Comparing the usefulness of the 1997 and 2009 WHO dengue case classification: a systematic literature review

Pre-or co-SARS-CoV-2 Infections Significantly Increase Severe Dengue Virus Disease Criteria: Implications for Clinicians

Few studies have investigated whether SARS-CoV-2 infections increase the incidence of dengue haemorrhagic fever/shock syndrome (DHF/DSS) and/or severe dengue (SD) in dengue virus (DENV)-infected patients. This study was performed on a site with high incidences of classical dengue, but relatively few DHF/DSS or SD cases as defined by the WHO 1997 or 2009 criteria, respectively. Clinical, haematological/biochemical, and viral diagnostic data were collected from febrile patients before, during, and after the COVID-19 epidemic to assess whether (a) DENV-infected patients with prior SARS-CoV-2 infections or (b) DENV-SARS-CoV-2-co-infected patients had increased incidences of SD/DHF/DSS using logistic regression and machine learning models. Higher numbers of DHF/DSS/SD occurred during the COVID-19 epidemic, particularly in males and 18-40-year-olds. Significantly increased symptoms in the DENV-SARS-CoV-2-co-infected cases were (a) haemoconcentration (p < 0.0009) and hypotension (p < 0.0005) (DHF/DSS and SD criteria), (b) thrombocytopenia and mucosal bleeding (DHF/DSS-criteria), (c) abdominal pain, persistent vomiting, mucosal bleeding, and thrombocytopenia (SD warning signs) and (d) dyspnoea, but without fluid accumulation. DENV-infected patients with prior SARS-CoV-2 infections had significantly increased incidences of thrombocytopenia (DHF/DSS-criteria) and/or abdominal pain and persistent vomiting and also thrombocytopenia (SD warning signs), but without significant haemoconcentration or hypotension. DENV-SARS-CoV-2 co-infections significantly increased the incidence of DHF/DSS/SD, while DENV-infected patients with prior SARS-CoV-2 infections displayed significantly increased incidences of thrombocytopenia (DHF/DSS-criteria) and three important SD warning signs, which are therefore very important for health workers/clinicians in assessing patients' DHF/DSS/SD risk factors and planning their optimal therapies.

Bamboo stumps that are artificially in use put pressure on dengue and chikungunya vector control in Dhaka city, Bangladesh

BACKGROUND OBJECTIVES

Aedes aegypti and Ae. albopictus mosquitoes breed in natural and artificial containers, and they transmit dengue and chikungunya. A study was conducted to identify the contribution of bamboo stumps to these disease vectors that were used in the flower garden as pillars to hold the bamboo flex fence.

METHODS

Two sizes of whole bamboo were used to hold fences around gardens at Dhaka University, Bangladesh, and were painted red and green. Mosquito larvae and pupae were collected from bamboo stumps between July and August, and vectors were identified up to the species level. The data were analyzed using the STATA/MP 14.2 version.

RESULTS

83.5% and 0.2% were Ae. albopictus and Ae. aegypti, respectively, and the remaining were Culex and Ar-migeres species. Ae. albopictus, Ae. aegypti, and both species-positive bamboo stumps were 46.9, 0.7, and 47.1%, respectively. 54.5% of the bamboo stumps had at least one mosquito species. The average stump depth for Aedes positive stumps (mean=11.7 cm, SE = 0.5) was significantly (p <0.001) higher than the Aedes negative stumps (mean = 9.5 cm, SE = 0.4). 53.8% and 38.0% stumps were found Aedes positive on the ground and upper sides of fences, respectively, and found significant (p<0.01) differences between both sides. A zero-inflated negative binomial count model is significant at a 5% level of significance, χ2(4) = 11.8, p = 0.019 (<0.05) for Ae. albopictus. Stump depth is found to have a significant positive effect on the number of Aedes-positive stumps.

INTERPRETATION CONCLUSION

Artificially used natural containers are adding pressure to current mosquito control activities as mosquitoes are breeding on them, which needs additional attention.

Severe dengue in the intensive care unit

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

The application of environmental management methods in combating dengue: a systematic review

Among several vector control methods commonly used, environmental management is one of the control measures to mitigate dengue in such vulnerable communities. Since there is no curative treatment for dengue yet, targeted environmental and ecosystem management is increasingly relevant. Hence, this review was conducted to identify the effectiveness of environmental management intervention strategy to reduce dengue cases. We searched PUBMED, CENTRAL, SCOPUS, Web of Science, CIJE, WHO ICTRP, and ClinicalTrials.gov up to January 2021. A total of 521 articles were screened. Only 16 studies were included in this review. There were 6 studies that applied all three types of environmental management interventions (manipulation, modification and behavior), 8 studies applied two types of interventions (manipulation and behavior) and 2 studies applied one type of intervention (manipulation or behavior). All included studies reported reduction of Aedes entomological indices. The studies showed reduction in dengue cases and density of Aedes population through environmental interventions. It is recommended for the health authority to incorporate environmental management intervention in dengue control activities and enhanced the community involvement to ensure sustainability with high impact on dengue reduction.

A predictive score for severity in patients with confirmed dengue fever in a tertiary care hospital in Kerala, India

BACKGROUND

The study aimed to identify predictors of severe dengue during the 2017 epidemic and to develop and validate a simple predictive score for severity.

METHODS

A retrospective analytical study was conducted using clinical and laboratory data from adult dengue patients with a confirmed microbiological diagnosis. The study included patients who presented to a tertiary care centre in Kerala, India, during the febrile phase (≤4 d) between June 2017 and February 2019. Using appropriate statistical tests, we derived predictors of severe disease and computed a risk score model.

RESULTS

Of the 153 patients (mean age 50±17 y; 64% males), 31 (20%) had severe dengue and 4 (3%) died. Petechial lesions, hypoalbuminemia (<3.5 g/dl), elevated alanine aminotransferase (>40 IU/l) and urea >40 IU/l were significant predictors. Our scoring system (cut-off: 2) showed excellent performance, with an area under the receiver operating characteristics curve of 0.9741, sensitivity of 100%, specificity of 96% and accuracy of 98%. The risk score was secondarily validated on 48 patients hospitalized from March 2019 to June 2019.

CONCLUSION

Our scoring system is easy to implement and will help primary healthcare practitioners in promptly identifying severe dengue cases upon hospital presentation.

The Innate Immune Response in DENV- and CHIKV-Infected Placentas and the Consequences for the Fetuses: A Minireview

Dengue virus (DENV) and chikungunya (CHIKV) are arthropod-borne viruses belonging to the Flaviviridae and Togaviridae families, respectively. Infection by both viruses can lead to a mild indistinct fever or even lead to more severe forms of the diseases, which are characterized by a generalized inflammatory state and multiorgan involvement. Infected mothers are considered a high-risk group due to their immunosuppressed state and the possibility of vertical transmission. Thereby, infection by arboviruses during pregnancy portrays a major public health concern, especially in countries where epidemics of both diseases are regular and public health policies are left aside. Placental involvement during both infections has been already described and the presence of either DENV or CHIKV has been observed in constituent cells of the placenta. In spite of that, there is little knowledge regarding the intrinsic earlier immunological mechanisms that are developed by placental cells in response to infection by both arboviruses. Here, we approach some of the current information available in the literature about the exacerbated presence of cells involved in the innate immune defense of the placenta during DENV and CHIKV infections.

National dengue surveillance, Cambodia 2002-2020

Global dengue incidence has increased dramatically over the past few decades from approximately 500 000 reported cases in 2000 to over 5 million in 2019. This trend has been attributed to population growth in endemic areas, rapid unplanned urbanization, increasing global connectivity, and climate change expanding the geographic range of the Aedes spp. mosquito, among other factors. Reporting dengue surveillance data is key to understanding the scale of the problem, identifying important changes in the landscape of disease, and developing policies for clinical management, vector control and vaccine rollout. However, surveillance practices are not standardized, and data may be difficult to interpret particularly in low- and middle-income countries with fragmented health-care systems. The latest national dengue surveillance data for Cambodia was published in 2010. Since its publication, the country experienced marked changes in health policies, population demographics, climate and urbanization. How these changes affected dengue control remains unknown. In this article, we summarize two decades of policy changes, published literature, country statistics, and dengue case data collected by the Cambodia National Dengue Control Programme to: (i) identify important changes in the disease landscape; and (ii) derive lessons to inform future surveillance and disease control strategies. We report that while dengue case morbidity and mortality rates in Cambodia fell between 2002 and 2020, dengue incidence doubled and age at infection increased. Future national surveillance, disease prevention and treatment, and vector control policies will have to account for these changes to optimize disease control.

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

BACKGROUND

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

OBJECTIVE

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

DESIGN

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

SETTING

20 of 71 international GeoSentinel sites.

PATIENTS

Returning travelers with complicated dengue.

MEASUREMENTS

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

RESULTS

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

LIMITATIONS

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

CONCLUSION

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

PRIMARY FUNDING SOURCE

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

Changing epidemiology of dengue fever in children in South America

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

Majority of pediatric dengue virus infections in Kenya do not meet 2009 WHO criteria for dengue diagnosis

From 1975-2009, the WHO guidelines classified symptomatic dengue virus infections as dengue fever, dengue hemorrhagic fever, and dengue shock syndrome. In 2009 the case definition was changed to a clinical classification after concern the original criteria was challenging to apply in resource-limited settings and not inclusive of a substantial proportion of severe dengue cases. Our goal was to examine how well the current WHO definition identified new dengue cases at our febrile surveillance sites in Kenya. Between 2014 and 2019 as part of a child cohort study of febrile illness in our four clinical study sites (Ukunda, Kisumu, Msambweni, Chulaimbo) we identified 369 dengue PCR positive symptomatic cases and characterized whether they met the 2009 revised WHO diagnostic criteria for dengue with and without warning signs and severe dengue. We found 62% of our PCR-confirmed dengue cases did not meet criteria per the guidelines. Our findings also correlate with our experience that dengue disease in children in Kenya is less severe as reported in other parts of the world. Although the 2009 clinical classification has recently been criticized for being overly inclusive and non-specific, our findings suggest the 2009 WHO dengue case definition may miss more than 50% of symptomatic infections in Kenya and may require further modification to include the African experience.

Pathogenesis and virulence of flavivirus infections

The Flavivirus genus consists of >70 members including several that are considered significant human pathogens. Flaviviruses display a broad spectrum of diseases that can be roughly categorised into two phenotypes - systemic disease involving haemorrhage exemplified by dengue and yellow Fever virus, and neurological complications associated with the likes of West Nile and Zika viruses. Attempts to develop vaccines have been variably successful against some. Besides, mosquito-borne flaviviruses can be vertically transmitted in the arthropods, enabling long term persistence and the possibility of re-emergence. Therefore, developing strategies to combat disease is imperative even if vaccines become available. The cellular interactions of flaviviruses with their human hosts are key to establishing the viral lifecycle on the one hand, and activation of host immunity on the other. The latter should ideally eradicate infection, but often leads to immunopathological and neurological consequences. In this review, we use Dengue and Zika viruses to discuss what we have learned about the cellular and molecular determinants of the viral lifecycle and the accompanying immunopathology, while highlighting current knowledge gaps which need to be addressed in future studies.

Survey of knowledge, attitude and practice of healthcare professionals on dengue transmission, diagnosis and clinical classification

BACKGROUND

To investigate the knowledge, attitudes, and practices of the healthcare professionals (HCPs) including physicians and nurses regarding dengue transmission, diagnosis and clinical classification using the warning signs of World Health Organization (WHO) 2009 classification.

RESULTS

Out of 471 respondents from three countries, 80.9% of physicians and 74% of nurses did not receive previous training regarding the dengue infection. The majority of respondents could identify the primary dengue vector (86%), while only a third of HCPs knew the biting time of dengue mosquitoes. Only half of our respondents knew about immunity induced by serotypes; Moreover, half of our participants could determine the diagnostic tests. On the other hand, about 90% of the respondents took responsibility for talking to the patients about preventive measures. Our respondents also showed wide variations in definition of warning signs listed in the WHO 2009 classification. Multivariate analysis linked the impact of different cofactors including prior training on dengue infection, type of profession, frequency of taking care of dengue patients and country on how HCPs defined these warning signs.

CONCLUSIONS

This study could declare the variation in employing the warning signs listed in the WHO 2009 classification. We have figured that most of the HCPs did not take prior training on the dengue viral infection; Also, we found gaps in the knowledge regarding various topics in dengue fever. This paper recommends the gathering of efforts to establish the proper knowledge of dengue infection and the warning signs listed by the WHO.

Knowledge gaps in the epidemiology of severe dengue impede vaccine evaluation

The most severe consequences of dengue virus infection include shock, haemorrhage, and major organ failure; however, the frequency of these manifestations varies, and the relative contribution of pre-existing anti-dengue virus antibodies, virus characteristics, and host factors (including age and comorbidities) are not well understood. Reliable characterisation of the epidemiology of severe dengue first depends on the use of consistent definitions of disease severity. As vaccine trials have shown, severe dengue is a crucial interventional endpoint, yet the infrequency of its occurrence necessitates the inclusion of thousands of study participants to appropriately compare its frequency among participants who have and have not been vaccinated. Hospital admission is frequently used as a proxy for severe dengue; however, lack of specificity and variability in clinical practices limit the reliability of this approach. Although previous infection with a dengue virus is the best characterised risk factor for developing severe dengue, the influence of the timing between dengue virus infections and the sequence of dengue virus infections on disease severity is only beginning to be elucidated. To improve our understanding of the diverse factors that shape the clinical spectrum of disease resulting from dengue virus infection, prospective, community-based and clinic-based immunological, virological, genetic, and clinical studies across a range of ages and geographical regions are needed.

Clinical signs and symptoms associated with WHO severe dengue classification: a systematic review and meta-analysis

The World Health Organization (WHO) introduced the new dengue classification in 2009. We aimed to assess the association of clinical signs and symptoms with WHO severe dengue classification in clinical practice. A systematic literature search was performed using the databases of PubMed, Embase, and Scopus between 2009 and 2018 according to PRISMA guideline. Meta-analysis was performed with the RevMan software. A random or fixed-effect model was applied to pool odds ratios and 95% confidence intervals of important signs and symptoms across studies. Thirty nine articles from 1790 records were included in this review. In our meta-analysis, signs and symptoms associated with higher risk of severe dengue were comorbidity, vomiting, persistent vomiting, abdominal pain or tenderness, pleural effusion, ascites, epistaxis, gum bleeding, GI bleeding, skin bleeding, lethargy or restlessness, hepatomegaly (>2 cm), increased HCT with decreased platelets, shock, dyspnea, impaired consciousness, thrombocytopenia, elevated AST and ALT, gall bladder wall thickening and secondary infection. This review shows new factors comorbidity, epistaxis, GI and skin bleeding, dyspnea, gall bladder wall thickening and secondary infection may be useful to refine the 2009 classification to triage severe dengue patients.

Assessing the serum chymase level as an early predictor of dengue severity

We conducted a prospective, observational study to assess the serum chymase level, a mast cell derived protease, as a predictor of dengue severity. NS1-positive non-severe dengue patients of age ≥14 years with duration of fever ≤4 days were included in the study. At the time of admission, the serum sample was taken for chymase estimation. Patients were followed up to four days after they became afebrile to find out the final diagnosis. Total of 338 non-severe dengue patients were recruited (mean age: 29.15 years; male: 66%). On follow-up, 26 patients (7.8%) developed severe dengue. Only chymase level (adjusted odds ratio [aOR]: 1.787; 95% confidence interval [CI]: 1.309-2.440) and platelet count at admission (aOR: 0.981; 95% CI: 0.968-0.993) were able to predict the severity after adjustment for all variables. But, for prediction of severe dengue, the area under receiver's operating curve of chymase was 0.835 (95% CI: 0.765-0.905), which was significantly higher than that of the platelet count at admission (0.760, 95% CI: 0.650-0.870) (p < .001). Patients who developed severe dengue in due course of illness had significantly higher serum chymase level at admission as compared with the rest of the patients. Similar findings were noted across all age-groups. At an optimum cut-off value of 1.35 ng/ml, chymase had a positive likelihood ratio (LR) of 3.5 and a negative LR of 0.15, for predicting severe dengue. This study demonstrated the potential ability of serum chymase levels at admission, as a biomarker for prediction of severe dengue in due course of illness.

Developing and using a dengue patient care guideline for patients admitted from households to primary care units and the district hospital: A community participatory approach in Southern Thailand

BACKGROUND

Dengue has been an important health issue in southern Thailand. However, this area has only a surveillance-prevention system, without step-by-step guidelines on dengue treatment for patients admitted from households to primary care units (PCUs) and district hospitals. Therefore, this study were to develop and use a dengue patient care guideline (DPCG), and to evaluate knowledge, attitude, practice (KAP) of dengue patient care.

METHODS

26 health care providers (13 nurses, and 13 public health officials) from eight PCUs and the district hospital developed the DPCG. The study design was based on the community participatory action research that integrated the Iowa model involving the following steps: preparation, guideline development, use and monitoring, evaluation and conclusion, and referring technology. We assessed the improvement between before and after using the DPCG regarding the participants' KAP on patient care and preparedness of equipment. McNamara's test was used to compare the changing results before and after using the DPCG. Qualitative data collection was performed in two meeting discussions with six open-end items. Using a thematic analysis technique, we extracted conclusions and suggested solutions.

RESULTS

The guideline included four steps for patients' care provision at households, PCUs, outpatient departments, emergency rooms, and inpatient departments. After using the DPCG in 39 dengue patients of which 30 patients were admitted to the inpatient department1 and two patients were referred to the tertiary care hospital without mortality. The overall participants' knowledge and attitude, two of six aspects of patients' care, and three of eight types of equipment management were significantly improved (p < 0.05). Eleven themes were evaluated which were associated with the quantitative data.

CONCLUSION

The DPCG instructed dengue patient's care for health care providers from households to the PCUs and district hospital. All participants improved KAP, and equipment management. Step-by-step of DPCG use and participation of all stakeholders are needed.

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.

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.

Point-of-care thrombocyte function testing using multiple-electrode aggregometry in dengue patients: an explorative study

Background

Dengue virus (DENV) causes the hospitalisation of an estimated 500,000 people every year. Outbreaks can severely stress healthcare systems, especially in rural settings. It is difficult to discriminate patients who need to be hospitalized from those that do not. Earlier work identified thrombocyte count and subsequent function as a promising prognostic marker of DENV severity. Herein, we investigated the potential of quantitative thrombocyte function tests in those admitted in the very early phase of acute DENV infections, using Multiplate™ multiple-electrode aggregometry to explore its potential in triage.

Methods

In this prospective cohort study all patients aged ≥13 admitted to Universitas Airlangga Hospital in Surabaya, Indonesia with a fever (≥38 °C) between 25 January and 1 August 2018 and with a clinical suspicion of DENV, were eligible for inclusion. Exclusion criteria were a thrombocyte count below 100 × 109/L and the use of any medication with a known anticoagulant effect, nonsteroidal anti-inflammatory drugs and acetyl salicylic acid. Clinical data was collected and blood was taken on admission, day 1 and day 7. Samples were tested for acute DENV, using Panbio NS1 ELISA. Platelet aggregation using ADP-, TRAP- and COL-test were presented as Area Under the aggregation Curve (AUC). Significance was tested between DENV+, probably DENV, fever of another origin, and healthy controls (HC).

Results

A total of 59 patients (DENV+ n = 10, DENV probable n = 25, fever other origin n = 24) and 20 HC were included. We found a significantly lower thrombocyte aggregation in the DENV+ group, compared with both HCs and the fever of another origin group (p < .001). Low ADP AUC values on baseline correlated to a longer hospital stay in DENV+ and probable DENV cases.

Conclusion

Thrombocyte aggregation induced by Adenosine diphosphate, Collagen and Thrombin receptor activating peptide-6 is impaired in human DENV cases, compared with healthy controls and other causes of fever. This explorative study provides insights to thrombocyte function in DENV patients and could potentially serve as a future marker in DENV disease.

A Haemophilic Dengue Patient with Pleural Effusion and Earache

About 2.5 billion people are living at a higher risk of dengue fever in hundreds of tropical and sub-tropical countries. Treatment of dengue fever is quite complicated and challenging because of the lack of effective treatment approaches. We herein report a rare case of a 25-year-old female with a past medical history of haemophilia A, suffering from dengue fever, pleural effusion, earache, myalgia, headache, and vomiting. Dengue was confirmed by the non-structural protein 1 (NS1) antigen and immunoglobulin M (IgM) antibody test. She had low blood pressure (80/60 mmHg), frequent vomiting, and low platelet count during hospitalization. Moreover, a genetic disorder like haemophilia with plasma leakage and earache made the patient's condition worse. However, by repeated platelet infusion, the platelet counts elevated and the patient was discharged from the hospital after nine days. Complete recovery was achieved after 27 days. This is a rare case of dengue; physicians should be aware of the severity of the disease and its management tactics. More discussion and research need to be carried out to develop an effective and optimized treatment and management options to reduce the mortality and morbidity due to dengue fever with a co-morbid disease.

Serum chymase levels correlate with severe dengue warning signs and clinical fluid accumulation in hospitalized pediatric patients

Dengue induces a spectrum of severity in humans from the milder dengue fever to severe disease, or dengue hemorrhagic fever (DHF). Chymase is a candidate biomarker that may aid dengue prognosis. This prospective study aimed to identify whether warning signs of severe dengue, including hypovolemia and fluid accumulation, were associated with elevated chymase. Serum chymase levels were quantified prospectively and longitudinally in hospitalized pediatric dengue patients in Sri Lanka. Warning signs were determined based on daily clinical assessments, laboratory tests and ultrasound findings. Chymase was significantly elevated during the acute phase of disease in DHF or Severe dengue, defined by either the 1997 or 2009 WHO diagnosis guidelines, and persisted longer in the most severe patients. Chymase levels were higher in patients with narrow pulse pressure and clinical warning signs such as severe leakage, fluid accumulation, pleural effusion, gall-bladder wall thickening and rapid haematocrit rise concurrent with thrombocytopenia. No association between chymase and liver enlargement was observed. This study confirms that serum chymase levels are associated with DHF/Severe dengue disease in hospitalized pediatric patients. Chymase levels correlate with warning signs of vascular dysfunction highlighting the possible functional role of chymase in vascular leakage during dengue.

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.

Predictors of dengue-related mortality in young adults in a tertiary care centre in North India

Background

Outbreaks of dengue fever cause widespread mortality. There is a paucity of studies on predictors of morbidity and mortality in dengue. This observational study was performed to study the factors predicting adverse outcomes caused due to dengue fever thereby optimally manage the patient's to reduce mortality.

Methods

The study included a 1-year retrospective and 1-year prospective period were clinical, laboratory and outcome data of patients between 18-30 years of age, having serology proven (NS1/dengue IgM) dengue fever were recorded and analysed.

Results

Out of 418 patients, 404 (96.64%) recovered and 14 (3.35%) expired, resulting in a 3.35% mortality rate. Platelet count did not determine the outcome in dengue patients. The shock factor was present in 45 (11.1%) patients who recovered and 10 out of 14 patients who expired (71.4%), P value was statistically significant. Mean value of SGOT and SGPT in dengue patients who expired were 2865.43 and 1510.07 IU/L, respectively, which were significantly higher than the mean values of SGOT and SGPT in those who survived. Bleeding was present in 39 (9.7%) patients who recovered. Out of the 14 expired patients, bleeding was present in 5 (35.7%) which is statistically significant. Hence, on multivariate logistics analysis, bleeding, a higher SGOT and SGPT value and shock were found to be significant risk factors for mortality in dengue fever patients.

Conclusion

Bleeding, shock and raised SGOT and SGPT levels were identified as predictors of adverse outcomes and mortality in dengue fever. Timely identification of these risk factors and active management is important to reduce dengue-related mortality.

Health facility use by dengue patients in the Klang Valley, Malaysia: a secondary analysis of dengue surveillance data

Background

Dengue patients in Malaysia have the choice to seek care from either public or private sector providers. This study aims to analyse the pattern of health facility use among dengue patients to provide input for the ongoing policy discussion regarding public-private integration. The focus of this study is in the Klang Valley, which has a high dengue burden as well as a high number of private facilities.

Methods

This is a cross-sectional study using an available secondary data source - the Malaysian national dengue passive surveillance system, e-Dengue registry. A total of 61 455 serologically confirmed dengue cases from the Klang Valley, registered in year 2014, were included. We retrospectively examined the relationship between demographic factors and the choice of health-care sector by logistic regression.

Results

The median age of the cohort was 26 (interquartile range: 17 to 37) years. More private facilities (54.4%) were used for inpatient care; more public facilities (68.2%) were used for outpatient care. The Chinese and urban populations showed significantly higher use of the private health-care sector with an adjusted odds ratio of 4.8 [95% confidence interval (CI): 4.6-5.1] and 2.3 (95% CI: 2.2-2.4), respectively.

Conclusion

Both public and private health facilities bear significant responsibilities in delivering health-care services to dengue patients. The workload of both sectors should be included in future health policy planning by public agencies.

Unusual clinical manifestations of dengue disease - Real or imagined?

The disease caused by each of the four serotypes of dengue virus (DENV) have plagued humans since last century. Symptoms of dengue virus (DENV) infection range from asymptomatic to dengue fever (DF) to severe dengue disease (SDD). One third of the world's population lives in regions with active urban DENV transmission, and thousands of serologically naïve travelers visit these areas annually, making a significant portion of the human population at risk of being infected. Even though lifelong immunity to the homotypic serotype is achieved after a primary DENV infection. Heterotypic DENV infections may be exacerbated by a pre-existing immune memory to the primary infection and can result in an increased probability of severe disease. Not only, age, comorbidities and presence of antibodies transferred passively from dengue-immune mother to infants are considered risk factors to dengue severe forms. Plasma leakage and multiple organ impairment are well documented in the literature, affecting liver, lung, brain, muscle, and kidney. However, unusual manifestation, severe or not, have been reported and may require medical attention. This review will summarize and discuss the increasing reports of unusual manifestations in the clinical course of dengue infection.

Small molecule grp94 inhibitors block dengue and Zika virus replication

Two major flaviviruses, dengue virus (DENV) and Zika virus (ZIKV), cause severe health and economic burdens worldwide. Recently, genome-wide screenings have uncovered the importance of regulators of the Hrd1 ubiquitin ligase-mediated endoplasmic reticulum (ER)-associated degradation (ERAD) pathway for flavivirus replication in host cells. Here we report the identification of the compound Bardoxolone methyl (CDDO-me) as a potent inhibitor of the Hrd1 ubiquitin ligase-mediated ERAD, which possesses a broad-spectrum activity against both DENV and ZIKV. Cellular thermal shift assay (CETSA) suggested that CDDO-me binds to grp94, a key component of the Hrd1 pathway, at a low nanomolar concentration, whereas interaction was not detected with its paralog Hsp90. CDDO-me and the grp94 inhibitor PU-WS13 substantially suppressed DENV2 replication and the cytopathic effects caused by DENV and ZIKV infection. The antiviral activities of both compounds were demonstrated for all four DENV serotypes and four ZIKV strains in multiple human cell lines. This study defines grp94 as a crucial host factor for flavivirus replication and identified CDDO-me as a potent small molecule inhibitor of flavivirus infection. Inhibition of grp94 may contribute to the antiviral activity of CDDO-me. Further investigation of grp94 inhibitors may lead to a new class of broad-spectrum anti-flaviviral medications.

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.

[Dengue fever : Symptoms, epidemiology, entomology, pathogen diagnosis and prevention]

Dengueinfektionen gehören zu den häufigsten Ursachen fieberhafter Erkrankungen im tropischen Umfeld. Die Infektion wird durch ein Flavivirus verursacht, das durch Aedes-Moskitos übertragen wird. Hauptüberträger für Dengueviren sind die weltweit in den Tropen verbreiteten Aedes-aegypti-Stechmücken. Da diese einerseits tagaktiv und andererseits sog. „container breeder“ sind, bedarf es besonderer Vorbeugungs- und Bekämpfungsmaßnahmen. Die Schwere der Symptomatik variiert und kann vom milden grippeähnlichen klinischen Bild bis hin zu schweren Hämorrhagien und Schock reichen. Zu den häufigsten Symptomen bei Reisenden gehören Fieber, Muskelschmerzen, Kopfschmerzen und Hautausschlag. Zur Diagnostik kommen, in Abhängigkeit vom Stadium der Infektion, patientennah einsetzbare Schnellteste oder – in der virämischen Phase – molekulare Erregerdirektnachweise infrage. Die serologische Diagnostik ist aufgrund von serologischen Kreuzreaktionen mit anderen Flaviviren hinsichtlich ihrer Interpretation anspruchsvoll.

Classification of dengue cases in Southwest India based on the WHO systems-a retrospective analysis

Background

The WHO dengue classification 1997 was revised in 2009 and the revised classification system has now been in use for the past decade. This study was carried out to compare the 1997 and revised classifications in assessing the severity of dengue infection among all age groups during a dengue outbreak in southwest India.

Methodology

This retrospective cross-sectional study was carried out including serologically confirmed dengue cases. A total of 1033 dengue cases were classified on the basis of the 1997 WHO classification and 2009 revised classification. The statistical analysis was carried out using SPSS 15.0 for Windows (SPSSTM Inc, Chicago, IL, USA).

Results

Both the 1997 and revised WHO classifications were applied to 1033 confirmed dengue cases, including 692 males (67%) and 341 females (33%). The median age of the study participants was 23 years (IQR 10-33), including 112 (10.8%) children at and below the age of 5 years. The level of agreement between the two systems of classification was poor (kappa=0.143, 0.055-0.198, p-value <0.001).

Conclusion

A greater sensitivity and specificity of the revised classification was observed in comparison with the 1997 WHO classification. In the context of changing dengue epidemiology and geographical expansion, the revised classification is helpful in the identification of severe cases, facilitating timely management.

Clinical and Laboratory Factors Associated with Severe Dengue: A Case-Control Study of Hospitalized Children

BACKGROUND

More than half of the hospitalizations because of dengue in Brazil occurred in children <15 years of age in 2007 and 2008, an unexpected change in the epidemiological pattern. We sought to determine clinical and laboratory parameters associated with severity.

METHODS

A case-control study was conducted in three pediatric hospitals in Rio de Janeiro, Brazil; 233 laboratory-confirmed dengue patients were included: 69 cases and 164 controls. Specific clinical and laboratory factors were assessed using univariate and multivariate logistic regression models.

RESULTS

Lethargy [adjusted odds ratio (ORa): 9.15, 95% confidence interval (CI): 3.08-27.12], dyspnea (ORa: 8.24, 95% CI: 3.27-20.72) and abdominal pain (ORa: 6.78, 95% CI: 1.44-31.84) were independently associated with severe dengue in children. Lethargy and dyspnea presented as early as 72 and 48 h, respectively, before shock.

CONCLUSIONS

Abdominal pain and lethargy confirmed their role as warning signs, which along with dyspnea might be helpful in identifying cases progressing to severe dengue.

The predictive and diagnostic accuracy of vascular endothelial growth factor and pentraxin-3 in severe dengue

This study aimed to evaluate vascular endothelial growth factor (VEGF) and pentraxin 3 (PTX-3) as predictive and diagnostic markers in differentiating severe dengue from non-severe dengue. The study was conducted in Ampang Health Clinic, Ampang Hospital and Serdang Hospital. The plasma levels of VEGF and PTX-3 were compared between severe dengue and non-severe dengue by ELISA from the day of presentation until discharged. Multiple logistic regression was used to develop predictive and diagnostic models by incorporating other clinical parameters. The receiver operating characteristics (ROC) analysis was used to assess the accuracy of the biomarkers and the developed models. Eighty-two patients were recruited, 29 with severe dengue and four died. The Area Under the Curve (AUC) was statistically significant in VEGF as diagnostic marker at Day 2 and 3 of illness with sensitivity of 80.00%-100.00% and specificity of 76.47%-80.00%. The predictive model with AUC of 0.84 (p < 0.01) has a sensitivity of 100.00% and specificity of 79.25% for predicting severe dengue. The diagnostic model with AUC of 0.71 (p < 0.01) has a sensitivity of 76.19% and specificity of 73.58% for diagnosing severe dengue. The AUC for PTX-3 was not statistically significant. VEGF may be used in combination with other clinical parameters to predict the severity of the disease. As a single biomarker, it may be used as an adjunct investigation to support the diagnosis of severe dengue. PTX-3 was not able to differentiate severe dengue from non-severe dengue.

Development of a Prognostic Prediction Model to Determine Severe Dengue in Children

OBJECTIVE

To develop a prognostic prediction model using the seven warning signs highlighted by WHO revised Dengue fever classification 2009 to determine severe dengue in children.

METHODS

In this prospective analytical study conducted in a tertiary care centre, consecutive sampling of all children aged 1mo to 12y admitted with serologically confirmed Dengue was done from May 2015 through August 2016. After excluding 27 patients with co-infections and co-morbidities, 359 patients were followed up daily to assess clinical and laboratory progression till discharge/ death. Independent predictors were abdominal pain or tenderness, persistent vomiting, lethargy, mucosal bleed, clinical fluid accumulation, hepatomegaly >2 cm and rising hematocrit concurrent with platelet count <100 × 10⁹/L. Outcome measure was severe dengue defined as per WHO guidelines 2009.

RESULTS

Among 359 children, 93 progressed to severe dengue. In univariate analysis, significant predictors were clinical fluid accumulation (OR 4.773, p = 0.000, 95%CI 2.511-9.075), persistent vomiting (OR 1.944, p = 0.010, 95%CI 1.170-3.225), mucosal bleed (OR 2.045, p = 0.019, 95%CI 1.127-3.711) and hematocrit ≥0.40 concurrent with platelet count <100 × 10⁹/L (OR 2.985, p = 0.000, 95%CI 1.783-4.997). The final multivariable model included clinical fluid accumulation (aOR 3.717, p = 0.000, 95%CI 1.901-7.269), hematocrit ≥0.40 concurrent with platelet count <100 × 10⁹/L (aOR 2.252, p = 0.004, 95%CI 1.302-3.894) and persistent vomiting (p = 0.056) as predictors of severe dengue.

CONCLUSIONS

Among seven WHO warning signs, predictors of severe dengue as suggested by the present multivariable prediction model include clinical fluid accumulation, persistent vomiting and hematocrit ≥0.40 concurrent with platelet count <100 × 10⁹/L.

Climate variability and dengue hemorrhagic fever in Southeast Sulawesi Province, Indonesia

To determine the association of climatic factors and dengue hemorrhagic fever and to develop the prediction approach of future dengue transmission. The study used totally monthly dengue hemorrhagic fever cases at Health Office Kendari, Southeast Sulawesi, Indonesia. Monthly meteorological data, consisting of temperature, rainfall, and humidity, was obtained from the Meteorology, Climatology and Geophysics Agency in Kendari district. All data analysis, including Spearman and Poisson distribution, was carried out in R Studio (version 3.3.2) utilizing the R statistical language version 2.15. The highest rate of dengue hemorrhagic fever cases was found in January, February, and March. Temperature averages at lag 2 (p = 0.53, p < 0.0001), lag 3 (p = 0.59, p < 0.0001), and lag 4 (p = 0.41, p < 0.01)) correlated with the incident rate of DHF. The average temperature at lag 2 was found to have a positive impact on the incidence of DHF by Poisson function. This study provides preliminary evidence of the influence of climatic factors on dengue transmission.

Evaluation of the WHO 2009 classification for diagnosis of acute dengue in a large cohort of adults and children in Sri Lanka during a dengue-1 epidemic

BACKGROUND

Dengue is a leading cause of fever and mimics other acute febrile illnesses (AFI). In 2009, the World Health Organization (WHO) revised criteria for clinical diagnosis of dengue.

METHODOLOGY/PRINCIPAL FINDINGS

The new WHO 2009 classification of dengue divides suspected cases into three categories: dengue without warning signs, dengue with warning signs and severe dengue. We evaluated the WHO 2009 classification vs physicians' subjective clinical diagnosis (gestalt clinical impression) in a large cohort of patients presenting to a tertiary care center in southern Sri Lanka hospitalized with acute febrile illness. We confirmed acute dengue in 388 patients (305 adults ≥ 18 years and 83 children), including 103 primary and 245 secondary cases, of 976 patients prospectively enrolled with AFI. At presentation, both adults and children with acute dengue were more likely than those with other AFI to have leukopenia and thrombocytopenia. Additionally, adults were more likely than those with other AFI to have joint pain, higher temperatures, and absence of crackles on examination whereas children with dengue were more likely than others to have sore throat, fatigue, oliguria, and elevated hematocrit and transaminases. Similarly, presence of joint pain, thrombocytopenia, and absence of cough were independently associated with secondary vs primary dengue in adults whereas no variables were different in children. The 2009 WHO dengue classification was more sensitive than physicians' clinical diagnosis for identification of acute dengue (71.5% vs 67.1%), but was less specific. However, despite the absence of on-site diagnostic confirmation of dengue, clinical diagnosis was more sensitive on discharge (75.2%). The 2009 WHO criteria classified almost 75% as having warning signs, even though only 9 (2.3%) patients had evidence of plasma leakage and 16 (4.1%) had evidence of bleeding.

CONCLUSIONS/SIGNIFICANCE

In a large cohort with AFI, we identified features predictive of dengue vs other AFI and secondary vs primary dengue in adults versus children. The 2009 WHO dengue classification criteria had high sensitivity but low specificity compared to physicians' gestaldt diagnosis. Large cohort studies will be needed to validate the diagnostic yield of clinical impression and specific features for dengue relative to the 2009 WHO classification criteria.

Improved tools and strategies for the prevention and control of arboviral diseases: A research-to-policy forum

BACKGROUND

Research has been conducted on interventions to control dengue transmission and respond to outbreaks. A summary of the available evidence will help inform disease control policy decisions and research directions, both for dengue and, more broadly, for all Aedes-borne arboviral diseases.

METHOD

A research-to-policy forum was convened by TDR, the Special Programme for Research and Training in Tropical Diseases, with researchers and representatives from ministries of health, in order to review research findings and discuss their implications for policy and research.

RESULTS

The participants reviewed findings of research supported by TDR and others. Surveillance and early outbreak warning. Systematic reviews and country studies identify the critical characteristics that an alert system should have to document trends reliably and trigger timely responses (i.e., early enough to prevent the epidemic spread of the virus) to dengue outbreaks. A range of variables that, according to the literature, either indicate risk of forthcoming dengue transmission or predict dengue outbreaks were tested and some of them could be successfully applied in an Early Warning and Response System (EWARS). Entomological surveillance and vector management. A summary of the published literature shows that controlling Aedes vectors requires complex interventions and points to the need for more rigorous, standardised study designs, with disease reduction as the primary outcome to be measured. House screening and targeted vector interventions are promising vector management approaches. Sampling vector populations, both for surveillance purposes and evaluation of control activities, is usually conducted in an unsystematic way, limiting the potentials of entomological surveillance for outbreak prediction. Combining outbreak alert and improved approaches of vector management will help to overcome the present uncertainties about major risk groups or areas where outbreak response should be initiated and where resources for vector management should be allocated during the interepidemic period.

CONCLUSIONS

The Forum concluded that the evidence collected can inform policy decisions, but also that important research gaps have yet to be filled.

Hospital-based Surveillance: Accuracy, Adequacy, and Timeliness of Dengue Case Report in Bandung, West Java, Indonesia of 2015

Context:

Dengue fever (DF) altogether with its severe forms, dengue hemorrhagic fever (DHF) and dengue shock syndrome, has become public health concerns. Indonesia belongs to category A of endemicity for DF/DHF. One of the several efforts to control dengue virus infection in Indonesia is a passive surveillance called “Dengue Case Surveillance.” Timeliness report defined as a report sent within 24 h after the clinical diagnosis is needed to have a proper surveillance. The study on the evaluation of dengue case report in terms of accuracy, adequacy, and timeliness in Indonesia is still limited.

Aims:

The aim of this study was to identify the accuracy, adequacy, and timeliness from the reports of dengue viral infection (DVI) cases admitted from January 1 to December 31, 2015 to 7 major hospitals in Bandung, West Java, Indonesia.

Settings and Design:

This was a retrospective analysis study.

Materials and Methods:

To evaluate the accuracy, all medical records of DVI patients were reviewed epidemiologically, clinically, and laboratory using a standardized questionnaire. To evaluate the adequacy, hospital data were compared with reported data in Bandung Municipality Health Authority. To evaluate the timeliness of report, interview to the person in charge for dengue reporting cases in each hospital and in Bandung Municipality Health Authority were performed.

Statistical Analysis Used:

Univariate analysis was used for statistical analysis.

Results:

A total of 4096 (72%) of 5712 hospitalized DVI cases lived in Bandung Municipality. The accuracy of the clinical diagnosis was 3397 out of 4096 cases (82.9%). The adequacy of the accurate cases was 1553 out of 3397 cases (45.7%).

Conclusions:

The timeliness of report was varied, ranging from days to month. The accuracy of dengue cases was good, but the adequacy and timely reporting should be strengthened.

Symptoms associated with adverse dengue fever prognoses at the time of reporting in the 2015 dengue outbreak in Taiwan

BACKGROUND

Tainan experienced the most severe dengue epidemic in Taiwan in 2015. This study investigates the association between the signs and symptoms at the time of reporting with the adverse dengue prognoses.

METHODS

A descriptive study was conducted using secondary data from the Dengue Disease Reporting System in Tainan, Taiwan, between January 1 and December 31, 2015. A multivariate stepwise logistic regression was used to identify the risk factors for the adverse prognoses: ICU admissions and mortality.

RESULTS

There were 22,777 laboratory-confirmed reported cases (mean age 45.6 ± 21.2 years), of which 3.7% were admitted to intensive care units (ICU), and 0.8% were fatal. The most common symptoms were fever (92.8%), myalgia (26.6%), and headache (22.4%). The prevalence of respiratory distress, altered consciousness, shock, bleeding, and thrombocytopenia increased with age. The multivariate analysis indicated that being in 65-89 years old age group [Adjusted Odds Ratio (aOR):4.95], or the 90 years old and above age group (aOR: 9.06), and presenting with shock (aOR: 8.90) and respiratory distress (aOR: 5.31) were significantly associated with the risk of ICU admission. While old age (aOR: 1.11), respiratory distress (aOR: 9.66), altered consciousness (aOR: 7.06), and thrombocytopenia (aOR: 2.55) were significantly associated with the risk of mortality.

CONCLUSIONS

Dengue patients older than 65 and those with severe and non-specific signs and symptoms at the time of reporting were at a higher risk of ICU admission and mortality. First-line healthcare providers need to be aware of the varied presentations between the different age groups to allow early diagnosis and in-time management, which would prevent ICU admissions and fatalities in dengue patients.

Predictors of Dengue-Related Mortality and Disease Severity in a Tertiary Care Center in North India

Background

There is lack of reliable predictors of disease severity and mortality in dengue. The present study was carried out to identify these predictors during the 2015 outbreak in India.

Methods

This prospective observational study included confirmed adult dengue patients hospitalized between August and November 2015 in a tertiary care centre in New Delhi, India. Appropriate statistical tests were used to compare clinicolaboratory characteristics, derive predictors of severe disease and mortality, and compute a predictive score for mortality. Serotyping was done.

Results

Data of 369 patients were analyzed (mean age, 30.9 years; 67% males). Of these, 198 (54%) patients had dengue fever, 125 (34%) had dengue hemorrhagic fever (grade 1 or 2), and 46 (12%) developed dengue shock syndrome (DSS). Twenty-two (6%) patients died. Late presentation to the hospital (≥5 days after onset) and dyspnea at rest were identified as independent predictors of severe disease. Age ≥24 years, dyspnea at rest and altered sensorium were identified as independent predictors of mortality. A clinical risk score was developed (12*age + 14*sensorium + 10*dyspnea), which, if ≥22, predicted mortality with a high sensitivity (81.8%) and specificity (79.2%). The predominant serotypes in Delhi (2015) were dengue virus DENV2 and DENV4.

Conclusion

Age ≥24 years, dyspnea at rest, and altered sensorium were identified as independent predictors of mortality. Platelet counts did not determine outcome in dengue patients. Timely referral/access to healthcare is important. The clinical risk score for mortality prediction that was developed in this study can be used in all healthcare settings, after validation in larger cohorts.

Impediments of reporting dengue cases in India

Dengue has emerged as one of the most important mosquito-borne, fatal flaviviral disease, apparently expanding as a global health problem. An estimated 3.6 billion people are at risk for dengue, with 50 million infections per year occurring across 100 countries globally. The annual number of dengue fever cases in India is many times higher than it is officially reported. This under reporting would play a major role in the government's decision-making. Underestimating of the disease in India encumbers its people from taking preventive measures, discourages efforts to ensnare the sources of the disease and deliberates efforts for vaccine research. In this article, we highlight the probable impediments of under reporting leading to its impact on national and global public health and also offer key remedies to effectively address the issues across the clinics to the community level.

Dengue, Zika and Chikungunya: Emerging Arboviruses in the New World

The arboviruses that cause dengue, chikungunya, and Zika illnesses have rapidly expanded across the globe in recent years, with large-scale outbreaks occurring in Western Hemisphere territories in close proximity to the United States (U.S.). In March 2016, the Centers for Disease Control and Protection (CDC) expanded its vector surveillance maps for A. aegypti and A. albopictus, the mosquito vectors for these arboviruses. They have now been shown to inhabit a larger portion of the U.S., including the heavily populated northeast corridor. Emergency physicians need to further familiarize themselves with these diseases, which have classically been considered only in returning travelers but may soon be encountered in the U.S. even in the absence of travel. In this paper, we discuss the presentation and treatment of dengue, Zika, and chikungunya, as well as special challenges presented to the emergency physician in evaluating a patient with a suspected arbovirus infection.

Current management of severe dengue infection

INTRODUCTION

Traditionally a disease mainly affecting the pediatric population, dengue burden has increased significantly in recent decades and adults with severe disease may become more common. There is currently no effective anti-viral agent available for the treatment of dengue and supportive care is the mainstay of management. Areas covered: We present a review of current literature on dengue severity classification systems and the management of severe dengue in adults. In particular, emphasis was placed on organ impairment in dengue and management of elderly individuals with multiple medical problems. Expert commentary: There is an urgent need to search for an effective anti-viral agent to treat infected individuals. The commercial availability of a dengue vaccine in older children has provided optimism in reducing the disease burden but long term efficacy and safety are unknown. The results from phase III trials of two new candidate vaccines are eagerly awaited.

Factors Associated with the Time of Admission among Notified Dengue Fever Cases in Region VIII Philippines from 2008 to 2014

In cases of Dengue fever, late hospital admission can lead to treatment delay and even death. In order to improve early disease notification and management, it is essential to investigate the factors affecting the time of admission of Dengue cases. This study determined the factors associated with the time of admission among notified Dengue cases. The study covered the period between 2008 and 2014 in Region VIII, Philippines. The factors assessed were age, sex, hospital sector, hospital level, disease severity based on the 1997 WHO Dengue classification, and period of admission (distinguishing between the 2010 Dengue epidemic and non-epidemic time). We analysed secondary data from the surveillance of notified Dengue cases. We calculated the association through chi-square test, ordinal logistic regression and linear regression at p value < 0.05. The study included 16,357 admitted Dengue cases. The reported cases included a majority of children (70.09%), mild cases of the disease (64.00%), patients from the public sector (69.82%), and non-tertiary hospitals (62.76%). Only 1.40% of cases had a laboratory confirmation. The epidemic period in 2010 comprised 48.68% of all the admitted cases during this period. Late admission was more likely among adults than children (p<0.05). The severe type of the disease was more likely to be admitted late than the mild type (p<0.05). Late admission was also more likely in public hospitals than in private hospitals (p<0.05); and within tertiary level hospitals than non-tertiary hospitals (p<0.05). Late admission was more likely during the non-epidemic period than the 2010 epidemic period (p<0.05). A case fatality rate of 1 or greater was significantly associated with children, severe diseases, tertiary hospitals and public hospitals when admitted late (p<0.05). Data suggests that early admission among child cases was common in Region VIII. This behavior is encouraging, and should be continued. However, further study is needed on the late admission among tertiary, public hospitals and non-epidemic period with reference to the quality of care, patient volume, out of pocket expense, and accessibility We recommend the consistent use of the 2009 WHO Dengue guidelines in order to standardize the admission criteria and time across hospitals.

A variety of factors affect the time of admission of Dengue fever cases. These must be investigated, as delayed treatment of this disease can result in death. The authors of this study determined the factors associated with the time of admission among notified Dengue cases of Region VIII, Philippines, from 2008 to 2014. The factors assessed were age and sex of the patient, hospital sector, hospital level, disease severity and the presence of Dengue epidemic. A secondary surveillance data of Dengue was used. The associations were determined using chi-square test and regression. Late admission was more likely amongst adults, severe cases of the disease, public hospitals, tertiary level hospitals, and during the non-epidemic period. In comparison, early admission was more likely in cases concerning children, mild cases of the disease, private hospitals, non-tertiary hospitals and during an epidemic period. Case fatality was significantly associated to children, severe diseases, public hospitals and tertiary hospitals when admitted late. The routine early admission of children should be promoted, as severe cases of Dengue fever are more likely among children. Consistent admission criteria for Dengue should be implemented across all hospital sectors and levels.

Use of Warning Signs for Dengue by Pediatric Health Care Staff in Brazil

OBJECTIVE

The aim of this study was to describe the use of dengue warning signs by pediatric healthcare staff in the Brazilian public health care system.

METHODS

Cross-sectional study (2012) with physicians, nurses, and nurse technicians assisting children in five health care facilities. Participants reported the use and importance of dengue warning signs in pediatrics clinical practice through a structured questionnaire. Differences in the use of signs (chi-square test) and in the ranking assigned to each of them (Kruskal-Wallis) were assessed according to health care occupation and level of care (p<0.05).

RESULTS

The final sample comprised 474 participants (97%), mean age of 37 years (standard deviation = 10.3), mainly females (83.8%), physicians (40.1%) and from tertiary care (75.1%). The majority (91%) reported using warning signs for dengue in pediatrics clinical practice. The most widely used and highly valued signs were major hemorrhages (gastrointestinal, urinary), abdominal pain, and increase in hematocrit concurrent or not with rapid decrease in platelet count. Persistent vomiting as well as other signs of plasma leakage such as respiratory distress and lethargy/restlessness were not identified as having the same degree of importance, especially by nurse technicians and in primary or secondary care.

DISCUSSION

Although most health care staff reported using dengue warning signs, it would be useful to extend the training for identifying easily recognizable signs of plasma leakage that occur regardless of bleeding.

Dengue Contingency Planning: From Research to Policy and Practice

BACKGROUND

Dengue is an increasingly incident disease across many parts of the world. In response, an evidence-based handbook to translate research into policy and practice was developed. This handbook facilitates contingency planning as well as the development and use of early warning and response systems for dengue fever epidemics, by identifying decision-making processes that contribute to the success or failure of dengue surveillance, as well as triggers that initiate effective responses to incipient outbreaks.

METHODOLOGY/PRINCIPAL FINDINGS

Available evidence was evaluated using a step-wise process that included systematic literature reviews, policymaker and stakeholder interviews, a study to assess dengue contingency planning and outbreak management in 10 countries, and a retrospective logistic regression analysis to identify alarm signals for an outbreak warning system using datasets from five dengue endemic countries. Best practices for managing a dengue outbreak are provided for key elements of a dengue contingency plan including timely contingency planning, the importance of a detailed, context-specific dengue contingency plan that clearly distinguishes between routine and outbreak interventions, surveillance systems for outbreak preparedness, outbreak definitions, alert algorithms, managerial capacity, vector control capacity, and clinical management of large caseloads. Additionally, a computer-assisted early warning system, which enables countries to identify and respond to context-specific variables that predict forthcoming dengue outbreaks, has been developed.

CONCLUSIONS/SIGNIFICANCE

Most countries do not have comprehensive, detailed contingency plans for dengue outbreaks. Countries tend to rely on intensified vector control as their outbreak response, with minimal focus on integrated management of clinical care, epidemiological, laboratory and vector surveillance, and risk communication. The Technical Handbook for Surveillance, Dengue Outbreak Prediction/ Detection and Outbreak Response seeks to provide countries with evidence-based best practices to justify the declaration of an outbreak and the mobilization of the resources required to implement an effective dengue contingency plan.

Serum Procalcitonin and Peripheral Venous Lactate for Predicting Dengue Shock and/or Organ Failure: A Prospective Observational Study

Background

Currently, there are no biomarkers that can predict the incidence of dengue shock and/or organ failure, although the early identification of risk factors is important in determining appropriate management to reduce mortality. Therefore, we sought to determine the factors associated with dengue shock and/or organ failure and to evaluate the prognostic value of serum procalcitonin (PCT) and peripheral venous lactate (PVL) levels as biomarkers of dengue shock and/or organ failure.

Methodology/Principal Findings

A prospective observational study was conducted among adults hospitalized for confirmed viral dengue infection at the Hospital for Tropical Diseases in Bangkok, Thailand between October 2013 and July 2015. Data, including baseline characteristics, clinical parameters, laboratory findings, serum PCT and PVL levels, management, and outcomes, were recorded on pre-defined case report forms. Of 160 patients with dengue, 128 (80.0%) patients had dengue without shock or organ failure, whereas 32 (20.0%) patients developed dengue with shock and/or organ failure. Using a stepwise multivariate logistic regression analysis, PCT ≥0.7 ng/mL (odds ratio [OR]: 4.80; 95% confidence interval [CI]: 1.60–14.45; p = 0.005) and PVL ≥2.5 mmol/L (OR: 27.99, 95% CI: 8.47–92.53; p <0.001) were independently associated with dengue shock and/or organ failure. A combination of PCT ≥0.7 ng/mL and PVL ≥2.5 mmol/L provided good prognostic value for predicting dengue shock and/or organ failure, with an area under the receiver operating characteristics curve of 0.83 (95% CI: 0.74–0.92), a sensitivity of 81.2% (95% CI: 63.6–92.8%), and a specificity of 84.4% (95% CI: 76.9–90.2%). Dengue shock patients with non-clearance of PCT and PVL expired during hospitalization.

Conclusions/Significance

PCT ≥0.7 ng/mL and PVL ≥2.5 mmol/L were independently associated with dengue shock and/or organ failure. The combination of PCT and PVL levels could be used as prognostic biomarkers for the prediction of dengue shock and/or organ failure.

Dengue is a major global health concern, particularly in tropical countries, and affects all age groups. Mortality rates among patients who have been hospitalized with severe dengue are 1.6–10.9%, and death in adults is mainly due to the development of dengue shock and organ dysfunction. In states of poor tissue circulation or shock, lactate is produced. Additionally, procalcitonin is a highly specific biomarker of systemic inflammation. Therefore, we assessed whether procalcitonin and peripheral venous lactate could be used to predict the incidence of dengue shock and/or organ failure in patients with dengue. Our study showed that a combination of serum procalcitonin levels ≥0.7 ng/mL and peripheral venous lactate levels ≥2.5 mmol/L at admission could discriminate between patients who did and did not develop shock and/or organ failure, with high sensitivity and specificity. These parameters may therefore be useful as prognostic biomarkers. Our results suggest that serum procalcitonin is indicative of an extensive early inflammatory response, which may occur during the systemic phase of dengue. Peripheral venous lactate may be produced as a result of the poor tissue circulation that precedes dengue shock. Our findings may help clinicians to predict dengue shock and/or organ failure earlier to reduce in-hospital mortality.