Multicentre prospective study on dengue classification in four South-east Asian and three Latin American countries

Identification of Bacteria and Viruses Associated with Patients with Acute Febrile Illness in Khon Kaen Province, Thailand

The majority of cases of undifferentiated acute febrile illness (AFI) in the tropics have an undefined etiology. In Thailand, AFI accounts for two-thirds of illnesses reported to the Ministry of Public Health. To characterize the bacterial and viral causes of these AFIs, we conducted molecular pathogen screening and serological analyses in patients who sought treatment in Chum Phae Hospital, Khon Kaen province, during the period from 2015 to 2016. Through integrated approaches, we successfully identified the etiology in 25.5% of cases, with dengue virus infection being the most common cause, noted in 17% of the study population, followed by scrub typhus in 3.8% and rickettsioses in 6.8%. Further investigations targeting viruses in patients revealed the presence of Guadeloupe mosquito virus (GMV) in four patients without other pathogen co-infections. The characterization of four complete genome sequences of GMV amplified from AFI patients showed a 93-97% nucleotide sequence identity with GMV previously reported in mosquitoes. Nucleotide substitutions resulted in amino acid differences between GMV amplified from AFI patients and mosquitoes, observed in 37 positions. However, these changes had undergone purifying selection pressure and potentially had a minimal impact on protein function. Our study suggests that the GMV strains identified in the AFI patients are relatively similar to those previously reported in mosquitoes, highlighting their potential role associated with febrile illness.

Wolbachia-carrying Aedes mosquitoes for preventing dengue infection

BACKGROUND

Dengue is a global health problem of high significance, with 3.9 billion people at risk of infection. The geographic expansion of dengue virus (DENV) infection has resulted in increased frequency and severity of the disease, and the number of deaths has increased in recent years. Wolbachia,an intracellular bacterial endosymbiont, has been under investigation for several years as a novel dengue-control strategy. Some dengue vectors (Aedes mosquitoes) can be transinfected with specific strains of Wolbachia, which decreases their fitness (ability to survive and mate) and their ability to reproduce, inhibiting the replication of dengue. Both laboratory and field studies have demonstrated the potential effect of Wolbachia deployments on reducing dengue transmission, and modelling studies have suggested that this may be a self-sustaining strategy for dengue prevention, although long-term effects are yet to be elucidated.

OBJECTIVES

To assess the efficacy of Wolbachia-carrying Aedes speciesdeployments (specifically wMel-, wMelPop-, and wAlbB- strains of Wolbachia) for preventing dengue virus infection.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, four other databases, and two trial registries up to 24 January 2024.

SELECTION CRITERIA

Randomized controlled trials (RCTs), including cluster-randomized controlled trials (cRCTs), conducted in dengue endemic or epidemic-prone settings were eligible. We sought studies that investigated the impact of Wolbachia-carrying Aedes deployments on epidemiological or entomological dengue-related outcomes, utilizing either the population replacement or population suppression strategy.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected eligible studies, extracted data, and assessed the risk of bias using the Cochrane RoB 2 tool. We used odds ratios (OR) with the corresponding 95% confidence intervals (CI) as the effect measure for dichotomous outcomes. For count/rate outcomes, we planned to use the rate ratio with 95% CI as the effect measure. We used adjusted measures of effect for cRCTs. We assessed the certainty of evidence using GRADE.

MAIN RESULTS

One completed cRCT met our inclusion criteria, and we identified two further ongoing cRCTs. The included trial was conducted in an urban setting in Yogyakarta, Indonesia. It utilized a nested test-negative study design, whereby all participants aged three to 45 years who presented at healthcare centres with a fever were enrolled in the study provided they had resided in the study area for the previous 10 nights. The trial showed that wMel-Wolbachia infected Ae aegypti deployments probably reduce the odds of contracting virologically confirmed dengue by 77% (OR 0.23, 95% CI 0.15 to 0.35; 1 trial, 6306 participants; moderate-certainty evidence). The cluster-level prevalence of wMel Wolbachia-carrying mosquitoes remained high over two years in the intervention arm of the trial, reported as 95.8% (interquartile range 91.5 to 97.8) across 27 months in clusters receiving wMel-Wolbachia Ae aegypti deployments, but there were no reliable comparative data for this outcome. Other primary outcomes were the incidence of virologically confirmed dengue, the prevalence of dengue ribonucleic acid in the mosquito population, and mosquito density, but there were no data for these outcomes. Additionally, there were no data on adverse events.

AUTHORS' CONCLUSIONS

The included trial demonstrates the potential significant impact of wMel-Wolbachia-carrying Ae aegypti mosquitoes on preventing dengue infection in an endemic setting, and supports evidence reported in non-randomized and uncontrolled studies. Further trials across a greater diversity of settings are required to confirm whether these findings apply to other locations and country settings, and greater reporting of acceptability and cost are important.

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.

Nanomedicine as a potential novel therapeutic approach against the dengue virus

Dengue is an arbovirus infection which is transmitted by Aedes mosquitoes. Its prompt detection and effective treatment is a global health challenge. Various nanoparticle-based vaccines have been formulated to present immunogen (antigens) to instigate an immune response or prevent virus spread, but no specific treatment has been devised. This review explores the role of nanomedicine-based therapeutic agents against dengue virus, taking into consideration the applicable dengue virus assays that are sensitive, specific, have a short turnaround time and are inexpensive. Various kinds of metallic, polymeric and lipid nanoparticles with safe and effective profiles present an alternative strategy that could provide a better remedy for eradicating the dengue virus.

Early transcriptomic host response signatures in the serum of dengue patients provides insights into clinical pathogenesis and disease severity

Dengue virus (DENV), known to cause viral infection, belongs to the family Flaviviridae, having four serotypes (DENV1-4) that spreads by the bite of the Aedes aegypti mosquito. India has been suffering from dengue outbreaks annually with widespread epidemics by prevalence of all the four DENV serotypes. The diverse spectrum of clinical manifestations in dengue infection, mild to severe forms, makes the need of timely diagnosis and prompt treatment an essence. The identification of a dengue host response signature in serum can increase the understanding of dengue pathogenesis since most dengue NS1 Ag tests have been developed and evaluated in serum samples. Here, to understand the same, we undertook a dual RNA-sequencing (RNA-Seq) based approach from the serum samples of dengue-infected patients. The results thus yield the early transcriptional signatures that discriminated the high viral reads patients from patients who had low dengue viral reads. We identified a significant upregulation of two sets of genes, key antiviral (IFIT3, RSAD2, SAT1) and vascular dysfunction (TNFS10, CXCL8) related genes in the high viral reads group. Deeper delving of this gene profile revealed a unique two-way response, where the antiviral genes can mediate the disease course to mild, contrarily the increased expression of the other gene set might act as pointers of severe disease course. Further, we explored the hematologic parameters from the complete blood count (CBC), which suggests that lymphocytes (low) and neutrophils (high) might serve as an early predictor of prognosis in dengue infection. Collectively, our findings give insights into the foundation for further investigation of the early host response using the RNA isolated from dengue patients' serum samples and opens the door for careful monitoring of the early clinical and transcriptome profiles for management of the dengue patients.

The Effect of Age on Dengue Presentation and the Diagnostic Accuracy of the 2015 Pan American Health Organization Case Criteria in a Puerto Rican Cohort

Background

We evaluated dengue presentation by age, the performance of the 2015 Pan American Health Organization (PAHO) case criteria in identifying dengue cases, and variables to improve specificity.

Methods

Patients with fever ≤7 days (N = 10 408) were recruited from 2 emergency departments from May 2012 through December 2015. Serum samples were tested for dengue, chikungunya, and nasopharyngeal swabs for respiratory viruses. Smoothing splines assessed differences in the frequencies of signs/symptoms by age. Least absolute shrinkage and selection operator regressions identified the variables that best predicted dengue.

Results

Among 985 dengue cases, children aged <5 years were least likely to have leukopenia, but most likely to have rash and petechiae. Adults had the highest odds of aches/pains and headaches/retro-orbital pain. The 2015 PAHO criteria had sensitivity of 93% and specificity of 25%. Specificity could be improved by requiring at least 2 of the following criteria: vomiting/nausea, petechiae, rash, or leukopenia (specificity 68%, sensitivity 71%) or by using 2015 PAHO criteria plus either (1) aspartate aminotransferase >50 IU/L or platelet count <100 000 platelets/μL (specificity 81%, sensitivity 56%) or (2) itchy skin or absence of rhinorrhea or cough (specificity 51%, sensitivity 82%).

Conclusions

The 2015 PAHO dengue case criteria had excellent sensitivity but poor specificity. This can be improved by adding signs/symptoms associated with dengue diagnosis.

Early diagnostic indicators of dengue versus other febrile illnesses in Asia and Latin America (IDAMS study): a multicentre, prospective, observational study

BACKGROUND

Improvements in the early diagnosis of dengue are urgently needed, especially in resource-limited settings where the distinction between dengue and other febrile illnesses is crucial for patient management.

METHODS

In this prospective, observational study (IDAMS), we included patients aged 5 years and older with undifferentiated fever at presentation from 26 outpatient facilities in eight countries (Bangladesh, Brazil, Cambodia, El Salvador, Indonesia, Malaysia, Venezuela, and Viet Nam). We used multivariable logistic regression to investigate the association between clinical symptoms and laboratory tests with dengue versus other febrile illnesses between day 2 and day 5 after onset of fever (ie, illness days). We built a set of candidate regression models including clinical and laboratory variables to reflect the need of a comprehensive versus parsimonious approach. We assessed performance of these models via standard measures of diagnostic values.

FINDINGS

Between Oct 18, 2011, and Aug 4, 2016, we recruited 7428 patients, of whom 2694 (36%) were diagnosed with laboratory-confirmed dengue and 2495 (34%) with (non-dengue) other febrile illnesses and met inclusion criteria, and were included in the analysis. 2703 (52%) of 5189 included patients were younger than 15 years, 2486 (48%) were aged 15 years or older, 2179 (42%) were female and 3010 (58%) were male. Platelet count, white blood cell count, and the change in these variables from the previous day of illness had a strong association with dengue. Cough and rhinitis had strong associations with other febrile illnesses, whereas bleeding, anorexia, and skin flush were generally associated with dengue. Model performance increased between day 2 and 5 of illness. The comprehensive model (18 clinical and laboratory predictors) had sensitivities of 0·80 to 0·87 and specificities of 0·80 to 0·91, whereas the parsimonious model (eight clinical and laboratory predictors) had sensitivities of 0·80 to 0·88 and specificities of 0·81 to 0·89. A model that includes laboratory markers that are easy to measure (eg, platelet count or white blood cell count) outperformed the models based on clinical variables only.

INTERPRETATION

Our results confirm the important role of platelet and white blood cell counts in diagnosing dengue, and the importance of serial measurements over subsequent days. We successfully quantified the performance of clinical and laboratory markers covering the early period of dengue. Resulting algorithms performed better than published schemes for distinction of dengue from other febrile illnesses, and take into account the dynamic changes over time. Our results provide crucial information needed for the update of guidelines, including the Integrated Management of Childhood Illness handbook.

FUNDING

EU's Seventh Framework Programme.

TRANSLATIONS

For the Bangla, Bahasa Indonesia, Portuguese, Khmer, Spanish and Vietnamese translations of the abstract see Supplementary Materials section.

Dengue algorithms integrated into the IMCI guidelines: An updated assessment in five Southeast-Asian countries

Background

Dengue is not included explicitly in the WHO Integrated Management of Childhood Illness (IMCI) algorithm. However, the assessment, classification and management of dengue has been incorporated into several IMCI country adaptations. We aimed to evaluate the dengue algorithms incorporated into IMCI guidelines and discuss the need for harmonization, including an extension of the age range for IMCI.

Methods

This study included three steps. First, we investigated dengue algorithms incorporated into five Southeast-Asian (Myanmar, Philippines, Vietnam, Indonesia, Cambodia) country IMCI guidelines through a desk-based analysis. Second, we conducted an expert survey to elicit opinions regarding the integration of dengue and extension of the age range in IMCI. Third, we compared our findings with data from a large multicentric prospective study on acute febrile illness.

Results

We found considerable heterogeneity between the country specific IMCI guidelines in the dengue algorithms as well as classification schemes. Most guidelines did not differentiate between diagnostic algorithms for the detection of dengue versus other febrile illness, and warning signs for progression to severe dengue. Our expert survey resulted in a consensus to further integrate dengue in IMCI and extend the age range for IMCI guidelines beyond 5 years of age. Most of the interviewees responded that their country had a stand-alone clinical guideline for dengue, which was not integrated into the IMCI approach and considered laboratory testing for dengue necessary on day three of consecutive fever. Using data from a large multicentric study of children 5–15 years of age, we could confirm that the likelihood of dengue increased with consecutive fever days. However, a significant proportion of children (36%) would be missed if laboratory testing was only offered on the third consecutive day of fever.

Conclusions

This study supports the extension of the IMCI age range beyond 5 years of age as well as the inclusion of dengue relevant content in the algorithm. Because of the challenge of distinguishing dengue from other febrile illnesses, simple laboratory testing (e.g., full blood count) should be offered at an early stage during the course of the illness. Testing only children with consecutive fever over 3 days may lead to an underdiagnosis of dengue among those with acute febrile illness in children 5–15 years of age. In addition, specific laboratory testing for dengue should be made available to peripheral health facilities.

The Integrated Management of Childhood Illness (IMCI) was developed for the identification and treatment of major childhood illnesses based on a syndromic approach that can be applied by local health care workers in rural health facilities. Dengue represents an important differential diagnosis for children and adolescents with acute febrile illness in Southeast Asia but is not officially included in the fever module of IMCI. Local adaptations in different countries, however, have integrated dengue into their guidelines. We analysed the available local IMCI guidelines in Southeast Asia, conducted an expert survey, and investigated out findings using data from a large multicentric prospective study on acute febrile illness. Our findings support the extension of the age range for IMCI and the inclusion of dengue relevant content. When children presented with fever, the likelihood of dengue increased with consecutive fever days. We were able to quantify how likely dengue is as a cause of fever in children living in endemic areas, stratified by duration of fever. This evidence is useful for policy makers to consider the effect of more specific diagnostic tools for the monitoring of early dengue.

A double whammy: The association between comorbidities and severe dengue among adult patients—A matched case-control study

Background

Dengue infection is the most prevalent mosquito-borne viral infection globally. Concurrently, there has also been an upsurge of non-communicable comorbidities. We aimed to investigate the association between these comorbidities and the development of severe dengue.

Methods

We performed a retrospective, case-control study involving 117 cases with severe dengue and 351 controls with non-severe dengue; matched according to gender, age (+/- 5 years old), and admission date (+/- 2 weeks). We analyzed the data using conditional odds ratio (cOR) and adjusted conditional odds ratio (AcOR) using univariate and multivariable conditional logistic regression respectively.

Results

Six main comorbidities namely obesity, diabetes mellitus, hypertension, hyperlipidemia, chronic pulmonary disease, and ischemic heart disease were observed among cases and controls. Multivariable conditional logistic regression model found only hypertension to be independently associated with the development of severe dengue (ACOR 2.46; 95% CI:1.09–5.53). Among symptoms at presentation, lethargy, vomiting, bleeding manifestations, and abdominal pain were associated with increased odds of severe dengue, although the associations were not statistically significant. Headache (ACOR: 0:32; 95% CI: 0.21–0.51) and skin rash (ACOR: 0.42; 95% CI: 0.22–0.81) were associated with significantly lower odds of severe dengue. Severe dengue patients were also found to have significantly higher white cell count, urea, creatinine, alanine aminotransferase, aspartate aminotransferase, creatine kinase, and lactate dehydrogenase on admission, while platelet and albumin were significantly lower compared to non-severe dengue patients.

Conclusions

Our study found a significant association between hypertension and the development of severe dengue in adult patients. For clinical practice, this finding suggests that dengue patients with underlying hypertension warrant closer clinical monitoring for deterioration. The association between significant derangement in various laboratory parameters and severe dengue as shown in this study is in keeping with previous reports. While further substantiation by larger prospective studies will be desirable, this association may serve to inform the dengue triaging process.

Association of self-reported allergic rhinitis with dengue severity: A case-control study

BACKGROUND

The severity of dengue infection has been reportedly associated with patients' allergic reactions. To further elucidate the role of allergy in dengue severity, we conducted a matched case-control study to assess the association between allergic background and dengue shock syndrome.

METHODS

This is a matched case-control study that was carried out in the Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam from January to December 2017. Dengue infection was determined by non-structure protein 1 (NS1) diagnostic quick test or anti-dengue antibodies (IgM). The total and dengue-specific IgE levels were measured using ELISA. Patients' demographics, clinical, and allergic profiles were collected using a structured questionnaire.

RESULTS

A total of 572 dengue patients with positive NS1 (92.7%) or IgM antibodies (7.3%) results were included in this study. Of these patients, 143 patients developed dengue shock syndrome (case group) while the other 429 patients did not (control group). None of the baseline characteristics including age, sex, or being overweight was significantly different between the two groups (p>0.05). In multivariable analysis, having a history of dengue infection (OR=3.35, 95% CI: 1.8-6.17, p<0.001) and allergic rhinitis (OR=1.95, 95% CI: 1.11-3.4, p = 0.019) were found to be associated with dengue shock syndrome. Higher levels of dengue-specific IgE were not associated with worse outcomes in patients with allergies (p = 0.204) or allergic rhinitis (p = 0.284).

CONCLUSION

Dengue patients presenting with a history of a previous dengue infection or allergic rhinitis should be considered high-risk patients for the development of dengue shock syndrome.

Warning Signs in Predicting Severe Pediatric Dengue Infection

Objective The uncertainty of dengue's progression from infection to its severe form represents a major health care challenge, especially in children. Clinical identification of impending clinical manifestations of severe dengue (SD), along with proper and immediate management, is crucial. Thus, this study assesses the ability of warning signs to predict SD infection in pediatric patients.

Methods This cross-sectional study utilized purposive sampling using medical records from January 2015 to December 2020. Children aged 0 to 18 years diagnosed with dengue fever and SD according to the World Health Organization's 2009 criteria were included.

Discussion Multivariate analysis revealed that abdominal pain (odds ratio [OR]: 16.34; 95% confidence interval [CI]: 3.78–70.64; p < 0.001), fluid accumulation (OR: 10.51, 95% CI: 1.17–94.3; p = 0.036), mucosal bleeding (OR: 4.77; 95% CI: 1.27–17.91; p = 0.021), lethargy (OR: 94.37; 95% CI: 4.92–180.79; p = 0.003), hepatomegaly (OR: 17.57; 95% CI: 2.14–144.13; p = 0.008), and increased hematocrit concurrent with a rapid decrease in platelets (OR: 6.89; 95% CI: 1.79–26.51, p = 0.005) were associated with SD infection, with a high quality of discrimination (area under the curve [AUC] = 0.96) and a high quality of fit (p = 0.73). Receiver operating characteristic analysis demonstrated that 1.5 warning signs was the optimal cut-off for predicting SD infection, with a sensitivity of 90.9 and a specificity of 89.8%.

Conclusion All six warning signs were significantly associated with SD infection. The optimal cut-off for predicting SD was 1.5 warning signs.

Dengue: current state one year before WHO 2010-2020 goals

BACKGROUND

Dengue is a possibly life-threatening human mosquito-borne viral infection widely spread in peridomestic (sub)tropical climates. The global incidence has expanded rapidly in the last decades, with 40% of the world's population currently at risk. To date, no anti-viral treatment other than supportive care exists. In 2015, the first and only dengue-vaccine, CYD-TDV, received marketing authorization.

OBJECTIVES

To present the current understanding of dengue in terms of epidemiology, transmission, pathogenesis, disease management and prevention. To illustrate the knowledge gaps that remain to be filled in order to control dengue and achieve the WHO 2010-2020 goals.

METHODS

An updated systematic review (2009-2019) was carried out. The databases Pubmed, Embase and The Cochrane Library were searched along with WHO and CDC guidelines.

RESULTS

In total, 39 articles were included. Contemporary climatic and economic factors significantly contributed to the emergence of epidemic dengue. Unfortunately, CYD-TDV failed to meet safety and efficacy demands. New vaccination approaches are in the pipeline along with innovative vector-control strategies. Current anti-viral drug research focuses on repurposing drugs in addition to specific anti-dengue strategies that interfere with viral replication.

CONCLUSION

The lack of understanding dengue pathogenesis and immunology has hampered the development of an effective vaccine. Recent research has provided new insights into the therapeutic and prophylactic approach. Implementation of complementary methods to control disease burden are required considering the socio-economic impact of this rapidly emerging global disease.

An 8-gene machine learning model improves clinical prediction of severe dengue progression

BACKGROUND

Each year 3-6 million people develop life-threatening severe dengue (SD). Clinical warning signs for SD manifest late in the disease course and are nonspecific, leading to missed cases and excess hospital burden. Better SD prognostics are urgently needed.

METHODS

We integrated 11 public datasets profiling the blood transcriptome of 365 dengue patients of all ages and from seven countries, encompassing biological, clinical, and technical heterogeneity. We performed an iterative multi-cohort analysis to identify differentially expressed genes (DEGs) between non-severe patients and SD progressors. Using only these DEGs, we trained an XGBoost machine learning model on public data to predict progression to SD. All model parameters were "locked" prior to validation in an independent, prospectively enrolled cohort of 377 dengue patients in Colombia. We measured expression of the DEGs in whole blood samples collected upon presentation, prior to SD progression. We then compared the accuracy of the locked XGBoost model and clinical warning signs in predicting SD.

RESULTS

We identified eight SD-associated DEGs in the public datasets and built an 8-gene XGBoost model that accurately predicted SD progression in the independent validation cohort with 86.4% (95% CI 68.2-100) sensitivity and 79.7% (95% CI 75.5-83.9) specificity. Given the 5.8% proportion of SD cases in this cohort, the 8-gene model had a positive and negative predictive value (PPV and NPV) of 20.9% (95% CI 16.7-25.6) and 99.0% (95% CI 97.7-100.0), respectively. Compared to clinical warning signs at presentation, which had 77.3% (95% CI 58.3-94.1) sensitivity and 39.7% (95% CI 34.7-44.9) specificity, the 8-gene model led to an 80% reduction in the number needed to predict (NNP) from 25.4 to 5.0. Importantly, the 8-gene model accurately predicted subsequent SD in the first three days post-fever onset and up to three days prior to SD progression.

CONCLUSIONS

The 8-gene XGBoost model, trained on heterogeneous public datasets, accurately predicted progression to SD in a large, independent, prospective cohort, including during the early febrile stage when SD prediction remains clinically difficult. The model has potential to be translated to a point-of-care prognostic assay to reduce dengue morbidity and mortality without overwhelming limited healthcare resources.

Correlation of Dengue Warning Signs during Febrile Phase with Rotational Thromboelastometry, Cortisol and Feritin

Dengue mortality remains high despite monitoring against warning signs (WS). The associations of WS at febrile phase (FP) and hemorrhage at defervescence with the levels and kinetics of ROTEM, platelet count, cortisol, and ferritin were analyzed. Patients with confirmed dengue serology and WS in two centers were screened (n = 275) and 62 eligible patients were recruited prospectively over 9 months. “Vomiting” was the commonest WS (62.9%), with shortened clotting time (CT) INTEM (p = 0.01). “Hematocrit increase” showed significant prolonged CT INTEM, EXTEM, and FIBTEM (p < 0.05). “Platelet decrease” showed reduced platelet function and reduced clot amplitude at 10 min (A10) and maximum clot firmness (MCF) in INTEM and EXTEM (p < 0.001). The kinetics were reduced in platelet count, CT EXTEM, and cortisol (p < 0.05) but increased in CT INTEM (p = 0.03). At FP, “vomiting”, “hematocrit increase”, and “platelet decrease” demonstrated impaired CT, clot strengths A10/MCF and platelet functions. Majority (60/62, 96.7%) had non-severe outcomes, consistent with increase in cortisol kinetics. In conclusion, “vomiting”, “hematocrit increase” and “platelet decrease” at FP correlated with ROTEM. No conclusion could be made further regarding ferritin and cortisol. Larger study is required to study “hematocrit increase” with ROTEM as a potential marker for hemorrhage.

A Population of CD4+CD8+ Double-Positive T Cells Associated with Risk of Plasma Leakage in Dengue Viral Infection

According to the WHO 2009 classification, dengue with warning signs is at the risk of developing severe form of dengue disease. One of the most important warning signs is plasma leakage, which can be a serious complication associated with higher morbidity and mortality. We report that the frequency of CD4+CD8+ double-positive (DP) T cells is significantly increased in patients at risk of developing plasma leakage. Transcriptomic analysis demonstrated that CD4+CD8+ DP cells were distinct from CD4+ Single Positive (SP) T cells but co-clustered with CD8+ SP cells, indicating a largely similar transcriptional profile. Twenty significant differentially expressed (DE) genes were identified between CD4+CD8+ DP and CD8+ SP cells. These genes encode OX40 and CCR4 proteins as well as other molecules associated with cell signaling on the cell surface (NT5E, MXRA8, and PTPRK). While comparing the profile of gene expression in CD4+CD8+ DP cells from patients with and without warning signs of plasma leakage, similar expression profile was observed, implying a role of CD4+CD8+ DP cells in plasma leakage through a quantitative increase rather than functional alteration. This study provided novel insight into the host immune response during the acute febrile phase of DENV infection and the role of CD4+CD8+ DP T cells in the pathogenesis of plasma leakage.

A study on maternal and foetal prognosis and predictive factors for adverse outcome in pregnant patients with dengue in an endemic state of India

Aims:

Dengue fever is a major health problem with high morbidity and mortality especially during epidemic season; pregnant females being no exception. But, there is paucity of published data on dengue fever during pregnancy. Hence, this study was planned to study the clinical profile, maternal outcome and predictors of poor outcome in pregnant dengue patients.

Materials and Methods:

All pregnant females attending labour room of Tata Main Hospital, Jamshedpur from April 2016 to October2020 with acute febrile illness caused by dengue virus at any gestational age were included in the study. Diagnosis of dengue was made by detection of NS1 antigen or dengue serology. A predesigned proforma was used to record materno-foetal outcomes and were analysed.

Results:

Dengue was the cause of fever in 7.1% febrile patients. Maternal complications included abortions (26%), abruptio (1.9%), postpartum haemorrhage (11.9%) . Of all the pregnant dengue patients, five had severe dengue(SD) with high mortality (3/5; 60%). Fetal complications were intrauterine death(7.7%),preterm(42.3%). Thrombocytopenia and elevated transaminases were associated with adverse outcome.

Conclusions:

Dengue fever in pregnancy is associated with poor outcomes more in cases of SD rather than dengue fever . Pregnant females with high risk predictors should be identified and managed aggressively in intensive care units to improve outcomes.

Clinical manifestations, laboratory profile and outcomes of dengue virus infection in hospitalised older patients

BACKGROUND

Due to an ageing population, dengue among older patients is encountered more frequently in many countries. Our study aimed to explore the clinico-laboratory parameters and outcomes among dengue-infected older patients in comparison with younger patients.

METHODS

This retrospective chart review involved dengue patients with dengue non-structural protein 1 (NS1) antigen positivity admitted to a tertiary hospital in Malaysia from January to July 2015. A comparison was made between older people (aged ≥60 y) and others.

RESULTS

Among 406 dengue patients, 43 (10.6%) were older people. Older dengue patients were less likely to present with persistent vomiting (adjusted OR [AOR] 0.247, 95% CI 0.093 to 0.656, p=0.005), while restlessness and confusion were more common at presentation (AOR 3.356, 95% CI 1.024 to 11.003, p=0.046). Older patients had significantly lower albumin upon admission (38 vs 40 g/L, p=0.036) and during hospital stay (35 vs 37 g/L, p=0.015). Compared with younger patients, older patients were more likely to have experienced nadir platelet counts of <50×109/L (AOR 2.897, 95% CI to 1.176 to 7.137, p=0.021). They were also more likely to require an extended hospital stay (AOR 3.547, 95% CI 1.575 to 7.986, p=0.002).

CONCLUSIONS

Diagnosis of dengue in older people may be challenging because of atypical presentations. Increased vigilance is necessary as there is an increased tendency to develop severe thrombocytopenia, hypoalbuminemia and prolonged hospitalisation in older people.

Concurrent circulation of dengue serotype 1, 2 and 3 among acute febrile patients in Cameroon

Acute febrile patients presenting at hospitals in Douala, Cameroon between July and December 2020, were screened for dengue infections using real time RT-PCR on fragments of the 5’ and 3’ UTR genomic regions. In total, 12.8% (41/320) of cases examined were positive for dengue. Dengue virus 3 (DENV-3) was the most common serotype found (68.3%), followed by DENV-2 (19.5%) and DENV-1 (4.9%). Co-infections of DENV-3 and DENV-2 were found in 3 cases. Jaundice and headache were the most frequent clinical signs associated with infection and 56% (23/41) of the cases were co-infections with malaria. Phylogenetic analysis of the envelope gene identified DENV-1 as belonging to genotype V, DENV-2 to genotype II and DENV-3 to genotype III. The simultaneous occurrence of three serotypes in Douala reveals dengue as a serious public health threat for Cameroon and highlights the need for further epidemiological studies in the major cities of this region.

Acute febrile patients presenting at hospitals in Douala, Cameroon between July and December 2020, were screened for dengue infections by Polymerase chain reaction. In total, 12.8% (41/320) of cases examined were infected by dengue virus. Dengue virus 3 (DENV-3) was the most common serotype found (68.3%), followed by DENV-2 (19.5%) and DENV-1 (4.9%). Co-infections of DENV-3 and DENV-2 were found in 3 cases. Jaundice and headache were the most frequent clinical signs associated with infection and 56% (23/41) of the cases were co-infections with malaria. The simultaneous occurrence of three serotypes in Douala reveals dengue as a serious public health threat for Cameroon and highlights the need for further epidemiological studies in the major cities of this region.

Plasma leakage in dengue: a systematic review of prospective observational studies

Plasma leakage is a precursor to life-threatening complications of dengue, but this group is poorly defined and not often reported in literature. Patients with Dengue haemorrhagic fever (DHF) as defined in the 1997 World Health Organization classification are often reported, and they all have plasma leakage, but some patients with plasma leakage do not meet the definition of DHF. The study aims to estimate the frequency of plasma leakage and DHF (as a surrogate of plasma leakage) in dengue and its variations based on virus serotype, geography, patient gender and pre-existing immunity to dengue. PUBMED, Scopus, EMBASE, CINAHL and Web of Science were searched for prospective observational studies reporting on plasma leakage or DHF. Quality of data was assessed using the NIH quality assessment tool for cohort studies. Forty-three studies that recruited 15,794 confirmed dengue patients were eligible. Cumulative frequency of plasma leakage was 36.8% (15 studies, 1642/4462, 95% CI 35.4-38.2%), but surprisingly the estimated cumulative frequency of DHF was higher (45.7%, 32 studies, 4758/10417, 95% CI 44.7-46.6%), indicating that current medical literature over-reports DHF or under-reports plasma leakage. Therefore, a reliable estimate for the proportion of dengue patients developing plasma leakage cannot be derived from existing medical literature even after applying rigorous inclusion criteria to select homogenous studies. Plasma leakage is an important marker of "at-risk" dengue patients and standardizing its definition, diagnosis and reporting should be a priority in research and global policy.

Direct costs of managing in-ward dengue patients in Sri Lanka: A prospective study

Introduction

The cost in managing hospitalised dengue patients varies across countries depending on access to healthcare, management guidelines, and state sponsored subsidies. For health budget planning, locally relevant, accurate costing data from prospective studies, is essential.

Objective

To characterise the direct costs of managing hospitalised patients with suspected dengue infection in Sri Lanka.

Methods

Colombo Dengue Study is a prospective single centre cohort study in Sri Lanka recruiting suspected hospitalised dengue fever patients in the first three days of fever and following them up until discharge. The diagnosis of dengue is retrospectively confirmed and the cohort therefore has a group of non-dengue fever patients with a phenotypically similar illness, managed as dengue while in hospital. The direct costs of hospital admission (base and investigation costs, excluding medication) were calculated for all recruited patients and compared between dengue and non-dengue categories as well as across subgroups (demographic, clinical or temporal) within each of these categories. We also explored if excluding dengue upfront, would lead to an overall cost saving in several hypothetical scenarios.

Results

From October 2017 to February 2020, 431 adult dengue patients and 256 non-dengue fever patients were recruited. The hospitalisation costs were USD 18.02 (SD: 4.42) and USD 17.55 (SD: 4.09) per patient per day for dengue and non-dengue patients respectively (p>0.05). Laboratory investigations (haematological, biochemical and imaging) accounted for more than 50% of the total cost. The costs were largely homogenous in all subgroups within or across dengue and non-dengue categories. Excluding dengue upfront by subsidised viral genomic testing may yield overall cost savings for non-dengue patients.

Conclusion

As non-dengue patients incur a similar cost per day as the dengue patients, confirming dengue diagnosis using subsidised tests for patients presenting in the first three days of fever may be cost-efficient.

Predictive markers for the early prognosis of dengue severity: A systematic review and meta-analysis

BACKGROUND

Predictive markers represent a solution for the proactive management of severe dengue. Despite the low mortality rate resulting from severe cases, dengue requires constant examination and round-the-clock nursing care due to the unpredictable progression of complications, posing a burden on clinical triage and material resources. Accordingly, identifying markers that allow for predicting disease prognosis from the initial diagnosis is needed. Given the improved pathogenesis understanding, myriad candidates have been proposed to be associated with severe dengue progression. Thus, we aim to review the relationship between the available biomarkers and severe dengue.

METHODOLOGY

We performed a systematic review and meta-analysis to compare the differences in host data collected within 72 hours of fever onset amongst the different disease severity levels. We searched nine bibliographic databases without restrictive criteria of language and publication date. We assessed risk of bias and graded robustness of evidence using NHLBI quality assessments and GRADE, respectively. This study protocol is registered in PROSPERO (CRD42018104495).

PRINCIPAL FINDINGS

Of 4000 records found, 40 studies for qualitative synthesis, 19 for meta-analysis. We identified 108 host and viral markers collected within 72 hours of fever onset from 6160 laboratory-confirmed dengue cases, including hematopoietic parameters, biochemical substances, clinical symptoms, immune mediators, viral particles, and host genes. Overall, inconsistent case classifications explained substantial heterogeneity, and meta-analyses lacked statistical power. Still, moderate-certainty evidence indicated significantly lower platelet counts (SMD -0.65, 95% CI -0.97 to -0.32) and higher AST levels (SMD 0.87, 95% CI 0.36 to 1.38) in severe cases when compared to non-severe dengue during this time window.

CONCLUSION

The findings suggest that alterations of platelet count and AST level-in the first 72 hours of fever onset-are independent markers predicting the development of severe dengue.

Evaluation of immature platelet fraction as a marker of dengue fever progression

OBJECTIVES

Progression of dengue is often associated with thrombocytopenia resulting from viral-induced bone marrow suppression and immune-mediated peripheral platelet consumption. Immature platelet fraction (IPF), which can be measured using a haematology analyser, is a precursor indicating platelet formation in the bone marrow. This study evaluated the trend of IPF as an early recovery indicator of platelets in dengue patients with thrombocytopenia, and its relationship with severe dengue in conjunction with reticulocyte count.

METHODS

Hospitalized patients with dengue were enrolled and followed-up daily until discharge. Blood investigations included daily full blood counts and IPF measured using a haematology analyser.

RESULTS

In total, 287 patients with confirmed dengue were enrolled in this study, 25 of whom had severe dengue. All patients had a decreasing trend in platelet count in the first week of illness, concomitant with an increasing trend in the percentage of immature platelets to total platelets (IPF%) for more than 3 days prior to platelet recovery. IPF% was significantly increased in patients with severe dengue compared with patients with non-severe dengue on days 3-5 after the onset of fever. Reticulocyte count increased significantly in patients with severe dengue on day 5.

CONCLUSIONS

IPF can be utilized as an early recovery indicator of platelets in patients with dengue and thrombocytopenia.

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

BACKGROUND

The ability to accurately predict early progression of dengue to severe disease is crucial for patient triage and clinical management. Previous systematic reviews and meta-analyses have found significant heterogeneity in predictors of severe disease due to large variation in these factors during the time course of the illness. We aimed to identify factors associated with progression to severe dengue disease that are detectable specifically in the febrile phase.

METHODS

We did a systematic review and meta-analysis to identify predictors identifiable during the febrile phase associated with progression to severe disease defined according to WHO criteria. Eight medical databases were searched for studies published from Jan 1, 1997, to Jan 31, 2020. Original clinical studies in English assessing the association of factors detected during the febrile phase with progression to severe dengue were selected and assessed by three reviewers, with discrepancies resolved by consensus. Meta-analyses were done using random-effects models to estimate pooled effect sizes. Only predictors reported in at least four studies were included in the meta-analyses. Heterogeneity was assessed using the Cochrane Q and I2 statistics, and publication bias was assessed by Egger's test. We did subgroup analyses of studies with children and adults. The study is registered with PROSPERO, CRD42018093363.

FINDINGS

Of 6643 studies identified, 150 articles were included in the systematic review, and 122 articles comprising 25 potential predictors were included in the meta-analyses. Female patients had a higher risk of severe dengue than male patients in the main analysis (2674 [16·2%] of 16 481 vs 3052 [10·5%] of 29 142; odds ratio [OR] 1·13 [95% CI 1·01-1·26) but not in the subgroup analysis of studies with children. Pre-existing comorbidities associated with severe disease were diabetes (135 [31·3%] of 431 with vs 868 [16·0%] of 5421 without; crude OR 4·38 [2·58-7·43]), hypertension (240 [35·0%] of 685 vs 763 [20·6%] of 3695; 2·19 [1·36-3·53]), renal disease (44 [45·8%] of 96 vs 271 [16·0%] of 1690; 4·67 [2·21-9·88]), and cardiovascular disease (nine [23·1%] of 39 vs 155 [8·6%] of 1793; 2·79 [1·04-7·50]). Clinical features during the febrile phase associated with progression to severe disease were vomiting (329 [13·5%] of 2432 with vs 258 [6·8%] of 3797 without; 2·25 [1·87-2·71]), abdominal pain and tenderness (321 [17·7%] of 1814 vs 435 [8·1%] of 5357; 1·92 [1·35-2·74]), spontaneous or mucosal bleeding (147 [17·9%] of 822 vs 676 [10·8%] of 6235; 1·57 [1·13-2·19]), and the presence of clinical fluid accumulation (40 [42·1%] of 95 vs 212 [14·9%] of 1425; 4·61 [2·29-9·26]). During the first 4 days of illness, platelet count was lower (standardised mean difference -0·34 [95% CI -0·54 to -0·15]), serum albumin was lower (-0·5 [-0·86 to -0·15]), and aminotransferase concentrations were higher (aspartate aminotransferase [AST] 1·06 [0·54 to 1·57] and alanine aminotransferase [ALT] 0·73 [0·36 to 1·09]) among individuals who progressed to severe disease. Dengue virus serotype 2 was associated with severe disease in children. Secondary infections (vs primary infections) were also associated with severe disease (1682 [11·8%] of 14 252 with vs 507 [5·2%] of 9660 without; OR 2·26 [95% CI 1·65-3·09]). Although the included studies had a moderate to high risk of bias in terms of study confounding, the risk of bias was low to moderate in other domains. Heterogeneity of the pooled results varied from low to high on different factors.

INTERPRETATION

This analysis supports monitoring of the warning signs described in the 2009 WHO guidelines on dengue. In addition, testing for infecting serotype and monitoring platelet count and serum albumin, AST, and ALT concentrations during the febrile phase of illness could improve the early prediction of severe dengue.

FUNDING

Wellcome Trust, National Institute for Health Research, Collaborative Project to Increase Production of Rural Doctors, and Royal Thai Government.

Combined score based on arterial lactate, aspartate transaminase and prolonged capillary refill time is a useful diagnostic criterion for identifying severe dengue

BACKGROUND

Taking into consideration, the variable performance of WHO's dengue case definition and the magnitude of epidemics in India, a score based on clinical and laboratory parameters is required for the early identification of severe dengue.

METHODS

A retrospective observational study of children (aged ≤12 y) presenting with dengue, defined as per the WHO 2009 classification and NS1 antigen/IgM ELISA positivity, was conducted at a tertiary care hospital from 2013 to 2015. Clinical laboratory parameters were compared between severe/non-severe dengue using univariate and multivariate analysis. Areas under receiver operating characteristic curves (AUROCs), sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were obtained for independent and composite markers.

RESULTS

Of 135 dengue patients, 46 (34.1%) had non-severe dengue and 89 (65.9%) had severe dengue. Logistic regression determined prolonged capillary refill time (CRT), lactate ≥2.9 mmol/L and serum aspartate transaminase (AST) ≥135 IU/L as predictive for severe dengue. AUROCs of lactate, AST and combined score incorporating AST, lactate and prolonged CRT for identifying severity were 7.55, 7.23 and 8.5, respectively. The combined score cut-off ≥1 had 87.6% sensitivity, 65.2% specificity, 83% PPV and 73.2% NPV. The combined score cut-off ≥3 had 100% specificity and 100% PPV.  However, AST >135 IU/L and lactate >2.9 mmol/L together had 97.8% specificity and 97.1% PPV for identifying severity.

CONCLUSIONS

The presence of either 'prolonged capillary refill time with one deranged biochemical parameter' or 'both deranged biochemical parameters' is nearly 100% specific for severity of dengue.

Kinetics of CD4+ T Helper and CD8+ Effector T Cell Responses in Acute Dengue Patients

Background: The protective or pathogenic role of T lymphocytes during the acute phase of dengue virus (DENV) infection has not been fully understood despite its importance in immunity and vaccine development.

Objectives: This study aimed to clarify the kinetics of T lymphocyte subsets during the clinical course of acute dengue patients.

Study design: In this hospital-based cohort study, 59 eligible Vietnamese dengue patients were recruited and admitted. They were investigated and monitored for T cell subsets and a panel of clinical and laboratory parameters every day until discharged and at post-discharge from the hospital.

Results: We described for the first time the kinetics of T cell response during the clinical course of DENV infection. Severe cases showed significantly lower levels of effector CD8⁺ T cells compared to mild cases at day −1 (p = 0.017) and day 0 (p = 0.033) of defervescence. After defervescence, these cell counts in severe cases increased rapidly to equalize with the levels of mild cases. Our results also showed a decline in total CD4⁺ T, Th1, Th1/17 cells during febrile phase of dengue patients compared to normal controls or convalescent phase. On the other hand, Th2 cells increased during DENV infection until convalescent phase. Cytokines such as interferon-γ, IL-12p70, IL-5, IL-23, IL-17A showed tendency to decrease on day 0 and 1 compared with convalescence and only IL-5 showed significance indicating the production during acute phase was not systemic.

Conclusion: With a rigorous study design, we uncovered the kinetics of T cells in natural DENV infection. Decreased number of effector CD8⁺ T cells in the early phase of infection and subsequent increment after defervescence day probably associated with the T cell migration in DENV infection.

Comparison of dengue case classification schemes and evaluation of biological changes in different dengue clinical patterns in a longitudinal follow-up of hospitalized children in Cambodia

BACKGROUND

The World Health Organization (WHO) proposed guidelines on dengue clinical classification in 1997 and more recently in 2009 for the clinical management of patients. The WHO 1997 classification defines three categories of dengue infection according to severity: dengue fever (DF), dengue hemorrhagic fever (DHF), and dengue shock syndrome (DSS). Alternative WHO 2009 guidelines provide a cross-sectional classification aiming to discriminate dengue fever from dengue with warning signs (DWWS) and severe dengue (SD). The primary objective of this study was to perform a comparison of two dengue classifications. The secondary objective was to describe the changes of hematological and biochemical parameters occurring in patients presenting with different degrees of severity during the course of the disease, since progression to more severe clinical forms is unpredictable.

METHODOLOGY/PRINCIPAL FINDINGS

We performed a prospective, monocentric, cross-sectional study of hospitalized children in Cambodia, aged from 2 to 15 years old with severe and non-severe dengue. We enrolled 243 patients with acute dengue-like illness: 71.2% were dengue infections confirmed using quantitative reverse transcription PCR or NS1 antigen capture ELISA, of which 87.2% and 9.0% of DF cases were respectively classified DWWS and SD, and 35.9% of DHF were designated SD using an adapted WHO 2009 classification for SD case definition. Systematic use of ultrasound at patient admission was crucial for detecting plasma leakage. No difference was observed in the concentration of secreted NS1 protein between different dengue severity groups. Lipid profiles were different between DWWS and SD at admission, characterized by a decrease in total cholesterol, HDL cholesterol, and LDL cholesterol, in SD.

CONCLUSIONS/SIGNIFICANCE

Our results show discrepancies between the two classifications, including misclassification of severe dengue cases as mild cases by the WHO 1997 classification. Using an adapted WHO 2009 classification, SD more precisely defines the group of patients requiring careful clinical care at a given time during hospitalization.

Zika virus infection enhances future risk of severe dengue disease

The Zika pandemic sparked intense interest in whether immune interactions among dengue virus serotypes 1 to 4 (DENV1 to -4) extend to the closely related Zika virus (ZIKV). We investigated prospective pediatric cohorts in Nicaragua that experienced sequential DENV1 to -3 (2004 to 2015), Zika (2016 to 2017), and DENV2 (2018 to 2020) epidemics. Risk of symptomatic DENV2 infection and severe disease was elevated by one prior ZIKV infection, one prior DENV infection, or one prior DENV infection followed by one ZIKV infection, compared with being flavivirus-naïve. By contrast, multiple prior DENV infections reduced dengue risk. Further, although high preexisting anti-DENV antibody titers protected against DENV1, DENV3, and ZIKV disease, intermediate titers induced by previous ZIKV or DENV infection enhanced future risk of DENV2 disease and severity, as well as DENV3 severity. The observation that prior ZIKV infection can modulate dengue disease severity like a DENV serotype poses challenges to development of dengue and Zika vaccines.

Development and Performance of Dengue Diagnostic Clinical Algorithms in Colombia

Diagnosing dengue in endemic areas remains problematic because of the low specificity of the symptoms and lack of accurate diagnostic tests. This study aimed to develop and prospectively validate, under routine care, dengue diagnostic clinical algorithms. The study was carried out in two phases. First, diagnostic algorithms were developed using a database of 1,130 dengue and 918 non-dengue patients, expert opinion, and literature review. Algorithms with > 70% sensitivity were prospectively validated in a single-group quasi-experimental trial with an adaptive Bayesian design. In the first phase, the algorithms that were developed with the continuous Bayes formula and included leukocytes and platelet counts, in addition to selected signs and symptoms, showed the highest sensitivities (> 80%). In the second phase, the algorithms were applied on admission to 1,039 consecutive febrile subjects in three endemic areas in Colombia of whom 25 were laboratory-confirmed dengue, 307 non-dengue, 514 probable dengue, and 193 undetermined. Including parameters of the hemogram consistently improved specificity without affecting sensitivity. In the final analysis, considering only confirmed dengue and non-dengue cases, an algorithm with a sensitivity and specificity of 65.4% (95% credibility interval 50-83) and 40.1% (34.7-45.7) was identified. All tested algorithms had likelihood ratios close to 1, and hence, they are not useful to confirm or rule out dengue in endemic areas. The findings support the use of hemograms to aid dengue diagnosis and highlight the challenges of clinical diagnosis of dengue.

Association of serum C-reactive protein level and polymorphisms with susceptibility to dengue infection and severe clinical outcome among eastern Indian patients

Dengue virus (DENV) infection is a major public health concern in India ranging from simple febrile illness to severe outcome. This study aimed to investigate association of serum CRP level and CRP gene polymorphisms towards development of dengue disease susceptibility and severity among eastern Indian patients. Blood was collected from 348 symptomatic patients. Sera was subjected to serological diagnosis for the presence of anti-dengue IgM, anti-dengue IgG antibodies and dengue NS1 antigen by ELISA. Viral RNA was extracted and the presence of DENV genome, viral load, serotypes was determined by qRT-PCR. CRP level and polymorphisms were determined by immunoturbidimetry and polymerase chain reaction-restriction fragment length polymorphism, respectively. Statistical analysis was performed by GraphPad-Prism. Among 206 dengue patients, CRP level increased significantly among patients within acute phase, and patients with qRT-PCR/NS1 antigen positivity, high viral load (HVL), secondary infection, and DENV4 and DENV2 infections. rs3091244, TT genotype positively associated with dengue susceptibility (p = 0.03). CT genotype of rs3093059 and TT genotype of rs3091244 were found to correlate with elevated CRP level and development of WHO-defined warning signs. TT genotype of rs3091244 was more prevalent among HVL patients. Thus, these CRP polymorphic variants and CRP concentration might act as potential prognostic biomarkers for predicting disease severity among acute-stage dengue patients.

Chikungunya Case Classification after the Experience with Dengue Classification: How Much Time Will We Lose?

In 2013, cases of chikungunya virus (CHIKV) infection were first detected in the Caribbean. Chikungunya virus rapidly spread through Central and South America, causing explosive outbreaks in naive populations. Since its emergence in 2004, the number of case and series reports describing severe, atypical manifestations seen in chikungunya patients has increased substantially, calling into question whether clinicians and health services are failing to diagnose these atypical cases because of not only insufficient knowledge but also limitations in the case classification. Although this classification based on the duration of the musculoskeletal (acute, subacute, and chronic forms) complaints helped guide therapeutic approaches directed to these manifestations, patients presenting severe or complicated forms, which are less frequent but produce most of the fatal outcomes, were not properly addressed. In Brazil and the Caribbean, a clear temporal and spatial association between excess overall mortality and the occurrence of chikungunya epidemics has been shown, supporting the hypothesis that many of these excess deaths were a consequence of CHIKV infections. Thus, accumulated experience has highlighted that the current chikungunya case classification does not encompass the actual needs presented by certain cases with atypical features nor does it contribute to early detection and management of potentially severe cases. With continued CHIKV circulation in three continents and recent reemergence in Asia and Europe, we need a classification that is prospective and informed both by initial clinical presentation and by progression of signs and symptoms.

Severe dengue categories as research endpoints-Results from a prospective observational study in hospitalised dengue patients

Severe dengue was perceived as one clinical disease entity until the WHO 2009 classification stratified it into severe vascular leakage, severe bleeding, and severe organ dysfunction. The objectives of this study were to investigate the potential use of severe dengue categories as endpoints for intervention research. 271 patients with severe dengue among 1734 confirmed dengue patients were followed prospectively in this hospital-based observational study in Latin America and Asia. We compared the distribution of severe dengue categories according to gender and age (below/above 15y), and determined the relative frequency and the overlap of severe dengue categories in the same patients. In a next step, we extended the analysis to candidate moderate severity categories, based on recently suggested definitions which were adapted for our purposes. Severe vascular leakage occurred in 244 (90%), severe bleeding in 39 (14%), and severe organ dysfunction in 28 (10%) of 271 severe dengue patients. A higher frequency of severe leakage was seen in children or adolescents (<15y) compared to adults. More than 80% of the severe leakage cases, and 30-50% of the cases with severe bleeding or severe organ dysfunction, were defined as severe on the basis of that feature alone. In 136 out of 213 patients with severe leakage alone, neither moderate bleeding manifestation nor hepatic involvement was recorded. On the other hand, moderate leakage manifestations were detected in 4 out of 12 cases that were classified as severe based on bleeding alone. A major proportion of severe dengue patients exhibited clinical manifestations of severe vascular leakage only, which may constitute a useful endpoint for intervention research or pathophysiology studies. Severe bleeding and severe organ manifestation were recorded less frequently and exhibited a higher degree of overlap with severe leakage. Severe bleeding without leakage may be associated with individual predisposition or the presence of comorbidities. More detailed assessments are needed to explore this hypothesis. Candidate moderate disease endpoints were investigated and need to be further validated.

Towards Predicting Progression to Severe Dengue

There is an urgent need for prognostic assays to predict progression to severe dengue infection, which is a major global threat. While the majority of symptomatic dengue patients experience an acute febrile illness, 5-20% progress to severe infection associated with significant morbidity and mortality. Early monitoring and administration of supportive care reduce mortality and clinically usable biomarkers to predict severe dengue are needed. Here, we review recent discoveries of gene sets, anti-dengue antibody properties, and inflammatory markers with potential utility as predictors of disease progression. Upon larger scale validation and development of affordable sample-to-answer technologies, some of these biomarkers may be utilized to develop the first prognostic assay for improving patient care and allocating healthcare resources more effectively in dengue endemic countries.

Contribution of Toll like receptor polymorphisms to dengue susceptibility and clinical outcome among eastern Indian patients

Dengue infection has been one of the major public health concerns in India causing simple dengue fever (DF) to severe dengue infection. In the present study, contribution of TLR3, 7 and 8 polymorphisms towards dengue disease susceptibility and severity among Eastern Indian patients was analysed. Genomic DNA was extracted from blood of 201 dengue infected patients and 157 healthy individuals, followed by genotyping of eight polymorphisms of TLR3 (rs3775290), TLR7 (rs5741880, rs3853839, rs179008 and rs179010) and TLR8 (rs3764879, rs3764880 and rs5744080) genes by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Functional analyses of the polymorphisms were predicted. Genotypic association of polymorphisms, alone and in combination, with dengue disease susceptibility and development of WHO-defined warning signs among patients was calculated by using SPSS software. TLR7-rs179008 & TLR8-rs3764880 were implicated to be non-synonymous polymorphisms. Specific genotypes of majority of the analysed TLR polymorphisms exhibited significant positive association with disease susceptibility. CC/C and AA/A of TLR7-rs179008 (p < 0.0001) and TLR8-rs3764880 (p < 0.00001) respectively were significantly associated with development of warning signs among dengue infected patients. Particular genotypic combinations of rs3853839-rs5744080 and rs179008-rs3764880 increased the risk of dengue infectivity, whereas, presence of last combination was more prevalent among dengue patients with warning signs. Thus these polymorphic variants of TLR3, 7 and 8 might act as potential prognostic biomarkers for predicting disease severity among dengue virus infected patients.

Assessment of the new World Health Organization's dengue classification for predicting severity of illness and level of healthcare required

The objective of this study was to assess the validity of the new dengue classification proposed by the World Health Organization (WHO) in 2009 and to develop pragmatic guidelines for case triage and management. This retrospective study involved 357 laboratory-confirmed cases of dengue infection diagnosed at King Abdulaziz University Hospital, Jeddah, Saudi Arabia over a 4-year period from 2014 to 2017. The sensitivity of the new classification for identifying severe cases was limited (65%) but higher than the old one (30%). It had a higher sensitivity for identifying patients who needed advanced healthcare compared to the old one (72% versus 32%, respectively). We propose adding decompensation of chronic diseases and thrombocytopenia-related bleeding to the category of severe dengue in the new classification. This modification improves sensitivity from 72% to 98% for identifying patients who need advanced healthcare without altering specificity (97%). It also improves sensitivity in predicting severe outcomes from 32% to 88%. In conclusion, the new classification had a low sensitivity for identifying patients needing advanced care and for predicting morbidity and mortality. We propose to include decompensation of chronic diseases and thrombocytopenia-related bleeding to the category of severe dengue in the new classification to improve the sensitivity of predicting cases requiring advanced care.

Dengue fever, the most prevalent arthropod-borne viral disease in humans, has been conventionally classified into four main categories: non-classical, classical, dengue hemorrhagic fever, and dengue shock syndrome. Several studies reported lack of correlation between the categories of the conventional classification and the disease severity. As a consequence, the World Health Organization proposed in 2008 a new classification that divides dengue into two categories: non-severe and severe dengue; the non-severe dengue is further divided into two categories: dengue with warning signs and dengue without warning signs. In this retrospective study we reviewed 357 cases of dengue diagnosed in our institution over a 4-year period to assess the validity of the new dengue classification in order to develop pragmatic guidelines for case triage and management in the Emergency Departments. We found that the sensitivity of the new classification for identifying severe cases was limited even though it had a higher sensitivity for identifying patients who needed advanced healthcare compared to the old one. We propose adding decompensation of chronic diseases and low platelets-related bleeding to the category of severe dengue in the new classification. This modification dramatically improves the sensitivity for identifying patients who need advanced healthcare and the sensitivity to predict severe outcomes.

Diagnostic accuracy and predictive value in differentiating the severity of dengue infection

OBJECTIVE

To review the diagnostic test accuracy and predictive value of statistical models in differentiating the severity of dengue infection.

METHODS

Electronic searches were conducted in the Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, MEDLINE (complete), PubMed and Scopus. Eligible studies to be included in this review were cohort studies with participants confirmed by laboratory test for dengue infection and comparison among the different severity of dengue infection by using statistical models. The methodological quality of the paper was assessed by independent reviewers using QUADAS-2.

RESULTS

Twenty-six studies published from 1994 to 2017 were included. Most diagnostic models produced an accuracy of 75% to 80% except one with 86%. Two models predicting severe dengue according to the WHO 2009 classification have 86% accuracy. Both of these logistic regression models were applied during the first three days of illness, and their sensitivity and specificity were 91-100% and 79.3-86%, respectively. Another model which evaluated the 30-day mortality of dengue infection had an accuracy of 98.5%.

CONCLUSION

Although there are several potential predictive or diagnostic models for dengue infection, their limitations could affect their validity. It is recommended that these models be revalidated in other clinical settings and their methods be improved and standardised in future.

Development of clinical algorithms for the diagnosis of dengue in Colombia

Introduction: Due to the increase in dengue incidence and mortality, its diagnosis is relevant for endemic countries. Clinical classifications and laboratory tests have a variable performance in clinical practice with a sensitivity level between 45% and 98%, and a specificity level between 4% and 98% partly due to the variety of contexts where they are applied. Objective: To develop clinical algorithms for the diagnosis of dengue in the Colombian context. Materials and methods: A cross-sectional study was conducted based on secondary sources. We constructed clinical diagnostic algorithms of dengue based on Bayesian methods combining symptoms, signs, and blood count parameters, and then we compared them in terms of diagnostic accuracy with gold standard tests. In addition, an external validation of the algorithm with greater accuracy and sensibility was performed comparing it with the WHO-1997 and the WHO-2009 clinical classifications, the Colombian guide for 2010, and the diagnostic scale recommended by the Ministerio de Salud y Protección Social of Colombia for 2013. Results: Four algorithms were generated, two for signs and symptoms, and two that included leukocytes (≤4,500/mm3) and/or platelets (≤160,000/mm3) counts. The most accurate algorithm included blood count parameters with a sensitivity of 76.5% (95%CI: 71.9-80.5) and a specificity of 46.0% (95%CI: 37.6-54.7). In the external validation we found a sensitivity of 11.1% (95%CI: 4.9-20.7) and a specificity of 91.9% (95%CI: 87.5-93.9). The scale of the Ministerio de Salud had a sensitivity of 76.4% (95%CI: 64.9-85.6) and a specificity of 38.0% (95%CI: 32.8-43.4). Conclusion: The inclusion of blood count parameters improved the sensitivity of diagnostics algorithms based on signs and symptoms. Clinical diagnosis of dengue remains a challenge for health research.

30 years of fatal dengue cases in Brazil: a review

BACKGROUND

Over the last 30 years, extensive dengue epidemics have occurred in Brazil, characterized by emergences and re-emergences of different serotypes, a change in the epidemiological profile and an increase in the number of severe and fatal cases. Here, we present a review on the dengue fatal cases that occurred in Brazil in 30 years (1986-2015).

METHODS

We performed an ecological study by using secondary data on dengue fatal cases obtained in the National System of Reported Diseases (Sistema de Informação de Agravos de Notificação -SINAN) and in the Mortality Information System (SIM), both maintained by the Brazilian Ministry of Health. Cases were analyzed by region, demographic variables, clinical classification and complications based on the data available.

RESULTS

In 30 years (1986-2015), the Southeast region reported 43% (n = 2225) of all dengue deaths in the country. The Midwest region was responsible for 18% of the fatal cases. After 2000, deaths occurred in almost all states, with the exception of Santa Catarina and Rio Grande do Sul, South region. From 2006 to 2010, the number of deaths increased, with higher rates of mortality, especially in Goiás and Mato Grosso. From 2011 to 2015, Goiás became the state with the highest mortality rate in the country, and Rio Grande do Sul reported its first dengue deaths. In 30 years, a total of 2682 dengue deaths occurred in males and 2455 in females, and an equal distribution between the sexes was observed. From 1986 to 2006, dengue deaths occurred predominantly in individuals over 15 years old, but this scenario changed in 2007-2008. After 2009, fatal cases on individuals above 15 years old became more frequent, with peaks in the years of 2010, 2013 and 2015.

CONCLUSIONS

The Brazil is experiencing a hyperendemic scenario, which has resulted in the co-circulation of the four DENV serotypes and with the increasing occurrence of severe and fatal cases. The disease surveillance and studies characterizing what has been reported overtime, are still important tools to better understand the factors involved in the disease outcome.

Clinical Indicators of Fatal Dengue in Two Endemic Areas of Colombia: A Hospital-Based Case-Control Study

According to the World Health Organization, 98% of fatal dengue cases can be prevented; however, endemic countries such as Colombia have recorded higher case fatality rates during recent epidemics. We aimed to identify the predictors of mortality that allow risk stratification and timely intervention in patients with dengue. We conducted a hospital-based, case-control (1:2) study in two endemic areas of Colombia (2009-2015). Fatal cases were defined as having either 1) positive serological test (IgM or NS1), 2) positive virological test (RT-PCR or viral isolation), or 3) autopsy findings compatible with death from dengue. Controls (matched by state and year) were hospitalized nonfatal patients and had a positive serological or virological dengue test. Exposure data were extracted from medical records by trained staff. We used conditional logistic regression (adjusting for age, gender, disease's duration, and health-care provider) in the context of multiple imputation to estimate exposure to case-control associations. We evaluated 110 cases and 217 controls (mean age: 35.0 versus 18.9; disease's duration pre-admission: 4.9 versus 5.0 days). In multivariable analysis, retro-ocular pain (odds ratios [OR] = 0.23), nausea (OR = 0.29), and diarrhea (OR = 0.19) were less prevalent among fatal than nonfatal cases, whereas increased age (OR = 2.46 per 10 years), respiratory distress (OR = 16.3), impaired consciousness (OR = 15.9), jaundice (OR = 32.2), and increased heart rate (OR = 2.01 per 10 beats per minute) increased the likelihood of death (AUC: 0.97, 95% confidence interval: 0.96, 0.99). These results provide evidence that features of severe dengue are associated with higher mortality, which strengthens the recommendations related to triaging patients in dengue-endemic areas.

A 20-Gene Set Predictive of Progression to Severe Dengue

There is a need to identify biomarkers predictive of severe dengue. Single-cohort transcriptomics has not yielded generalizable results or parsimonious, predictive gene sets. We analyzed blood samples of dengue patients from seven gene expression datasets (446 samples, five countries) using an integrated multi-cohort analysis framework and identified a 20-gene set that predicts progression to severe dengue. We validated the predictive power of this 20-gene set in three retrospective dengue datasets (84 samples, three countries) and a prospective Colombia cohort (34 patients), with an area under the receiver operating characteristic curve of 0.89, 100% sensitivity, and 76% specificity. The 20-gene dengue severity scores declined during the disease course, suggesting an infection-triggered host response. This 20-gene set is strongly associated with the progression to severe dengue and represents a predictive signature, generalizable across ages, host genetic factors, and virus strains, with potential implications for the development of a host response-based dengue prognostic assay.

Dengue

Mortality from severe dengue is low, but the economic and resource burden on health services remains substantial in endemic settings. Unfortunately, progress towards development of effective therapeutics has been slow, despite notable advances in the understanding of disease pathogenesis and considerable investment in antiviral drug discovery. For decades antibody-dependent enhancement has been the prevalent model to explain dengue pathogenesis, but it was only recently demonstrated in vivo and in clinical studies. At present, the current mainstay of management for most symptomatic dengue patients remains careful observation and prompt but judicious use of intravenous hydration therapy for those with substantial vascular leakage. Various new promising technologies for diagnosis of dengue are currently in the pipeline. New sample-in, answer-out nucleic acid amplification technologies for point-of-care use are being developed to improve performance over current technologies, with the potential to test for multiple pathogens using a single specimen. The search for biomarkers that reliably predict development of severe dengue among symptomatic individuals is also a major focus of current research efforts. The first dengue vaccine was licensed in 2015 but its performance depends on serostatus. There is an urgent need to identify correlates of both vaccine protection and disease enhancement. A crucial assessment of vector control tools should guide a research agenda for determining the most effective interventions, and how to best combine state-of-the-art vector control with vaccination.

Cytokine Signature Associated with Disease Severity in Dengue

Dengue is the most rapidly spreading viral disease transmitted by the bite of infected Aedes mosquitos. The pathogenesis of dengue is still unclear; although host immune responses and virus serotypes have been proposed to contribute to disease severity. In this study, we examined the circulating dengue virus (DENV) and measured plasma levels of inflammatory mediators. Ninety-eight patients during a dengue outbreak in eastern India in 2016 were included in the study. The presence of DENV was demonstrated by detecting NS1 antigen; IgM capture ELISA and serotypes were discriminated by type-specific RT-PCR and/or sequencing. Plasma samples were assayed for 41-plex cytokine/chemokines using multiplex Luminex assay. Eighty-five (87%) samples were positive by NS1/IgM capture ELISA/RT-PCR. All four serotypes of DENV were detected in this outbreak, with DENV-2 as the predominant type, seen in 55% of cases. Mixed infections were seen in 39% of subjects. Among the host inflammatory biomarkers, GM-CSF, IFN-γ, IL-10, IL-15, IL-8, MCP-1, IL-6, MIP-1β, and TNF-α levels were significantly increased in dengue with and without warning signs, in severe dengue patients in comparison to healthy controls. Four cytokines IFN-γ, GM-CSF, IL-10, and MIP-1β correlated significantly with disease severity and could serve as potential predictor for disease severity. Information on the host biomarkers and the dengue serotype may help guide in optimizing effective intervention strategies.

Development of standard clinical endpoints for use in dengue interventional trials: introduction and methodology

Background

As increasing numbers of dengue vaccines and therapeutics are in clinical development, standardized consensus clinical endpoint definitions are urgently needed to assess the efficacy of different interventions with respect to disease severity. We aimed to convene dengue experts representing various sectors and dengue endemic areas to review the literature and propose clinical endpoint definitions for moderate and severe disease based on the framework provided by the WHO 2009 classification.

Methods

The endpoints were first proposed and discussed in a structured expert consultation. After that, the Delphi method was carried out to assess the usefulness, validity and feasibility of the standardized clinical disease endpoints for interventional dengue research.

Results

Most respondents (> 80%) agreed there is a need for both standardized clinical endpoints and operationalization of severe endpoints. Most respondents (67%) felt there is utility for moderate severity endpoints, but cited challenges in their development. Hospitalization as a moderate endpoint of disease severity or measure of public health impact was deemed to be useful by only 47% of respondents, but 89% felt it could bring about supplemental information if carefully contextualized according to data collection setting. Over half of the respondents favored alignment of the standard endpoints with the WHO guidelines (58%), but cautioned that the endpoints could have ramifications for public health practice. In terms of data granularity of the endpoints, there was a slight preference for a categorical vs numeric system (e.g. 1–10) (47% vs 34%), and 74% of respondents suggested validating the endpoints using large prospective data sets.

Conclusion

The structured consensus-building process was successful taking into account the history of the debate around potential endpoints for severe dengue. There is clear support for the development of standardized endpoints for interventional clinical research and the need for subsequent validation with prospective data sets. Challenges include the complexity of developing moderate disease research endpoints for dengue.

Validation of Serum Aminotransferases Levels to Define Severe Dengue Fever in Children

PURPOSE

We aimed to study the pattern of liver-injury in children with dengue fever (DF) and validate serum aminotransferase ≥1,000 IU/L as a marker of severe DF.

METHODS

Children admitted with DF were included. DF was defined by presence of clinical criteria and positive serological or antigen tests in absence of other etiology. DF severity was graded as dengue without or with warning signs and severe dengue. Liver-injury was defined as alanine aminotransferase (ALT) more than twice the upper limit of normal (boys, 30 IU/L; girls, 21 IU/L).

RESULTS

Of 372 children with DF, 144 (38.7%) had liver-injury. Risk of liver-injury and aminotransferase levels increased with DF severity (p<0.001). Recommended ALT and aspartate aminotransferase (AST) cut-off at ≥1,000 IU/L had sensitivity 4.8% (5/105), specificity 99.3% (265/267) for detection of severe DF. In children with ALT and AST <1,000 IU/L (n=365), the area under receiver operating curves for prediction for severe DF, were 0.651 (95% confidence interval [CI], 0.588-0.714; p<0.001) for ALT and 0.647 (95% CI, 0.582-0.712; p<0.001) for AST. Serum ALT at 376 IU/L and AST at 635 IU/L had sensitivity and specificity comparable to ≥1,000 IU/L for defining severe DF.

CONCLUSION

Liver-injury is common in DF. The ALT and AST levels increase with DF severity. ALT and AST levels of ≥1,000 IU/L could be lowered to 376 IU/L and 635 IU/L respectively for defining severe DF.

The Sensitivity, Specificity and Accuracy of Warning Signs in Predicting Severe Dengue, the Severe Dengue Prevalence and Its Associated Factors

Objectives: To study Malaysian dengue clinical practice guideline (CPG) warning signs (WS) in predicting severe dengue (SD) and its associated factors among confirmed cases presented to a teaching hospital in north-eastern Malaysia in 2014. Methods: A cross-sectional study was performed in February 2015 using secondary data acquired from the hospital records. There were 2607 confirmed dengue cases presented to Hospital Universiti Sains Malaysia (HUSM) in 2014. Seven hundred patients were selected after proportionate stratified random sampling conducted according to the number of cases in 12 different months in 2014. Data were collected and analysed using SPSS version 22.0. Results: Severe dengue outcomes represented 4.9% of cases. The prevalence of any of WS in SD was 91.2%. The most common WSs prior to SD were persistent vomiting (55.9%), and abdominal pain/tenderness (52.9%). The most sensitive warning sign in detecting SD was abdominal pain (59%). Specificity of individual WS were generally good, especially of clinical fluid accumulation (99%), hepatomegaly (98%) and mucosal bleeding (93%). Factors associated with SD were persistent vomiting (Adjusted odds ratio (aOR)): 2.41), mucosal bleeding (aOR: 4.73) and haematocrit rise with rapid platelet drop (aOR: 2.74). Conclusion: A focus on sensitivity, specificity, predictive values and association of a number of particular WS should be emphasized in order to better predict severe dengue outcomes.

Warning sign as a predictor of dengue infection severity in children

Background: Dengue has emerged as a global public health problem, about 500,000 affected patients of 50–100 million cases will develop severe dengue infection. Therefore, early identification of severe dengue infection symptoms can save a patient’s life. The 2009 WHO dengue infection classification proposed seven warning signs to identify the risk of severe dengue. This study was conducted to predict the severity of dengue infection based on the number of warning signs.Methods: This was a diagnostic study conducted with a retrospective analytic observation of patients admitted to Adam Malik hospital with a diagnosis of dengue infection from January 2014–May 2016. The association between warning signs and severe dengue infection was analyzed using logistic regression. We also analyzed the sensitivity, specificity, positive predictive value and negative predictive value.Results: Of 140 patients who fulfilled the research criteria were collected from the medical records. The patients were classified as severe dengue (n=28) and nonsevere dengue (n =112). The warning signs that were associated with severe dengue were persistent vomiting (p<0.05, OR 31.9, 95%CI), fluid accumulation (p<0.05, OR 22.4, 95%CI), mucosal bleeding (p<0.05, OR 9.1, 95%CI), lethargy (p<0.05, OR 43.1, 95%CI). After analyzing the diagnostic tests, the combination of three or more warning signs showed that sensitivity of 92.9%, specificity of 78.6%, positive predictive value of 52%, negative predictive value of 97.7% was found to be associated with a severe dengue infection.Conclusion: The combination of three or more warning signs showed a high sensitivity and specificity for predicting a severe dengue infection.

The association between obesity and dengue virus (DENV) infection in hospitalised patients

Both obesity and DENV infections are growing public health concerns that have far-ranging socioeconomic effects, especially in developing countries. Despite the increasing prevalence of these conditions, there is a scarcity of data investigating the potential relationships between these two entities. Our study aims to examine the influence of obesity on various clinical and laboratory parameters amongst patients with DENV infections. A total of 335 hospitalized patients aged >12 years who were DENV non-structural protein 1 (NS1) antigen-positive were enrolled in this study. Clinical and laboratory variables were compared between patients with and without obesity. Multivariate analysis showed that the following admission clinical findings and laboratory results were independently associated with obesity; chills and rigors (AOR:2.653, 95% CI: 1.286–5.474), higher temperature (AOR:1.485, 95% CI: 1.080–2.042), higher systolic BP (AOR:1.057, 95% CI:1.037–1.078), raised haematocrit (AOR: 1.953, 95% CI: 1.010–3.778), elevated creatinine (AOR:3.504, 95% CI:1.351–9.008) and elevated ALT (AOR: 4.146, 95% CI:1.878–9.154). Obesity was found to be significantly associated with hospitalization >3 days (AOR: 1.990, 95% CI: 1.134–3.494) and the presence of increasing haematocrit with decreasing platelets (AOR: 2.134, 95% CI = 1.235–3.688). Serial assessment of laboratory data revealed that peak haematocrit was significantly higher and nadir platelets levels were significantly lower in obese patients. Both peak and admission levels of leukocyte counts, AST, ALT and creatinine were significantly higher in the obese group. Conversely, both admission and nadir albumin levels were lower for the obese group, although only nadir albumin levels achieved statistical significance. These findings support closer clinical monitoring of obese patients who present with DENV infections, as this patient cohort may possess an increased tendency towards developing more severe clinical manifestations of DENV infections as compared to non-obese patients.

Improving Dengue Diagnostics and Management Through Innovative Technology

PURPOSE OF REVIEW

Dengue continues to be a major global public health threat. Symptomatic infections can cause a spectrum of disease ranging from a mild febrile illness to severe and potentially life-threatening manifestations. Management relies on supportive treatment with careful fluid replacement. The purpose of this review is to define the unmet needs and challenges in current dengue diagnostics and patient monitoring and outline potential novel technologies to address these needs.

RECENT FINDINGS

There have been recent advances in molecular and point-of-care (POC) diagnostics as well as technologies including wireless communication, low-power microelectronics, and wearable sensors that have opened up new possibilities for management, clinical monitoring, and real-time surveillance of dengue. Novel platforms utilizing innovative technologies for POC dengue diagnostics and wearable patient monitors have the potential to revolutionize dengue surveillance, outbreak response, and management at population and individual levels. Validation studies of these technologies are urgently required in dengue-endemic areas.

Global dengue death before and after the new World Health Organization 2009 case classification: A systematic review and meta-regression analysis

BACKGROUND

Since the introduction of 2009 WHO dengue case classification, no literature was found regarding its effect on dengue death. This study was to evaluate the effect of 2009 WHO dengue case classification towards dengue case fatality rate.

METHODS

Various databases were used to search relevant articles since 1995. Studies included were cohort and cross-sectional studies, all patients with dengue infection and must report the number of death or case fatality rate. The Joanna Briggs Institute appraisal checklist was used to evaluate the risk of bias of the full-texts. The studies were grouped according to the classification adopted: WHO 1997 and WHO 2009. Meta-regression was employed using a logistic transformation (log-odds) of the case fatality rate. The result of the meta-regression was the adjusted case fatality rate and odds ratio on the explanatory variables.

RESULTS

A total of 77 studies were included in the meta-regression analysis. The case fatality rate for all studies combined was 1.14% with 95% confidence interval (CI) of 0.82-1.58%. The combined (unadjusted) case fatality rate for 69 studies which adopted WHO 1997 dengue case classification was 1.09% with 95% CI of 0.77-1.55%; and for eight studies with WHO 2009 was 1.62% with 95% CI of 0.64-4.02%. The unadjusted and adjusted odds ratio of case fatality using WHO 2009 dengue case classification was 1.49 (95% CI: 0.52, 4.24) and 0.83 (95% CI: 0.26, 2.63) respectively, compared to WHO 1997 dengue case classification. There was an apparent increase in trend of case fatality rate from the year 1992-2016. Neither was statistically significant.

CONCLUSIONS

The WHO 2009 dengue case classification might have no effect towards the case fatality rate although the adjusted results indicated a lower case fatality rate. Future studies are required for an update in the meta-regression analysis to confirm the findings.