Exotic viral hepatitis: A review on epidemiology, pathogenesis, and treatment.

Certain "exotic" viruses are known to cause clinical diseases with potential liver involvement. These include viruses, beyond regular hepatotropic viruses (hepatitis A, -B(D), -C, -E, cytomegalovirus, Epstein-Barr virus), that can be found in (sub)tropical areas and can cause "exotic viral hepatitis". Transmission routes typically involve arthropods (Crimean Congo haemorrhagic fever, dengue, Rift Valley fever, yellow fever). However, some of these viruses are transmitted by the aerosolised excreta of rodents (Hantavirus, Lassa fever), or via direct contact or contact with bodily fluids (Ebola). Although some exotic viruses are associated with high fatality rates, such as Ebola for example, the clinical presentation of most exotic viruses can range from mild flu-like symptoms, in most cases, right through to being potentially fatal. A smaller percentage of people develop severe disease with haemorrhagic fever, possibly with (fulminant) hepatitis. Liver involvement is often caused by direct tropism for hepatocytes and Kupffer cells, resulting in virus-mediated and/or immune-mediated necrosis. In all exotic hepatitis viruses, PCR is the most sensitive diagnostic method. The determination of IgM/IgG antibodies is a reasonable alternative, but cross-reactivity can be a problem in the case of flaviviruses. Licenced vaccines are available for yellow fever and Ebola, and they are currently under development for dengue. Therapy for exotic viral hepatitis is predominantly supportive. To ensure that preventive measures can be introduced to control possible outbreaks, the timely detection of these viruses is very important.

Program Planning to Develop Infrastructure for Cancer Care in Liberia.

Liberia's health infrastructure was completely devastated after 14 years of back-to-back civil war. Postconflict rebuilding of the country's health workforce and infrastructure has become a priority. Initially, the focus was on the diagnosis and treatment of communicable diseases that caused multigenerational family losses. With the increasing burden of noncommunicable diseases, however, the country has turned its attention to addressing diabetes, cancer, and cardiovascular and respiratory diseases, with the development of the noncommunicable disease unit under the Ministry of Health. Recovering from another setback caused by the Ebola virus outbreak in 2014, the country assembled a diverse group of stakeholders to form Liberia's first National Cancer Committee. To structure a program that would address the increasing burden of cervical and breast cancers, the major cause of mortality among reproductive-aged women in Liberia, input from the International Atomic Energy Agency was critical. This article describes the preplanning activities for developing infrastructure to support cancer care in Liberia that occurred between 2013 and 2020 and is still ongoing. This case study is intended to serve as a planning guide for countries with limited resources as they work toward the goal of eliminating cervical cancer and developing infrastructure to address their country's burden of all cancers.

Screening at ports of entry for Ebola Virus Disease in England-a descriptive analysis of screening assessment data, 2014-2015.

BACKGROUND: In response to the outbreak of Ebola Virus Disease (EVD) in West Africa in 2014 and evidence of spread to other countries, pre-entry screening was introduced by PHE at five major ports of entry in the England. METHODS: All passengers that entered the England via the five ports returning from Liberia, Guinea and Sierra Leonne were required to complete a Health Assessment Form and have their temperature taken. The numbers, characteristics and outcomes of these passengers were analysed. RESULTS: Between 14 October 2014 and 13 October 2015, a total of 12 648 passengers from affected countries had been screened. The majority of passengers were assessed as having no direct contact with EVD cases or high-risk events (12 069, 95.4%), although 535 (4.2%) passengers were assessed as requiring public health follow-up. In total, 39 passengers were referred directly to secondary care, although none were diagnosed with EVD. One high-risk passenger was later referred to secondary care and diagnosed with EVD. CONCLUSIONS: Collection of these screening data enabled timely monitoring of the numbers and characteristics of passengers screened for EVD, facilitated resourcing decisions and acted as a mechanism to inform passengers of the necessary public health actions.

Application of pseudotyped virus particles to monitor Ebola virus and SARS-CoV-2 viral entry in human cell lines.

Experimental work on highly pathogenic viruses such as Ebola virus (EBOV) and severe acute respiratory syndrome coronavirus-2 requires high-level biosafety facilities. Here, we provide a detailed step-by-step protocol which details the production and application of replication-incompetent murine leukemia virus-based pseudotyped particles to monitor and quantify the viral entry efficiency in human cell lines under biosafety level-2 conditions. We describe the use of viral particles encoding luciferase gene and the quantification of transduction efficiency by measuring luciferase activity. For complete details on the use and execution of this protocol, please refer to Imre et al. (2021).

Simultaneous detection of Marburg virus and Ebola virus with TaqMan-based multiplex real-time PCR method.

BACKGROUND: Marburg virus (MARV) and Ebola virus (EBOV) are acute infections with high case fatality rates. It is of great significance for epidemic monitoring and prevention and control of infectious diseases by the development of a rapid, specific, and sensitive quantitative PCR method to detect two pathogens simultaneously. METHODS: Primers and TaqMan probes were designed according to highly conserved sequences of these viruses. Sensitivity, specificity, linear range, limit of detection, and the effects of hemolysis and lipid on real-time qPCR were evaluated. RESULTS: The linearity of the curve allowed quantification of nucleic acid concentrations in range from 103 to 109  copies/ml per reaction (MARV and EBOV). The limit of detection of EBOV was 40 copies/ml, and MARV was 100 copies/ml. It has no cross-reaction with other pathogens such as hepatitis b virus (HBV), hepatitis c virus (HCV), human papillomavirus (HPV), Epstein-Barr virus (EBV), herpes simplex virus (HSV), cytomegalovirus (CMV), and human immunodeficiency virus (HIV). Repeatability analysis of the two viruses showed that their coefficient of variation (CV) was less than 5.0%. The above results indicated that fluorescence quantitative PCR could detect EBOV and MARV sensitively and specifically. CONCLUSIONS: The TaqMan probe-based multiplex fluorescence quantitative PCR assays could detect EBOV and MARV sensitively specifically and simultaneously.

Antibody affinity as a driver of signal generation in a paper-based immunoassay for Ebola virus surveillance.

During epidemics, such as the frequent and devastating Ebola virus outbreaks that have historically plagued regions of Africa, serological surveillance efforts are critical for viral containment and the development of effective antiviral therapeutics. Antibody serology can also be used retrospectively for population-level surveillance to provide a more complete estimate of total infections. Ebola surveillance efforts rely on enzyme-linked immunosorbent assays (ELISAs), which restrict testing to laboratories and are not adaptable for use in resource-limited settings. In this manuscript, we describe a paper-based immunoassay capable of detecting anti-Ebola IgG using Ebola virus envelope glycoprotein ectodomain (GP) as the affinity reagent. We evaluated seven monoclonal antibodies (mAbs) against GP-KZ52, 13C6, 4G7, 2G4, c6D8, 13F6, and 4F3-to elucidate the impact of binding affinity and binding epitope on assay performance and, ultimately, result interpretation. We used biolayer interferometry to characterize the binding of each antibody to GP before assessing their performance in our paper-based device. Binding affinity (KD) and on rate (kon) were major factors influencing the sensitivity of the paper-based immunoassay. mAbs with the best KD (3-25 nM) exhibited the lowest limits of detection (ca. µg mL-1), while mAbs with KD > 25 nM were undetectable in our device. Additionally, and most surprisingly, we determined that observed signals in paper devices were directly proportional to kon. These results highlight the importance of ensuring that the quality of recognition reagents is sufficient to support desired assay performance and suggest that the strength of an individual's immune response can impact the interpretation of assay results.

Internet of medical things (IoMT)-integrated biosensors for point-of-care testing of infectious diseases.

On global scale, the current situation of pandemic is symptomatic of increased incidences of contagious diseases caused by pathogens. The faster spread of these diseases, in a moderately short timeframe, is threatening the overall population wellbeing and conceivably the economy. The inadequacy of conventional diagnostic tools in terms of time consuming and complex laboratory-based diagnosis process is a major challenge to medical care. In present era, the development of point-of-care testing (POCT) is in demand for fast detection of infectious diseases along with "on-site" results that are helpful in timely and early action for better treatment. In addition, POCT devices also play a crucial role in preventing the transmission of infectious diseases by offering real-time testing and lab quality microbial diagnosis within minutes. Timely diagnosis and further treatment optimization facilitate the containment of outbreaks of infectious diseases. Presently, efforts are being made to support such POCT by the technological development in the field of internet of medical things (IoMT). The IoMT offers wireless-based operation and connectivity of POCT devices with health expert and medical centre. In this review, the recently developed POC diagnostics integrated or future possibilities of integration with IoMT are discussed with focus on emerging and re-emerging infectious diseases like malaria, dengue fever, influenza A (H1N1), human papilloma virus (HPV), Ebola virus disease (EVD), Zika virus (ZIKV), and coronavirus (COVID-19). The IoMT-assisted POCT systems are capable enough to fill the gap between bioinformatics generation, big rapid analytics, and clinical validation. An optimized IoMT-assisted POCT will be useful in understanding the diseases progression, treatment decision, and evaluation of efficacy of prescribed therapy.

A Review of Piezoelectric and Magnetostrictive Biosensor Materials for Detection of COVID-19 and Other Viruses.

The spread of the severe acute respiratory syndrome coronavirus has changed the lives of people around the world with a huge impact on economies and societies. The development of wearable sensors that can continuously monitor the environment for viruses may become an important research area. Here, the state of the art of research on biosensor materials for virus detection is reviewed. A general description of the principles for virus detection is included, along with a critique of the experimental work dedicated to various virus sensors, and a summary of their detection limitations. The piezoelectric sensors used for the detection of human papilloma, vaccinia, dengue, Ebola, influenza A, human immunodeficiency, and hepatitis B viruses are examined in the first section; then the second part deals with magnetostrictive sensors for the detection of bacterial spores, proteins, and classical swine fever. In addition, progress related to early detection of COVID-19 (coronavirus disease 2019) is discussed in the final section, where remaining challenges in the field are also identified. It is believed that this review will guide material researchers in their future work of developing smart biosensors, which can further improve detection sensitivity in monitoring currently known and future virus threats.

Development of an antigen detection assay for early point-of-care diagnosis of Zaire ebolavirus.

The 2013-2016 Ebola virus (EBOV) outbreak in West Africa and the ongoing cases in the Democratic Republic of the Congo have spurred development of a number of medical countermeasures, including rapid Ebola diagnostic tests. The likelihood of transmission increases as the disease progresses due to increasing viral load and potential for contact with others. Early diagnosis of EBOV is essential for halting spread of the disease. Polymerase chain reaction assays are the gold standard for diagnosing Ebola virus disease (EVD), however, they rely on infrastructure and trained personnel that are not available in most resource-limited settings. Rapid diagnostic tests that are capable of detecting virus with reliable sensitivity need to be made available for use in austere environments where laboratory testing is not feasible. The goal of this study was to produce candidate lateral flow immunoassay (LFI) prototypes specific to the EBOV glycoprotein and viral matrix protein, both targets known to be present during EVD. The LFI platform utilizes antibody-based technology to capture and detect targets and is well suited to the needs of EVD diagnosis as it can be performed at the point-of-care, requires no cold chain, provides results in less than twenty minutes and is low cost. Monoclonal antibodies were isolated, characterized and evaluated in the LFI platform. Top performing LFI prototypes were selected, further optimized and confirmed for sensitivity with cultured live EBOV and clinical samples from infected non-human primates. Comparison with a commercially available EBOV rapid diagnostic test that received emergency use approval demonstrates that the glycoprotein-specific LFI developed as a part of this study has improved sensitivity. The outcome of this work presents a diagnostic prototype with the potential to enable earlier diagnosis of EVD in clinical settings and provide healthcare workers with a vital tool for reducing the spread of disease during an outbreak.

The Utility of a Travel Screen at Triage in Pediatric Emergency Medicine.

BACKGROUND: The travel screen was implemented by emergency departments (EDs) across the country in 2014 to detect patients exposed to Ebola early and prevent local outbreaks. It remains part of the triage protocol in many EDs to detect communicable disease from abroad and has become a defacto screen for other travel-related illness. Its utility has not been studied in the pediatric ED. METHODS: This was a retrospective review of electronic medical records across 3 EDs from January 1, 2016, to December 31, 2016. The screening question reads, "Has the child or a close contact of the child traveled outside the United States in the past 21 days?" A follow-up question requesting travel details is included for positive screens. We compared length of stay, return-visit rates, and differences in disposition between patients with positive and negative travel screens using generalized linear regression. Matched regression estimates, 95% confidence intervals, and P values were reported. RESULTS: The study population included 152,945 patients with a total of 322,229 encounters in 2016, of which 232,787 encounters had a travel screen documented during triage. There were 2258 patient encounters that had positive travel screens. Only 201 (8.9%) of these encounters had further description of the travel in the comments box. The odds of hospital admission for patients with positive travel screens were 1.76 (95% confidence interval, 1.54-2.01; P < 0.001) times the odds of hospital admission for patients screened negative. The significance of this finding was largely driven by general hospital admission. Other metrics did not differ significantly between the groups. CONCLUSIONS: Although a positive travel screen was mildly predictive of inpatient admission, information is not available to providers about travel-related risk. Recent literature suggests integrating a travel history with presenting symptoms and region of travel and could produce a more specific travel screen. A revised travel screen should be implemented and studied in the pediatric ED.

Care of Pregnant Women: Experience from a Maternity-Specific Ebola Isolation Unit in Sierra Leone.

INTRODUCTION: The Ebola virus disease epidemic was devastating to the West African region, particularly for pregnant women. Prior to the epidemic, maternal mortality in this region was among the highest in the world. Throughout the region, screening of patients with Ebola was difficult, as the symptoms of malaria or typhoid mimicked Ebola, but even more difficult for pregnant women, because of the large overlap between Ebola symptoms and pregnancy-related complications. In November 2014, the world's first maternity-specific isolation and screening system, to our knowledge, was created at the Princess Christian Maternity Hospital in Freetown to meet the emergent needs of the population of pregnant women during the epidemic. PROCESS: Starting in December 2014 through June 2016, in collaboration with hospital leadership and the Ministry of Health and Sanitation, Partners In Health supported Princess Christian Maternity Hospital in creating a safer health care environment with the shared goal of improving safety and health outcomes and of addressing the unique needs of pregnant women, by focusing on improving 4 key areas: 1) screening, 2) isolation, 3) laboratory diagnostics, and 4) clinical service delivery in isolation, including human resource management and training. OUTCOMES: The screening guidelines were adapted to include maternal health care considerations, a new screening area was constructed, the laboratory result turnaround time was reduced, and the isolation unit was improved to enhance safety and care delivery. Human resources were supported with additional staff hired and trainings on infection prevention and control, overall resulting in better preparing Princess Christian Maternity Hospital to provide care for pregnant women during outbreaks. DISCUSSION: The authors' experience at Princess Christian Maternity Hospital provides a model of screening, isolation, and care specifically for maternity patients, and directly addresses infection risk and mortality. The recommendations we provide can be used in future outbreaks.

Ultrasensitive Ebola Virus Antigen Sensing via 3D Nanoantenna Arrays.

Sensitive detection of pathogens is crucial for early disease diagnosis and quarantine, which is of tremendous need in controlling severe and fatal illness epidemics such as of Ebola virus (EBOV) disease. Serology assays can detect EBOV-specific antigens and antibodies cost-effectively without sophisticated equipment; however, they are less sensitive than reverse transcriptase polymerase chain reaction (RT-PCR) tests. Herein, a 3D plasmonic nanoantenna assay sensor is developed as an on-chip immunoassay platform for ultrasensitive detection of Ebola virus (EBOV) antigens. The EBOV sensor exhibits substantial fluorescence intensity enhancement in immunoassays compared to flat gold substrate. The nanoantenna-based biosensor successfully detects EBOV soluble glycoprotein (sGP) in human plasma down to 220 fg mL-1 , a significant 240 000-fold sensitivity improvement compared to the 53 ng mL-1 EBOV antigen detection limit of the existing rapid EBOV immunoassay. In a mock clinical trial, the sensor detects sGP-spiked human plasma samples at two times the limit of detection with 95.8% sensitivity. The results combined highlight the nanosensor's extraordinary capability of detecting EBOV antigen at ultralow concentration compared to existing immunoassay methods. It is a promising next-generation bioassay platform for early-stage disease diagnosis and pathogen detection for both public health and national security applications.

Electrochemically Exfoliated High-Quality 2H-MoS2 for Multiflake Thin Film Flexible Biosensors.

2D molybdenum disulfide (MoS2 ) gives a new inspiration for the field of nanoelectronics, photovoltaics, and sensorics. However, the most common processing technology, e.g., liquid-phase based scalable exfoliation used for device fabrication, leads to the number of shortcomings that impede their large area production and integration. Major challenges are associated with the small size and low concentration of MoS2 flakes, as well as insufficient control over their physical properties, e.g., internal heterogeneity of the metallic and semiconducting phases. Here it is demonstrated that large semiconducting MoS2 sheets (with dimensions up to 50 µm) can be obtained by a facile cathodic exfoliation approach in nonaqueous electrolyte. The synthetic process avoids surface oxidation thus preserving the MoS2 sheets with intact crystalline structure. It is further demonstrated at the proof-of-concept level, a solution-processed large area (60 × 60 µm) flexible Ebola biosensor, based on a MoS2 thin film (6 µm thickness) fabricated via restacking of the multiple flakes on the polyimide substrate. The experimental results reveal a low detection limit (in femtomolar-picomolar range) of the fabricated sensor devices. The presented exfoliation method opens up new opportunities for fabrication of large arrays of multifunctional biomedical devices based on novel 2D materials.

Macrophage Activation Marker Soluble CD163 Associated with Fatal and Severe Ebola Virus Disease in Humans1.

Ebola virus disease (EVD) is associated with elevated cytokine levels, and hypercytokinemia is more pronounced in fatal cases. This type of hyperinflammatory state is reminiscent of 2 rheumatologic disorders known as macrophage activation syndrome and hemophagocytic lymphohistiocytosis, which are characterized by macrophage and T-cell activation. An evaluation of 2 cohorts of patients with EVD revealed that a marker of macrophage activation (sCD163) but not T-cell activation (sCD25) was associated with severe and fatal EVD. Furthermore, substantial immunoreactivity of host tissues to a CD163-specific antibody, predominantly in areas of extensive immunostaining for Ebola virus antigens, was observed in fatal cases. These data suggest that host macrophage activation contributes to EVD pathogenesis and that directed antiinflammatory therapies could be beneficial in the treatment of EVD.

Airport Entry and Exit Screening during the Ebola Virus Disease Outbreak in Sierra Leone, 2014 to 2016.

We present entry and exit screening outcomes on all persons passing through Freetown International Airport (FNA) in Sierra Leone during the period 1st September 2014 to 4th February 2016. A total of 166,242 persons underwent screening for Ebola Virus Disease (EVD) at FNA. Five persons were denied air travel from Sierra Leone after secondary screening. Laboratory testing revealed none were positive for EVD. No cases were identified through entry screening route. The public health value of airport screening for EVD is discussed.

Adherence to Universal Travel Screening in the Emergency Department During Epidemic Ebola Virus Disease.

BACKGROUND: During the 2014 West African Ebola Virus Disease (EVD) outbreak, the U.S. Centers for Disease Control and Prevention recommended that all emergency department (ED) patients undergo travel screening for risk factors of importing EVD. OBJECTIVES: We sought to determine the overall adherence rate to the recommended travel screening protocol and to identify factors associated with nonadherence to the protocol. METHODS: We conducted a multicenter, retrospective analysis of adherence to the travel screening program in an academic hospital and three affiliated community hospitals. A regression model identified patient and hospital factors associated with nonadherence. RESULTS: Of the 147,062 patients included for analysis, 93.7% (n = 137,834) had travel screenings completed. We identified several characteristics of patients that were most likely to be missed by the screening protocol-patients with low English proficiency, patients who arrive via ambulance or helicopter, and patients with more severe illness or injury based on initial triage acuity. CONCLUSIONS: These findings should be used to improve adherence to the travel screening protocol for future emerging infectious disease threats.

Dual monoclonal antibody-based sandwich ELISA for detection of in vitro packaged Ebola virus.

BACKGROUND: Rapid transmission and high mortality of Ebola virus disease (EVD) highlight a urgent need of large scale, convenient and effective measure for Ebola virus screening. Application of monoclonal antibodies (mAbs) are crucial for establishment of an enzyme-linked immunosorbent assay (ELISA) with high sensitivity and specificity. METHODS: The traditional cell fusion technique was used to generate a panel of hybridomas. Two mAbs were characterized by SDS-PAGE, Western blot, Indirect immunofluorescence assay (IFA). A sandwich ELISA was established using the two mAbs. The detection capability of the ELISA was evaluated. RESULTS: In the current study, we produced two murine-derived mAbs (designated as 6E3 and 3F21) towards Zaire Ebola virus glycoprotein (GP), the major viral transmembrane spike protein associated with viral attachment. It was shown that 6E3 and 3F21 recognized GP1 and GP2 subunits of the GP respectively. Furthermore, 6E3 and 3F21 bound to corresponding epitopes on GP without reciprocal topographical interpretation. Subsequently, a sandwich ELISA based on the two mAbs were established and evaluated. The detection limit was 3.6 ng/ml, with a linear range of 3.6-100 ng/ml. More importantly, Ebola virus like particles (eVLPs) were able to be detected by this established virus detection measure. CONCLUSIONS: We produced and characterized two murine-derived mAbs (designated as 6E3 and 3F21) towards Zaire Ebola virus glycoprotein (GP), and established a sandwich ELISA based on the mAbs. It was suggested that the sandwich ELISA provided an alternative method for specific and sensitive detection of Ebola virus in the field setting.