Recombinase polymerase amplification assay for rapid detection of Monkeypox virus

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.

Assessment of the knowledge, attitude, and perception of the world's population towards monkeypox and its vaccines: A systematic review and descriptive analysis of cross-sectional studies

Background

Prevention and treatment of the monkeypox virus (Mpox) remain challenging in areas where it is endemic. This systematic review and meta-analysis aimed to collect this information from various studies in one study to give a comprehensive view of people's opinions, fears, and behaviors about this virus.

Methods

We searched PubMed, Scopus, Web of Science, the Cochrane Library, and Google Scholar for descriptive cross-sectional study designs conducted in 2022 and 2023 addressing knowledge, attitude, perception, preparedness, willingness to get vaccinated, and practices against Mpox infection.

Results

Among the included studies, 16 studies assessed the level of knowledge of study participants regarding Mpox with a total of 9066 participants. Among them, 4222 (46.6 %) were reported to have good knowledge, and 4844 (53.4%) were reported to have poor knowledge about Mpox. Regarding willingness to get vaccinated against Mpox, 14 studies with a total of 10,696 participants were included. Among them, 7006 (65 %) were willing to get vaccinated while 3690 (35 %) weren't willing to be vaccinated.

Conclusion

Knowledge about Mpox should be increased and awareness should be spread regarding the importance of preventive measures such as vaccination to protect the population from another COVID-19-like pandemic.

Novel point-of-care rapid detection of monkeypox virus

Monkeypox, a viral zoonotic disease caused by MPXV, has emerged as a significant global health concern since the first outbreak outside Africa in 2003. As of the current data, there have been 30 189 confirmed cases of monkeypox in 88 countries, with 29 844 cases reported in 81 countries. Given the absence of prior documented instances of the disease, swift and accurate testing is imperative to contain the spread of monkeypox. In this study, we developed a LAMP detection reagent for monkeypox and evaluated its performance in terms of sensitivity, specificity, repeatability, stability, linear range, and linearity, utilizing a commercial magnetic bead-based nucleic acid extraction system. This has led to the establishment of an integrated on-site detection platform for the monkeypox virus, utilizing a closed cartridge. The sensitivity was found to be 100 copies per μL, with no cross-reactivity observed with three other viruses, indicating robust performance. The parameters of repeatability, stability, linear range, and linearity were also assessed. For 28 simulated samples, the detection results obtained from the integrated system were consistent with those from conventional laboratory methods, specifically qPCR and LAMP detection following nucleic acid extraction. The entire process can be completed in approximately one hour, making it highly suitable for immediate rapid testing.

Red Fluorescent Copper Nanoclusters for Fluorescence, Smartphone, and Electrochemical Sensor Arrays to Detect the Monkeypox A29 Protein

An Orthopox zoonotic viral infection called monkeypox (MPXV) is the leading infectious disease globally. MPXV can easily spread from human to human through direct and indirect sexual contact; therefore, accurate and early detection of MPXV is crucial for reducing mortality. Fluorescence-based materials have received significant attention in recent years for biomedical applications. In this study, we synthesized red-fluorescent copper nanoclusters (CuNCs) with a size of less than 10 nm, which was confirmed by high-resolution transmission electron microscopy (HR-TEM) and atomic force microscopy (Bio-AFM) analysis. The synthesized CuNCs had a high fluorescence nature and were utilized for the detection of the MPXV (A29P) by an antigen-antibody conjugation using fluorescence, smartphone colorimetric, and electrochemical sensing techniques. The antigen (A29P) and antibody (Ab A29) interaction mechanisms were studied by X-ray photoelectron spectroscopic (XPS) analysis. Furthermore, fluorescence and electrochemical sensing were performed in PBS with detection limits of 0.096 and 0.114 nM, respectively. For real-world applications, the prepared immunosensor array can detect A29P in spiked serum samples, and point-of-care (POC) analysis, a smartphone-integrated sensor array, was used to measure the RGB color changes. The results showed that synthesized CuNCs are potential materials for detecting A29P via fluorescence and smartphone colorimetric and electrochemical sensing techniques.

Diagnostic Strategies in the Era of Monkeypox Resurgence: A Comprehensive Analysis

The resurgence of monkeypox (Mpox), an orthopoxvirus infection closely related to smallpox, presents a significant global health challenge. This study presents a comprehensive overview of Mpox, focusing on its clinical manifestations, diagnostic strategies, and testing methodologies. A thorough review of the literature and available data on Mpox, emphasizing diagnostic assays, clinical indicators, and laboratory testing, constitutes the core of this analysis. The study involves insights from Mpox patients and healthcare professionals engaged in its diagnosis and management. Contextualizing the research within the global spread of Mpox addresses the complexities associated with the diagnosis of the disease. The findings illuminate diverse Mpox diagnostic techniques, encompassing viral culture, immunological methods, serology, quantitative polymerase chain reaction (qPCR), electron microscopy, and advanced technologies such as artificial intelligence (AI) and the GeneXpert system. qPCR is highlighted as the benchmark for MPXV detection and quantification. These diagnostic advancements have significantly enhanced the precision and efficiency of Mpox diagnosis, facilitating prompt identification and treatment of infected individuals. The study underscores the critical importance of accurate and timely diagnosis, proper handling and transportation of clinical specimens, and the imperative for point-of-care (POC) testing to control the global spread of Mpox.

The Re-Emergence of Mpox: Old Illness, Modern Challenges

The Mpox virus (MPXV) is known to cause zoonotic disease in humans. The virus belongs to the genus Orthopoxvirus, of the family Poxviridae, and was first reported in monkeys in 1959 in Denmark and in humans in 1970 in the Congo. MPXV first appeared in the U.S. in 2003, re-emerged in 2017, and spread globally within a few years. Wild African rodents are thought to be the reservoir of MPXV. The exotic trade of animals and international travel can contribute to the spread of the Mpox virus. A phylogenetic analysis of MPXV revealed two distinct clades (Central African clade and West African clade). The smallpox vaccine shows cross-protection against MPXV infections in humans. Those who have not previously been exposed to Orthopoxvirus infections are more vulnerable to MPXV infections. Clinical manifestations in humans include fever, muscle pain, headache, and vesicle formation on the skin of infected individuals. Pathognomonic lesions include ballooning degenerations with Guarnieri-like inclusions in vesicular epithelial cells. Alterations in viral genome through genetic mutations might favor the re-emergence of a version of MPXV with enhanced virulence. As of November 2023, 92,783 cases and 171 deaths have been reported in 116 countries, representing a global public health concern. Here, we provide insights on the re-emergence of MPXV in humans. This review covers the origin, emergence, re-emergence, transmission, pathology, diagnosis, control measures, and immunomodulation of the virus, as well as clinical manifestations. Concerted efforts of health professionals and scientists are needed to prevent the disease and stop its transmission in vulnerable populations.

Electrochemical Immunoassay Platform for Human Monkeypox Virus Detection

In this study, we reported a selective impedimetric biosensor for the detection of A29 which is the target protein of the monkeypox virus (MPXV). The working principle of the biosensor relies on the interaction mechanism between A29, which is an internal membrane protein of MPXV, and the heparan sulfate receptor. For this purpose, after immobilizing heparan sulfate onto the gold screen-printed electrode surface, its interaction with A29 protein was monitored using electrochemical impedance spectroscopy. After the optimization of experimental parameters, the analytical characteristics of the developed MPVX immunosensor were examined. The developed immunosensor exhibited a linear detection range between 2.0 and 50 ng mL-1, with a detection limit of 2.08 ng mL-1 and a quantification limit of 6.28 ng mL-1. Furthermore, a relative standard deviation value of 2.82% was determined for 25 ng mL-1. Apart from that, sample application studies were also performed with the standard addition of A29 protein to 1:10 diluted real serum samples that were taken from healthy individuals, and very good recovery values were obtained.

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.

Fabrication of label-free immunoprobe for monkeypox A29 detection using one-step electrodeposited molybdenum oxide-graphene quantum rods

Monkeypox is a zoonotic viral infection caused by the monkeypox virus (MPXV), which belongs to the Poxviridae family of the Orthopoxvirus (OPXV) genus. Monkeypox is transmitted from animals to humans and humans to humans; therefore, the accurate and early detection of MPXV is crucial for reducing mortality. A novel graphene-based material, graphene quantum rods (GQRs) was synthesized and confirmed using high-resolution transmission electron microscopy (HR-TEM) and atomic force microscopy (AFM). In this study, molybdenum oxide was electrodeposited and one-pot electrodeposition of MoO3-GQRs composite on carbon fiber paper (CFP) enabled by an antibody (Ab A29)/MoO3-GQRs immunoprobe was developed for the early diagnosis of MPXV protein (A29P). Several studies were conducted to analyze the MoO3-GQRs composite, and the prepared Ab A29/MoO3-GQRs immunoprobe selectively bound to the A29P antigen that was measured using differential pulse voltammetry (DPV) analysis and impedance spectroscopy. The antigen-antibody interaction was analyzed using X-ray photoelectron spectroscopy. DPV analysis showed a wide linear range of detection from 0.5 nM to 1000 nM, a detection limit of 0.52 nM, and a sensitivity of 4.51 µA in PBS. The prepared immunoprobe was used to analyze A29P in serum samples without reducing electrode sensitivity. This system is promising for the clinical analysis of A29P antigen and offers several advantages, including cost-effectiveness, ease of use, accuracy, and high sensitivity.

Simple, sensitive, and visual detection of 12 respiratory pathogens with one-pot-RPA-CRISPR/Cas12a assay

Respiratory infections pose a serious threat to global public health, underscoring the urgent need for rapid, accurate, and large-scale diagnostic tools. In recent years, the CRISPR/Cas (clustered regularly interspaced short palindromic repeats/CRISPR-associated) system, combined with isothermal amplification methods, has seen widespread application in nucleic acid testing (NAT). However, achieving a single-tube reaction system containing all necessary components is challenging due to the competitive effects between recombinase polymerase amplification (RPA) and CRISPR/Cas reagents. Furthermore, to enable precision medicine, distinguishing between bacterial and viral infections is essential. Here, we have developed a novel NAT method, termed one-pot-RPA-CRISPR/Cas12a, which combines RPA with CRISPR molecular diagnostic technology, enabling simultaneous detection of 12 common respiratory pathogens, including six bacteria and six viruses. RPA and CRISPR/Cas12a reactions are separated by paraffin, providing an independent platform for RPA reactions to generate sufficient target products before being mixed with the CRISPR/Cas12a system. Results can be visually observed under LED blue light. The sensitivity of the one-pot-RPA-CRISPR/Cas12a method is 2.5 × 100 copies/μL plasmids, with no cross-reaction with other bacteria or viruses. Additionally, the clinical utility was evaluated by testing clinical isolates of bacteria and virus throat swab samples, demonstrating favorable performance. Thus, our one-pot-RPA-CRISPR/Cas12a method shows immense potential for accurate and large-scale detection of 12 common respiratory pathogens in point-of-care testing.

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.

Loop-mediated isothermal amplification coupled with nanoparticle-based lateral flow biosensor for monkeypox virus detection

Monkeypox virus (MPXV) infection is currently an evolving public health concern, highlighting an urgent need for early and rapid detection of MPXV. Here, we present a diagnostic test called MPXV-LAMP-LFB, which combines loop-mediated isothermal amplification (LAMP) and nanoparticle-based lateral flow biosensor (LFB) for the simple, sensitive and specific detection of MPXV and differentiation of its two clades. The MPXV-LAMP-LFB can be conducted at a heating block and the detection results can be visually indicated with the biosensor without any specialized apparatus. Two sets of LAMP primers targeting the D14L and ATI genes were designed for the Central and West African MPXV isolates, respectively. The optimal amplification condition was 64 °C for 40 min. Thus, the MPXV-LAMP-LFB test can be completed within 1 h, incorporating rapid DNA extraction (∼15 min), LAMP reaction (∼40 min) and result indicating (∼5 min). The MPXV-LAMP-LFB assay could detect down to 5 copies of plasmid template and 12.5 copies of pseudotyped virus in simulated blood samples. Furthermore, the MPXV-LAMP-LFB assay correctly identified all the positive controls and successfully avoided cross-reactivity with the non-MPXV pathogens or clinical samples, demonstrating its high specificity. Overall, the MPXV-LAMP-LFB test developed in this study showed great promise as a rapid, sensitive and accurate molecular tool for diagnosing MPXV infection.

Monkeypox virus: insights into pathogenesis and laboratory testing methods

The monkeypox virus (MPXV) is a zoonotic pathogen that transmits between monkeys and humans, exhibiting clinical similarities with the smallpox virus. Studies on the immunopathogenesis of MPXV revealed that an initial strong innate immune response is elicited on viral infection that subsequently helps in circumventing the host defense. Once the World Health Organization (WHO) declared it a global public health emergency in July 2022, it became essential to clearly demarcate the MPXV-induced symptoms from other viral infections. We have exhaustively searched the various databases involving Google Scholar, PubMed, and Medline to extract the information comprehensively compiled in this review. The primary focus of this review is to describe the diagnostic methods for MPXV such as polymerase chain reaction (PCR), and serological assays, along with developments in viral isolation, imaging techniques, and next-generation sequencing. These innovative technologies have the potential to greatly enhance the accuracy of diagnostic procedures. Significant discoveries involving MPXV immunopathogenesis have also been highlighted. Overall, this will be a knowledge repertoire that will be crucial for the development of efficient monitoring and control strategies in response to the MPXV infection helping clinicians and researchers in formulating healthcare strategies.

Amplification-free detection of Mpox virus DNA using Cas12a and multiple crRNAs

Mpox virus (MPXV) is a zoonotic DNA virus that caused human Mpox, leading to the 2022 global outbreak. MPXV infections can cause a number of clinical syndromes, which increases public health threats. Therefore, it is necessary to develop an effective and reliable method for infection prevention and control of epidemic. Here, a Cas12a-based direct detection assay for MPXV DNA is established without the need for amplification. By targeting the envelope protein gene (B6R) of MPXV, four CRISPR RNAs (crRNAs) are designed. When MPXV DNA is introduced, every Cas12a/crRNA complex can target a different site of the same MPXV gene. Concomitantly, the trans-cleavage activity of Cas12a is triggered to cleave the DNA reporter probes, releasing a fluorescence signal. Due to the application of multiple crRNAs, the amount of active Cas12a increases. Thus, more DNA reporter probes are cleaved. As a consequence, the detection signals are accumulated, which improves the limit of detection (LOD) and the detection speed. The LOD of the multiple crRNA system can be improved to ~ 0.16 pM, which is a decrease of the LOD by approximately ~ 27 times compared with the individual crRNA reactions. Furthermore, using multiple crRNAs increases the specificity of the assay. Given the outstanding performance, this assay has great potential for Mpox diagnosis.

Ultrasensitive one-pot detection of monkeypox virus with RPA and CRISPR in a sucrose-aided multiphase aqueous system

IMPORTANCE

The monkeypox virus was declared as a Public Health Emergency of International Concern (PHEIC) by the World Health Organization (WHO) and continues to cause infection cases worldwide. Given the risk of virus evolution, it is essential to identify monkeypox virus infection in a timely manner to prevent outbreaks. This study establishes a novel one-pot recombinase polymerase amplification-Clustered Regularly Interspaced Short Palindromic Repeats (RPA-CRISPR) assay for monkeypox virus with an ultra-high sensitivity. The assay shows good specificity, accuracy, and the rapidness and convenience important for point-of-care testing. It provides an effective tool for the early diagnosis of monkeypox, which is useful for the prevention of an epidemic.

Development of a Rapid Epstein-Barr Virus Detection System Based on Recombinase Polymerase Amplification and a Lateral Flow Assay

The quality of cellular products used in biological research can directly impact the ability to obtain accurate results. Epstein-Barr virus (EBV) is a latent virus that spreads extensively worldwide, and cell lines used in experiments may carry EBV and pose an infection risk. The presence of EBV in a single cell line can contaminate other cell lines used in the same laboratory, affecting experimental results. We developed three EBV detection systems: (1) a polymerase chain reaction (PCR)-based detection system, (2) a recombinase polymerase amplification (RPA)-based detection system, and (3) a combined RPA-lateral flow assay (LFA) detection system. The minimum EBV detection limits were 1 × 103 copy numbers for the RPA-based and RPA-LFA systems and 1 × 104 copy numbers for the PCR-based system. Both the PCR and RPA detection systems were applied to 192 cell lines, and the results were consistent with those obtained by the EBV assay methods specified in the pharmaceutical industry standards of the People's Republic of China. A total of 10 EBV-positive cell lines were identified. The combined RPA-LFA system is simple to operate, allowing for rapid result visualization. This system can be implemented in laboratories and cell banks as part of a daily quality control strategy to ensure cell quality and experimental safety and may represent a potential new technique for the rapid detection of EBV in clinical samples.

Molecular Methods for Diagnosis of Monkeypox: A Mini-review

BACKGROUND

Monkeypox is a global public health issue caused by the monkeypox virus (MPXV). As of October 28, 2022, a total of 77,115 laboratoryconfirmed cases and 3,610 probable cases, including 36 deaths, were reported, with 9,070 cases reported in Brazil, the second most affected country. The need to develop national technologies for the rapid diagnosis of emerging diseases for mass testing of the population is evident, as observed in the SARS-CoV-2 pandemic.

OBJECTIVE

With that in mind, this article provides an overview of current methods, techniques, and their applications in the molecular detection of monkeypox, focusing the search on real-time polymerase chain reaction (qPCR), polymerase chain reaction (PCR), and polymerase chain reaction-enzyme linked immunosorbent assay (PCRELISA).

METHODS

The relevant documents or papers covered in this study were selected by a search in international bibliographic databases. The search terms used in the databases were aimed at summarizing existing knowledge on molecular diagnostic methods, such as monkeypox; MPX, MPXV, qPCR, PCR, PCR-ELISA, diagnosis and detection searched separately or together using the Boolean operator "AND" either in the title or abstract. The searches took place in September 2022, and the corresponding articles were selected between 2012 and 2022.

RESULTS

We found 256 documents in total and twelve studies addressing the molecular diagnosis of monkeypox were classified as possible sources for this review.

CONCLUSION

It is evident there is a pressing need to develop national technologies for rapid diagnosis of emerging diseases for mass testing of the population. It is also extremely important to have national detection kits with greater diagnostic capacity to assist in developing effective public policies in countries affected by this disease.

Biological Characteristics and Pathogenesis of Monkeypox Virus: An Overview

Although the smallpox virus has been eradicated worldwide, the World Health Organization (WHO) has issued a warning about the virus's potential to propagate globally. The WHO labeled monkeypox a world public health emergency in July 2022, requiring urgent prevention and treatment. The monkeypox virus is a part of the Poxviridae family, Orthopoxvirus genus, and is accountable for smallpox, which has killed over a million people in the past. Natural hosts of the virus include squirrels, Gambian rodents, chimpanzees, and other monkeys. The monkeypox virus has transmitted to humans through primary vectors (various animal species) and secondary vectors, including direct touch with lesions, breathing particles from body fluids, and infected bedding. The viral particles are ovoid or brick-shaped, 200-250 nm in diameter, contain a single double-stranded DNA molecule, and reproduce only in the cytoplasm of infected cells. Monkeypox causes fever, cold, muscle pains, headache, fatigue, and backache. The phylogenetic investigation distinguished between two genetic clades of monkeypox: the more pathogenic Congo Basin clade and the West Africa clade. In recent years, the geographical spread of the human monkeypox virus has accelerated despite a paucity of information regarding the disease's emergence, ecology, and epidemiology. Using lesion samples and polymerase chain reaction (PCR), the monkeypox virus was diagnosed. In the USA, the improved Ankara vaccine can now be used to protect people who are at a higher risk of getting monkeypox. Antivirals that we have now work well against smallpox and may stop the spread of monkeypox, but there is no particular therapy for monkeypox.

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.

Label-free detection of virus based on surface-enhanced Raman scattering

Due to the background interference from biological samples, detecting viruses using surface-enhanced Raman scattering (SERS) in clinical samples is challenging. This study is based on SERS by reducing sodium borohydride and aggregating silver nanoparticles to develop suitable virus detection "hot spot." The monkeypox virus and human papillomavirus fingerprints were quickly obtained, tested, and identified in serum and artificial vaginal discharge, respectively, by combining the principal component analysis method. Therefore, these viruses were successfully identified in the biological background. In addition, the lowest detection limit was 100 copies/mL showing good reproducibility and signal-to-noise ratio. The concentration-dependent curve of the monkeypox virus had a good linear relationship. This method helps solve the SERS signal interference problem in complex biological samples, with low detection limits and high selectivity in virus characterization and quantitative analysis. Therefore, this method has a reasonable prospect of clinical application.

Comprehensive overview of 2022 human monkeypox outbreak and its pathology, prevention, and treatment: A strategy for disease control

The 2022 Monkeypox virus, an evolved DNA strain originating in Africa, exhibits heightened human-to-human transmissibility and potential animal transmission. Its host remains unidentified. While its initial slow transmission rate restrained global impact, 2022 saw a surge in cases, causing widespread concern in over 103 countries by September. This virus's distinctive human-to-human transmission marks a crucial shift, demanding a prompt revaluation of containment strategies. However, the host source for this shift requires urgent research attention. Regrettably, no universal preventive or curative methods have emerged for this evolved virus. Repurposed from smallpox vaccines, only some vaccinations offer a partial defense. Solely one therapeutic drug is available. The article's essence is to provide a comprehensive grasp of the virus's epidemiology, morphology, immune invasion mechanisms, and existing preventive and treatment measures. This knowledge equips researchers to devise strategies against its spread and potential public health implications.

Extraction-free LAMP assays for generic detection of Old World Orthopoxviruses and specific detection of Mpox virus

Mpox is a neglected zoonotic disease endemic in West and Central Africa. The Mpox outbreak with more than 90,000 cases worldwide since 2022 generated great concern about future outbreaks and highlighted the need for a simple and rapid diagnostic test. The Mpox virus, MPV, is a member of the Orthopoxvirus (OPV) genus that also contains other pathogenic viruses including variola virus, vaccinia virus, camelpox virus, and cowpox virus. Phylogenomic analysis of 200 OPV genomes identified 10 distinct phylogroups with the New World OPVs placed on a very long branch distant from the Old World OPVs. Isolates derived from infected humans were found to be distributed across multiple phylogroups interspersed with isolates from animal sources, indicating the zoonotic potential of these viruses. In this study, we developed a simple and sensitive colorimetric LAMP assay for generic detection of Old World OPVs. We also developed an MPV-specific probe that differentiates MPV from other OPVs in the N1R LAMP assay. In addition, we described an extraction-free protocol for use directly with swab eluates in LAMP assays, thereby eliminating the time and resources needed to extract DNA from the sample. Our direct LAMP assays are well-suited for low-resource settings and provide a valuable tool for rapid and scalable diagnosis and surveillance of OPVs and MPV.

Recombinase Polymerase Amplification-Based Biosensors for Rapid Zoonoses Screening

Recent, outbreaks of new emergency zoonotic diseases have prompted an urgent need to develop fast, accurate, and portable screening assays for pathogen infections. Recombinase polymerase amplification (RPA) is sensitive and specific and can be conducted at a constant low temperature with a short response time, making it especially suitable for on-site screening and making it a powerful tool for preventing or controlling the spread of zoonoses. This review summarizes the design principles of RPA-based biosensors as well as various signal output or readout technologies involved in fluorescence detection, lateral flow assays, enzymatic catalytic reactions, spectroscopic techniques, electrochemical techniques, chemiluminescence, nanopore sequencing technologies, microfluidic digital RPA, and clustered regularly interspaced short palindromic repeats/CRISPR-associated systems. The current status and prospects of the application of RPA-based biosensors in zoonoses screening are highlighted. RPA-based biosensors demonstrate the advantages of rapid response, easy-to-read result output, and easy implementation for on-site detection, enabling development toward greater portability, automation, and miniaturization. Although there are still problems such as high cost with unstable signal output, RPA-based biosensors are increasingly becoming one of the most important means of on-site pathogen screening in complex samples involving environmental, water, food, animal, and human samples for controlling the spread of zoonotic diseases.

Rapid detection of monkeypox virus using a CRISPR-Cas12a mediated assay: a laboratory validation and evaluation study

BACKGROUND

The 2022 outbreak of mpox (formerly known as monkeypox) led to the spread of monkeypox virus (MPXV) in over 110 countries, demanding effective disease management and surveillance. As current diagnostics rely largely on centralised laboratory testing, our objective was to develop a simple rapid point-of-care assay to detect MPXV in clinical samples using isothermal amplification coupled with CRISPR and CRISPR-associated protein (Cas) technology.

METHODS

In this proof-of-concept study, we developed a portable isothermal amplification CRISPR-Cas12a-based assay for the detection of MPXV. We designed a panel of 22 primer-guide RNA sets using pangenome and gene-agnostic approaches, and subsequently shortlisted the three sets producing the strongest signals for evaluation of analytical sensitivity and specificity using a fluorescence-based readout. The set displaying 100% specificity and the lowest limit of detection (LOD) was selected for further assay validation using both a fluorescence-based and lateral-flow readout. Assay specificity was confirmed using a panel of viral and bacterial pathogens. Finally, we did a blind concordance study on genomic DNA extracted from 185 clinical samples, comparing assay results with a gold-standard quantitative PCR (qPCR) assay. We identified the optimal time to detection and analysed the performance of the assay relative to qPCR using receiver operating characteristic (ROC) curves. We also assessed the compatibility with lateral-flow strips, both visually and computationally, where strips were interpreted blinded to the fluorescence results on the basis of the presence or absence of test bands.

FINDINGS

With an optimal run duration of approximately 45 min from isothermal amplification to CRISPR-assay readout, the MPXV recombinase polymerase amplification CRISPR-Cas12a-based assay with the selected primer-guide set had an LOD of 1 copy per μL and 100% specificity against tested viral pathogens. Blinded concordance testing of 185 clinical samples resulted in 100% sensitivity (95% CI 89·3-100) and 99·3% specificity (95% CI 95·7-100) using the fluorescence readout. For optimal time to detection by fluorescence readout, we estimated the areas under the ROC curve to be 0·98 at 2 min and 0·99 at 4 min. Lateral-flow strips had 100% sensitivity (89·3-100) and 98·6% specificity (94·7-100) with both visual and computational assessment. Overall, lateral-flow results were highly concordant with fluorescence-based readouts (179 of 185 tests, 96·8% concordant), with discrepancies associated with low viral load samples.

INTERPRETATION

Our assay for the diagnosis of mpox displayed good performance characteristics compared with qPCR. Although optimisation of the assay will be required before deployment, its usability and versatility present a potential solution to MPXV detection in low-resource and remote settings, as well as a means of community-based, on-site testing.

FUNDING

Victorian Medical Research Accelerator Fund and the Australian Government Department of Health.

Establishment and Application of CRISPR-Cas12a-Based Recombinase Polymerase Amplification and a Lateral Flow Dipstick and Fluorescence for the Detection and Distinction of Deformed Wing Virus Types A and B

Deformed wing virus (DWV) is one of the important pathogens of the honey bee (Apis mellifera), which consists of three master variants: types A, B, and C. Among them, DWV types A (DWV-A) and B (DWV-B) are the most prevalent variants in honey bee colonies and have been linked to colony decline. DWV-A and DWV-B have different virulence, but it is difficult to distinguish them via traditional methods. In this study, we established a visual detection assay for DWV-A and DWV-B using recombinase polymerase amplification (RPA) and a lateral flow dipstick (LFD) coupled with the clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein (Cas) 12a fluorescence system (RPA-CRISPR-Cas12a-LFD). The limit of detection of this system was ~6.5 × 100 and 6.2 × 101 copies/μL for DWV-A and DWV-B, respectively. The assays were specific and non-cross-reactive against other bee viruses, and the results could be visualized within 1 h. The assays were validated by extracting cDNA from 36 clinical samples of bees that were suspected to be infected with DWV. The findings were consistent with those of traditional reverse transcription-quantitative polymerase chain reaction, and the RPA-CRISPR-Cas12a assay showed the specific, sensitive, simple, and appropriate detection of DWV-A and DWV-B. This method can facilitate the visual and qualitative detection of DWV-A and DWV-B as well as the monitoring of different subtypes, thereby providing potentially better control and preventing current and future DWV outbreaks.

Monitoring Monkeypox: Safeguarding Global Health through Rapid Response and Global Surveillance

Monkeypox, a viral zoonotic disease, has emerged as a significant global threat in recent years. This review focuses on the importance of global monitoring and rapid response to monkeypox outbreaks. The unpredictable nature of monkeypox transmissions, its potential for human-to-human spread, and its high morbidity rate underscore the necessity for proactive surveillance systems. By analyzing the existing literature, including recent outbreaks, this review highlights the critical role of global surveillance in detecting, containing, and preventing the further spread of monkeypox. It also emphasizes the need for enhanced international collaboration, data sharing, and real-time information exchange to effectively respond to monkeypox outbreaks as a global health concern. Furthermore, this review discusses the challenges and opportunities of implementing robust surveillance strategies, including the use of advanced diagnostic tools and technologies. Ultimately, these findings underscore the urgency of establishing a comprehensive global monitoring framework for monkeypox, enabling early detection, prompt response, and effective control measures to protect public health worldwide.

Development of a specific MPXV antigen detection immunodiagnostic assay

Human monkeypox (mpox) has recently become a global public health emergency; however, assays that detect mpox infection are not widely available, largely due to cross-reactivity within the Orthopoxvirus genus. Immunoassay development was largely confined to researchers who focus on biothreats and endemic areas (Central and West Africa) until the 2022 outbreak. As was noted in the COVID-19 pandemic, antigen detection assays, integrated with molecular assays, are necessary to help curb the spread of disease. Antigen-detecting immunoassays offer the advantage of providing results ranging from within min to h and in lateral flow formats; they can be deployed for point-of-care, home, or field use. This study reports the development of an mpox-specific antigen detection immunoassay developed on a multiplexed, magnetic-bead-based platform utilizing reagents from all research sectors (commercial, academic, and governmental). Two semi-quantitative assays were developed in parallel and standardized with infectious mpox virus (MPXV) cell culture fluid and MPXV-positive non-human primate (NHP) sera samples. These assays could detect viral antigens in serum, were highly specific toward MPXV as compared to other infectious orthopoxviruses (vaccinia virus, cowpox virus, and camelpox virus), and exhibited a correlation with quantitative PCR results from an NHP study. Access to a toolbox of assays for mpox detection will be key for identifying cases and ensuring proper treatment, as MPXV is currently a global traveler.

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.

Development of Enzymatic Recombinase Amplification Assays for the Rapid Visual Detection of HPV16/18

Human papillomavirus (HPV) types 16 and 18 are the major causes of cervical lesions and are associated with 71% of cervical cancer cases globally. However, public health infrastructures to support cervical cancer screening may be unavailable to women in low-resource areas. Therefore, sensitive, convenient, and cost-efficient diagnostic methods are required for the detection of HPV16/18. Here, we designed two novel methods, real-time ERA and ERA-LFD, based on enzymatic recombinase amplification (ERA) for quick point-of-care identification of the HPV E6/E7 genes. The entire detection process could be completed within 25 min at a constant low temperature (35-43°C), and the results of the combined methods could be present as the amplification curves or the bands presented on dipsticks and directly interpreted with the naked eye. The ERA assays evaluated using standard plasmids carrying the E6/E7 genes and clinical samples exhibited excellent specificity, as no cross-reaction with other common HPV types was observed. The detection limits of our ERA assays were 100 and 101 copies/μl for HPV16 and 18 respectively, which were comparable to those of the real-time PCR assay. Assessment of the clinical performance of the ERA assays using 114 cervical tissue samples demonstrated that they are highly consistent with real-time PCR, the gold standard for HPV detection. This study demonstrated that ERA-based assays possess excellent sensitivity, specificity, and repeatability for HPV16 and HPV18 detection with great potential to become robust diagnostic tools in local hospitals and field studies.

Mpox: a review of laboratory detection techniques

Mpox (formerly monkeypox) is a zoonotic disease caused by monkeypox virus (MPXV), which, like smallpox, is characterised by skin rashes. While the world is currently grappling with the coronavirus disease 2019 pandemic, the appearance of MPXV has presented a global threat and raised concerns worldwide. Since May 2022, MPXV has spread rapidly in non-endemic mpox areas. As of 27 June 2023, the virus has spread to more than 112 countries and regions, with over 88,060 laboratory-confirmed cases and 147 deaths. Thus, measures to control the mpox epidemic are urgently needed. As the principal methods for identifying and monitoring mpox, laboratory detection techniques play an important role in mpox diagnosis. This review summarises the currently-used laboratory techniques for MPXV detection, discusses progress in improving these methods, and compares the benefits and limitations of various diagnostic detection methods. Currently, nucleic acid amplification tests, such as the polymerase chain reaction, are the most commonly used. Immunological methods have also been applied to diagnose the disease, which can help us discover new features of MPXV, improve diagnostic accuracy, track epidemic trends, and guide future prevention and control strategies, which are also vital for controlling mpox epidemics. This review provides a resource for the scientific community and should stimulate more research and development in alternative diagnostics to be applied to this and future public health crises.

The prospective outcome of the monkeypox outbreak in 2022 and characterization of monkeypox disease immunobiology

A new threat to global health re-emerged with monkeypox's advent in early 2022. As of November 10, 2022, nearly 80,000 confirmed cases had been reported worldwide, with most of them coming from places where the disease is not common. There were 53 fatalities, with 40 occurring in areas that had never before recorded monkeypox and the remaining 13 appearing in the regions that had previously reported the disease. Preliminary genetic data suggest that the 2022 monkeypox virus is part of the West African clade; the virus can be transmitted from person to person through direct interaction with lesions during sexual activity. It is still unknown if monkeypox can be transmitted via sexual contact or, more particularly, through infected body fluids. This most recent epidemic's reservoir host, or principal carrier, is still a mystery. Rodents found in Africa can be the possible intermediate host. Instead, the CDC has confirmed that there are currently no particular treatments for monkeypox virus infection in 2022; however, antivirals already in the market that are successful against smallpox may mitigate the spread of monkeypox. To protect against the disease, the JYNNEOS (Imvamune or Imvanex) smallpox vaccine can be given. The spread of monkeypox can be slowed through measures such as post-exposure immunization, contact tracing, and improved case diagnosis and isolation. Final Thoughts: The latest monkeypox epidemic is a new hazard during the COVID-19 epidemic. The prevailing condition of the monkeypox epidemic along with coinfection with COVID-19 could pose a serious condition for clinicians that could lead to the global epidemic community in the form of coinfection.

Creating an ultra-sensitive detection platform for monkeypox virus DNA based on CRISPR technology

The recent major worldwide outbreak of monkeypox virus (MPXV) has highlighted the urgent need for accurate MPXV detection methods. Although quantitative PCR (qPCR) technique is currently the gold standard for MPXV diagnosis, the high costs associated with the technique and the need for complex instrumentation, limits its application in resource-poor settings. CRISPR technology has developed rapidly in recent years and provides an effective tool for point-of-care testing pathogen identification. Here, we exploited the cleavage properties of the Cas12a enzyme and Cas13a enzyme, to detect the MPXV specific genes, F3L gene and B6R gene, respectively. We developed two detection protocols: a 2-step method in which the CRISPR Dual System reaction and the multiplex recombinase polymerase amplification reaction were carried out in separate tubes and a single-tube method in which both reactions were carried out in one tube. Evaluation of the two methods showed that our protocol can detect the MPXV genome down to 10° copies/μL with good specificity and no cross-reactivity with other poxviruses pseudoviruses, and bacteria. Mock positive samples were used to assess clinical applicability, with the results showing satisfactory concordance with the qPCR method for parallel testing. In conclusion, our study provides a reliable molecular diagnostic strategy for detection of MPXV.

Monkeypox vaccination in the global south: Fighting a war without a weapon

Background

The Mpox outbreak awakened countries worldwide to renew efforts in epidemiological surveillance and vaccination of susceptible populations. In terms of Mpox vaccination, various challenges exist in the global south, which impede adequate vaccine coverage, especially in Africa. This paper reviewed the situation of Mpox vaccination in the global south and potential ameliorative approaches.

Methods

A review of online literature from PubMed and Google Scholar concerning Mpox vaccination in countries belonging to the 'global south' category was done between August and September, 2022. The major focus areas included inequity in global vaccine distribution, challenges impeding vaccine coverage in the global south, and potential strategies for bridging the gap in vaccine equity. The papers that met the inclusion criteria were collated and narratively discussed.

Results

Our analysis revealed that, while the high-income countries secured large supplies of the Mpox vaccines, the low- and middle-income countries were unable to independently access substantial quantities of the vaccine and had to rely on vaccine donations from high-income countries, as was the case during the COVID-19 pandemic. The challenges in the global south particularly revolved around inadequate vaccine production capacity due to lack of qualified personnel and specialized infrastructure for full vaccine development and manufacturing, limited cold chain equipment for vaccine distribution, and consistent vaccine hesitancy.

Conclusion

To tackle the trend of vaccine inequity in the global south, African governments and international stakeholders must invest properly in adequate production and dissemination of Mpox vaccines in low- and middle-income countries.

Rapid, sensitive, and highly specific detection of monkeypox virus by CRISPR-based diagnostic platform

Background

Monkeypox (MPX), caused by the Monkeypox virus (MPXV), has incurred global attention since it broke out in many countries in recent times, which highlights the need for rapid and reliable diagnosis of MPXV infection.

Methods

We combined recombinase polymerase amplification (RPA) with CRISPR/Cas12a-based detection to devise a diagnostic test for detection of MPXV and differentiation of its two clades [Central Africa clade (MPXV-CA) and West Africa clade (MPXV-WA)], and called it MPXV-RCC. The sensitivity, specificity and practicability of this method have been analyzed.

Results

The optimal conditions of MPXV-RCC assay include two RPA reactions at 38°C for 25 min and a CRISPR/Cas12a-gRNA detection at 37°C for 10 min. The results of MPXV-RCC assay were indicated by a real-time fluorescence analysis software. Thus, the whole detection process, including rapid template preparation (20 min), RPA reaction (25 min) and CRISPR-based detection (10 min), could be finished within 1 hour. The sensitivity of MPXV-RCC for MPXV-CA and MPXV-WA detection was down to 5~10 copies of recombination plasmids and pseudovirus per reaction. Particularly, MPXV-RCC assay could clearly differentiate MPXV-CA from MPXV-WA, and had no cross-reactivity with other pathogens. In addition, the feasibility of MPXV-RCC assay was further validated by using spiked clinical samples.

Conclusion

The MPXV-RCC assay developed here is a promising tool for quick and reliable diagnosis of MPXV infection.

Clinical and laboratory diagnosis of monkeypox (mpox): Current status and future directions

The emergence and rapid spread of the monkeypox virus (MPXV) to non-endemic countries has brought this once obscure pathogen to the forefront of global public health. Given the range of conditions that cause similar skin lesions, and because the clinical manifestation may often be atypical in the current mpox outbreak, it can be challenging to diagnose patients based on clinical signs and symptoms. With this perspective in mind, laboratory-based diagnosis assumes a critical role for the clinical management, along with the implementation of countermeasures. Here, we review the clinical features reported in mpox patients, the available laboratory tests for mpox diagnosis, and discuss the principles, advances, advantages, and drawbacks of each assay. We also highlight the diagnostic platforms with the potential to guide ongoing clinical response, particularly those that increase diagnostic capacity in low- and middle-income countries. With the outlook of this evolving research area, we hope to provide a resource to the community and inspire more research and the development of diagnostic alternatives with applications to this and future public health crises.

Global transmission of monkeypox virus-a potential threat under the COVID-19 pandemic

Monkeypox virus (MPXV) cases have increased dramatically worldwide since May 2022. The Atlanta Center for Disease Control and Prevention (Atlanta CDC) had reported a total of 85,922 cases as of February 20^th, 2023. During the COVID-19 pandemic, MPXV has emerged as a potential public threat. MPXV transmission and prevalence must be closely monitored. In this comprehensive review, we explained the basic characteristics and transmission routes of MPXV, individuals susceptible to it, as well as highlight the impact of the behavior of men who have sex with men (MSM) and airline traveling on recent outbreaks of MPXV. We also describe the clinical implications, the prevention of MPXV, and clinical measures of viral detection.

Development of a CRISPR/Cas12a-recombinase polymerase amplification assay for visual and highly specific identification of the Congo Basin and West African strains of mpox virus

Human mpox is a zoonotic disease, similar to smallpox, caused by the mpox virus, which is further subdivided into Congo Basin and West African clades with different pathogenicity. In this study, a novel diagnostic protocol utilizing clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated 12a nuclease (CRISPR/Cas12a)-mediated recombinase polymerase amplification (RPA) was developed to identify mpox in the Congo Basin and West Africa (CRISPR-RPA). Specific RPA primers targeting D14L and ATI were designed. CRISPR-RPA assay was performed using various target templates. In the designed CRISPR-RPA reaction system, the exponentially amplified RPA amplification products with a protospacer adjacent motif (PAM) site can locate the Cas12a/crRNA complex to its target regions, which successfully activates the CRISPR/Cas12a effector and achieves ultrafast trans-cleavage of a single-stranded DNA probe. The limit of detection for the CRISPR-RPA assay was 10 copies per reaction for D14L- and ATI-plasmids. No cross-reactivity was observed with non-mpox strains, confirming the high specificity of the CRISPR-RPA assay for distinguishing between the Congo Basin and West African mpox. The CRISPR-RPA assay can be completed within 45 min using real-time fluorescence readout. Moreover, the cleavage results were visualized under UV light or an imaging system, eliminating the need for a specialized apparatus. In summary, the developed CRISPR/RPA assay is a visual, rapid, sensitive, and highly specific detection technique that can be used as an attractive potential identification tool for Congo Basin and West African mpox in resource-limited laboratories.

Rapid and effective detection of Macrobrachium rosenbergii nodavirus using a combination of nucleic acid sequence-based amplification test and immunochromatographic strip

Nucleic acid sequence-based amplification (NASBA) provides a fast and convenient approach for nucleic acid amplification under isothermal conditions, and its combination with an immunoassay-based lateral flow dipstick (LFD) could produce a higher detection efficiency for M. rosenbergii nodavirus isolated from China (MrNV-chin). In this study, two specific primers and a labelled probe of the capsid protein gene of MrNV-chin were constructed. The process of this assay mainly included a single-step amplification at a temperature of 41 ℃ for 90 min, and hybridization with an FITC-labeled probe for 5 min, with the hybridization been required for visual identification during LFD assay. The test results indicated that, the NASBA-LFD assay showed sensitivity for 1.0 fg M. rosenbergii total RNA with MrNV-chin infection, which was 10⁴ times that of the present RT-PCR approach for the detection of MrNV. In addition, no products were created for shrimps with infection of other kinds of either DNA or RNA virus, which indicated that the NASBA-LFD was specific for MrNV. Therefore, the combination of NASBA and LFD is a new alternative detection method for MrNV which is rapid, accurate, sensitive and specific without expensive equipment and specialised personnel. Early detection of this infectious disease among aquatic organisms will help implement efficient therapeutic strategy to prevent its spread, enhance animal health and limit loss of aquatic breeds in the event of an outbreak.

Ultrasensitive and Specific Identification of Monkeypox Virus Congo Basin and West African Strains Using a CRISPR/Cas12b-Based Platform

Human monkeypox (MPX) is a severe and reemerging infectious disease caused by monkeypox virus (MPXV) and forms two distinct lineages, including Congo Basin and West African clades. Due to the absence of specific vaccines and antiviral drugs, developing a point-of-care (POC) testing system to identify MPXV is critical for preventing and controlling MPX transmission. Here, a CRISPR/Cas12b diagnostic platform was integrated with loop-mediated isothermal amplification (LAMP) to devise a novel CRISPR-MPXV approach for ultrasensitive, highly specific, rapid, and simple detection of MPXV Congo Basin and West African strains, and the detection results were interpreted with real-time fluorescence and a gold nanoparticle-based lateral flow biosensor (AuNP-LFB). The optimal detection process, including genomic DNA extraction (15 min), LAMP preamplification (35 min at 66°C), CRISPR/Cas12b-based detection (5 min at 45°C), and AuNP-LFB readout (~2 min), can be completed within 60 min without expensive instruments. Our assay has a limit of detection of 10 copies per test and produces no cross-reaction with any other types of pathogens. Hence, our CRISPR-MPXV assay exhibited considerable potential for POC testing for identifying and distinguishing MPXV Congo Basin and West African strains, especially in regions with resource shortages. IMPORTANCE Monkeypox (MPX), a reemerging zoonotic disease caused by monkeypox virus (MPXV), causes a smallpox-like disease in humans. Early diagnosis is critical to prevent MPX epidemics. Here, CRISPR/Cas12b was integrated with LAMP amplification to devise a novel CRISPR-MPXV approach to achieve highly specific, ultrasensitive, rapid, and visual identification of MPXV Congo Basin and West African strains.

Nanomedicine as a Potential Tool against Monkeypox

Human monkeypox is a rare viral zoonosis that was first identified in 1970; since then, this infectious disease has been marked as endemic in central and western Africa. The disease has always been considered rare and self-limiting; however, recent worldwide reports of several cases suggest otherwise. Especially with monkeypox being recognized as the most important orthopoxvirus infection in humans in the smallpox post-eradication era, its spread across the globe marks a new epidemic. Currently, there is no proven treatment for human monkeypox, and questions about the necessity of developing a vaccine persist. Notably, if we are to take lessons from the COVID-19 pandemic, developing a nanomedicine-based preventative strategy might be prudent, particularly with the rapid growth of the use of nanotechnology and nanomaterials in medical research. Unfortunately, the collected data in this area is limited, dispersed, and often incomplete. Therefore, this review aims to trace all reported nanomedicine approaches made in the monkeypox area and to suggest possible directions that could be further investigated to develop a counteractive strategy against emerging and existing viruses that could diminish this epidemic and prevent it from becoming a potential pandemic, especially with the world still recovering from the COVID-19 pandemic.

Molecular detection of monkeypox and related viruses: challenges and opportunities

The recent widespread emergence of monkeypox (mpox), a rare and endemic zoonotic disease by monkeypox virus (MPXV), has made global headlines. While transmissibility (R₀ ≈ 0.58) and fatality rate (0-3%) are low, as it causes prolonged morbidity, the World Health Organization has declared monkeypox as a public health emergency of international concern. Thus, effective containment and disease management require quick and efficient detection of MPXV. In this bioinformatic overview, we summarize the numerous molecular tests available for MPXV, and discuss the diversity of genes and primers used in the polymerase chain reaction-based detection. Over 90 primer/probe sets are used for the detection of poxviruses. While hemagglutinin and A-type inclusion protein are the most common target genes, tumor necrosis factor receptor and complement binding protein genes are frequently used for distinguishing Clade I and Clade II of MPXV. Problems and possibilities in the detection of MPXV have been discussed.

Development of rapid nucleic acid assays based on the recombinant polymerase amplification for monkeypox virus

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Two RPA methods (F-RPA and VF- RPA) have been developed for monkeypox virus rapid detection.

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The limit of detection was 15.32 copies/μL for F-RPA and 8.53 copies/μL for VF-RPA.

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No cross-reaction was found in 14 rash and fever-associated viruses.

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The two RPA methods are simple and rapid, making them potentially useful for detection of MPXV in the field/clinic.

Rapid detection of monkeypox virus by multiple cross displacement amplification combined with nanoparticle-based biosensor platform

The current outbreak of monkeypox virus (MPXV) has become a public health emergency of international concern that highlights the need for rapid, sensitive MPXV diagnostic assays. Here, we combined isothermal multiple cross displacement amplification (MCDA) with nanoparticle-based lateral flow biosensor (LFB) to devise a diagnostic test for the diagnosis of MPXV infection (called MPXV-MCDA-LFB) and differentiation of West and Central African MPXV isolates. The MPXV-MCDA-LFB protocol conducts isothermal MCDA reaction for DNA templates followed by LFB detection of preamplification target sequences. Two MCDA primer sets were designed targeting the D41L and ATI genes of Central and West African MPXV isolates, respectively, and the optimal condition of two MCDA reactions was 64°C for 30 min. The two MCDA reactions were decoded by LFB, which was devised for detecting three targets, including two amplicons yielded from two MCDA reactions and a chromatography control. Thus, the MPXV-MCDA-LFB assay could be completed within 50 min including rapid template preparation (15 min), MCDA reaction (30 min) and reporting of result (<5 min). The MPXV-MCDA-LFB method is very sensitive and can detect the target genes (D14L and ATI) with as low as five copies of plasmid template per reaction and 12.5 copies of pseudotyped virus in human blood samples. The MPXV-MCDA-LFB assay does not cross-react with non-MPXV templates, validating its specificity. Therefore, the MPXV-MCDA-LFB assay developed here is a useful tool for rapid and reliable diagnosis of MPXV infection.

Useful public health countermeasures to control the current multicountry outbreak of Monkeypox disease

Monkeypox is a viral disease endemic to some countries in Central and Western Africa. However, sporadic human cases have also been reported outside of Africa. The first human case was reported in 1970 in the Democratic Republic of Congo. Very similar to the eradicated smallpox regarding its clinical representation, the Monkeypox disease is most common in children aged between 5 and 9 years with a fatality rate ranging from 1 to 11% in Africa. During the past decade, the number of countries that reported human cases of the disease grew significantly, while experts still sought knowledge on the characteristics of the virus. The recent increase in Monkeypox cases in many countries raises the concern about a possible global health threat. There is a need to subsequently provide insights into the incidence of Monkeypox disease and come up with mechanisms to prevent its emergence and contain its spread. Furthermore, it is crucial to have a better view of the global diagnostic capacity of the Monkeypox virus. This review aims to assess useful public health countermeasures to control the current multicountry outbreak of Monkeypox disease. Articles were searched in PubMed and Google Scholar electronic databases on 30 June 2022, using selected keywords, without language and date restriction. A total of 44 scientific records were published between 1 January 1962 and 30 June 2022. Herein, we discuss the epidemiological and public health situation at a global scale, provide an updated overview and data of utility for a better understanding of knowledge and research gaps in the epidemiology of the Monkeypox disease, and give useful measures for controlling the current multicountry outbreak.

Construction a novel detection method for Trichomonas vaginalis based on recombinant enzyme polymerase amplification targeting the Actin gene

Trichomoniasis is a common and curable sexually transmitted disease worldwide. The rapid, convenient, and accurate diagnosis of trichomoniasis is an important link in the prevention and treatment of the disease. The current detection methods of Trichomonas vaginalis are mainly wet mount microscopy, culture, nested PCR, and loop-mediated isothermal amplification. However, these detection methods have some shortcomings. In this study, a recombinant enzyme polymerase amplification (RPA) assay had been conducted to detect T. vaginalis. The target gene and the corresponding primers were screened, and the reaction system and conditions were optimized in the assay of RPA. The sensitivity and specificity of this detection method were analyzed. The detection efficiency of wet mount microscopy, culture, nested PCR, and RPA was compared by testing 53 clinical samples from vaginal secretions. By screening, the actin gene of T. vaginalis could be used as a target gene for RPA detection of T. vaginalis, and the optimum reaction condition to amplify the actin gene by RPA was at 39°C for 30 min. The detection limit of T. vaginalis DNA using RPA was 1 pg, corresponding to a sensitivity of approximately five trophozoites. The RPA assay demonstrated high specificity for T. vaginalis, and there was no cross-reactivity with Giardia lamblia, Escherichia coli, Lactobacillus, Toxoplasma gondii, Staphylococcus aureus, and Candida albicans. Of the 53 clinical samples, the positive rates of T. vaginalis detected by wet mount microscopy, culture, nested PCR and RPA were 50.9 4% (27/53), 71.7% (38/53), 71.7% (38/53), and 69.81% (37/53), respectively. Compared with culture which was used as the gold standard for diagnosing trichomoniasis, testing clinical samples by wet mount microscopy showed 71.05% sensitivity, 100% specificity, and moderate diagnostic agreement with the culture (K = 0.581, Z = 4.661, p < 0.001). The nested PCR showed 100% sensitivity, 100% specificity, and excellent diagnostic agreement (K = 1, Z = 7.28, p < 0.001), while RPA displayed 97.37% sensitivity, 100% specificity, and excellent diagnostic agreement (K = 0.954, Z = 6.956, p < 0.001). At the present study, rapid amplification of actin gene by RPA could be used as a tool for detection of T. vaginalis. The detection method of RPA was more sensitive than wet mount microscopy and displayed excellent specificity. Moreover, RPA amplification of actin gene did not require a PCR instrument and the amplification time was shorter than that of ordinary PCR. Therefore, the RPA assay was proposed in this study as a point-of-care examination and a diagnostic method of T. vaginalis infection, which exhibited the potential value in the treatment and prevention of trichomoniasis.

Rapid detection of mpox virus using recombinase aided amplification assay

A recent, unprecedented outbreak of human mpox virus infection has led to cases in non-African nations, and the number of confirmed or suspected cases outside of Africa has exceeded 1,000 within 5 weeks. Mpox may pose a double threat to public health in the context of the ongoing COVID-19 pandemic. It is difficult to distinguish mpox virus infection from other diseases in the early stages, and patients are contagious from the onset of nonspecific symptoms; therefore, it is crucial to develop rapid and specific diagnostic methods. The diagnosis of mpox relies on real-time polymerase chain reaction, a time-consuming method that requires a highly sophisticated thermal cycler, which makes it unsuitable for widespread use in underdeveloped areas, where the outbreak is still severe. In this study, we developed a recombinase-aided amplification (RAA) assay that can detect mpox virus within 5-10 minutes. The conserved regions of the A27L gene and F3L gene were selected as targets, as they amplify well from different mpox virus clades with no cross-reaction from other pathogens. The sensitivity of this RAA assay is 10 copies/reaction for the A27L gene and 10² copies/reaction for the F3L gene. When applied to simulated clinical samples, both targets showed 100% specificity, and the detection limits were consistent with the sensitivity results. Moreover, through clinical blinded sample detection, RAA exhibits the same detection power as RT-PCR. In summary, the RAA mpox assay described here exhibits rapid detection, high sensitivity and specificity, and low operational difficulty, making it suitable for mpox virus detection in less developed countries and regions.

CRISPR-Cas12-based field-deployable system for rapid detection of synthetic DNA sequence of the monkeypox virus genome

The global outbreak of the monkeypox virus (MPXV) highlights the need for rapid and cost-effective MPXV detection tools to effectively monitor and control the monkeypox disease. Herein, we demonstrated a portable CRISPR-Cas-based system for naked-eye detection of MPXV. The system harnesses the high selectivity of CRISPR-Cas12 and the isothermal nucleic acid amplification potential of recombinase polymerase amplification. It can detect both the current circulating MPXV clade and the original clades. We reached a limit of detection (LoD) of 22.4 aM (13.5 copies/µl) using a microtiter plate reader, while the visual LoD of the system is 75 aM (45 copies/µl) in a two-step assay, which is further reduced to 25 aM (15 copies/µl) in a one-pot system. We compared our results with quantitative polymerase chain reaction and obtained satisfactory consistency. For clinical application, we demonstrated a sensitive and precise visual detection method with attomolar sensitivity and a sample-to-answer time of 35 min.

The pathophysiological and immunological background of the monkeypox virus infection: An update

In addition to the COVID-19 waves, the globe is facing global monkeypox (MPX) outbreak. MPX is an uncommon zoonotic infection characterized by symptoms similar to smallpox. It is caused by the monkeypox virus (MPXV), a double-stranded DNA virus that belongs to the genus Orthopoxvirus (OPXV). MPXV, which causes human disease, has been confined to Africa for many years, with only a few isolated cases in other areas. Outside of Africa, the continuing MPXV outbreak in multiple countries in 2022 is the greatest in recorded history. The current outbreak, with over 10 000 confirmed cases in over 50 countries between May and July 2022, demonstrates that MPXV may travel rapidly among humans and pose a danger to human health worldwide. The rapid spread of such outbreaks in recent times has elevated MPX to the status of a rising zoonotic disease with significant epidemic potential. While the MPXV is not as deadly or contagious as the variola virus that causes smallpox, it poses a threat because it could evolve into a more potent human pathogen. This review assesses the potential threat to the human population and provides a brief overview of what is currently known about this reemerging virus. By analyzing the biological effects of MPXV on human health, its shifting epidemiological footprint, and currently available therapeutic options, this review has presented the most recent insights into the biology of the virus. This study also clarifies the key potential causes that could be to blame for the present MPX outbreak and draw attention to major research questions and promising new avenues for combating the current MPX epidemic.

Mpox diagnostics: Review of current and emerging technologies

Mpox is a zoonotic disease caused by monkeypox virus (MPXV) from the Orthopoxvirus genus. Unprecedented transmission events have led to more than 70 000 cases reported worldwide by October 2022. The change in mpox epidemiology has raised concerns of its ability to establish endemicity beyond its traditional geographical locations. In this review, we discuss the current understanding of mpox virology and viral dynamics that are relevant to mpox diagnostics. A synopsis of the traditional and emerging laboratory technologies useful for MPXV detection and in guiding "elimination" strategies is outlined in this review. Importantly, development in MPXV genomics has rapidly advanced our understanding of the role of viral evolution and adaptation in the current outbreak.