Dengue virus: A global human threat: Review of literature

The impact of dengue viruses: Surveillance, response, and public health implications in Queensland, Australia

This study examines dengue transmission, symptoms, vaccination efforts, treatment options, and global impact, focusing on Australia, especially Queensland. It evaluates current surveillance and response systems, identifies areas for improvement, and proposes strategies to enhance public health preparedness. Highlighting the socioeconomic impact of dengue outbreaks, the study underscores the need for integrated public health measures, effective vaccines, advanced surveillance methods, and sustainable mosquito control programs to mitigate the threat of dengue outbreaks and potential endemicity.

Dengue and chikungunya virus dynamics, identification, and monitoring in wastewater

Monitoring wastewater is an effective strategy for supporting clinical surveillance for viral infections. Wastewater monitoring, also known as wastewater-based epidemiology (WBE), uses existing wastewater collection networks to obtain a composite sample of a population that can be used to predict disease dynamics in a specific area. Viruses such as dengue and chikungunya are primarily transmitted through the bites of infected Aedes mosquito species. The prevalence of the Aedes mosquito in tropical and subtropical regions makes these diseases a serious threat to public health. Employing wastewater surveillance, monitoring, and regulating the spread of diseases like dengue and chikungunya-notably caused by mosquitoes-has been recommended. However, understanding the dynamics of viral release and its persistence in wastewater is critical for monitoring purposes. Although methods for recovering RNA for some viruses from wastewater have been developed, the same approach does not work equally well for viruses such as dengue and chikungunya due to low levels of viral RNA and susceptibility to degradation. As a result, a tailored approach to recovering these viruses from wastewater is required. This review summarizes viral release from infected hosts, its dynamics, and approaches for dengue and chikungunya wastewater surveillance. The review also identifies existing knowledge gaps in viral persistence in wastewater and recovery.

Dengue virus surveillance in Nepal yields the first on-site whole genome sequences of isolates from the 2022 outbreak

BACKGROUND

The 4 serotypes of dengue virus (DENV1-4) can each cause potentially deadly dengue disease, and are spreading globally from tropical and subtropical areas to more temperate ones. Nepal provides a microcosm of this global phenomenon, having met each of these grim benchmarks. To better understand DENV transmission dynamics and spread into new areas, we chose to study dengue in Nepal and, in so doing, to build the onsite infrastructure needed to manage future, larger studies.

METHODS AND RESULTS

During the 2022 dengue season, we enrolled 384 patients presenting at a hospital in Kathmandu with dengue-like symptoms; 79% of the study participants had active or recent DENV infection (NS1 antigen and IgM). To identify circulating serotypes, we screened serum from 50 of the NS1+ participants by RT-PCR and identified DENV1, 2, and 3 - with DENV1 and 3 codominant. We also performed whole-genome sequencing of DENV, for the first time in Nepal, using our new on-site capacity. Sequencing analysis demonstrated the DENV1 and 3 genomes clustered with sequences reported from India in 2019, and the DENV2 genome clustered with a sequence reported from China in 2018.

CONCLUSION

These findings highlight DENV's geographic expansion from neighboring countries, identify China and India as the likely origin of the 2022 DENV cases in Nepal, and demonstrate the feasibility of building onsite capacity for more rapid genomic surveillance of circulating DENV. These ongoing efforts promise to protect populations in Nepal and beyond by informing the development and deployment of DENV drugs and vaccines in real time.

Investigation of small molecules disrupting dengue virus assembly by inhibiting capsid protein and blocking RNA encapsulation

Dengue fever is a significant global public health concern, causing substantial morbidity and mortality worldwide. The disease can manifest in various forms, from mild fever to potentially life-threatening complications. Developing effective treatments remains a critical challenge to healthcare systems. Despite extensive research, no antiviral drugs have been approved for either the prevention or treatment of dengue. Targeting the virus during its early phase of attachment is essential to inhibit viral replication. The capsid protein plays a crucial role in the virus's structural integrity, assembly, and viral genome release. In the present study, we employed a computational approach focused on the capsid protein to identify possible potent inhibitors against the dengue virus from a library of FDA-approved drugs. We employed high-throughput virtual screening on FDA-approved drugs to identify drug molecules that could potentially combat the disease and save both cost and time. The screening process identified four drug molecules (Nordihydroguaiaretic acid, Ifenprodil tartrate, Lathyrol, and Safinamide Mesylate) based on their highest binding affinity and MM/GBSA scores. Among these, Nordihydroguaiaretic acid showed higher binding affinity than the reference molecule with - 11.66 kcal/mol. In contrast, Ifenprodil tartrate and Lathyrol showed similar results to the reference molecule, with binding energies of - 9.42 kcal/mol and - 9.29 kcal/mol, respectively. Following the screening, molecular dynamic simulations were performed to explore the molecular stability and conformational possibilities. The drug molecules were further supported by post-molecular simulation analysis. Furthermore, binding energies were also computed using the MM/GBSA approach, and the free energy landscape was used to calculate the different transition states, revealing that the drugs exhibited significant transition states. Specifically, Nordihydroguaiaretic acid and Ifenprodil tartrate displayed higher flexibility, while Lathyrol and Safinamide Mesylate showed more predictable and consistent protein folding. This significant breakthrough offers new hope against dengue, highlighting the power of computational drug discovery in identifying potent inhibitors and paving the way for novel treatment approaches.

Characterization of the microbiome of Aedes albopictus populations in different habitats from Spain and São Tomé

The mosquito microbiome significantly influences vector competence, including in Aedes albopictus, a globally invasive vector. Describing the microbiome and Wolbachia strains of Ae. albopictus from different regions can guide area-specific control strategies. Mosquito samples from Spain and São Tomé were analyzed using 16S rRNA gene sequencing and metagenomic sequencing. Wolbachia infection patterns were observed by sex and population. Female mosquitoes were blood-fed, a factor considered in analyzing their microbiota. Results revealed a dominance of dual Wolbachia infections, strains A and B, in the microbiome of both populations of Ae. albopictus, especially among females. Both populations shared a core microbiome, although 5 and 9 other genera were only present in Spain and São Tomé populations, respectively. Genera like Pelomonas and Nevskia were identified for the first time in Aedes mosquitoes. This study is the first to describe the Ae. albopictus bacteriome in Spain and São Tomé, offering insights for the development of targeted mosquito control strategies. Understanding the specific microbiome composition can help in designing more effective interventions, such as microbiome manipulation and Wolbachia-based approaches, to reduce vector competence and transmission potential of these mosquitoes.

Diagnostic accuracy of Dengue NS1 lateral flow immunoassay in comparison to reverse transcriptase polymerase chain reaction and enzyme linked Immunosorbent Assay

The most widely used invitro diagnostic qualitative screening method for dengue virus infection is the lateral flow immunoassay technique. Testing of dengue non-structural antigen NS1 offers specificity in determining the active infection while testing of IgM and IgG helps in differentiating the primary and secondary dengue infections. The ELISA functions as the golden standard for dengue testing and PCR credits for the most accurate determination tool at the genetic level. The RT-PCR endorsed NS1 gene and in ELISA or LFIA NS1 antigen is used as the marker owing to the specificity and lesser chances of mutation effects. This study evaluated the performance of AG-Q Dengue NS1 LFIA kit in comparison with RT-PCR quantification cycle (Cq) Values and ELISA NS1 quantitation. The study also focused on differentiating the samples among dengue serotypes using the RealStar Dengue Type RT-PCR Kit 1.0. Dengue serotype 2 is the prominent viral strain in Kerala region succeeded by serotype 3 and 1 with a prevalence rate of 64 %, 20 % and 6 % respectively. Dengue serotype 4 was not reported during this study period. 10 % co-infection with DENV 1 & DENV 2 was also reported. The AG-Q Dengue NS1 kit stood as efficient in screening by providing positive results with samples having RT-PCR Cq values up to 43 and ELISA NS1 quantification minimum of 14 Panbio units.

Predicting repurposed drugs targeting the NS3 protease of dengue virus using machine learning-based QSAR, molecular docking, and molecular dynamics simulations

Dengue fever, prevalent in Southeast Asian countries, currently lacks effective pharmaceutical interventions for virus replication control. This study employs a strategy that combines machine learning (ML)-based quantitative-structure-activity relationship (QSAR), molecular docking, and molecular dynamics simulations to discover potential inhibitors of the NS3 protease of the dengue virus. We used nine molecular fingerprints from PaDEL to extract features from the NS3 protease dataset of dengue virus type 2 in the ChEMBL database. Feature selection was achieved through the low variance threshold, F-Score, and recursive feature elimination (RFE) methods. Our investigation employed three ML models - support vector machine (SVM), random forest (RF), and extreme gradient boosting (XGBoost) - for classifier development. Our SVM model, combined with SVM-RFE, had the best accuracy (0.866) and ROC_AUC (0.964) in the testing set. We identified potent inhibitors on the basis of the optimal classifier probabilities and docking binding affinities. SHAP and LIME analyses highlighted the significant molecular fingerprints (e.g. ExtFP69, ExtFP362, ExtFP576) involved in NS3 protease inhibitory activity. Molecular dynamics simulations indicated that amphotericin B exhibited the highest binding energy of -212 kJ/mol and formed a hydrogen bond with the critical residue Ser196. This approach enhances NS3 protease inhibitor identification and expedites the discovery of dengue therapeutics.

Risks of anxiety disorders, depressive disorders, and sleep disorders in patients with dengue fever: A nationwide, population-based cohort study

BACKGROUND

Dengue virus (DENV) infection, a common mosquito-borne disease, has been linked to several mental disorders like depression and anxiety. However, the temporal risk of these disorders after DENV infection is not well studied.

METHODS

This population-based cohort study encompassed 45,334 recently lab-confirmed dengue patients in Taiwan spanning 2002 to 2015, matched at a 1:5 ratio with non-dengue individuals based on age, gender, and residence (n = 226,670). Employing subdistribution hazard regression analysis, we assessed the immediate (<3 months), intermediate (3-12 months), and prolonged (>12 months) risks of anxiety disorders, depressive disorders, and sleep disorders post DENV infection. Corrections for multiple comparisons were carried out using the Benjamini-Hochberg procedure.

RESULTS

A significant increase in depressive disorder risk across all timeframes post-infection was observed (<3 months [aSHR 1.90, 95% CI 1.20-2.99], 3-12 months [aSHR 1.68, 95% CI 1.32-2.14], and >12 months [aSHR 1.14, 95% CI 1.03-1.25]). Sleep disorder risk was higher only during 3-12 months (aSHR 1.55, 95% CI 1.18-2.04). No elevated anxiety disorder risk was found. Subgroup analysis of hospitalized dengue patients showed increased risk of anxiety disorders within 3 months (aSHR 2.14, 95% CI 1.19-3.85) and persistent risk of depressive disorders across all periods. Hospitalized dengue patients also had elevated sleep disorder risk within the first year.

CONCLUSION

Dengue patients exhibited significantly elevated risks of depressive disorders in both the short and long term. However, dengue's impact on sleep disorders and anxiety seems to be short-lived. Further research is essential to elucidate the underlying mechanisms.

In Silico-Based Identification of Natural Inhibitors from Traditionally Used Medicinal Plants that can Inhibit Dengue Infection

Dengue fever (DF) is an endemic disease that has become a public health concern around the globe. The NS3 protease-helicase enzyme is an important target for the development of antiviral drugs against DENV (dengue virus) due to its impact on viral replication. Inhibition of the activity of the NS3 protease-helicase enzyme complex significantly inhibits the infection associated with DENV. Unfortunately, there are no scientifically approved antiviral drugs for its prevention. However, this study has been developed to find natural bioactive molecules that can block the activity of the NS3 protease-helicase enzyme complex associated with DENV infection through molecular docking, MM-GBSA (molecular mechanics-generalized born surface area), and molecular dynamics (MD) simulations. Three hundred forty-two (342) compounds selected from twenty traditional medicinal plants were retrieved and screened against the NS3 protease-helicase protein by molecular docking and MM-GBSA studies, where the top six phytochemicals have been identified based on binding affinities. The six compounds were then subjected to pharmacokinetics and toxicity analysis, and we conducted molecular dynamics simulations on three protein-ligand complexes to validate their stability. Through computational analysis, this study revealed the potential of the two selected natural bioactive inhibitors (CID-440015 and CID-7424) as novel anti-dengue agents.

Dengue Virus Surveillance in Nepal Yields the First On-Site Whole Genome Sequences of Isolates from the 2022 Outbreak

Background

The 4 serotypes of dengue virus (DENV1-4) can each cause potentially deadly dengue disease, and are spreading globally from tropical and subtropical areas to more temperate ones. Nepal provides a microcosm of this global phenomenon, having met each of these grim benchmarks. To better understand DENV transmission dynamics and spread into new areas, we chose to study dengue in Nepal and, in so doing, to build the onsite infrastructure needed to manage future, larger studies.

Methods and Results

During the 2022 dengue season, we enrolled 384 patients presenting at a hospital in Kathmandu with dengue-like symptoms; 79% of the study participants had active or recent DENV infection (NS1 antigen and IgM). To identify circulating serotypes, we screened serum from 50 of the NS1 + participants by RT-PCR and identified DENV1, 2, and 3 - with DENV1 and 3 codominant. We also performed whole-genome sequencing of DENV, for the first time in Nepal, using our new on-site capacity. Sequencing analysis demonstrated the DENV1 and 3 genomes clustered with sequences reported from India in 2019, and the DENV2 genome clustered with a sequence reported from China in 2018.

Conclusion

These findings highlight DENV's geographic expansion from neighboring countries, identify China and India as the likely origin of the 2022 DENV cases in Nepal, and demonstrate the feasibility of building onsite capacity for more rapid genomic surveillance of circulating DENV. These ongoing efforts promise to protect populations in Nepal and beyond by informing the development and deployment of DENV drugs and vaccines in real time.

The epidemiologic and economic burden of dengue in Singapore: A systematic review

BACKGROUND

Despite its well-regarded vector control program, Singapore remains susceptible to dengue epidemics. To assist evaluation of dengue interventions, we aimed to synthesize current data on the epidemiologic and economic burden of dengue in Singapore.

METHODOLOGY

We used multiple databases (PubMed, Embase, Cochrane, international/national repositories, surveillance) to search for published and gray literature (2000-2022). We included observational and cost studies, and two interventional studies, reporting Singapore-specific data on our co-primary outcomes, dengue incidence and dengue-related costs. Quality was assessed using the Newcastle-Ottawa Scale and an adapted cost-of-illness evaluation checklist. We performed a narrative synthesis and grouped studies according to reported outcomes and available stratified analyses.

FINDINGS

In total, 333 reports (330 epidemiological, 3 economic) were included. Most published epidemiological studies (89%) and all economic studies were of good quality. All gray literature reports were from the Ministry of Health or National Environment Agency. Based predominantly on surveillance data, Singapore experienced multiple outbreaks in 2000-2021, attaining peak incidence rate in 2020 (621.1 cases/100,000 person-years). Stratified analyses revealed the highest incidence rates in DENV-2 and DENV-3 serotypes and the 15-44 age group. Among dengue cases, the risk of hospitalization has been highest in the ≥45-year-old age groups while the risks of dengue hemorrhagic fever and death have generally been low (both <1%) for the last decade. Our search yielded limited data on deaths by age, severity, and infection type (primary, secondary, post-secondary). Seroprevalence (dengue immunoglobulin G) increases with age but has remained <50% in the general population. Comprising 21-63% indirect costs, dengue-related total costs were higher in 2010-2020 (SGD 148 million) versus the preceding decade (SGD 58-110 million).

CONCLUSION

Despite abundant passive surveillance data, more stratified and up-to-date data on the epidemiologic and economic burden of dengue are warranted in Singapore to continuously assess prevention and management strategies.

Investigating the antiviral therapeutic potentialities of marine polycyclic lamellarin pyrrole alkaloids as promising inhibitors for SARS-CoV-2 and Zika main proteases (Mpro)

The new coronavirus variant (SARS-CoV-2) and Zika virus are two world-wide health pandemics. Along history, natural products-based drugs have always crucially recognized as a main source of valuable medications. Considering the SARS-CoV-2 and Zika main proteases (Mpro) as the re-production key element of the viral cycle and its main target, herein we report an intensive computer-aided virtual screening for a focused list of 39 marine lamellarins pyrrole alkaloids, against SARS-CoV-2 and Zika main proteases (Mpro) using a set of combined modern computational methodologies including molecular docking (MDock), molecule dynamic simulations (MDS) and structure-activity relationships (SARs) as well. Indeed, the molecular docking studies had revealed four promising marine alkaloids including [lamellarin H (14)/K (17)] and [lamellarin S (26)/Z (39)], according to their notable ligand-protein energy scores and relevant binding affinities with the SARS-CoV-2 and Zika (Mpro) pocket residues, respectively. Consequentially, these four chemical hits were further examined thermodynamically though investigating their MD simulations at 100 ns, where they showed prominent stability within the accommodated (Mpro) pockets. Moreover, in-deep SARs studies suggested the crucial roles of the rigid fused polycyclic ring system, particularly aromatic A- and F- rings, position of the phenolic -OH and δ-lactone functionalities as essential structural and pharmacophoric features. Finally, these four promising lamellarins alkaloids were investigated for their in-silico ADME using the SWISS ADME platform, where they displayed appropriated drug-likeness properties. Such motivating outcomes are greatly recommending further in vitro/vivo examinations regarding those lamellarins pyrrole alkaloids (LPAs).Communicated by Ramaswamy H. Sarma.

Navigating the Complexity: A Comprehensive Review of Hemophagocytic Lymphohistiocytosis Associated With Dengue Infection

Hemophagocytic lymphohistiocytosis (HLH) associated with dengue infection presents a unique challenge in clinical practice due to its rarity, rapid progression, and overlapping clinical features. This comprehensive review navigates the complexity of HLH-dengue syndrome by examining its pathophysiology, clinical manifestations, diagnostic criteria, and therapeutic strategies. HLH, characterized by uncontrolled immune activation and cytokine dysregulation, can occur as a secondary complication of dengue infection, leading to severe multiorgan dysfunction and high mortality if not promptly recognized and treated. The review underscores the significance of early diagnosis through vigilant clinical monitoring and appropriate diagnostic tests, such as bone marrow examinations and genetic studies. Collaboration between infectious disease specialists, hematologists, and critical care teams is essential for optimal management. Despite advancements in understanding HLH-dengue syndrome, further research is needed to elucidate its underlying mechanisms and explore novel treatment approaches. This review provides insights into the clinical implications of HLH-dengue syndrome and emphasizes the importance of a multidisciplinary approach to improve patient outcomes in this challenging clinical scenario.

Cytokine Storm Syndrome Associated with Hemorrhagic Fever and Other Viruses

A wide variety of infections can trigger cytokine storm syndromes including those caused by bacteria, viruses, fungi and parasites. The most frequent viral trigger is Epstein-.Barr virus which is covered in Chapter 16. CSS associated with COVID-19 is also discussed separately (Chapter 22). This chapter will focus on other viruses including the hemorrhagic fever viruses, influenza, parainfluenza, adenovirus, parvovirus, hepatitis viruses, measles, mumps, rubella, enterovirus, parechovirus, rotavirus, human metapneumovirus and human T-lymphotropic virus. The published literature consists of many single case reports and moderate-sized case series reporting CSS, in most circumstances meeting the 2004 diagnostic criteria for hemophagocytic lymphohistiocytosis (HLH). There is no published clinical trial evidence specifically for management of HLH associated with these viruses. In some situations, patients received supportive therapy and blood product transfusions only but in most cases, they were treated with one or more of intravenous corticosteroids, intravenous immunoglobulin and/or etoposide. These were successful in many patients although in significant numbers progression of infection to CSS was associated with mortality.

Different mechanisms of X-ray irradiation-induced male and female sterility in Aedes aegypti

BACKGROUND

Aedes aegypti (Ae. aegypti) is the major vector that transmits many diseases including dengue, Zika, and filariasis in tropical and subtropical regions. Due to the growing resistance to chemical-based insecticides, biological control methods have become an emerging direction to control mosquito populations. The sterile insect technique (SIT) deploys high doses of ionizing radiation to sterilize male mosquitoes before the release. The Wolbachia-based population suppression method of the incompatible insect technique (IIT) involves the release of Wolbachia-infected males to sterilize uninfected field females. Due to the lack of perfect sex separation tools, a low percentage of female contamination is detected in the male population. To prevent the unintentional release of these Wolbachia-infected females which might result in population replacement, a low dose of X-ray irradiation is deployed to sterilize any female escapees. However, it remains unclear whether these irradiation-induced male and female sterilizations share common mechanisms.

RESULTS

In this work, we set out to define the minimum dose of X-ray radiation required for complete female sterilization in Ae. aegypti (NEA-EHI strain). Further results showed that this minimum dose of X-ray irradiation for female sterilization significantly reduced male fertility. Similar results have been reported previously in several operational trials. By addressing the underlying causes of the sterility, our results showed that male sterility is likely due to chromosomal damage in the germ cells induced by irradiation. In contrast, female sterility appears to differ and is likely initiated by the elimination of the somatic supporting cells, which results in the blockage of the ovariole maturation. Building upon these findings, we identified the minimum dose of X-ray irradiation on the Wolbachia-infected NEA-EHI (wAlbB-SG) strain, which is currently being used in the IIT-SIT field trial. Compared to the uninfected parental strain, a lower irradiation dose could fully sterilize wAlbB-SG females. This suggests that Wolbachia-carrying mosquitoes are more sensitive to irradiation, consistent with a previous report showing that a lower irradiation dose fully sterilized Wolbachia-infected Ae. aegypti females (Brazil and Mexican strains) compared to those uninfected controls.

CONCLUSIONS

Our findings thus reveal the distinct mechanisms of ionizing X-ray irradiation-induced male or female sterility in Ae. aegypti mosquitoes, which may help the design of X-ray irradiation-based vector control methods.

Genus Culex Linnaeus, 1758 (Diptera: Culicidae) as an Important Potential Arbovirus Vector in Brazil: An Integrative Review

The genus Culex has 817 species subdivided into 28 subgenera. It has a cosmopolitan distribution, being most abundant in countries with a tropical climate. Understanding the ecology and diversity of viruses circulating in the species of this genus is important for understanding their role as arbovirus vectors in Brazil. To conduct an integrative review to identify the importance of the Culex genus as arbovirus vectors in Brazil. A search was carried out for scientific papers in the PubMed, BVSalud, Patuá-IEC and International Catalogue of Arboviruses: including certain other viruses of vertebrates databases. 36 publications describing arbovirus detections in Culex mosquitoes collected in the field in Brazil were evaluated. A total of 42 arbovirus species were detected, as well as studies analyzing the vector competence of C. quinquefasciatus for the transmission of four different arboviruses. The study of the Culex genus and its role as a vector of arboviruses in Brazil is essential for understanding transmission cycles, with the main aim of reducing cases of human infection. Thus, entomovirological surveillance guides the implementation of actions to detect circulating arboviruses among vectors to anticipate measures aimed at preventing or reducing the risk of arbovirus outbreaks in the country.

Dengue hemorrhagic fever: a growing global menace

Dengue virus is an arthropod-borne virus, transmitted by Aedes aegypti among humans. In this review, we discussed the epidemiology of dengue hemorrhagic fever (DHF) as well as the disease's natural history, cycles of transmission, clinical diagnosis, aetiology, prevention, therapy, and management. A systematic literature search was done by databases such as PubMed and Google Scholar using search terms, 'dengue fever', 'symptoms and causes of dengue fever', 'dengue virus transmission', and 'strategies to control dengue'. We reviewed relevant literature to identify hazards related to DHF and the most recent recommendations for its management and prevention. Clinical signs and symptoms of dengue infection range from mild dengue fever (DF) to potentially lethal conditions like DHF or dengue shock syndrome (DSS). Acute-onset high fever, muscle and joint pain, myalgia, a rash on the skin, hemorrhagic episodes, and circulatory shock are among the most common symptoms. An early diagnosis is vital to lower mortality. As dengue virus infections are self-limiting, but in tropical and subtropical areas, dengue infection has become a public health concern. Hence, developing and executing long-term control policies that can reduce the global burden of DHF is a major issue for public health specialists everywhere.

Antiviral and antimicrobial applications of chalcones and their derivatives: From nature to greener synthesis

Chalcones and their derivatives have been widely studied due to their versatile pharmacological and biological activities, such as anti-inflammatory, antibacterial, antiviral, and antitumor effects. These compounds have shown suitable antiviral effects through the selective targeting of a variety of viral enzymes, including lactate dehydrogenase, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), fumarate reductase, protein tyrosine phosphatase, topoisomerase-II, protein kinases, integrase/protease, and lactate/isocitrate dehydrogenase, among others. Chalcones and their derivatives have displayed excellent potential for combating pathogenic bacteria and fungi (especially, multidrug-resistant bacteria). However, relevant mechanisms should be further explored, focusing on inhibitory effects against DNA gyrase B, UDP-N-acetylglucosamine enolpyruvyl transferase (MurA), and efflux pumps (e.g., NorA), among others. In addition, the antifungal and antiparasitic activities of these compounds (e.g., antitrypanosomal and antileishmanial properties) have prompted additional explorations. Nonetheless, systematic analysis of the relevant mechanisms, biosafety issues, and pharmacological properties, as well as clinical translation studies, are vital for practical applications. Herein, recent advancements pertaining to the antibacterial, antiviral, antiparasitic, and antifungal activities of chalcones and their derivatives are deliberated, focusing on the relevant mechanisms of action, crucial challenges, and future prospects. Furthermore, due to the great importance of greener and more sustainable synthesis of these valuable compounds, especially on an industrial scale, the progress made in this field has been briefly discussed. Hopefully, this review can serve as a catalyst for researchers to delve deeper into the exploration and designing of novel chalcone compounds with medicinal properties, especially against pathogenic viruses and multidrug-resistant bacteria as major causes of concern for human health.

Prospective study to compare results of FIA (fluorescent immunoassay) test with gold standard ELISA test in Dengue NS1 patients admitted in a tertiary care hospital

PURPOSE

The objective of this study was to compare the performance of STANDARD F Dengue NS1 Ag FIA SD Biosensor and ELISA for diagnosis of dengue in patients admitted in a tertiary care hospital. The results of the FIA test were compared with ELISA test, the gold standard in terms of sensitivity, specificity, positive predictive value, negative predictive value.

METHODS

Total 19,890 patients suffering from acute febrile illness suspecting dengue were screened for dengue NS1 antigen by rapid immunochromatography test during the period of one year and six months from June 2020 to November 2021. Out of them, a total of 300 blood samples were selected by simple random sampling method for the study. The blood samples were collected and subjected to dengue NS1 ELISA and FIA test according to the kit literature.

RESULTS

Out of total 300 samples, 67.67% (203) patients were positive for dengue NS1 antigen by FIA test. Total 200 patients (66.67%) were positive for dengue NS1 antigen by ELISA and (190) 63.33% were positive for dengue NS1 antigen by rapid ICT. It was also seen that there was an inverse relation between the Cutoff Index (COI) value of FIA and the platelet count of the dengue NS1 positive patients.

CONCLUSION

We conclude that the results of Dengue NS1 Microwell ELISA test and Dengue NS1 FIA test are almost equivalent in relation to sensitivity, specificity, positive predictive value, and negative predictive value. FIA gives rapid test results, thus is time saving and can be routinely used. The COI value can also give a relative idea about the severity of the disease.

Dengue, Chikungunya, and Zika: The Causes and Threats of Emerging and Re-emerging Arboviral Diseases

The recent emergence and re-emergence of viral infections transmitted by vectors, Zika, chikungunya, dengue, and others, is a cause for international concern. Here, we provide a summary of the current understanding of the transmission, clinical features, diagnosis, global burden, and the likelihood of future epidemics by these viruses. Arboviruses transmitted by mosquitoes are challenging to diagnose and can have surprising clinical complications. Dengue, chikungunya, and Zika are the most important diseases caused by arboviruses worldwide, especially in tropical and subtropical regions. These are transmitted to humans by day-biting Aedes aegypti and Aedes albopictus mosquitoes. In India, the increase in the incidence of dengue and chikungunya cases is primarily linked to the dissemination of Aedes aegypti. A rapid and accurate diagnosis is paramount for effectively controlling dengue outbreaks. As there is no vaccination or specific treatment available for these viruses, vector control is the only comprehensive solution available.

Dengue Fever-Induced Hypokalemic Paralysis in a Pregnant Patient: An Uncommon Presentation of a Common Disease

Dengue fever is a globally prevalent, viral disease transmitted by Aedes mosquitoes, which is becoming increasingly common and can cause a range of symptoms, including fever, flu-like symptoms, and circulatory failure. Although it is classified as a non-neurotropic virus, research has suggested that dengue fever can also affect the nervous system and lead to conditions such as myositis, Guillain-Barré syndrome, or hypokalemic paralysis. We describe a case study of a young pregnant female with dengue-associated hypokalemic paralysis, who made a full recovery within 48 hours of receiving potassium supplementation. The case underscores the importance of recognizing and treating neurological complications of dengue fever promptly, particularly in areas where the disease is prevalent.

Simulation of Hemorrhage Pathogenesis in Mice through Dual Stimulation with Dengue Envelope Protein Domain III-Coated Nanoparticles and Antiplatelet Antibody

Dengue hemorrhagic fever (DHF) is a severe form of dengue virus (DENV) infection that can lead to abnormal immune responses, endothelial vascular dysfunction, and hemorrhage pathogenesis. The virion-associated envelope protein domain III (EIII) is thought to play a role in the virulence of DENV by damaging endothelial cells. However, it is unclear whether EIII-coated nanoparticles simulating DENV virus particles could cause a more severe pathogenesis than soluble EIII alone. This study aimed to investigate whether EIII-coated silica nanoparticles (EIII-SNPs) could elicit greater cytotoxicity in endothelial cells and hemorrhage pathogenesis in mice compared to EIII or silica nanoparticles alone. The main methods included in vitro assays to assess cytotoxicity and in vivo experiments to examine hemorrhage pathogenesis in mice. EIII-SNPs induced greater endothelial cytotoxicity in vitro than EIII or silica nanoparticles alone. Two-hit combined treatment with EIII-SNPs and antiplatelet antibodies to simulate DHF hemorrhage pathogenesis during secondary DENV infections resulted in higher endothelial cytotoxicity than either treatment alone. In mouse experiments, two-hit combined treatment with EIII-SNPs and antiplatelet antibodies resulted in more severe hemorrhage pathogenesis compared to single treatments of EIII, EIII-SNPs, or antiplatelet antibodies alone. These findings suggest that EIII-coated nanoparticles are more cytotoxic than soluble EIII and could be used to develop a tentative dengue two-hit hemorrhage pathogenesis model in mice. Additionally, our results indicated that EIII-containing DENV particles could potentially exacerbate hemorrhage pathogenesis in DHF patients who have antiplatelet antibodies, highlighting the need for further research on the potential role of EIII in DHF pathogenesis.

Trends in ELISA-Based Flavivirus IgG Serosurveys: A Systematic Review

Flaviviruses include virus species that are major public health threats worldwide. To determine the immunity landscape of these viruses, seroprevalence studies are often performed using IgG ELISA, which is a simple and rapid alternative to the virus neutralization test. In this review, we aim to describe the trends in flavivirus IgG ELISA-based serosurveys. A systematic literature review using six databases was performed to collate cohort and cross-sectional studies performed on the general population. A total of 204 studies were included in this review. The results show that most studies were performed on dengue virus (DENV), whereas Japanese Encephalitis Virus (JEV) was the least studied. For geographic distribution, serosurveys followed known disease prevalence. Temporally, the number of serosurveys increased after outbreaks and epidemics except for JEV, for which studies were performed to demonstrate the effectiveness of vaccination campaigns. Commercial kits were more commonly used than in-house assays for DENV, West Nile Virus (WNV), and Zika virus (ZIKV). Overall, most studies employed an indirect ELISA format, and the choice of antigens varied per virus. This review shows that flavivirus epidemiology is related to the regional and temporal distribution of serosurveys. It also highlights that endemicity, cross-reactivities, and kit availabilities affect assay choice in serosurveys.

Tomato flu 2022 outbreak in India: Issues, challenges, and possible solutions

Background and Aims

The outbreak of Tomato flu in India has affected the children making the parents tremble in worry and pain. The outbreak of this disease first occurred in India affecting young children below 5 years of age, thereby causing a threat to the country, neighboring countries, and the rest of the world-although no death is yet recorded. The aim of this research is to discuss the issues, challenges, and possible solutions associated with 2022 Tomato flu outbreaks in India.

Results

Tomato flu is caused by Coxsackievirus A16 as confirmed in the United Kingdom. The health authorities are currently monitoring the spread of the virus and trying to understand it to develop strategies to contain it. But they are left with some challenges relating to the health system, surveillance, and adherence to preventive protocols among others.

Conclusion

To prevent the spread of Tomato flu to other neighboring countries like China, Bangladesh, Pakistan, Sri Lanka, Myanmar, Afghanistan, Bhutan, Nepal, and the Maldives, the Indian Government must provide adequate public health control measures to contain the disease in children. Various recommendations have been given below.

Laboratory Evaluation and Field Testing of Dengue NS1 and IgM/IgG Rapid Diagnostic Tests in an Epidemic Context in Senegal

In Senegal, the burden of dengue is increasing and expanding. As case management and traditional diagnostic techniques can be difficult to implement, rapid diagnostic tests (RDTs) deployed at point of care are ideal for investigating active outbreaks. The aim of this study was to evaluate the diagnostic performance of the Dengue NS1 and Dengue IgM/IgG RDTs on the serum/plasma samples in a laboratory setting and in the field. During laboratory evaluation, performance of the NS1 RDT was assessed using NS1 ELISA as the gold standard. Sensitivity and specificity were 88% [75–95%] and 100% [97–100%], respectively. Performance of the IgM/IG RDT was assessed using the IgM Antibody Capture (MAC) ELISA, indirect IgG, and PRNT as gold standards. The IgM and IgG test lines respectively displayed sensitivities of 94% [83–99%] and 70% [59–79%] and specificities of 91% [84–95%] and 91% [79–98%]. In the field, the Dengue NS1 RDT sensitivity and specificity was 82% [60–95%] and 75% [53–90%], respectively. The IgM and IgG test lines displayed sensitivities of 86% [42–100%] and 78% [64–88%], specificities of 85% [76–92%] and 55% [36–73%], respectively. These results demonstrate that RDTs are ideal for use in a context of high prevalence or outbreak setting and can be implemented in the absence of a confirmatory test for acute and convalescent patients.

Assessing the role of family level variation and heat shock gene expression in the thermal stress response of the mosquito Aedes aegypti

The geographical range of the mosquito vector for many human disease-causing viruses, Aedes aegypti, is expanding, in part owing to changing climate. The capacity of this species to adapt to thermal stress will affect its future distributions. It is unclear how much heritable genetic variation may affect the upper thermal limits of mosquito populations over the long term. Nor are the genetic pathways that confer thermal tolerance fully understood. In the short term, cells induce a plastic, protective response known as 'heat shock'. Using a physiological 'knockdown' assay, we investigated mosquito thermal tolerance to characterize the genetic architecture of the trait. While families representing the extreme ends of the distribution for knockdown time differed from one another, the trait exhibited low but non-zero broad-sense heritability. We then explored whether families representing thermal performance extremes differed in their heat shock response by measuring gene expression of heat shock protein-encoding genes Hsp26, Hsp83 and Hsp70. Contrary to prediction, the families with higher thermal tolerance demonstrated less Hsp expression. This pattern may indicate that other mechanisms of heat tolerance, rather than heat shock, may underpin the stress response, and the costly production of HSPs may instead signal poor adaptation. This article is part of the theme issue 'Infectious disease ecology and evolution in a changing world'.

TORCH Congenital Syndrome Infections in Central America's Northern Triangle

TORCH pathogens are a group of globally prevalent infectious agents that may cross the placental barrier, causing severe negative sequalae in neonates, including fetal death and lifelong morbidity. TORCH infections are classically defined by Toxoplasma gondii, other infectious causes of concern (e.g., syphilis, Zika virus, malaria, human immunodeficiency virus), rubella virus, cytomegalovirus, and herpes simplex viruses. Neonatal disorders and congenital birth defects are the leading causes of neonatal mortality in Central America's Northern Triangle, yet little is known about TORCH congenital syndrome in this region. This review synthesizes the little that is known regarding the most salient TORCH infections among pregnant women and neonates in Central America's Northern Triangle and highlights gaps in the literature that warrant further research. Due to the limited publicly available information, this review includes both peer-reviewed published literature and university professional degree theses. Further large-scale studies should be conducted to clarify the public health impact these infections in this world region.

Recent Developments in DNA-Nanotechnology-Powered Biosensors for Zika/Dengue Virus Molecular Diagnostics

Zika virus (ZIKV) and dengue virus (DENV) are highly contagious and lethal mosquito-borne viruses. Global warming is steadily increasing the probability of ZIKV and DENV infection, and accurate diagnosis is required to control viral infections worldwide. Recently, research on biosensors for the accurate diagnosis of ZIKV and DENV has been actively conducted. Moreover, biosensor research using DNA nanotechnology is also increasing, and has many advantages compared to the existing diagnostic methods, such as polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA). As a bioreceptor, DNA can easily introduce a functional group at the 5' or 3' end, and can also be used as a folded structure, such as a DNA aptamer and DNAzyme. Instead of using ZIKV and DENV antibodies, a bioreceptor that specifically binds to viral proteins or nucleic acids has been fabricated and introduced using DNA nanotechnology. Technologies for detecting ZIKV and DENV can be broadly divided into electrochemical, electrical, and optical. In this review, advances in DNA-nanotechnology-based ZIKV and DENV detection biosensors are discussed.

Machine Learning-Based Detection of Dengue from Blood Smear Images Utilizing Platelet and Lymphocyte Characteristics

Dengue fever, also known as break-bone fever, can be life-threatening. Caused by DENV, an RNA virus from the Flaviviridae family, dengue is currently a globally important public health problem. The clinical methods available for dengue diagnosis require skilled supervision. They are manual, time-consuming, labor-intensive, and not affordable to common people. This paper describes a method that can support clinicians during dengue diagnosis. It is proposed to automate the peripheral blood smear (PBS) examination using Artificial Intelligence (AI) to aid dengue diagnosis. Nowadays, AI, especially Machine Learning (ML), is increasingly being explored for successful analyses in the biomedical field. Digital pathology coupled with AI holds great potential in developing healthcare services. The automation system developed incorporates a blob detection method to detect platelets and thrombocytopenia from the PBS images. The results achieved are clinically acceptable. Moreover, an ML-based technique is proposed to detect dengue from the images of PBS based on the lymphocyte nucleus. Ten features are extracted, including six morphological and four Gray Level Spatial Dependance Matrix (GLSDM) features, out of the lymphocyte nucleus of normal and dengue cases. Features are then subjected to various popular supervised classifiers built using a ten-fold cross-validation policy for automated dengue detection. Among all the classifiers, the best performance was achieved by Support Vector Machine (SVM) and Decision Tree (DT), each with an accuracy of 93.62%. Furthermore, 1000 deep features extracted using pre-trained MobileNetV2 and 177 textural features extracted using Local binary pattern (LBP) from the lymphocyte nucleus are subjected to feature selection. The ReliefF selected 100 most significant features are then fed to the classifiers. The best performance was attained using an SVM classifier with 95.74% accuracy. With the obtained results, it is evident that this proposed approach can efficiently contribute as an adjuvant tool for diagnosing dengue from the digital microscopic images of PBS.

Elevated serum PAR-1 levels as an emerging biomarker of inflammation to predict the dengue infection severity

The present study was designed to check the serum levels of protease-activated receptor (PAR-1) in patients during different phases of dengue severity. Moreover, a correlation between serum PAR-1 levels and hematological parameters, inflammatory cytokine levels, and liver functional changes was also determined. Based on the World Health Organization criteria, the study population was divided into: nonsevere dengue fever (DF; n = 30), severe dengue hemorrhagic fever (DHF; n = 19), and severe dengue shock syndrome (DSS; n = 11). The platelet count (PLT) and hematocrit (HCT) were analyzed using an automated hematology analyzer and liver function enzymes aspartate transaminase (AST), alanine transaminase (ALT), and alkaline phosphate (ALP), bilirubin were checked by auto-analyzer using diagnostic kits. Moreover, the levels of inflammatory mediators C-reactive protein (CRP), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-17 (IL-17), and PAR-1 were determined using respective ELISA kits. The HCT levels were elevated and platelet count decreased significantly during dengue complications (DHF and DSS) compared to the DF patients, while the levels of liver functional biomarkers AST, ALT, ALP, and bilirubin remained elevated in DHF and DSS groups than in the corresponding DF group. Similarly, the inflammatory cytokine levels of CRP, TNF-α, IL-6, and IL-17 in DHF and DSS subjects were markedly increased when observed against DF subjects. Notably, the PAR-1 levels were significantly elevated in DHF and DSS groups than in the DF group and positively correlated with changes in HCT levels, inflammatory biomarkers, and liver enzymes. Our findings conclude that PAR-1 levels persistently increased with the severity of the dengue infection and are strongly associated with various clinical manifestations. Thus, PAR-1 levels can be used as a diagnostic marker for assessing dengue severity.

Immunopathology of Renal Tissue in Fatal Cases of Dengue in Children

Dengue virus (DENV) infection represents a worldwide public health concern and can cause damage to multiple organs, including the kidney. In this work, we investigated the histopathological changes caused by dengue virus infection along with the detection of inflammatory mediators, cytokines, and cell expression patterns in the renal tissue of three fatal cases in children. Hematoxylin and Eosin staining was performed to analyze these histopathological changes. Immunohistochemistry allowed for the detection of immunological inflammatory markers in renal tissues that were quantified and further analyzed. Vascular congestion, edema and glomerular infiltrate were observed in the three cases, in addition to the thickening of the matrix area around the glomerular capillaries and mononuclear infiltrate associated with vascular congestion in the medullary region. The renal tissues exhibited collagen deposition and high expression of CD68⁺ Mø, CD8⁺ T, CD56⁺ cells and MMP-9, and the cytokine profile was mainly characterized by the expression of IFN-γ and TNF-α. Additionally, the expression of RANTES, VEGFR-2 and VCAM-1 were observed. The replication of DENV was evidenced by the detection of the NS3 protein. These results contributed to clarifying the main factors that may be involved in changes in the renal tissue of fatal cases of dengue in children.

Emerging quinoline- and quinolone-based antibiotics in the light of epidemics

Pandemics are large-scale outbreaks of infectious disease that can greatly increase morbidity and mortality all the globe. Since past 1990 till twentieth century, these infectious diseases have been major threat all over the globe associated with poor hygiene and sanitation. In light of these epidemics, researches have gained enormous rise in the developing the potential therapeutic treatment. Thus, revolutionized antibiotics have led to the near eradication of such ailments. Around 50 million prescription of antibiotics written in US per year according to center for disease control and prevention (CDC) report. There is a wide range of antibiotics available which differ in their usage and their mechanism of action. Among these quinoline and quinolone class of antibiotics get attention as they show tremendous potential in fighting the epidemics. Quinoline and quinolone comprise of two rings along with substitutions at different positions which is synthetically obtained by structural modifications of quinine. Quinoline and quinolone antibiotics exhibit extensive activities approved by FDA in the treatment of the several ailments such as gastrointestinal infections, urinary tract infections, prostate inflammation, malaria, gonorrhea, skin infection, colorectal cancer, respiratory tract infections. These are active against both gram-negative and gram-positive bacteria. This basic core of quinoline and quinolone is vital due to its capability of targeting the pathogen causing disease and beneficial in treating the infectious disease. They inhibit the synthesis of nucleic acid of bacteria which results in the rupture of bacterial chromosome due to the interruption of enzymes such as DNA gyrase and topoisomerase IV. There are various quinoline and quinolone compounds that are synthetically derived by applying different synthesis approaches which show a wide range of pharmacological activities in several diseases. The most commonly used are fluoro, chloro, and hydroxychloro derivatives of quinoline and quinolone. These compounds are helpful in the treatment of numerous epidemics as a chief and combination therapy. These quinoline and quinolone pharmacophore fascinate the interest of researchers as they inhibit the entry of virus in host cell and cease its replication by blocking the host receptor glycosylation and proteolytic processing. They act as immune modulator by inhibiting autophagy and reduction of both lysosomal activity and production of cytokine. Therefore, quinoline and quinolone derivatives attain significance in area of research and treatment of various life-threatening epidemics such as SARS, Zika virus, Ebola virus, dengue, and COVID-19 (currently). In this chapter, the research and advancements of quinoline- and quinolone-based antibiotics in epidemic management are briefly discussed.

Development of multivariate classification models for the diagnosis of dengue virus infection

The dengue virus (DENV) infection is a worldwide cause of serious illness and death. Early and efficient prediction of disease may help in proper medical management to control disease. Keeping this in view, multivariate classification models by combining with Raman spectroscopy have been developed for the diagnosis of DENV infection in human blood sera. For study design, a statistical analysis is performed to select the sample size for training of models. Total 1240 Raman spectra have been acquired from 39 DENV infected and 23 healthy sera samples. Prior to model development, Raman spectra were examined using ANOVA test for significant differences present in the intensities of newly appeared Raman bands at 622, 645, 700, 746, 800, 814, 873, 890, 948, 1002, 1018, 1080, 1235, 1250, 1272, 1386, 1404, 1446, 1609 and 1645 cm^-1. The significant differences and characteristic patterns of Raman bands induced by disease played decisive role and are exploited for development of multivariate model. Classification models are developed by utilizing principal component analysis (PCA) to extract discriminant features from multidimensional Raman spectral dataset and followed by support vector machines (SVM) with Polynomial of 5, RBF, and liner kernels. The proposed model for this study is built using 10-fold cross validation technique and evaluated on independent dataset to demonstrate its robustness. PCA-SVM (poly-5) model successfully yielded high diagnostic accuracy of 99.52%, sensitivity of 99.75%, specificity of 99.09% for classification of unknown suspected samples. For comparison, PCA discriminant analysis (PCA-DA), partial least squares regression (PLSR) are PLS-DA have been compared. It is found that PCA-SVM (poly-5) approach is more effective and robust compared to other state-of-the-art approaches and it can be used for clinical prediction of DENV infection in human blood sera.

SARS-CoV-2 and Dengue Virus Coinfection in a Mexican Pediatric Patient: A Case Report from Early Molecular Diagnosis

Mexico is an endemic region for dengue virus (DENV). The increase in this disease coincides with outbreaks of COVID-19, both of which are single-stranded positive RNA viruses. These characteristics make it difficult to distinguish each disease because they share clinical and laboratory features, which can consequently result in misdiagnoses. This is why the use of precision confirmatory tests (qRT-PCR) are crucial for early diagnosis. We herein report a pediatric patient who presented a coinfection for DENV and COVID-19, “SARS-CoV-2/Dengue”. This patient initially presented a fever, cough, and headache and, three days later, developed generalized pain and epistaxis. Blood studies revealed thrombocytopenia and leukopenia, and the patient was admitted to the hospital for a probable DENV infection. Within 48 h, qRT-PCR tests specific for SARS-CoV-2 and DENV were performed and resulted as positive. The patient immediately received pharmacological treatment with azithromycin, oseltamivir, and metamizole. During hospitalization (9 days), the patient had no signs of respiratory distress and maintained normal body temperature and normal blood oxygen saturation. This case warns of the need for early diagnosis and adequate clinical and pharmacological management in the face of a “SARS-CoV-2/Dengue” coinfection. Early molecular detection of both viruses and timely treatment helped the patient to achieve a favorable recovery.

A Privacy-Preserved Internet-of-Medical-Things Scheme for Eradication and Control of Dengue Using UAV

Dengue is a mosquito-borne viral infection, found in tropical and sub-tropical climates worldwide, mostly in urban and semi-urban areas. Countries like Pakistan receive heavy rains annually resulting in floods in urban cities due to poor drainage systems. Currently, different cities of Pakistan are at high risk of dengue outbreaks, as multiple dengue cases have been reported due to poor flood control and drainage systems. After heavy rain in urban areas, mosquitoes are provided with a favorable environment for their breeding and transmission through stagnant water due to poor maintenance of the drainage system. The history of the dengue virus in Pakistan shows that there is a closed relationship between dengue outbreaks and a rainfall. There is no specific treatment for dengue; however, the outbreak can be controlled through internet of medical things (IoMT). In this paper, we propose a novel privacy-preserved IoMT model to control dengue virus outbreaks by tracking dengue virus-infected patients based on bedding location extracted using call data record analysis (CDRA). Once the bedding location of the patient is identified, then the actual infected spot can be easily located by using geographic information system mapping. Once the targeted spots are identified, then it is very easy to eliminate the dengue by spraying the affected areas with the help of unmanned aerial vehicles (UAVs). The proposed model identifies the targeted spots up to 100%, based on the bedding location of the patient using CDRA.

Host immune response against DENV and ZIKV infections

Dengue is a major public health concern, affecting almost 400 million people worldwide, with about 70% of the global burden of disease in Asia. Despite revised clinical classifications of dengue infections by the World Health Organization, the wide spectrum of the manifestations of dengue illness continues to pose challenges in diagnosis and patient management for clinicians. When the Zika epidemic spread through the American continent and then later to Africa and Asia in 2015, researchers compared the characteristics of the Zika infection to Dengue, considering both these viruses were transmitted primarily through the same vector, the Aedes aegypti female mosquitoes. An important difference to note, however, was that the Zika epidemic diffused in a shorter time span compared to the persisting feature of Dengue infections, which is endemic in many Asian countries. As the pathogenesis of viral illnesses is affected by host immune responses, various immune modulators have been proposed as biomarkers to predict the risk of the disease progression to a severe form, at a much earlier stage of the illness. However, the findings for most biomarkers are highly discrepant between studies. Meanwhile, the cross-reactivity of CD8+ and CD4+ T cells response to Dengue and Zika viruses provide important clues for further development of potential treatments. This review discusses similarities between Dengue and Zika infections, comparing their disease transmissions and vectors involved, and both the innate and adaptive immune responses in these infections. Consideration of the genetic identity of both the Dengue and Zika flaviviruses as well as the cross-reactivity of relevant T cells along with the actions of CD4+ cytotoxic cells in these infections are also presented. Finally, a summary of the immune biomarkers that have been reported for dengue and Zika viral infections are discussed which may be useful indicators for future anti-viral targets or predictors for disease severity. Together, this information appraises the current understanding of both Zika and Dengue infections, providing insights for future vaccine design approaches against both viruses.

Temporal trend and spatial clustering of the dengue fever prevalence in West Java, Indonesia

Dengue fever is a notable vector-borne viral disease, currently becoming the most dreaded worldwide health problem in terms of the number of people affected. A data set of confirmed dengue incidences collected in the province of West Java has allowed us to explore dengue's temporal trends and spatial distributions to obtain more obvious insights into its spatial-temporal evolution. We utilized the Richards model to estimate the growth rate and detect the peak (or turning point) of the dengue infection wave by identifying the temporal progression at each location. Using spatial analysis of geo-referenced data from a local perspective, we investigated the changes in the spatial clusters of dengue cases and detected hot spots and cold spots in each weekly cycle. We found that the trend of confirmed dengue incidences significantly increases from January to March. More than two-third (70.4%) of the regions in West Java had their dengue infection turning point ranging from the first week of January to the second week of March. This trend clearly coincides with the peak of precipitation level during the rainy season. Further, the spatial analysis identified the hot spots distributed across central, northern, northeastern, and southeastern regions in West Java. The densely populated areas were likewise seen to be associated with the high-risk areas of dengue exposure. Recognizing the peak of epidemic and geographical distribution of dengue cases might provide important insights that may help local authorities optimize their dengue prevention and intervention programs.

Clinical Characteristics and Symptomatology Associated With Dengue Fever

Background

Early diagnosis and prompt treatment are critical to reducing overall morbidity and mortality associated with dengue fever. Thus, to better understand the condition, the present study was conducted to assess the clinical signs and symptomatology associated with dengue fever in patients in a tertiary care hospital.

Methods

This prospective observational study was conducted at a tertiary care hospital in Karachi, Pakistan between July and December 2021. All patients who tested positive for the dengue virus either based on antigen or antibodies were included in the study. Convenient sampling was used. A structured proforma was used for data collection. Microsoft Excel (Microsoft Corporation, Redmond, WA) and Statistical Package for the Social Sciences (SPSS, IBM Corp., Armonk, NY) were used for the entry and analysis of data, respectively.

Results

More than half of the patients were suffering from fever (82.5%), headache/body ache/joint pain (80.5%), and vomiting (55%). Bleeding was observed in 16 (8%) patients and was directly related to platelet count (OR: 0.981; 95% CI: 0.971-0.992), and more than half of the patients (56%) required platelet transfusion. Laboratory values included a mean platelet count of 145.22 ± 90.36 thousand, a mean total leukocyte count (TLC) of 6.87 ± 5.76 thousand, and a mean hemoglobin level of 13.71 ± 2.11 g/dl. Of the patients, 171 (85.5%) individuals tested positive for antigen nonstructural protein 1 (Ns1Ag), and 68 (34%) tested positive for either immunoglobulin G (IgG) or immunoglobulin M (IgM), or both dengue-specific antibodies. Those with dengue-specific antibodies were less likely to bleed as 6.2% were IgG and IgM positive and 31.2% were positive for both antibodies. The regression model showed a significant relationship between bleeding and platelet transfusion (p < 0.001), hospital stay (p < 0.005), and diarrhea (p < 0.001).

Conclusion

In conclusion, the study revealed that males were more frequently infected with the virus as compared to females. Furthermore, fever, headache/joint pain/body aches, diarrhea, and low platelet count are the major clinical and laboratory outcomes. Patients with a low level of platelets are more prone to bleeding, and platelet transfusion increased survival chances in such patients.

Isolated subdural hematoma due to dengue hemorrhagic fever: Surgical intervention and review of the literature

Background:

Central nervous system (CNS) complications of dengue fever, a mosquito-borne single standard RNA virus illness, are reported in <1% of all cases. Hemorrhagic complications in severe forms of the disease can be life-threatening. The literature on cases, where hemorrhagic CNS complications necessitated neurosurgical intervention, is exceedingly sparse. The authors report their experience of a patient who developed an isolated acute subdural hematoma (SDH) due to dengue hemorrhagic fever (DHF) in the critical period of the illness with a poor prognosis. Despite a moribund patient, the SDH was immediately evacuated, achieving a good outcome.

Case Description:

A 65-year-old male patient was admitted with high-grade febrile illness and diagnosed with dengue. The patient had no focal neurology and was managed adequately following the primary survey on admission but, then, developed severe thrombocytopenia and eventually the critical phase of dengue illness. On the 5^th admission day, the patient collapsed. Glasgow Coma Score was 3/15 with bilaterally dilated, fixed pupils. Immediate computed tomography head revealed a large left SDH with a significant midline shift. SDH was emergently evacuated with two units of platelets transfused peroperatively and two additional units postoperatively. Thrombocytopenia resolved within 48 h, and interval scanning showed gradual resolution of SDH. The patient was discharged 18 days later. Five months later, on follow-up, the patient is well with mild left-sided weakness and an Extended Glasgow Outcome Score of 7.

Conclusion:

Isolated SDH is a rare but life-threatening hemorrhagic complication of DHF. Even in the critical phase of illness, with severe thrombocytopenia, surgical evacuation should be considered if the SDH is present in isolation, within an accessible area, and can be operated on immediately.

Diagnosis of dengue virus infection using spectroscopic images and deep learning

Dengue virus (DENV) infection is one of the major health issues and a substantial epidemic infectious human disease. More than two billion humans are living in dengue susceptible regions with annual infection mortality rate is about 5%-20%. At initial stages, it is difficult to differentiate dengue virus symptoms with other similar diseases. The main objective of this research is to diagnose dengue virus infection in human blood sera for better treatment and rehabilitation process. A novel and robust approach is proposed based on Raman spectroscopy and deep learning. In this regard, the ResNet101 deep learning model is modified by exploiting transfer learning (TL) concept on Raman spectroscopic data of human blood sera. Sample size was selected using standard statistical tests. The proposed model is evaluated on 2,000 Raman spectra images in which 1,200 are DENV-infected of human blood sera samples, and 800 are healthy ones. It offers 96.0% accuracy on testing data for DENV infection diagnosis. Moreover, the developed approach demonstrated minimum improvement of 6.0% and 7.0% in terms of AUC and Kappa index respectively over the other state-of-the-art techniques. The developed model offers superior performance to capture minute Raman spectral variations due to the better residual learning capability and generalization ability compared to others deep learning models. The developed model revealed that it might be applied for diagnosis of DENV infection to save precious human lives.

The Role of Angiopoietin-2 on Plasma Leakage in the Critical Phase and Convalescence of Dengue Virus Infection in Children

Abstract Background: The worst complication of dengue haemorrhagic fever (DHF) that lead to death is hypovolemic shock due to plasma leakage from intravascular to extravascular space caused by endothelial dysfunction. This study is aimed to analyze the difference of Ang-2 level in dengue haemorrhagic fever patients related to plasma leakage between critical phase and convalescence.   Aim: One hundred and ten children with DHF confirmed serologically with positive IgM anti-dengue or IgM and IgG anti-dengue were recruited in this study. We examine the clinical manifestations, laboratory parameters (platelet count, AST and ALT levels), and molecular test (Ang-2). The molecular indicator was tested by Enzyme-Linked Immunosorbent Assay (ELISA). Data were collected between July – November 2019. This is an observational study with cross-sectional comparative design.   Results: In our study, we found correlation of clinical symptoms (abdominal pain, persistent vomit, and hepatomegaly) with the occurrence of plasma leakage in DHF patients. We also found that Ang-2 level is significantly higher in children with DHF during critical phase compared to convalescence (p< 0.01).   Conclusion: There is a significant difference of Ang-2 level in DHF patients during critical phase and convalescence.   Keywords: Dengue hemorrhagic fever, children, Ang-2, critical phase, convalescence

New Insights into the Role of the Complement System in Human Viral Diseases

The complement system (CS) is part of the human immune system, consisting of more than 30 proteins that play a vital role in the protection against various pathogens and diseases, including viral diseases. Activated via three pathways, the classical pathway (CP), the lectin pathway (LP), and the alternative pathway (AP), the complement system leads to the formation of a membrane attack complex (MAC) that disrupts the membrane of target cells, leading to cell lysis and death. Due to the increasing number of reports on its role in viral diseases, which may have implications for research on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), this review aims to highlight significant progress in understanding and defining the role of the complement system in four groups of diseases of viral etiology: (1) respiratory diseases; (2) acute liver failure (ALF); (3) disseminated intravascular coagulation (DIC); and (4) vector-borne diseases (VBDs). Some of these diseases already present a serious global health problem, while others are a matter of concern and require the collaboration of relevant national services and scientists with the World Health Organization (WHO) to avoid their spread.

Short-term, medium-term, and long-term risks of nonvariceal upper gastrointestinal bleeding after dengue virus infection

Dengue patients have an increased risk of acute gastrointestinal (GI) bleeding. However, whether dengue virus (DENV) infection can cause an increased long-term risk of GI bleeding remains unknown, especially among elderly individuals who commonly take antithrombotic drugs. A retrospective population-based cohort study was conducted by analyzing the National Health Insurance Research Databases. Laboratory-confirmed dengue patients from 2002 to 2012 and four matched nondengue controls were identified. Multivariate Cox proportional hazard regression was used to evaluate the acute (<30 days), medium-term (31–365 days), and long-term (>365 days) risks of nonvariceal upper GI bleeding after DENV infection. Stratified analyses by age group (≤50, 51–64, ≥65 years old) were also performed. In total, 13267 confirmed dengue patients and 53068 nondengue matched controls were included. After adjusting for sex, age, area of residence, comorbidities, and medications, dengue patients had a significantly increased risk of nonvariceal upper GI bleeding within 30 days of disease onset (adjusted HR 55.40; 95% CI: 32.17–95.42). However, DENV infection was not associated with increased medium-term and long-term risks of upper GI bleeding overall or in each age group. Even dengue patients who developed acute GI bleeding did not have increased medium-term (adjusted HR; 0.55, 95% CI 0.05–6.18) and long-term risks of upper GI bleeding (adjusted HR; 1.78, 95% CI 0.89–3.55). DENV infection was associated with a significantly increased risk of nonvariceal upper GI bleeding within 30 days but not thereafter. Recovered dengue patients with acute GI bleeding can resume antithrombotic treatments to minimize the risk of thrombosis.

Dengue fever is a mosquito-borne tropical disease caused by the dengue virus. Dengue patients can have low platelet counts and might have acute gastrointestinal bleeding (tarry stool, bloody stool or bloody vomiting). Most dengue patients will fully recover and return to their previous health levels. Previous studies have indicated that some dengue patients have persistent low platelet counts and high inflammatory responses. The medium-term and long-term upper gastrointestinal bleeding risks remain unknown. Our study suggested that dengue was significantly associated with an increased risk of nonvariceal upper GI bleeding within 30 days after infection but was not associated with increased medium-term (31–365 days) and long-term risks (>365 days) of upper GI bleeding. Therefore, the risk of acute gastroenterology bleeding returned to baseline levels after 30 days. Recovered dengue patients with acute GI bleeding can resume antiplatelet, antithrombotic, and oral anticoagulation (OAC) treatments.