Risk predictors of progression to severe disease during the febrile phase of dengue: a systematic review and meta-analysis

Mathematical analysis and prediction of future outbreak of dengue on time-varying contact rate using machine learning approach

This article introduces a novel mathematical model analyzing the dynamics of Dengue in the recent past, specifically focusing on the 2023 outbreak of this disease. The model explores the patterns and behaviors of dengue fever in Bangladesh. Incorporating a sinusoidal function reveals significant mid-May to Late October outbreak predictions, aligning with the government's exposed data in our simulation. For different amplitudes (A) within a sequence of values (A = 0.1 to 0.5), the highest number of infected mosquitoes occurs in July. However, simulations project that when βM = 0.5 and A = 0.1, the peak of human infections occurs in late September. Not only the next-generation matrix approach along with the stability of disease-free and endemic equilibrium points are observed, but also a cutting-edge Machine learning (ML) approach such as the Prophet model is explored for forecasting future Dengue outbreaks in Bangladesh. Remarkably, we have fitted our solution curve of infection with the reported data by the government of Bangladesh. We can predict the outcome of 2024 based on the ML Prophet model situation of Dengue will be detrimental and proliferate 25 % compared to 2023. Finally, the study marks a significant milestone in understanding and managing Dengue outbreaks in Bangladesh.

Aspartate Aminotransferase-to-Platelet Ratio Index (APRI) as a Novel Score in Early Detection of Complicated Dengue Fever

Introduction

The occurrence of dengue fever presents a considerable burden for public health care in developing countries. This study aims to validate APRI as predictor score for severity of dengue fever so that catastrophic events could be prevented, and early triage can save lives.

Methods

The retrospective cross-sectional study was done on dengue positive patients from August to November 2023. APRI score was calculated for every patient at the time of admission. The primary end-point was non-complicated disease (Simple dengue fever) vs complicated disease (dengue hemorrhagic fever and dengue shock syndrome). ROC curve was used to identify the role of APRI in prediction of dengue complication. Youden index was used to find the cut-off value of APRI along with sensitivity, specificity, positive and negative likelihood ratios. To further evaluate the role of APRI score, patients were divided into two groups, patients with APRI score greater and lesser than cut-off value. The qualitative variables among two groups were compared by chi-square testing. The predictors of complicated dengue were first determined by univariate regression analysis and then confirmed by multivariate regression analysis.

Results

The mean APRI score of 135 patients was 20.06 ± 6.31. AUC for APRI score was 0.93 (p < 0.0001) indicating that APRI score calculated at the time of admission is an excellent marker in determining the complicated dengue. The cut-off value for APRI score was 9.04 (sensitivity 84.91%, specificity 89.02%, p < 0.0001). The patients with APRI <9.04 mostly developed simple dengue fever (54.1%) vs DHF (4.4%) and DSS (1.5%), while patients with APRI >9.04 had more DHF (20.7%) and DSS (12.6%) vs simple dengue fever (6.7%). None of the patient died with APRI <9.04 while the mortality rate was 3.7% in patients with APRI >9.04.

Conclusion

The APRI score, calculated at the time of admission, is an excellent marker in determining the severe dengue.

Retrospective Analysis of Severe Dengue by Dengue Virus Serotypes in a Population with Social Security, Mexico 2023

BACKGROUND

Risk factors for severe dengue manifestations have been attributed to various factors, including specific serotypes, sex, and age. Mexico has seen the re-emergence of DENV-3, which has not circulated in a decade.

OBJECTIVE

To describe dengue serotypes by age, sex, and their association with disease severity in dengue-positive serum samples from epidemiological surveillance system units.

MATERIALS AND METHODS

A descriptive analysis was conducted to evaluate the frequency of dengue severity by sex, age, disease quarter, geographical location, and dengue virus serotypes. The study was conducted using laboratory samples from confirmed dengue cases through RT-qPCR from the epidemiological surveillance laboratory network of the Mexican Social Security Institute, Mexico. Simple frequencies and proportions were calculated using the z-test for proportional differences between groups. Bivariate analysis with adjusted Chi2 was performed, and binary logistic regression models were constructed using the forward Wald method considering the model's predictive capacity. The measure of association was the odds ratio, with 95% confidence intervals. Statistical significance was set to an alpha level of <0.05.

RESULTS

In 2023, 10,441 samples were processed for dengue RT-qPCR at the IMSS, with a predominance of serotype DENV-3 (64.4%). The samples were mostly from women (52.0%) and outpatient cases (63.3%). The distribution of dengue severity showed significant variations by age, with a lower proportion of severe cases in young children and a higher proportion in the 5- to 14-year-old group. Hospitalizations increased significantly with severity. Warm regions had more cases overall and severity. Cases were most frequent from July to September. While DENV-2 was associated with severity, DENV-4 was not. Binary regression identified higher risk in women, age extremes, and DENV-2, with an overall predictive model of 58.5%.

CONCLUSIONS

Women, age groups at the extremes of life, and the DENV-2 serotype presented severe risk of dengue in a population with social security in Mexico during 2023.

Molecular mechanisms in the pathogenesis of dengue infections

Dengue is the most rapidly emerging climate-sensitive infection, and morbidity/mortality and disease incidence are rising markedly, leading to healthcare systems being overwhelmed. There are currently no specific treatments for dengue or prognostic markers to identify those who will progress to severe disease. Owing to an increase in the burden of illness and a change in epidemiology, many patients experience severe disease. Our limited understanding of the complex mechanisms of disease pathogenesis has significantly hampered the development of safe and effective treatments, vaccines, and biomarkers. We discuss the molecular mechanisms of dengue pathogenesis, the gaps in our knowledge, and recent advances, as well as the most crucial questions to be answered to enable the development of therapeutics, biomarkers, and vaccines.

Febrile Phase Soluble Urokinase Plasminogen Activator Receptor and Olfactomedin 4 as Prognostic Biomarkers for Severe Dengue in Adults

BACKGROUND

Dengue cases continue to rise and can overwhelm healthcare systems during outbreaks. In dengue, neutrophil mediators, soluble urokinase plasminogen activator receptor (suPAR) and olfactomedin 4, and mast cell mediators, chymase and tryptase, have not been measured longitudinally across the dengue phases. The utility of these proteins as prognostic biomarkers for severe dengue has also not been assessed in an older adult population.

METHODS

We prospectively enrolled 99 adults with dengue-40 dengue fever, 46 dengue with warning signs and 13 severe dengue, along with 30 controls. Plasma levels of suPAR, olfactomedin 4, chymase and tryptase were measured at the febrile, critical and recovery phases in dengue patients.

RESULTS

The suPAR levels were significantly elevated in severe dengue compared to the other dengue severities and controls in the febrile (P < .001), critical (P < .001), and recovery (P = .005) phases. In the febrile phase, suPAR was a prognostic biomarker of severe dengue, with an AUROC of 0.82. Using a cutoff derived from Youden's index (5.4 ng/mL) and an estimated prevalence of severe dengue (16.5%) in our healthcare institution, the sensitivity was 71.4% with a specificity of 87.9% in the febrile phase, and the positive and negative predictive values were 54.7% and 95.8%, respectively. Olfactomedin 4 was elevated in dengue patients but not in proportion to disease severity in the febrile phase (P = .04) There were no significant differences in chymase and tryptase levels between dengue patients and controls.

CONCLUSIONS

In adult dengue, suPAR may be a reliable prognostic biomarker for severe dengue in the febrile phase.

Using Computational Simulations Based on Fuzzy Cognitive Maps to Detect Dengue Complications

Dengue remains a globally prevalent and potentially fatal disease, affecting millions of people worldwide each year. Early and accurate detection of dengue complications is crucial to improving clinical outcomes and reducing the burden on healthcare systems. In this study, we explore the use of computational simulations based on fuzzy cognitive maps (FCMs) to improve the detection of dengue complications. We propose an innovative approach that integrates clinical data into a computational model that mimics the decision-making process of a medical expert. Our method uses FCMs to model complexity and uncertainty in dengue. The model was evaluated in simulated scenarios with each of the dengue classifications. These maps allow us to represent and process vague and fuzzy information effectively, capturing relationships that often go unnoticed in conventional approaches. The results of the simulations show the potential of our approach to detecting dengue complications. This innovative strategy has the potential to transform the way clinical management of dengue is approached. This research is a starting point for further development of complication detection approaches for events of public health concern, such as dengue.

Harness risk stratification of diabetic patients with dengue in a cohort study

BACKGROUND

Identifying predictors of severe dengue (SD) is key for triage and management of patients as well as for advising travellers to countries where dengue is endemic. In this, meta-analyses have raised diabetes mellitus as a risk factor for SD and a prognostic factor for dengue-related mortality. The purpose of this study was to assess whether diabetic patients (DPs) are at increased risk for SD in comparison to non-diabetic patients (NDPs) in a setting of high prevalence of type 2 diabetes mellitus and increasing endemicity for dengue.

METHODS

In a cohort study conducted during the 2019 dengue epidemic on Reunion Island, we estimated the risk ratios (RR) of DPs for SD (WHO 2009 definition), hospitalisation, intensive care unit (ICU) admission, critical care need or death in the ICU, and scales rating severity or multiple organ dysfunction syndrome (MODS), among confirmed cases of dengue (positive RT-PCR or NS1 antigen).

RESULTS

In a Poisson regression model adjusted for age, gender and comorbidity, DPs were more likely to develop SD (adjusted RR: 1.46, 95%CI 1.10-1.95), to be hospitalised, admitted to the ICU, and need critical care or die in the ICU. Subgroup analyses identified female DPs, non-elderly DPs (< 65 years) and DPs with low Charlson score (< 3) to be at higher risk for SD, the two first subgroups trough more severe presentation (higher Simplified Acute Physiology Score-2 values; higher MODS scores, respectively). Male gender, age less than 65 years and mixed comorbidity were identified as prognostic factors for critical care need or death in the ICU, male and non-elderly DPs being more likely to develop MODS than their non-diabetic counterparts.

CONCLUSIONS

Together, these data highlight the role of diabetes mellitus in the progression from dengue to SD through higher severity per se or the event of MODS.

Dengue

Dengue, caused by four closely related viruses, is a growing global public health concern, with outbreaks capable of overwhelming health-care systems and disrupting economies. Dengue is endemic in more than 100 countries across tropical and subtropical regions worldwide, and the expanding range of the mosquito vector, affected in part by climate change, increases risk in new areas such as Spain, Portugal, and the southern USA, while emerging evidence points to silent epidemics in Africa. Substantial advances in our understanding of the virus, immune responses, and disease progression have been made within the past decade. Novel interventions have emerged, including partially effective vaccines and innovative mosquito control strategies, although a reliable immune correlate of protection remains a challenge for the assessment of vaccines. These developments mark the beginning of a new era in dengue prevention and control, offering promise in addressing this pressing global health issue.

Frequency, Markers and Costs of Secondary Bacterial Infection in Pediatric Dengue

BACKGROUND

Secondary bacterial infection (SBI) occurs in a proportion of individuals with dengue and results in longer hospitalization, higher mortality, and increased health-related costs. However, the frequency, risk factors and predictive biomarkers of this comorbidity in pediatric dengue is partially known.

METHODS

We conducted a retrospective multicenter study in a dengue hyperendemic region of Colombia, analyzing 1597 children from two pediatric cohorts. We included children with confirmed dengue (mild to severe disease) and evaluated the rate of SBI, their clinical characteristics, diagnostic predictors and attention costs. We also assessed the diagnostic performance of plasma interleukin (IL)-6 for detecting SBI in pediatric dengue.

RESULTS

The frequency of SBI in children with dengue with warning signs in cohorts 1 and 2 was 2.4% and 7.3%, respectively, and this rate reached 30.7% and 38.2% in children with severe disease. Staphylococcus aureus and Escherichia coli were the more frequent infectious agents. Increased total leukocytes and C-reactive protein levels, as well as high IL-6 at hospital admission, in children <48 months of age were early indications of SBI in dengue. Higher rates of organ dysfunction, the requirement of a longer hospitalization and a 2.3-fold increase in attention costs were observed in SBI.

CONCLUSIONS

An important proportion of children with dengue course with SBI and exhibit higher morbidity. Elevated leukocytes, C-reactive protein and IL-6 in young children are early markers of SBI. Physicians should identify children with dengue and risk factors for SBI, microbiologically confirm the bacterial infection, and rationally and timely provide antimicrobial therapy.

Live, Attenuated, Tetravalent Butantan-Dengue Vaccine in Children and Adults

BACKGROUND

Butantan-Dengue Vaccine (Butantan-DV) is an investigational, single-dose, live, attenuated, tetravalent vaccine against dengue disease, but data on its overall efficacy are needed.

METHODS

In an ongoing phase 3, double-blind trial in Brazil, we randomly assigned participants to receive Butantan-DV or placebo, with stratification according to age (2 to 6 years, 7 to 17 years, and 18 to 59 years); 5 years of follow-up is planned. The objectives of the trial were to evaluate overall vaccine efficacy against symptomatic, virologically confirmed dengue of any serotype occurring more than 28 days after vaccination (the primary efficacy end point), regardless of serostatus at baseline, and to describe safety up to day 21 (the primary safety end point). Here, vaccine efficacy was assessed on the basis of 2 years of follow-up for each participant, and safety as solicited vaccine-related adverse events reported up to day 21 after injection. Key secondary objectives were to assess vaccine efficacy among participants according to dengue serostatus at baseline and according to the dengue viral serotype; efficacy according to age was also assessed.

RESULTS

Over a 3-year enrollment period, 16,235 participants received either Butantan-DV (10,259 participants) or placebo (5976 participants). The overall 2-year vaccine efficacy was 79.6% (95% confidence interval [CI], 70.0 to 86.3) - 73.6% (95% CI, 57.6 to 83.7) among participants with no evidence of previous dengue exposure and 89.2% (95% CI, 77.6 to 95.6) among those with a history of exposure. Vaccine efficacy was 80.1% (95% CI, 66.0 to 88.4) among participants 2 to 6 years of age, 77.8% (95% CI, 55.6 to 89.6) among those 7 to 17 years of age, and 90.0% (95% CI, 68.2 to 97.5) among those 18 to 59 years of age. Efficacy against DENV-1 was 89.5% (95% CI, 78.7 to 95.0) and against DENV-2 was 69.6% (95% CI, 50.8 to 81.5). DENV-3 and DENV-4 were not detected during the follow-up period. Solicited systemic vaccine- or placebo-related adverse events within 21 days after injection were more common with Butantan-DV than with placebo (58.3% of participants, vs. 45.6%).

CONCLUSIONS

A single dose of Butantan-DV prevented symptomatic DENV-1 and DENV-2, regardless of dengue serostatus at baseline, through 2 years of follow-up. (Funded by Instituto Butantan and others; DEN-03-IB ClinicalTrials.gov number, NCT02406729, and WHO ICTRP number, U1111-1168-8679.).

APRI as a predictor of severe dengue fever

Introduction

The AST/platelet ratio index (APRI) is a well-researched indicator of liver fibrosis. Some studies have shown that APRI can be used as a predictor of severe dengue, but the data is limited. As dengue epidemics are common in our country with limited healthcare resources, we believe APRI can help emergency physicians/primary physicians in predicting the severity of dengue and plan for the appropriate use of limited healthcare resources.

Objective

1) To determine the utility of APRI as a predictor of severe dengue. 2) To determine the association of APRI with length of hospital stay and platelet requirement.

Materials and Methods

A retrospective cross-sectional study was done on patients presented to the Emergency Medicine department at Travancore Medicity Medical College with a positive Dengue NS1 antigen or IgM antibody.

Results

We found from the univariate analysis results that ALT > 74.5 IU/L has a sensitivity of 59.6 and a specificity of 76.3 (AUC: 0.696; 95% CI: 0.606-0.786), AST > 160.5 IU/L has a sensitivity of 42.3 and a specificity of 93.7 (AUC: 0.747; 95% CI: 0.665-0.829), and APRI > 3.2 has a sensitivity of 69.2 and a specificity of 84.2 (AUC: 0.806; 95% CI: 0.72-0.884) to predict severe dengue. Patients with an APRI of >3.2 required a mean hospital stay of 5.47 days (P = 0.005); 27 (81.8%) requiring platelet transfusion had an APRI of > 3.2 (P = 0.00).

Conclusion

APRI is a straightforward index that can be easily derived from AST and platelet values. APRI values of >3.2 can predict severe dengue with a sensitivity of 69.2 and a specificity of 84.2. APRI values of >3.2 are also associated with the length of hospital stay and requirement of platelet transfusion.

Severe dengue in the intensive care unit

Dengue fever is considered the most prolific vector-borne disease in the world, with its transmission rate increasing more than eight times in the last two decades. While most cases present mild to moderate symptoms, 5% of patients can develop severe disease. Although the mechanisms are yet not fully comprehended, immune-mediated activation leading to excessive cytokine expression is suggested as a cause of the two main findings in critical patients: increased vascular permeability that may shock and thrombocytopenia, and coagulopathy that can induce hemorrhage. The risk factors of severe disease include previous infection by a different serotype, specific genotypes associated with more efficient replication, certain genetic polymorphisms, and comorbidities such as diabetes, obesity, and cardiovascular disease. The World Health Organization recommends careful monitoring and prompt hospitalization of patients with warning signs or propensity for severe disease to reduce mortality. This review aims to update the diagnosis and management of patients with severe dengue in the intensive care unit.

Postural fall in systolic blood pressure is a useful warning sign in dengue fever

Background

Capillary leak is the hallmark of development of severe dengue. A rise in haematocrit has been a major warning sign in WHO guidelines. Postural hypotension, which could reflect the intravascular volume reduction in capillary leak has been noted as warning sign in CDC and Pan American Health Organisation guidelines. We evaluated the diagnostic accuracy of postural hypotension as a marker of development of severe dengue.

Methods

150 patients admitted with dengue fever were recruited in this prospective observational study. Diagnostic accuracy of conventional warning signs (abdominal pain, persistent vomiting, fluid accumulation, mucosal bleeding, lethargy, liver enlargement, increasing hematocrit with decreasing platelets) and postural hypotension was evaluated.

Results

23 (15.3%) subjects developed severe dengue. Multiple logistic regression analysis showed that ascites/pleural effusion and postural fall in systolic blood pressure of >10.33% had odds ratio of 5.024(95%CI:1.11 - 22.75) and 11.369 (95% CI:2.27 - 56.87), respectively. Other parameters did not reach statistical significance. Sensitivity and specificity of ascites/pleural effusion were 82.6% and 88.2% for development of severe dengue whereas postural fall in systolic blood pressure had sensitivity and specificity of 87% and 82.7%.

Conclusions

These findings present a strong case for including postural hypotension as a warning sign in patients with dengue fever, especially in resource limited settings.

Facing the escalating burden of dengue: Challenges and perspectives

Dengue is the most rapidly emerging mosquito-borne infection and, due to climate change and unplanned urbanization, it is predicted that the global burden of dengue will rise further as the infection spreads to new geographical locations. Dengue-endemic countries are often unable to cope with such increases, with health care facilities becoming overwhelmed during each dengue season. Furthermore, although dengue has been predominantly a childhood illness in the past, it currently mostly affects adults in many countries, with higher incidence of severe disease and mortality rates in pregnant women and in those with comorbidities. As there is currently no specific treatment for dengue and no early biomarker to identify those who will progress to develop vascular leakage, all individuals with dengue are closely monitored in case they need fluid management. Furthermore, diagnosing patients with acute dengue is challenging due to the similarity of clinical symptoms during early illness and poor sensitivity and specificity of point-of-care diagnostic tests. Novel vector control methods, such as the release of Wolbachia-infected mosquitoes, have shown promising results by reducing vector density and dengue incidence in clinical trial settings. A new dengue vaccine, TAK-003, had an efficacy of 61.2% against virologically confirmed dengue, 84.1% efficacy against hospitalizations and a 70% efficacy against development of dengue haemorrhagic fever (DHF) at 54 months. While vaccines and mosquito control methods are welcome, they alone are unlikely to fully reduce the burden of dengue, and a treatment for dengue is therefore essential. Several novel antiviral drugs are currently being evaluated along with drugs that inhibit host mediators, such as mast cell products. Although viral proteins such as NS1 contribute to the vascular leak observed in severe dengue, the host immune response to the viral infection also plays a significant role in progression to severe disease. There is an urgent need to discover safe and effective treatments for dengue to prevent disease progression.

Comparison of clinical and laboratory parameters of primary vs secondary dengue fever in travellers

BACKGROUND

Dengue fever (DF), caused by the dengue virus (DENV), is the most common arboviral disease in travellers worldwide. It is hypothesized that compared with primary DF, secondary DF may result in antibody-dependent enhancement of the immune response, resulting in more severe disease. We aimed to compare clinical and laboratory parameters in travellers with primary and secondary DF to determine whether secondary DF is associated with markers of severe disease.

METHODS

We conducted a retrospective cohort study, which included all patients diagnosed with DF at the Central Virology Laboratory of the Israeli Ministry of Health during 2008-19. Clinical, laboratory and virological data were extracted from laboratory and patient records. A diagnosis of DENV infection was based on a positive nonstructural protein 1 (NS1) test, polymerase chain reaction or serology testing for immunoglobulin M (IgM) and immunoglobulin G (IgG). Primary and secondary infections were classified based on travel history, NS1 result and IgM/IgG ratio. Severe DF was defined according to WHO classification.

RESULTS

We identified 245 DF cases: 210 (86%) primary and 35 (14%) secondary. Whilst fever duration was significantly longer in secondary compared with primary infections (6.4 vs 5.3 days, P = 0.027), mean Aspartate aminotransferase levels were significantly higher in primary compared with secondary cases (146 vs 65 U/L, P < 0.001), and no other clinical or laboratory parameter differed significantly between the groups. Of note, only four patients had severe DF, all had primary infections and none died.

CONCLUSIONS

In a cohort of returning travellers with DF, secondary infection, compared with primary infection, was not associated with a consistent trend towards greater severity of the clinical and laboratory markers examined in this study.

Genetic Association Studies of MICB and PLCE1 with Severity of Dengue in Indonesian and Taiwanese Populations

Dengue is an arboviral disease that has spread globally and become a major public health concern. A small proportion of patients may progress from symptomatic dengue fever (DF) to dengue hemorrhagic fever (DHF) or dengue shock syndrome (DSS). Findings from a previous genome-wide association study (GWAS) demonstrated that variations in the major histocompatibility complex (MHC) class I chain-related B (MICB) and the phospholipase C epsilon 1 (PLCE1) genes were related to DSS in a Vietnamese population. This study investigated associations of variations in MICB (rs3132468) and PLCE1 (rs3740360, rs3765524) with dengue severity and thrombocytopenia in both the Indonesian and Taiwanese populations. We sampled 160 patients from the Indonesian population and 273 patients from the Taiwanese population. None of the patients had DSS in the Taiwanese population. Based on age demographics, we found that dengue is more prevalent among younger individuals in the Indonesian population, whereas it has a greater impact on adults in the Taiwanese population. Our results showed the association between MICB rs3132468 and DSS. In addition, an association was identified between PLCE1 rs3740360 and DHF in secondary dengue in Indonesian patients. However, there is no association of MICB or PLCE1 variants with thrombocytopenia. This study highlights the value of genetic testing, which might be included in the clinical pathway for specific patients who can be protected from severe dengue.

Influence of previous Zika virus infection on acute dengue episode

BACKGROUND

The co-circulation of flaviviruses in tropical regions has led to the hypothesis that immunity generated by a previous dengue infection could promote severe disease outcomes in subsequent infections by heterologous serotypes. This study investigated the influence of antibodies generated by previous Zika infection on the clinical outcomes of dengue infection.

METHODOLOGY/PRINCIPAL FINDINGS

We enrolled 1,043 laboratory confirmed dengue patients and investigated their prior infection to Zika or dengue. Severe forms of dengue disease were more frequent in patients with previous Zika infection, but not in those previously exposed to dengue.

CONCLUSIONS/SIGNIFICANCE

Our findings suggest that previous Zika infection may represent a risk factor for subsequent severe dengue disease, but we did not find evidence of antibody-dependent enhancement (higher viral titer or pro-inflammatory cytokine overexpression) contributing to exacerbation of the subsequent dengue infection.

Early biomarkers for prediction of severe manifestations of dengue fever: a systematic review and a meta-analysis

Early identification of dengue patients at risk of adverse outcomes is important to prevent hospital overcrowding in low- to middle- income countries during epidemics. We performed a systematic review to identify which biomarkers measured in first 96 h of fever could predict dengue haemorrhagic fever (DHF, World Health Organization 1997 clinical classification) or severe dengue (SD, WHO 2009, clinical classification). PubMed, Scopus, CINAHL, Web of Science, and EMBASE databases were searched for prospective cohort and nested case-control studies published from 1997 to Feb 27, 2022. The protocol for the study was registered in PROSPERO (ID: CRD42021230053). After screening 6747 publications, and analysing 37 eligible studies reporting on 5925 patients, elevated C-reactive protein, aspartate aminotransferase, interleukin-8 and decreased albumin levels were strongly associated with dengue haemorrhagic fever (by meta-analyses of multiple studies, p < 0.05), while elevated vascular cell adhesion protein 1, syndecan-1, aspartate aminotransferase and C-reactive protein levels were strongly associated with severe dengue (by meta-analyses of multiple studies, p < 0.05). Further 44 and 28 biomarkers were associated with the risk of DHF and SD respectively, but only in a single study. The meta-analyses suggest the importance of early acute inflammation with hepatic involvement in determining the subsequent course of illness in dengue.

Bayesian Analysis Used to Identify Clinical and Laboratory Variables Capable of Predicting Progression to Severe Dengue among Infected Pediatric Patients

The current contribution aimed to evaluate the capacity of the naive Bayes classifier to predict the progression of dengue fever to severe infection in children based on a defined set of clinical conditions and laboratory parameters. This case-control study was conducted by reviewing patient files in two public hospitals in an endemic area in Mexico. All 99 qualifying files showed a confirmed diagnosis of dengue. The 32 cases consisted of patients who entered the intensive care unit, while the 67 control patients did not require intensive care. The naive Bayes classifier could identify factors predictive of severe dengue, evidenced by 78% sensitivity, 91% specificity, a positive predictive value of 8.7, a negative predictive value of 0.24, and a global yield of 0.69. The factors that exhibited the greatest predictive capacity in the model were seven clinical conditions (tachycardia, respiratory failure, cold hands and feet, capillary leak leading to the escape of blood plasma, dyspnea, and alterations in consciousness) and three laboratory parameters (hypoalbuminemia, hypoproteinemia, and leukocytosis). Thus, the present model showed a predictive and adaptive capacity in a small pediatric population. It also identified attributes (i.e., hypoalbuminemia and hypoproteinemia) that may strengthen the WHO criteria for predicting progression to severe dengue.

Mechanisms and clinical relevance of the bidirectional relationship of viral infections with metabolic diseases

Viruses have been present during all evolutionary steps on earth and have had a major effect on human history. Viral infections are still among the leading causes of death. Another public health concern is the increase of non-communicable metabolic diseases in the last four decades. In this Review, we revisit the scientific evidence supporting the presence of a strong bidirectional feedback loop between several viral infections and metabolic diseases. We discuss how viruses might lead to the development or progression of metabolic diseases and conversely, how metabolic diseases might increase the severity of a viral infection. Furthermore, we discuss the clinical relevance of the current evidence on the relationship between viral infections and metabolic disease and the present and future challenges that should be addressed by the scientific community and health authorities.

Adipokine levels and their association with clinical disease severity in patients with dengue

Adipokines have not been studied in acute dengue, despite their emerging role in inducing and regulating inflammation. Therefore, we sought to identify adipokine levels in patients with varying severities of acute dengue to understand their role in disease pathogenesis. We determined the levels of leptin, resistin, omentin, adiponectin, as well as IFNβ, and NS1 using quantitative ELISA in patients with dengue fever (DF = 49) and dengue haemorrhagic fever (DHF = 22) at admission (febrile phase) and at the time of discharge (recovery phase). The viral loads and serotypes of all samples were quantified using quantitative real-time RT-PCR. Resistin levels (p = 0.04) and omentin (p = 0.006) levels were significantly higher in patients who developed DHF. Omentin levels in the febrile phase also correlated with the AST (Spearman's r = 0.38, p = 0.001) and ALT levels (Spearman's r = 0.24, p = 0.04); as well as serum leptin levels with both AST (Spearman's r = 0.27, p = 0.02) and ALT (Spearman's r = 0.28, p = 0.02). Serum adiponectin levels in the febrile phase did not correlate with any of the other adipokines or with liver enzymes, but inversely correlated with CRP levels (Spearman's r = -0.31, p = 0.008). Although not significant (p = 0.14) serum IFNβ levels were lower in the febrile phase in those who progressed to develop DHF (median 0, IQR 0 to 39.4 pg/ml), compared to those who had DF (median 37.1, IQR 0 to 65.6 pg.ml). The data suggest that adipokines are likely to play a role in the pathogenesis of dengue, which should be further explored for the potential to be used as prognostic markers and as therapeutic targets.

Advanced Age and Increased Risk for Severe Outcomes of Dengue Infection, Taiwan, 2014-2015

Dengue, a mosquitoborne flavivirus infection, is increasingly a disease of older adults who are more likely to have chronic diseases that confer risk for severe outcomes of dengue infection. In a population-based study in Taiwan, adjusted risks for dengue-related hospitalization, intensive care unit admission, and death increased progressively with age.

Identification of prior dengue-naïve Dengvaxia recipients with an increased risk for symptomatic dengue during fever surveillance in the Philippines

Introduction

Dengue virus (DENV) is the leading cause of mosquito-borne viral diseases in humans. Dengvaxia, the first licensed dengue vaccine, is recommended for DENV-seropositive individuals aged 9-45 years. In the Philippines, Dengvaxia was administered to more than 830,000 children without prior serological testing in 2016-2017. Subsequently, it was revealed that DENV-seronegative children who received Dengvaxia developed severe disease following breakthrough DENV infection. As a result, thousands of children participating in the mass vaccination campaign were at higher risk of severe dengue disease. It is vital that an assay that identifies baseline DENV-naïve Dengvaxia recipients be developed and validated. This would permit more frequent and extensive assessments and timely treatment of breakthrough DENV infections.

Methods

We evaluated the performance of a candidate assay, the DENV1-4 nonstructural protein 1 (NS1) IgG enzyme-linked immunosorbent assay (ELISA), developed by the University of Hawaii (UH), using well-documented serum/plasma samples including those >20 years post-DENV infection, and tested samples from 199 study participants including 100 Dengvaxia recipients from the fever surveillance programs in the Philippines.

Results

The sensitivity and specificity of the assay were 96.6% and 99.4%, respectively, which are higher than those reported for pre-vaccination screening. A significantly higher rate of symptomatic breakthrough DENV infection was found among children that were DENV-naïve (10/23) than among those that were DENV-immune (7/53) when vaccinated with Dengvaxia (p=0.004, Fisher's exact test), demonstrating the feasibility of the assay and algorithms in clinical practice.

Conclusion

The UH DENV1-4 NS1 IgG ELISA can determine baseline DENV serostatus among Dengvaxia recipients not only during non-acute dengue but also during breakthrough DENV infection, and has implications for assessing the long-term safety and effectiveness of Dengvaxia in the post-licensure period.

Twenty-two years of dengue outbreaks in Bangladesh: epidemiology, clinical spectrum, serotypes, and future disease risks

Dengue is the most rapidly spreading mosquito-borne disease and has become a major public health threat, particularly for tropical and subtropical countries including Bangladesh. This comprehensive review aims to summarize the overall scenario of dengue, including disease burden, clinical spectrum, seroprevalence, circulating serotypes/genotypes, and spatial distribution since the first recorded outbreak in Bangladesh. Since the first recorded outbreak in 2000, dengue epidemiology has shown the typical epidemic pattern with more frequent and bigger outbreaks and gradual geographic expansion to non-endemic regions in Bangladesh. For instance, highly confined Rohingya refugee camps that provide shelters to nearly 1.2 million forcibly displaced vulnerable Myanmar nationals in Cox's Bazar district confronted a massive outbreak in 2022. Recent major outbreaks are found to be associated with the emergence of serotype DENV-3, which was undetected for a long time. Consequently, changes in serotypes might be attributed to increased severity in clinical manifestation in recent years. The existing weak surveillance and risk management systems are inadequate to deal with impending dengue risks. The healthcare system, particularly at the district level, is not prepared to manage impending large-scale dengue outbreaks in Bangladesh. Our findings would contribute to the development of strategies for dengue control and management in Bangladesh as well as other similar settings elsewhere in the world.

From dengue outbreaks to endemicity: Reunion Island, France, 2018 to 2021

BackgroundAfter 40 years of limited viral circulation, Reunion Island has since 2018 experienced recurrent dengue outbreaks of increasing intensity and severity.AimWe aimed to report on the epidemiology and characteristics of dengue in Reunion Island between 2018 and 2021.MethodsBetween 2018 and August 2021, we systematically collected data on dengue cases via an automated transmission system between the health authorities and the medical laboratories. We set up additional surveillance systems for dengue-related activity in primary care, in emergency departments and in inpatient departments.ResultsUntil 2020, despite numerous cases, outbreaks had a limited public health impact because of few severe cases, low lethality and no heavy burden for the health care system. In 2021, however, the number of severe cases increased (from 0.4% of all cases in 2018 to 0.8% in 2021), as did the number of paediatric cases (from 8% in 2018 to 15% in 2021) and atypical clinical forms of dengue (108 cases of post-dengue maculopathy). Of note, haemorrhagic forms were rare and multi-organ failure was the most frequent severity throughout the study period. In parallel, the dominant serotype switched from DENV2 to DENV1 in 2020 and DENV1 became the only serotype detected in 2021.ConclusionThese findings indicate that dengue is becoming endemic in Reunion Island. Since comorbidities associated with severity of dengue are common in the population, health authorities should carefully consider the impact of dengue when addressing public health policies.

Dengue clinical features and harbingers of severity in the diabetic patient: A retrospective cohort study on Reunion island, 2019

AIM

Diabetes mellitus is associated with both the risks of severe dengue and dengue-related deaths, however the factors characterizing dengue in the diabetic patient are ill-recognized. The objective of this hospital-based cohort study was to identify the factors characterizing dengue and those able to early identify dengue severity in the diabetic patient.

METHODS

We retrospectively analysed demographic, clinical and biological parameters at admission in the cohort of patients who consulted at the university hospital between January and June 2019 with confirmed dengue. Bivariate and multivariate analyses were conducted.

RESULTS

Of 936 patients, 184 patients (20%) were diabetic. One hundred and eighty-eight patients (20%) developed severe dengue according to the WHO 2009 definition. Diabetic patients were older and had more comorbidities than non-diabetics. In an age-adjusted logistic regression model, loss of appetite, altered mental status, high neutrophil to platelet ratios (>14.7), low haematocrit (≤ 38%), upper-range serum creatinine (>100 µmol/l) and high urea to creatinine ratio (>50) were indicative of dengue in the diabetic patient. A modified Poisson regression model identified four key independent harbingers of severe dengue in the diabetic patient: presence of diabetes complications, non-severe bleeding, altered mental status and cough. Among diabetes complications, diabetic retinopathy and neuropathy, but not diabetic nephropathy nor diabetic foot, were associated with severe dengue.

CONCLUSION

At hospital first presentation, dengue in the diabetic patient is characterized by deteriorations in appetite, mental and renal functioning, while severe dengue can be early identified by presence of diabetes complications, dengue-related non-severe haemorrhages, cough, and dengue-related encephalopathy.

Clinical Characteristics and Outcomes Among Travelers With Severe Dengue : A GeoSentinel Analysis

BACKGROUND

Dengue virus is a flavivirus transmitted by Aedes mosquitoes and is an important cause of illness worldwide. Data on the severity of travel-associated dengue illness are limited.

OBJECTIVE

To describe the epidemiology, clinical characteristics, and outcomes among international travelers with severe dengue or dengue with warning signs as defined by the 2009 World Health Organization classification (that is, complicated dengue).

DESIGN

Retrospective chart review and analysis of travelers with complicated dengue reported to GeoSentinel from January 2007 through July 2022.

SETTING

20 of 71 international GeoSentinel sites.

PATIENTS

Returning travelers with complicated dengue.

MEASUREMENTS

Routinely collected surveillance data plus chart review with abstraction of clinical information using predefined grading criteria to characterize the manifestations of complicated dengue.

RESULTS

Of 5958 patients with dengue, 95 (2%) had complicated dengue. Eighty-six (91%) patients had a supplemental questionnaire completed. Eighty-five of 86 (99%) patients had warning signs, and 27 (31%) were classified as severe. Median age was 34 years (range, 8 to 91 years); 48 (56%) were female. Patients acquired dengue most frequently in the Caribbean (n = 27 [31%]) and Southeast Asia (n = 21 [24%]). Frequent reasons for travel were tourism (46%) and visiting friends and relatives (32%). Twenty-one of 84 (25%) patients had comorbidities. Seventy-eight (91%) patients were hospitalized. One patient died of nondengue-related illnesses. Common laboratory findings and signs were thrombocytopenia (78%), elevated aminotransferase (62%), bleeding (52%), and plasma leakage (20%). Among severe cases, ophthalmologic pathology (n = 3), severe liver disease (n = 3), myocarditis (n = 2), and neurologic symptoms (n = 2) were reported. Of 44 patients with serologic data, 32 confirmed cases were classified as primary dengue (IgM+/IgG-) and 12 as secondary (IgM-/IgG+) dengue.

LIMITATIONS

Data for some variables could not be retrieved by chart review for some patients. The generalizability of our observations may be limited.

CONCLUSION

Complicated dengue is relatively rare in travelers. Clinicians should monitor patients with dengue closely for warning signs that may indicate progression to severe disease. Risk factors for developing complications of dengue in travelers need further prospective study.

PRIMARY FUNDING SOURCE

Centers for Disease Control and Prevention, International Society of Travel Medicine, Public Health Agency of Canada, and GeoSentinel Foundation.

Dengue hepatitis: Incidence, spectrum and outcome

BACKGROUND AND AIMS

While dengue infection is common in India, there is scarce information on dengue hepatitis. The aim of this study was to analyze the incidence, spectrum and outcome of dengue hepatitis.

METHODS

We retrospectively analyzed consecutive patients, who had hepatitis among those with dengue infection admitted to two tertiary care hospitals in western India from January 2016 to March 2021. Diagnosis of dengue infection was made by serology. Dengue hepatitis was diagnosed and the severity of dengue was categorized by standard criteria.

RESULTS

Of 1664 patients admitted with dengue fever during the study period, 199 patients had hepatitis (i.e. incidence of dengue hepatitis was 11.9%). Of the 199 dengue hepatitis patients (age: 29 [13 - 80] years, median [range], 67% males), 100 patients (50%) had severe dengue, 73 (36%) had severe dengue hepatitis, 32 (16%) had dengue shock syndrome and eight (4%) had acute liver failure. Forty-five patients (23%) had acute lung injury and 32 (16%) had acute kidney injury. The dengue hepatitis patients were treated with standard medical care, including vital organ support, as needed-166 (83%) patients survived, while 33 patients (17%) died (cause of death: multi-organ failure: 24 patients, septic shock: nine patients). The presence of shock independently predicted mortality (odds ratio 6.4, 95% confidence interval: 1.2 - 34). Among patients with dengue hepatitis, mortality rate was higher in those with severe dengue (23%), dengue shock syndrome (47%), severe dengue hepatitis (24%) and acute liver failure (38%).

CONCLUSION

In this large series of hospitalized patients with dengue infection, the incidence of dengue hepatitis was 11.9%. Among 199 dengue hepatitis, 17% died; multi-organ failure was the commonest cause for death and death rate was higher in patients with more severe disease. The presence of shock at presentation independently predicted mortality.

Aminotransferases in Relation to the Severity of Dengue: A Systematic Review

A systematic review was conducted to investigate the relationship between aminotransferases and the severity of dengue infection, which is a prevalent and significant infection in tropical and subtropical regions. Aminotransferases are enzymes that are often elevated in dengue due to the liver's physiological and immunological response to the infection. This review focused on analyzing various studies that examined the correlation between aminotransferase levels and the severity of dengue. Extensive literature searches were performed using ("dengue*" OR "dengue fever*" OR "dengue haemorrhagic fever*" OR "dengue shock syndrome*") AND ("alanine aminotransferase*" OR "aspartate aminotransferase*") on PubMed. The selected articles were thoroughly reviewed, encompassing epidemiology, pathogenesis, and clinical manifestations of dengue. The consistent findings across the studies indicated that aminotransferases can serve as predictive markers for dengue severity. Therefore, early assessment of liver enzyme levels is crucial in dengue cases, and elevated levels should be closely monitored to prevent adverse outcomes.

Associated risk factors of severe dengue in Reunion Island: A prospective cohort study

BACKGROUND

Since 2018, a dengue epidemic has been raging annually in Reunion Island, which poses the major problem of its morbidity and mortality. However, there is no consensus in the literature on factors associated with severity of illness. The objective of this study was to identify the factors associated with the occurrence of severe dengue (SD) according to the criteria adopted in 2009 by the World Health Organization (WHO), during the 2019 epidemic.

METHODOLOGY/PRINCIPAL FINDINGS

A total of 163 patients with RT-PCR-confirmed dengue were included in a multicenter prospective cohort study in Reunion Island between January and June 2019. Of these, 37 (23%) were classified as SD, which involves presentation dominated by at least one organ failure, and 126 (77%) classified as non-SD (of which 90 (71%) had warning signs). Confusion, dehydration, and relative hypovolemia were significantly associated with SD in bivariate analysis (p < 0.05). The factors associated with SD in multivariate analysis were a time from first symptom to hospital consultation over 2 days (OR: 2.46, CI: 1.42-4.27), a history of cardiovascular disease (OR: 2.75, 95%CI: 1.57-4.80) and being of Western European origin (OR: 17.60, CI: 4.15-74).

CONCLUSIONS/SIGNIFICANCE

This study confirms that SD is a frequent cause of hospitalization during dengue epidemics in Reunion Island. It suggests that cardiovascular disease, Western European origin, and delay in diagnosis and management are risk factors associated with SD fever, and that restoration of blood volume and correction of dehydration must be performed early to be effective.

TRIAL REGISTRATION

NCT01099852; clinicaltrials.gov.

Is new dengue vaccine efficacy data a relief or cause for concern?

Dengue is a major global public health problem requiring a safe and efficacious vaccine as the foundation of a comprehensive countermeasure strategy. Despite decades of attempts, the world has a single dengue vaccine licensed in numerous countries, but restrictions and conditions of its use have deterred uptake. Recently, clinical efficacy data has been revealed for two additional dengue vaccine candidates and the data appears encouraging. In this perspective I discuss dengue, the complexities of dengue vaccine development, early development setbacks, and how the latest data from the field may be cause for measured optimism. Finally, I provide some perspectives on evaluating dengue vaccine performance and how the pursuit of the perfect dengue vaccine may prevent advancement of vaccines which are good enough.

The association of obesity and dengue severity in hospitalized adult patients

BACKGROUND

Obesity is associated with unfavorable outcomes for infectious diseases. Most researches exploring the association between nutritional status and dengue severity have focused on pediatric populations, with only few studies assessing adult patients.

METHODS

Adult patients with laboratory-confirmed dengue admitted to a tertiary hospital in southern Taiwan between 2014 and 2015 were enrolled retrospectively. Demographics, comorbidities, clinical presentation, laboratory findings, and outcomes were obtained from case-record forms. Patients were categorized into obese group and nonobese group. The obese group comprised patients with a body mass index of ≥27.5 kg/m².

RESULTS

A total of 1417 hospitalized patients with dengue were evaluated. The mean age was 57.9 years (range: 18-92 years). The obese and nonobese groups comprised 333 (23.5%) and 1084 (76.5%) patients, respectively. The obese group included more patients with hypertension (85%, p < 0.001), diabetes mellitus (33%, p < 0.001), and congestive heart failure (6.3%, p = 0.049). Multivariate analysis revealed that the obese group had more petechiae (AOR: 1.353, 95% CI: 1.025-1.786, p = 0.033), more dyspnea (AOR: 1.380, 95% CI: 1.015-1.876, p = 0.040), and more severe hepatitis (AOR: 2.061, 95% CI: 1.050-4.048, p = 0.036). The obese group also had higher peak hematocrit values (44.1%, p < 0.001) and lower nadir platelet count (45.3 × 10³/μL, p = 0.049) than the nonobese group.

CONCLUSION

In adult patients with dengue, obese group had more petechiae, dyspnea, severe hepatitis, lower nadir of platelet count, and higher peak hematocrit level. We observed no difference in severe dengue or mortality between obese and nonobese group.

Changing epidemiology of dengue fever in children in South America

PURPOSE OF REVIEW

Dengue is the most important arthropod-borne viral disease of public health significance. Its geographic distribution includes 128 countries worldwide, affecting 390 million people every year causing significant morbidity and mortality in children and adults everywhere.

RECENT FINDINGS

In the past, severe dengue affected mostly adults in the Americas; this scenario has changed and now cases of dengue, severe dengue, and dengue deaths have increased in children under 15 years in Brazil and in Colombia. Dengue and COVID-19 co-infections have been reported in South America, with increased hospitalization. A dengue vaccine for 9-year-old children and older children and adults who have serological evidence of previous dengue has been licensed in many countries; a different dengue vaccine trial for 4-16-year-old children has demonstrated decrease in clinical dengue and decrease in dengue hospitalizations.

SUMMARY

There is no specific treatment of dengue, and a changing climate, insecticide resistance and urban expansion have permitted the vector's spread, making the vector control almost impossible. The hope for dengue control relies on vaccine development; there is important research on this area with one vaccine already licensed and another one showing promising results.

Development and Utility of Practical Indicators of Critical Outcomes in Dengue Patients Presenting to Hospital: A Retrospective Cross-Sectional Study

Global travel and climate change have drastically increased the number of countries with endemic or epidemic dengue. The largest dengue outbreak in Taiwan, with 43,419 cases and 228 deaths, occurred in 2015. Practical and cost-effective tools for early prediction of clinical outcomes in dengue patients, especially the elderly, are limited. This study identified the clinical profile and prognostic indicators of critical outcomes in dengue patients on the basis of clinical parameters and comorbidities. A retrospective cross-sectional study was conducted in a tertiary hospital from 1 July 2015 to 30 November 2015. Patients diagnosed with dengue were enrolled, and the initial clinical presentations, diagnostic laboratory data, details of the underlying comorbidities, and initial management recommendations based on 2009 World Health Organization (WHO) guidelines were used to evaluate prognostic indicators of critical outcomes in dengue patients. Dengue patients from another regional hospital were used to evaluate accuracy. A group B (4 points) classification, temperature < 38.5 °C (1 point), lower diastolic blood pressure (1 point), prolonged activated partial thromboplastin time (aPTT) (2 points), and elevated liver enzymes (1 point) were included in the scoring system. The area under the receiver operating characteristic curve of the clinical model was 0.933 (95% confidence interval [CI]: 0.905–0.960). The tool had good predictive value and clinical applicability for identifying patients with critical outcomes.

Magnitude and kinetics of the human immune cell response associated with severe dengue progression by single-cell proteomics

Approximately 5 million dengue virus-infected patients progress to a potentially life-threatening severe dengue (SD) infection annually. To identify the immune features and temporal dynamics underlying SD progression, we performed deep immune profiling by mass cytometry of PBMCs collected longitudinally from SD progressors (SDp) and uncomplicated dengue (D) patients. While D is characterized by early activation of innate immune responses, in SDp there is rapid expansion and activation of IgG-secreting plasma cells and memory and regulatory T cells. Concurrently, SDp, particularly children, demonstrate increased proinflammatory NK cells, inadequate expansion of CD16⁺ monocytes, and high expression of the FcγR CD64 on myeloid cells, yet a signature of diminished antigen presentation. Syndrome-specific determinants include suppressed dendritic cell abundance in shock/hemorrhage versus enriched plasma cell expansion in organ impairment. This study reveals uncoordinated immune responses in SDp and provides insights into SD pathogenesis in humans with potential implications for prediction and treatment.

Discrepant Activation Pattern of Inflammation and Pyroptosis Induced in Dermal Fibroblasts in Response to Dengue Virus Serotypes 1 and 2 and Nonstructural Protein 1

Four serotypes of dengue virus (DENV-1 to DENV-4) cause mild to severe disease in humans through infected mosquito bites. Dermal fibroblasts were found to be susceptible to DENV, and this may play a critical role in establishing the initial infection stage. However, the cellular response induced by the different DENV serotypes in dermal fibroblasts during the early stage of infection remains unclear. To determine this, normal human dermal fibroblast WS1 cells were infected with DENV-1 or DENV-2. Compared with the response elicited by DENV-1 infection, DENV-2 induced a stronger innate inflammatory response and cell death in the WS1 cells. However, DENV-1 activated a higher level of pyroptosis signaling than did DENV-2, which was associated with higher virion production. Caspase-1 inhibitor Ac-YVAD-cmk and imipramine, an antidepressant drug, reduced DENV-mediated caspase-1 and interleukin 1β (IL-β) cleavage in the pyroptosis pathway. Ac-YVAD-cmk and imipramine downregulated DENV virion production in WS1 cells. Furthermore, DENV-1 and DENV-2 NS1 proteins promoted diverse activation levels of cell death, inflammatory response, and activation of caspase-1 and IL-β in dermal fibroblasts at different time points. Collectively, these data suggest that DENV-1, DENV-2, and their nonstructural protein 1 (NS1) induce discrepant activation patterns of inflammation and pyroptosis in dermal fibroblasts. The pyroptosis caused by virus and NS1 may facilitate DENV replication in dermal fibroblasts. IMPORTANCE Skin fibroblasts are the primary cells of DENV infection through mosquito bites. Establishing a successful infection in dermal fibroblasts might be critical for dengue disease. However, the cellular response induced by DENV in dermal fibroblasts remains unclear. In this in vitro study, we found that DENV-2 and DENV-1 showed different time course patterns of virus replication and inflammation in dermal fibroblasts. We demonstrated that DENV-1 and DNEV-2 and their viral protein NS1 activate the cellular pyroptosis response to regulate virus replication in dermal fibroblasts. This finding suggests that pyroptosis activation in the DENV primary inoculation site plays a role in the establishment of a DENV infection.

Identification of risk areas for arboviruses transmitted by Aedes aegypti in northern Brazil: A One Health analysis

Introduction

The complex and growing problem generated by the rapid expansion of unplanned urban areas includes high population density and increased infestation by vectors responsible for the transmission of several diseases. This requires interdisciplinary and intersectoral interventions due to the burden of diseases, especially those caused by arboviruses, which can present severe forms and generate significant pressure on health systems, especially in more vulnerable regions. The objective of this study was to analyze the spatial distribution of arboviruses transmitted by Aedes aegypti (dengue, Zika, and chikungunya) and assess their correlations with demographic, social, and environmental data from the state of Tocantins, Brazil.

Methods

This was an ecological time series study of the dengue, Zika, and chikungunya arboviruses in the state of Tocantins. Local Moran's indices were used to observe the spatial autocorrelation of cases and to delimit clusters of high and low risks, correlating them with socioenvironmental indicators, in addition to analyses to detect case clusters.

Results

The state reported a mean incidence of 591 annual cases of arbovirus infections per 100,000 inhabitants and a stationary trend with seasonal pattern. Female Pardo individuals aged 20-39 years, with an education level of below college education, were the most affected; Palmas and Araguaína, the two largest cities in the state in terms of economy and population, were the most affected.

Conclusion

A better understanding of the interaction between social characteristics, the environment, and ecology of wild animals and vectors is important for the development of mechanisms to predict outbreaks as well as to develop strategies to reduce and/or mitigate recurring arboviral epidemics and other diseases.

Mapping patient pathways and understanding clinical decision-making in dengue management to inform the development of digital health tools

BACKGROUND

Dengue is a common viral illness and severe disease results in life-threatening complications. Healthcare services in low- and middle-income countries treat the majority of dengue cases worldwide. However, the clinical decision-making processes which result in effective treatment are poorly characterised within this setting. In order to improve clinical care through interventions relating to digital clinical decision-support systems (CDSS), we set out to establish a framework for clinical decision-making in dengue management to inform implementation.

METHODS

We utilised process mapping and task analysis methods to characterise existing dengue management at the Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam. This is a tertiary referral hospital which manages approximately 30,000 patients with dengue each year, accepting referrals from Ho Chi Minh city and the surrounding catchment area. Initial findings were expanded through semi-structured interviews with clinicians in order to understand clinical reasoning and cognitive factors in detail. A grounded theory was used for coding and emergent themes were developed through iterative discussions with clinician-researchers.

RESULTS

Key clinical decision-making points were identified: (i) at the initial patient evaluation for dengue diagnosis to decide on hospital admission and the provision of fluid/blood product therapy, (ii) in those patients who develop severe disease or other complications, (iii) at the point of recurrent shock in balancing the need for fluid therapy with complications of volume overload. From interviews the following themes were identified: prioritising clinical diagnosis and evaluation over existing diagnostics, the role of dengue guidelines published by the Ministry of Health, the impact of seasonality and caseload on decision-making strategies, and the potential role of digital decision-support and disease scoring tools.

CONCLUSIONS

The study highlights the contemporary priorities in delivering clinical care to patients with dengue in an endemic setting. Key decision-making processes and the sources of information that were of the greatest utility were identified. These findings serve as a foundation for future clinical interventions and improvements in healthcare. Understanding the decision-making process in greater detail also allows for development and implementation of CDSS which are suited to the local context.

Dengue in Pregnancy: A Southeast Asian Perspective

Dengue cases have been rising in recent years. In 2019 alone, over 658,301 of the 5.6 million reported cases originated from Southeast Asia (SEA). Research has also shown detrimental outcomes for pregnant infected women. Despite this, existing literature describing dengue's effects on pregnancy in SEA is insufficient. Through this narrative review, we sought to describe dengue's effects on pregnancy systemically and emphasize the existing gaps in the literature. We extensively searched various journals cited in PubMed and Ovid Medline, national clinical practice guidelines, and governmental reports. Dengue in pregnancy increases the risk of pre-eclampsia, Dengue Hemorrhagic Fever (DHF), fetal distress, preterm delivery, Caesarean delivery, and maternal mortality. Vertical transmission, intrauterine growth restriction, and stillbirth are possible sequelae of dengue in fetuses. We found that trimester-specific physiological impacts of dengue in pregnancy (to both mother and child) and investigations and management methods demanded further research, especially in the SEA region.

Adipokine levels and their association with clinical disease severity in patients with dengue

Adipokines have not been studied in acute dengue, despite their emerging role in inducing and regulating inflammation. Therefore, we sought to identify adipokine levels in patients with varying severities of acute dengue to understand their role in disease pathogenesis. We determined the levels of leptin, resistin, omentin, adiponectin, as well as IFNβ, and NS1 using quantitative ELISA in patients with dengue fever (DF=49) and dengue haemorrhagic fever (DHF=22) at admission (febrile phase) and at the time of discharge (recovery phase). The viral loads and serotypes of all samples were quantified using quantitative real-time RT-PCR. Resistin levels (p =0.04) and omentin (p=0.006) levels were significantly higher in patients who developed DHF. Omentin levels in the febrile phase also correlated with the AST (Spearman's r=0.38, p=0.001) and ALT levels (Spearman's r=0.24, p=0.04); as well as serum leptin levels with both AST (Spearman's r=0.27, p=0.02) and ALT (Spearman's r=0.28, p=0.02). Serum adiponectin levels in the febrile phase did not correlate with any of the other adipokines or with liver enzymes, but inversely correlated with CRP levels (Spearman's r=-0.31, p=0.008). Although not significant (p=0.14) serum IFNβ levels were lower in the febrile phase in those who progressed to develop DHF (median 0, IQR 0 to 39.4 pg/ml), compared to those who had DF (median 37.1, IQR 0 to 65.6 pg.ml). The data suggest that adipokines are likely to play a role in the pathogenesis of dengue, which should be further explored for the potential to be used as prognostic markers and as therapeutic targets.

Learning meaningful latent space representations for patient risk stratification: Model development and validation for dengue and other acute febrile illness

Background

Increased data availability has prompted the creation of clinical decision support systems. These systems utilise clinical information to enhance health care provision, both to predict the likelihood of specific clinical outcomes or evaluate the risk of further complications. However, their adoption remains low due to concerns regarding the quality of recommendations, and a lack of clarity on how results are best obtained and presented.

Methods

We used autoencoders capable of reducing the dimensionality of complex datasets in order to produce a 2D representation denoted as latent space to support understanding of complex clinical data. In this output, meaningful representations of individual patient profiles are spatially mapped in an unsupervised manner according to their input clinical parameters. This technique was then applied to a large real-world clinical dataset of over 12,000 patients with an illness compatible with dengue infection in Ho Chi Minh City, Vietnam between 1999 and 2021. Dengue is a systemic viral disease which exerts significant health and economic burden worldwide, and up to 5% of hospitalised patients develop life-threatening complications.

Results

The latent space produced by the selected autoencoder aligns with established clinical characteristics exhibited by patients with dengue infection, as well as features of disease progression. Similar clinical phenotypes are represented close to each other in the latent space and clustered according to outcomes broadly described by the World Health Organisation dengue guidelines. Balancing distance metrics and density metrics produced results covering most of the latent space, and improved visualisation whilst preserving utility, with similar patients grouped closer together. In this case, this balance is achieved by using the sigmoid activation function and one hidden layer with three neurons, in addition to the latent dimension layer, which produces the output (Pearson, 0.840; Spearman, 0.830; Procrustes, 0.301; GMM 0.321).

Conclusion

This study demonstrates that when adequately configured, autoencoders can produce two-dimensional representations of a complex dataset that conserve the distance relationship between points. The output visualisation groups patients with clinically relevant features closely together and inherently supports user interpretability. Work is underway to incorporate these findings into an electronic clinical decision support system to guide individual patient management.

John AL, Rathore APS. Dengue: Update on Clinically Relevant Therapeutic Strategies and Vaccines

Dengue viruses (DENV) continue to circulate worldwide, resulting in a significant burden on human health. There are four antigenically distinct serotypes of DENV, an infection of which could result in a potentially life-threatening disease. Current treatment options are limited and rely on supportive care. Although one dengue vaccine is approved for dengue-immune individuals and has modest efficacy, there is still a need for therapeutics and vaccines that can reduce dengue morbidities and lower the infection burden. There have been recent advances in the development of promising drugs for the treatment of dengue. These include direct antivirals that can reduce virus replication as well as host-targeted drugs for reducing inflammation and/or vascular pathologies. There are also new vaccine candidates that are being evaluated for their safety and efficacy in preventing dengue disease. This review highlights nuances in the current standard-of-care treatment of dengue. We also discuss emerging treatment options, therapeutic drugs, and vaccines that are currently being pursued at various stages of preclinical and clinical development.

Predominance of Severe Plasma Leakage in Pediatric Patients With Severe Dengue in Puerto Rico

BACKGROUND

We evaluated clinical and laboratory findings among patients with nonsevere or severe dengue in Puerto Rico to examine whether clinical manifestations vary by age.

METHODS

During 2012-2014, we enrolled patients who arrived at the emergency department with fever or history of fever within 7 days of presentation. Serum samples were tested for dengue virus (DENV) by reverse transcriptase-polymerase chain reaction (RT-PCR) and IgM enzyme-linked immunosorbent assay (ELISA). Severe dengue was defined as severe plasma leakage or shock, severe bleeding, or organ involvement at presentation, during hospitalization, or follow-up.

RESULTS

Of 1089 dengue patients identified, 281 (26%) were severe. Compared to those with nonsevere dengue, patients with severe dengue were more often aged 10-19 years (55% vs 40%, P < .001) and hospitalized (87% vs 30%, P < .001). Severe plasma leakage or shock was more common among children aged 0-9 (59%) or 10-19 years (86%) than adults (49%) (P < .01). Severe bleeding was less common among 10-19 year olds (24%) compared to 0-9 year olds (45%) and adults (52%; P < .01).

CONCLUSIONS

Severe plasma leakage was the most common presentation among children, highlighting important differences from adults. Vaccination against dengue could help prevent severe dengue among children in Puerto Rico.

Discovery and validation of circulating miRNAs for the clinical prognosis of severe dengue

Background

Early prognostic markers of severe dengue may improve case management and reduce dengue-related mortalities. This study aimed to identify circulating microRNAs (miRNAs) as biomarkers for predicting severe dengue.

Methodology

Serum samples from dengue-infected patients were collected on the first day of admission. Patients were followed up for 14 days after admission to determine the final diagnosis. Participants were divided into non-severe and severe dengue, as defined by WHO 2009 criteria. Circulating microtranscriptome analysis was performed using NanoString miRNA Expression Assay. The expression level of candidate miRNAs were then validated by quantitative reverse transcription-PCR method.

Principal findings

The discovery cohort (N = 19) lead to the identification of 37 differentially expressed miRNAs between the two groups. Six up-regulated candidate miRNAs were selected and further validated in the larger cohort (N = 135). MiR574-5p and miR1246 displayed the highest diagnostic performance in discriminating between severe from non-severe dengue (ROC-AUC = 0.83). Additionally, miR574-5p and miR1246 had high sensitivity and high negative predictive value for detecting severe dengue. Multivariate analysis suggested that serum miR574-5p was an independent predictor of severe dengue (odds ratio 3.30, 95% CI 1.81–6.04; p<0.001).

Conclusion

Our study indicated that circulating miRNAs, especially miR-574-5p and miR-1246, might be a promising diagnostic and prognostic biomarker for severe dengue upon hospital admission, especially when using these biomarkers on days 1 to 2 before the onset of severe dengue complications.

Dengue infection, a mosquito-borne disease, is an expanding global problem. It has a broad clinical spectrum that includes severe and non-severe clinical manifestations with a high risk of death. Identifying early prognostic markers of severe complications may improve case management and reduce dengue-related mortalities. The circulating microRNA (miRNA) profile has been widely used to identify potential biomarkers against viral infections. Our data revealed that the circulating miRNA expression pattern of severe dengue patients was significantly different from the non-severe group. In addition, circulating miRNAs, especially miR-574-5p and miR-1246, could be promising diagnostic and prognostic biomarkers for severe dengue. These data have implications for developing biomarkers for clinical use and could improve risk prediction in dengue patients.

Heart Disease and Arboviruses: A Systematic Review and Meta-Analysis

Dengue fever, chikungunya, and zika are highly prevalent arboviruses transmitted by hematophagous arthropods, with a widely neglected impact in developing countries. These diseases cause acute illness in diverse populations, as well as potential cardiovascular complications. A systematic review was carried out to investigate the burden of cardiac involvement related to these arboviruses. Multiple databases were searched for articles that investigated the association of cardiovascular diseases with arboviruses, published up to March 2022. Relevant articles were selected and rated by two independent reviewers. Proportion meta-analysis was applied to assess the frequency-weighted mean of the cardiovascular findings. A total of 42 articles were selected (n = 76,678 individuals), with 17 manuscripts on dengue and 6 manuscripts on chikungunya undergoing meta-analysis. The global pooled incidence of cardiac events in dengue fever using a meta-analysis was 27.21% (95% CI 20.21–34.83; I² = 94%). The higher incidence of dengue-related myocarditis was found in the population younger than 20 years old (33.85%; 95% CI 0.00–89.20; I² = 99%). Considering the studies on chikungunya (n = 372), the global pooled incidence of cardiac involvement using a meta-analysis was 32.81% (95% CI 09.58–61.49, I² = 96%). Two Zika studies were included that examined cases of infection by vertical transmission in Brazil, finding everything from structural changes to changes in heart rate variability that increase the risk of sudden death. In conclusion, cardiac involvement in arboviruses is not uncommon, especially in dengue fever.

Liver transcriptomics reveals features of the host response in a mouse model of dengue virus infection

Background

Dengue virus (DENV) infection induces various clinical manifestations and even causes organ injuries, leading to severe dengue haemorrhagic fever and dengue shock syndrome. Hepatic dysfunction was identified as a risk predictor of progression to severe disease during the febrile phase of dengue. However, the underlying mechanisms of hepatic injury remain unclear.

Methods

A model of dengue disease was established in IFNAR^−/− C57BL/6 mice by challenge with DENV-2. Body weight, symptoms, haematological parameters and liver pathological observations in mice were used to determine the effects of DENV infection. Liver transcriptome sequencing was performed to evaluate the features of the host response in IFNAR^−/− mice challenged with DENV. Functional enrichment analysis and analysis of significantly differentially expressed genes (DEGs) were used to determine the critical molecular mechanism of hepatic injury.

Results

We observed haemoconcentration, leukopenia and liver pathologies in mice, consistent with findings in clinical dengue patients. Some differences in gene expression and biological processes were identified in this study. Transcriptional patterns in the liver indicated that antiviral responses to DENV and tissue damage via abnormal expression of proinflammatory cytokines were induced. Further analysis showed that the upregulated DEGs were significantly enriched in the leukocyte transendothelial migration, complement and coagulation cascades, and cytokine-cytokine receptor interactions signalling pathways, which are considered to be closely associated with the pathogenic mechanism of dengue. IL6, IL 10, ICAM-1, VCAM-1, MMP9 and NLRP3 were identified as biomarkers of progression to severe disease.

Conclusions

The interactions of these cytokines, which activate inflammatory signalling, may lead to organ injury and haemoconcentration and even to vascular leakage in tissues, including the mouse liver. Our study identifies candidate host targets that could be used for further functional verification.

Re-emergence of arbovirus diseases in the State of Rio de Janeiro, Brazil: The role of simultaneous viral circulation between 2014 and 2019

The burden of arbovirus diseases in Brazil has increased within the past decade due to the emergence of chikungunya and Zika and endemic circulation of all four dengue serotypes. Changes in temperature and rainfall patterns may alter conditions to favor vector-host transmission and allow for cyclic re-emergence of disease. We sought to determine the impact of climate conditions on arbovirus co-circulation in Rio de Janeiro, Brazil. We assessed the spatial and temporal distributions of chikungunya, dengue, and Zika cases from Brazil's national notifiable disease information system (SINAN) and created autoregressive integrated moving average models (ARIMA) to predict arbovirus incidence accounting for the lagged effect of temperature and rainfall. Each year, we estimate that the combined arboviruses were associated with an average of 8429 to 10,047 lost Disability-Adjusted Life Years (DALYs). After controlling for temperature and precipitation, our model predicted a three cycle pattern where large arbovirus outbreaks appear to be primed by a smaller scale surge and followed by a lull of cases. These dynamic arbovirus patterns in Rio de Janeiro support a mechanism of susceptibility enhancement until the theoretical threshold of population immunity allows for temporary cross protection among certain arboviruses. This suspected synergy presents a major public health challenge due to overlapping locations and seasonality of arbovirus diseases, which may perpetuate disease burden and overwhelm the health system.

A cross-sectional study to assess the epidemiological situation and associated risk factors of dengue fever; knowledge, attitudes, and practices about dengue prevention in Khyber Pakhtunkhwa Province, Pakistan

Background

Dengue fever has been responsible for around 12 countrywide large outbreaks in Pakistan, resulting in 286,262 morbidities and 1,108 deaths. Khyber Pakhtunkhwa (KP) is the most recently impacted province. This study aimed to investigate the molecular, epidemiological, and potential elements that contribute to increasing dengue transmission patterns, and knowledge, attitude, and practice (KAP) toward dengue in KP province.

Method

This cross-sectional community-based study was conducted (June-December, 2021) in two phases. Phase I involved the epidemiological (n = 5,242) and molecular analysis of DENV in 500 randomly collected blood samples of the 2021 dengue outbreak in KP. Phase II focused on assessing dengue-KAP levels in healthy communities (n = 14,745, aged >18 years), adopting a cross-sectional clustered multistage sampling in eight districts (dengue-hotspot vs. non-hotspot) of KP. Chi-square tests and logistic regression analysis were applied.

Results

Peshawar district had the highest dengue cases (60.0%) associated with the predominant co-circulation of DENV-2 (45.8%) and DENV-3 (50.4%) serotypes. A rise in cases was reported in October (41.8%) followed by September (27.9%) and August (14.4%; p < 0.001). Males (63.7%, p < 0.001) and individuals aged 16–30 years (37.0%, p < 0.001) were highly affected. General workers (18.0%), families with a monthly income of 10,000–20,000 Pak rupees (50.5%), unmarried (71.0%), uneducated (31%), families with higher human density (>10 individuals per household), and those (29.0%) who faced power outages for more than 7/24 h were the most affected. Moreover, co-morbidities like renal failure and bronchial asthma were associated with disease severity. A community survey on KAP revealed that an average of 74, 60, and 43% of the participants demonstrated good knowledge, attitudes, and dengue preventive practices, respectively.

Conclusion

Multiple poor socioeconomic elements are influencing dengue fever transmission in the province. Higher KAP levels may explain the low frequency of dengue in non-hotspot districts. Our study emphasizes the need for effective and long-term public health education, strengthened vector surveillance, and expanded laboratory capacity for better diagnosis and management of dengue cases to better predict the burden and seasonality of disease in the country.