkeypox virus (Mpox) to summarize the available data regarding the potential effect on central nervous system (CNS), its complications, and diagnostic methods. We combed various international databases (including Scopus, PubMed, Web of Science, and Google Scholar) for articles mentioning Mpox infection, orthopox infection, and the central nervous system that were published between the years 2000 and 2022. Further evidence was evaluated from relevant studies published in the literature. There is emerging evidence of central nervous system neurological involvement. In addition to encephalopathy, which is one of the most serious neurological complications of Mpox, the most common complications of Mpox infection are headache, weakness, myalgia, anorexia, and altered consciousness. Anxiety and depression have also been identified as the most common psychiatric symptoms in these patients.

Human monkeypox: history, presentations, transmission, epidemiology, diagnosis, treatment, and prevention

Human monkeypox is a zoonotic infection that is similar to the diseases caused by other poxviruses. It is endemic among wild rodents in the rainforests of Central and Western Africa, and can be transmitted via direct skin contact or mucosal exposure to infected animals. The initial symptoms include fever, headache, myalgia, fatigue, and lymphadenopathy, the last of which is the main symptom that distinguishes it from smallpox. In order to prevent and manage the disease, those who are infected must be rapidly diagnosed and isolated. Several vaccines have already been developed (e.g., JYNNEOS, ACAM2000 and ACAM3000) and antiviral drugs (e.g., cidofovir and tecovirimat) can also be used to treat the disease. In the present study, we reviewed the history, morphology, clinical presentations, transmission routes, diagnosis, prevention, and potential treatment strategies for monkeypox, in order to enable health authorities and physicians to better deal with this emerging crisis.

Loop-mediated isothermal amplification combined with lateral flow biosensor for rapid and sensitive detection of monkeypox virus

The ongoing outbreak of the monkeypox, caused by monkeypox virus (MPXV), has been a public health emergency of international concern, indicating an urgent need for rapid and sensitive MPXV detection. Here, we designed a diagnostic test based on loop-mediated isothermal amplification (LAMP) and nanoparticle-based lateral flow biosensor(LFB)for diagnosis of MPXV infection, termed MPX-LAMP-LFB. A set of six LAMP primers was designed based the ATI gene of MPXV, and LAMP amplification of MPXV templates was performed at 63°C for only 40 min. The results were rapidly and visually decided using the LFB test within 2 min. The MPX-LAMP-LFB assay can specifically detect MPXV strains without cross-reaction with non-MPXV pathogens. The sensitivity of the MPX-LAMP-LFB assay is as low as 5 copies/μl of plasmid template and 12.5 copies/μl of pseudovirus in human blood samples. The whole process of the MPX-LAMP-LFB assay could be completed ~1 h, including rapid template preparation (15 min), LAMP reaction (40 min)and result reporting (<2 min). Collectively, MPX-LAMP-LFB assay developed here is a useful tool for rapid and reliable diagnosis of MPXV infection.

Potentially Asymptomatic Infection of Monkeypox Virus: A Systematic Review and Meta-Analysis

Background: Monkeypox is a global public health concern, given the recent outbreaks in non-endemic countries where little scientific evidence exists on the disease. Specifically, there is a lack of data on asymptomatic monkeypox virus infection. This study aims to evaluate the overall prevalence of asymptomatic monkeypox virus infection. Methods: In this systematic review and meta-analysis, we performed an extensive literature search in PubMed, Scopus, Web of Science, ProQuest, EMBASE, EBSCOHost, Cochrane, and preprint servers (medRxiv, arXiv, bioRxiv, BioRN, ChiRxiv, ChiRN, and SSRN) and assessed all published articles till September 2022. Primary studies reporting monkeypox infections among asymptomatic participants were included after quality assessment. The characteristics of the study and information on the number of cases and symptomatic status were extracted from the included studies. The heterogeneity between studies was assessed using the I2 statistic. Publication bias was analyzed using funnel plots and Egger regression tests. The primary outcome was the pooled prevalence of asymptomatic infections within the examined population. Results: A total of 16 studies were included for qualitative synthesis, while five studies, including 645 individuals, were included for quantitative synthesis. There was substantial heterogeneity between studies (I2 = 94.86%; p < 0.01), with a pooled percentage of asymptomatic infections in the studied population of 10.2% (95%CI, 2.5−17.9%). Conclusion: This meta-analysis suggests that many people infected with the monkeypox virus are asymptomatic and difficult to detect. Therefore, prompt detection of these cases of monkeypox virus and appropriate subsequent management is of utmost importance to global public health.