Mortality Predictors in Patients with Severe Dengue in the State of Amazonas, Brazil

Risk factors associated with severe dengue in Latin America: A systematic review and meta-analysis

OBJECTIVE

Severe dengue is a significant health problem in Latin America, with children being the most affected. Understanding risk factors for severe dengue is crucial for enhancing patient care. Therefore, this study aims to systematically review the literature to identify the risk factors associated with severe dengue in Latin America through systematic review and meta-analysis.

METHODS

PubMed, SciELO, LILACS and EMBASE databases were used to search for eligible scientific articles for the review. The outcomes considered were symptoms of severe dengue, hospitalisation and death. The Joanna Briggs Institute Critical Appraisal Checklist was used to assess the quality of the studies. Data analysis was performed using STATA v 13.0 software. The degree of heterogeneity between studies was quantified using the I2 measure, and statistically significant results were defined as those with p values <0.05.

RESULTS

Of the 1876 articles screened, 47 articles were included in the systematic review and 45 articles were analysed through meta-analysis. Identified risk factors associated with severe dengue included secondary dengue infection, female sex, white or Caucasian ethnicity and specific signs and symptoms such as headache, myalgia and/or arthralgia, vomiting/nausea, abdominal pain or tenderness, diarrhoea, prostration, lethargy, fatigue or similar. For the death outcome, respiratory symptoms and age <18 years were identified as risk factors. On the other hand, in women, the diagnosis of positive tourniquet test, platelet count <100,000 per μL and symptoms of capillary fragility were associated with a lower probability of death. These data highlight the importance of early screening of patients, to identify possible haemorrhagic signs and reduce deaths from dengue. This study has limitations, including possible publication bias, heterogeneity of results and study design biases.

CONCLUSION

These findings are significant for shaping strategies, management approaches and identifying high-risk groups, which will help establish future guidelines.

Case studies of clinical decision-making through prescriptive models based on machine learning

BACKGROUND

The development of computational methodologies to support clinical decision-making is of vital importance to reduce morbidity and mortality rates. Specifically, prescriptive analytic is a promising area to support decision-making in the monitoring, treatment and prevention of diseases. These aspects remain a challenge for medical professionals and health authorities.

MATERIALS AND METHODS

In this study, we propose a methodology for the development of prescriptive models to support decision-making in clinical settings. The prescriptive model requires a predictive model to build the prescriptions. The predictive model is developed using fuzzy cognitive maps and the particle swarm optimization algorithm, while the prescriptive model is developed with an extension of fuzzy cognitive maps that combines them with genetic algorithms. We evaluated the proposed approach in three case studies related to monitoring (warfarin dose estimation), treatment (severe dengue) and prevention (geohelminthiasis) of diseases.

RESULTS

The performance of the developed prescriptive models demonstrated the ability to estimate warfarin doses in coagulated patients, prescribe treatment for severe dengue and generate actions aimed at the prevention of geohelminthiasis. Additionally, the predictive models can predict coagulation indices, severe dengue mortality and soil-transmitted helminth infections.

CONCLUSIONS

The developed models performed well to prescribe actions aimed to monitor, treat and prevent diseases. This type of strategy allows supporting decision-making in clinical settings. However, validations in health institutions are required for their implementation.

Machine-learning prediction models for any blood component transfusion in hospitalized dengue patients

BACKGROUND

Blood component transfusions are a common and often necessary medical practice during the epidemics of dengue. Transfusions are required for patients when they developed severe dengue fever or thrombocytopenia of 10×109/L or less. This study therefore investigated the risk factors, performance and effectiveness of eight different machine-learning algorithms to predict blood component transfusion requirements in confirmed dengue cases admitted to hospital. The objective was to study the risk factors that can help to predict blood component transfusion needs.

METHODS

Eight predictive models were developed based on retrospective data from a private group of hospitals in India. A python package SHAP (SHapley Additive exPlanations) was used to explain the output of the "XGBoost" model.

RESULTS

Sixteen vital variables were finally selected as having the most significant effects on blood component transfusion prediction. The XGBoost model presented significantly better predictive performance (area under the curve: 0.793; 95 % confidence interval: 0.699-0.795) than the other models.

CONCLUSION

Predictive modelling techniques can be utilized to streamline blood component preparation procedures and can help in the triage of high-risk patients and readiness of caregivers to provide blood component transfusions when required. This study demonstrates the potential of multilayer algorithms to reasonably predict any blood component transfusion needs which may help healthcare providers make more informed decisions regarding patient care.

Factors associated with death from dengue and chikungunya virus infection during an epidemic period in Northeast Brazil: A retrospective cohort study

BACKGROUND

We investigated the time to death and factors associated with deaths from dengue and chikungunya during the first epidemic after the introduction of the chikungunya virus in Northeastern Brazil.

METHODS

This retrospective cohort study was conducted in Pernambuco between 2015 and 2018. Logistic regression was used to identify independent risk factors. The probability of survival among individuals with different arbovirus infections was estimated and the survival curves were compared using log-rank tests.

RESULTS

The lethality coefficients for dengue and chikungunya viruses were 0.08% and 0.35%, respectively. The chance of death due to chikungunya infection increased progressively from the age of 40 years. At 40-49 years, the odds ratio was 13.83 (95%CI, 1.80-106.41). At 50-59 years and 60 years or older, the odds ratio was 27.63 (95%CI, 3.70-206.48); and 78.72 (95%CI, 10.93-566.90), respectively. The probability of death associated with dengue virus infection increased from the age of 50 years. Among patients aged 50-59 years and 60 years or older, the odds ratio was 4.30 (95%CI, 1.80-10.30) and 8.97 (95%CI, 4.00-20.0), respectively. Independent factors associated death were headache and age of 50 years or older for dengue; and headache, nausea, back pain, intense arthralgia, age 0-9 years or 40 years and older, and male sex for chikungunya. The ratio between mortality rates revealed that the time to death from dengue was 2.1 times faster than that from chikungunya (95%CI, 1.57-2.72).

CONCLUSIONS

The time to death was shorter in patients with dengue than in those with chikungunya disease. This study reinforces the need for faster and more effective decision-making in public health services to enhance patient outcomes and minimize mortality.

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

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

Dengue, chikungunya, and Zika virus infections in Latin America and the Caribbean: a systematic review

Objectives

To characterize the distribution profile of dengue, chikungunya, and Zika virus infections in Latin America and the Caribbean and to identify possible factors associated with the risk of dissemination and severity of these arboviruses.

Methods

The protocol of this review was registered on the PROSPERO platform. Searches were carried out in the following databases: Virtual Health Library, MEDLINE/PubMed, and Embase. The search terms were: Zika virus, Zika virus infection, dengue, dengue virus, chikungunya virus, chikungunya fever, epidemiology, observational study, Latin America, and Caribbean region. Studies that addressed the distribution of these arboviruses and the risk factors associated with dengue, Zika virus disease, and chikungunya, published between January 2000 and August 2020 in English, Portuguese, and Spanish, were included.

Results

Of 95 studies included, 70 identified risk factors, clinical manifestations, and outcomes for arbovirus infections and 25 described complications and/or deaths. The highest frequency of confirmed cases was for dengue. Brazil reported most cases of the three arboviruses in the period analyzed. Environmental and socioeconomic factors facilitated the proliferation and adaptation of vectors, and host-related factors were reported to aggravate dengue. Most deaths were due to chikungunya, Zika virus disease caused most neurological alterations, and dengue resulted in greater morbidity leading to more frequent hospitalization.

Conclusions

The review provides a broad view of the three arboviruses and the intrinsic aspects of infections, and highlights the factors that influence the spread of these viruses in the populations studied.

Serum biomarkers and anti-flavivirus antibodies at presentation as indicators of severe dengue

BACKGROUND

Dengue is the most common vector-borne viral disease worldwide. Most cases are mild, but some evolve into severe dengue (SD), with high lethality. Therefore, it is important to identify biomarkers of severe disease to improve outcomes and judiciously utilize resources.

METHODS/PRINCIPAL FINDINGS

One hundred forty-five confirmed dengue cases (median age, 42; range <1-91 years), enrolled from February 2018 to March 2020, were selected from an ongoing study of suspected arboviral infections in metropolitan Asunción, Paraguay. Cases included dengue virus types 1, 2, and 4, and severity was categorized according to the 2009 World Health Organization guidelines. Testing for anti-dengue virus IgM and IgG and serum biomarkers (lipopolysaccharide binding protein and chymase) was performed on acute-phase sera in plate-based ELISAs; in addition, a multiplex ELISA platform was used to measure anti-dengue virus and anti-Zika virus IgM and IgG. Complete blood counts and chemistries were performed at the discretion of the care team. Age, gender, and pre-existing comorbidities were associated with SD vs. dengue with/without warning signs in logistic regression with odds ratios (ORs) of 1.07 (per year; 95% confidence interval, 1.03, 1.11), 0.20 (female; 0.05,0.77), and 2.09 (presence; 1.26, 3.48) respectively. In binary logistic regression, for every unit increase in anti-DENV IgG in the multiplex platform, odds of SD increased by 2.54 (1.19-5.42). Platelet count, lymphocyte percent, and elevated chymase were associated with SD in a combined logistic regression model with ORs of 0.99 (1,000/μL; 0.98,0.999), 0.92 (%; 0.86,0.98), and 1.17 (mg/mL; 1.03,1.33) respectively.

CONCLUSIONS

Multiple, readily available factors were associated with SD in this population. These findings will aid in the early detection of potentially severe dengue cases and inform the development of new prognostics for use in acute-phase and serial samples from dengue cases.

Epidemiology of dengue in SAARC territory: a systematic review and meta-analysis

BACKGROUND

Dengue is one of the common arboviral infections and is a public health problem in South East Asia. The aim of this systematic review and meta-analysis was to evaluate the prevalence and distribution of dengue in SAARC (South Asian Association for Regional Cooperation) countries.

METHODS

The PubMed, PubMed Central, Embase and Scopus databases were searched for relevant studies. Statistical analysis on data extracted from the selected studied was conducted using the Comprehensive Meta-Analysis Software (CMA) version 3 software package. Proportions were used to estimate the outcome with a 95% confidence interval (CI).

RESULTS

Across all studies, among cases of suspected dengue, 30.7% were confirmed dengue cases (proportion: 0.307, 95% CI: 0.277-0.339). The seroprevalence of dengue immunoglobulin (Ig)G, IgM or both (IgM and IgG) antibodies and dengue NS1 antigen was 34.6, 34.2, 29.0 and 24.1%, respectively. Among the different strains of dengue, dengue virus (DENV) strains DENV-1, DENV-2, DENV-3 and DENV-4 accounted for 21.8, 41.2, 14.7 and 6.3% of cases, respectively. The prevalence of dengue fever, dengue hemorrhagic fever and dengue shock syndrome was 80.5, 18.2 and 1.5%, respectively. Fever was a commonly reported symptom, and thrombocytopenia was present in 44.7% of cases. Mortality was reported in 1.9% of dengue cases.

CONCLUSIONS

Dengue is a common health problem in South East Asia with high seroprevalence. DENV-2 was found to be the most common strain causing infection, and most dengue cases were dengue fever. In addition, thrombocytopenia was reported in almost half of the dengue cases.

Cluster Analysis of Dengue Morbidity and Mortality in Mexico from 2007 to 2020: Implications for the Probable Case Definition

Dengue cases and deaths occur frequently in Mexico, although the trend is not uniform across the country. We performed a Spatio-temporal analysis of dengue cases and deaths in Mexico from 2007 to 2020, and clustered states according to whether there was a low, moderate, or high risk of dengue. A total of 501,600 confirmed dengue cases were registered from 2007 to 2020, with 378,122 cases classified as dengue fever (DF) and 123,478 cases classified as dengue hemorrhagic fever (DHF). For each confirmed case, there were 4.68 probable cases. There were 1,230 dengue deaths, with highest numbers reported in 2009, 2012, 2013, and 2019. The number of deaths had a significant correlation (P ≤ 0.01) with DF (r = 0.82), DHF (r = 0.94), and probable dengue cases (r = 0.84). States were clustered using Machine Learning technique according to select indices associated with dengue. Cluster 1 (low risk) primarily contained states in the northwest, northcentral, and east. Cluster 2 (moderate risk) includes states in the northeast. Cluster 3 (high risk) mostly contained coastal states in the southeast, southwest, and west. The generation of the clusters was supported by the Kruskal-Wallis test. A significant difference was found in the incidence, mortality rates, and case-fatality rates of dengue among the clusters (P ≤ 0.01). Notably, cluster 3 contributed 71.4% of the confirmed cases and 89.2% of the deaths. Public health and vector control strategies designed to mitigate the burden of dengue in Mexico should consider the states in cluster 3 as high priority areas.

Palatal Rash Sign is Reliable Predictor of Severe Thrombocytopenia in Dengue Fever

In dengue, which is an arthropod borne illness increasing in prevalence in India, a sudden drop in platelet count has serious connotations, and is frequently evidenced by a palatal rash.

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.

Outcomes among children and adults at risk of severe dengue in Sri Lanka: Opportunity for outpatient case management in countries with high disease burden

Background

Healthcare systems in dengue-endemic countries are often overburdened due to the high number of patients hospitalized according to dengue management guidelines. We systematically evaluated clinical outcomes in a large cohort of patients hospitalized with acute dengue to support triaging of patients to ambulatory versus inpatient management in the future.

Methods/Principal findings

From June 2017- December 2018, we conducted surveillance among children and adults with fever within the prior 7 days who were hospitalized at the largest tertiary-care (1,800 bed) hospital in the Southern Province, Sri Lanka. Patients who developed platelet count ≤100,000/μL (threshold for hospital admission in Sri Lanka) and who met at least two clinical criteria consistent with dengue were eligible for enrollment. We confirmed acute dengue by testing sera collected at enrollment for dengue NS1 antigen or IgM antibodies. We defined primary outcomes as per the 1997 and 2009 World Health Organization (WHO) classification criteria: dengue hemorrhagic fever (DHF; WHO 1997), dengue shock syndrome (DSS; WHO 1997), and severe dengue (WHO 2009). Overall, 1064 patients were confirmed as having acute dengue: 318 (17.4%) by NS1 rapid antigen testing and 746 (40.7%) by IgM antibody testing. Of these 1064 patients, 994 (93.4%) were adults ≥18 years and 704 (66.2%) were male. The majority (56, 80%) of children and more than half of adults (544, 54.7%) developed DHF during hospitalization, while 6 (8.6%) children and 22 (2.2%) adults developed DSS. Overall, 10 (14.3%) children and 113 (11.4%) adults developed severe dengue. A total of 2 (0.2%) patients died during hospitalization.

Conclusions

One-half of patients hospitalized with acute dengue progressed to develop DHF and a very small number developed DSS or severe dengue. Developing an algorithm for triaging patients to ambulatory versus inpatient management should be the future goal to optimize utilization of healthcare resources in dengue-endemic countries.

In countries where dengue is prevalent, hospitals are often overwhelmed due to the high numbers of patient admissions during dengue epidemics. We studied 1064 children and adults hospitalized with acute dengue in Sri Lanka to determine the prevalence of severe disease outcomes to support the development of a system which can limit hospitalizations in the future. We found that only half of patients developed severe disease outcomes during hospitalization and only a small minority of patients developed life-threatening disease. For dengue-prevalent countries, developing systems to identify patients with acute dengue who can be managed without hospital admission should be a priority.

Social, health system and clinical determinants of fever mortality during an outbreak of dengue fever in Kerala, India

Background and Objectives:

The morbidity and mortality spectrum of the south Indian state of Kerala is dominated by chronic non-communicable diseases, yet febrile illnesses because of neglected tropical diseases and emerging viral infections are often reported. As fever deaths are mostly avoidable, understanding the determinants of mortality is essential for implementing preventive measures.

Methods:

A case-control study was done during an ongoing dengue outbreak in Thiruvananthapuram district, Kerala during 2017–18. Cases included all fever deaths from the line list of Integrated Disease Surveillance Program (IDSP). Data were obtained from hospital case records and by interviewing patients or care givers. The theoretical model for determinants of mortality was constructed at three levels namely sociodemographic factors, access to health care and health seeking behavior, and clinical determinants.

Results:

This study confirmed association of mortality with age above 40 years (P = 0.010, OR = 3.48), being heavy built (P = 0.029, OR = 13.25), clinical symptoms of breathlessness (P < 0.001, OR = 24.89), restlessness (P < 0.001, OR = 97.26), clinical signs of drowsiness (P = 0.024, OR = 7.97), hypotension (P < 0.001, OR = 42.22), complications such as ARDS (P = 0.047, OR = 171.56), and myocarditis (P = 0.012, OR = 16.59). A low occupation status of semiskilled work or less (P = 0.012, OR = 0.30), choosing a nearby hospital for treatment (P = 0.018, OR = 0.48) and shortening the time gap between onset of symptom and final diagnosis (P = 0.044, OR = 0.72) was found to be protective.

Conclusion:

Along with biological and clinical factors, distal determinants like social factors, health seeking behavior, and health system factors are associated with fever mortality.

Early hematological parameters as predictors for outcomes in children with dengue in northern India: A retrospective analysis

INTRODUCTION

Dengue presents with a variable clinical course, ranging from mild illness to potentially fatal hemorrhage and shock. We aimed to evaluate the capabilities of various hematological parameters observed early in the course of illness for predicting the clinical outcomes of illness.

METHODS

We retrospectively analyzed the records of children admitted in the pediatric inpatient services of the institute with dengue between 2017 and 2019. We determined the relationships between the hematological parameters observed during the first evaluation and the various clinical outcomes.

RESULTS

We evaluated data from 613 patients (age range, 26 days to 17 years). Of these, 29.85% exhibited fever with warning signs, and 8.97% had severe dengue. Lower values of hemoglobin, platelet count, mean corpuscular volume, mean corpuscular hemoglobin concentration, and mean platelet volume, and higher values of total leukocyte count (TLC), hematocrit, and red cell distribution width variably correlated with numerous clinical outcomes-duration of hospital stay, development of complications, requirement of blood component transfusion, inotropic support, and mortality. Among the parameters, TLC ≥20,000/mL and initial platelet count ≤20,000/mL significantly associated with mortality, with odds ratios (95% confidence interval) of 11.81 (4.21-33.80) and 5.53 (1.90-16.09), respectively.

CONCLUSIONS

Hematological parameters observed early during dengue infection may predict its clinical outcomes in infected children. Initial high TLC and low platelet count are potential predictors of fatal outcomes in the course of disease.

Leucocytosis and early organ involvement as risk factors of mortality in adults with dengue fever

The clinical profile and risk factors for mortality in dengue fever have evolved over the years. The all-cause mortality in admitted dengue patients is around 6%. We aimed to evaluate the recent change in trends of the clinical characteristics and risk factors for in-hospital mortality in adults with dengue fever. This is a retrospective study on adults with confirmed dengue fever admitted in a medical unit of a tertiary care center in North India. Medical records of confirmed dengue fever patients admitted between January 2011, and December 2016 were reviewed. Chi-squared tests with Bonferroni correction for multiple testing were used to identify risk factors for mortality. 232 records were included, of which 66.8% were males. The mean age was 31.6 ± 14 years. There were 17 deaths with an all-cause mortality rate of 7.3% with 76.5% being classified as severe dengue at admission. Among the 17 mortality cases, dyspnea (47%), tachypnea (86.7%), leucocytosis (58.8%), raised urea (80%), and elevated serum creatinine (52.9%) at presentation were significantly associated with mortality (p < 0.001). Shock at any time during the hospital stay (58.8%) was also found to be significantly associated with mortality (p < 0.001). We found that dyspnea, tachypnea, acute kidney injury, and leucocytosis at presentation was significantly associated with in-hospital mortality. Based on our results, we recommend aggressive management of patients with severe dengue and those with mild/moderate disease with the above risk factors.

Exanthematic dengue fever mimicking rubella

The authors present a case of dengue fever mimicking rubella. Male patient, in the second episode of dengue fever, presented afebrile, with diffuse morbilliform rash and craniocaudal progression, having subsequently affected his palms and soles. On the third day of clinical evolution, serologies did not indicate IgM, IgG, or NS1, but on the sixth day of evolution, IgM and IgG were reactive for dengue fever. Previous episodes of dengue are a risk factor for the development of more severe conditions, but this was atypical because the patient was afebrile and had a rubelliform rash. The case also illustrates an early IgG anamnestic response, as it was a reinfection.

Dengue and Zika virus infections are enhanced by live attenuated dengue vaccine but not by recombinant DSV4 vaccine candidate in mouse models

Background

A tetravalent live attenuated dengue vaccine, Dengvaxia, sensitised naïve recipients to severe dengue illness upon a subsequent natural dengue infection and is suspected to be due to antibody-dependent enhancement (ADE). ADE has also been implicated in the severe neurological outcomes of Zika virus (ZIKV) infection. It has become evident that cross-reactive antibodies targeting the viral pre-membrane protein and fusion-loop epitope are ADE-competent. A pre-clinical tetravalent dengue sub-unit vaccine candidate, DSV4, eliminates these ADE-competent epitopes.

Methods

We compared protective efficacy and ADE-competence of murine polyclonal antibodies induced by DSV4, Dengvaxia and an ‘in house’ tetravalent mixture of all four laboratory DENV strains, TV DENV, using established mouse models.

Findings

DSV4-induced antibodies, known to be predominantly type-specific, provided significant protection against lethal DENV challenge, but did not promote ADE of either DENV or ZIKV infection in vivo. Antibodies elicited by Dengvaxia and TV DENV, which are predominantly cross-reactive, not only failed to offer protection against lethal DENV challenge, but also promoted ADE of both DENV and ZIKV infection in vivo.

Interpretation

Protective efficacy against DENV infection may be linked to the induction of neutralising antibodies which are type-specific rather than cross-reactive. Whole virus-based dengue vaccines may be associated with ADE risk, despite their potent virus-neutralising capacity. Vaccines designed to eliminate ADE-competent epitopes may help eliminate/minimise ADE risk.

Funding

This study was supported partly by ICGEB, India, the National Biopharma Mission, DBT, Government of India, Sun Pharmaceutical Industries Limited, India, and NIAID, NIH, USA.

Risk Factors and Predictors of Severe Dengue in Saudi Population in Jeddah, Western Saudi Arabia: A Retrospective Study

This study was performed to determine the risk factors and predictors of severe dengue fever (SDF) in Saudi population in Jeddah, Western Saudi Arabia. This 7-year retrospective study included children and adults with confirmed dengue from 2010 to 2016. Demographic, clinical, laboratory, serological, and virologic data were collected. Comparative analyses were performed between pediatric and adult SDF cases defined according to the WHO 2009 dengue classification. During the study period, dengue was confirmed in 17,646 cases with predominant infection of adults (6.5 times that of children) and males (3.8 times that of females). May and June were associated with 43.9% of total dengue cases. All 56 pediatric and 187 adult SDF cases were hospitalized. At least one warning sign of severe illness was present in 92.2% of total SDF cases. Mortality rates were 8.9% and 10.7% of pediatric and adult SDF cases, respectively. Multiple logistic regression detected that the most significant risk factors and predictors of SDF in adults versus children were significantly more secondary dengue infection (adjusted odds ratio [AOR]: 2.20, 95% CI: 1.09-4.44, P = 0.02), significantly less clinical fluid accumulation (AOR: 0.17, 95% CI: 0.07-0.44, P < 0.001) and significantly less neutropenia (AOR: 0.41, 95% CI: 0.17-0.97, P = 0.04). This was the first large multicenter study evaluating SDF in Saudi population and considering the WHO 2009 dengue classification, which showed predominant infection of adults and males with dengue, few SDF cases with low mortality and highlighted predictors of SDF in adults versus children. Consideration of warning signs for severe dengue may result in hospital admission, prompting closer monitoring, timely and proper interventions and reduced mortality in SDF cases.

Severe dengue and liver involvement: an overview and review of the literature

Introduction: Two billion population are at risk of dengue fever and by 2080, over six billion population will be at risk. Hepatitis is common in dengue and the liver is invariably involved in severe cases. We conducted a literature review using the PubMed database on articles covering a broad range of issues related to dengue and hepatitis.Areas covered: This article overviews available literature on changes in the definition of severe dengue, pathogenesis of liver involvement in dengue, clinical manifestations, and predictors of mortality in severe dengue with liver involvement, impact of viral hepatitis co-infections and hepatotoxic drugs, and hemophagocytic lymphohistiocytosis.Expert commentary: Hepatitis is commonly seen in dengue however the degree of elevation of transaminases did not correlate well with severity of illness in observational studies, except in the elderly. The underlying pathogenesis of liver injury is still being elucidated and further studies are required to fully understand the cellular pathways. Acute or chronic viral hepatitis does not appear to affect dengue outcomes. Commonly used medications such as paracetamol and statins may influence dengue outcomes.

Epidemiological and Clinical Features of Dengue Infection in Adults in the 2017 Outbreak in Vietnam

Purpose

The clinical features and laboratory results of dengue-infected adult patients admitted to the hospital during the 2017 outbreak were analyzed in this study.

Method

This is a cross-sectional study. 2922 patients aged 18 years or more with dengue fever in National Hospital for Tropical Diseases (NHTD) in the North and Hospital for Tropical Disease (HTD) in the South of Vietnam were recruited in this study.

Result

Patients were admitted in the hospital around the year and concentrated from August to December, in 53/63 (84.0%) provinces in Vietnam, and patients in all ages were affected. The number of patients with dengue fever was 1675 (57.3%), dengue with warning signs 914 (31.3%), and severe dengue 333 (11.4%), respectively. Among patients with severe dengue, severe plasma leakage and dengue shock account for 238 (8.1%), severe organ impairment 73 (2.5%), and severe bleeding 22 (0.75%). The rate of mortality was 0.8%, and the outcome of dengue patients is worse in the elderly and people with underlying diseases.

Conclusion

The 2017 dengue outbreak occurred in a larger scale than in the previous years in terms of time, location, and number of patients. More elderly patients were infected by dengue in this outbreak, and this may contribute to the mortality rate. Clinical manifestations of dengue patients in Southern Vietnam are more typical than the northern, but the rate of severe dengue is not different. The mortality risk and underlying conditions associated with dengue-infected elderly patients are worthy of further investigations in the future.

Prevalence of self-reported dengue infections in Manaus Metropolitan Region: a cross-sectional study

INTRODUCTION

Dengue is an endemic and epidemic disease in Brazil, with a high burden of disease. Amazonas State has a high risk of transmission. This study aimed to assess the self-reported prevalence of dengue in adults living in Manaus Metropolitan Region.

METHODS

A cross-sectional study was conducted with adults living in Manaus Metropolitan Region in 2015. We performed a three-phase probabilistic sampling to collect participants' clinical and sociodemographic data. Self-reported dengue infection in the previous year was the primary outcome. Descriptive statistics and Poisson regression analysis with robust variance were used to calculate the prevalence ratio (PR) of dengue infections with 95% confidence intervals (95% CIs). Multilevel analysis including city and neighborhood variables was calculated. All analyses considered the complex sampling.

RESULTS

Among the 4,001 participants, dengue in the previous year was self-reported by 7.0% (95% CI 6.3%-7.8%). Dengue was more frequent in women(PR 1.51; 95% CI 1.06-2.13), elderly participants (≥60 years old, PR 2.54; 95% CI 1.19-5.45), White and Asian participants (PR, 1.57; 95% CI, 1.11-2.23), and individuals who had not received endemic agent visits (PR, 2.28; 95% CI, 1.31-3.99). After multilevel analysis, sex was no longer a significant variable, with the remaining associations still significant.

CONCLUSIONS

Seven out of 100 inhabitants of Manaus Metropolitan Region reported dengue in the previous year. Dengue was predominantly observed in women, elderly individuals, White and Asian individuals, and individuals who did not receive endemic agent visits. The setting plays an important role in dengue infections.

Different Associations between DC-SIGN Promoter-336G/A (rs4804803) Polymorphism with Severe Dengue in Asians and South-Central Americans: a Meta-Analysis

Objective: This study was conducted to identify the association between rs4804803 polymorphism in DC-SIGN with the susceptibility of severe dengue. Methods: A comprehensive search was conducted to identify all eligible papers in PubMed, Web of Science, China National Knowledge Infrastructure (CNKI), and Google Scholar. Odds ratios (ORs) and corresponding 95% confidence intervals (95% CIs) were used to assess the association. Subgroup analyses were performed by ethnicity. Sensitivity analyses were performed through employing different statistical models (fixed versus random effect model). Results: A total of nine papers and 12 studies, with 1520 severe dengue and 1496 clinical dengue infection were included. The overall meta-analysis revealed significant associations between rs4804803 and severe dengue under the recession (GG versus GA/AA: OR = 0.44, 95%CI, 0.23–0.82) and a codominant model (GG versus AA: OR = 0.43, 95%CI, 0.23–0.81), but sensitivity analysis indicated that the significant pooled ORs were not robust. The subgroup analysis suggested that the carrier of G in rs4804803 was a risk factor for severe dengue under dominant (GG/GA versus AA: OR = 1.86,95%CI, 1.01–3.45), superdominant (GA versus GG/AA: OR = 1.81,95%CI, 1.02–3.21) and a codominant (GA versus AA: OR=1.82,95%CI, 1.02–3.26) models in Asians, while it was a protective factor for severe dengue in South-central Americans under recessive (GG versus GA/AA: OR = 0.27,95%CI, 0.10–0.70) and codominant (GG versus AA: OR=0.24,95%CI, 0.09–0.64) models. The results from subgroup analysis were robust. Conclusions: Dendritic cell-specific intercellular adhesion molecule-3-grabbing non-integrin (DC-SIGN) promoter-336G/A (rs4804803) polymorphism is association with severe dengue, and it acts in different directions for Asians and South-central Americans.

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 Profile and Outcome of Dengue Fever in Multidisciplinary Intensive Care Unit of a Tertiary Level Hospital in India

Background

India is one of the seven identified countries in South-East Asia region regularly reporting dengue fever (DF)/dengue hemorrhagic fever (DHF) outbreaks. Even though the dengue prodrome and evolution of illness are most often similar in many patients, progress and outcome may differ significantly depending on the severity of illness as well as treatment instituted. We studied the clinical manifestations, outcome and factors predicting mortality of serology confirmed dengue fever cases admitted in Multidisciplinary Intensive Care Unit (MICU) of a high acuity healthcare facility in India.

Methodology

All patients with serology proven dengue fever admitted to MICU between 1st July 2015 and1st December 2015 were included in the study. Clinical presentation, laboratory findings, severity of illness scores and outcome were recorded.

Results

Majority of the patients (58.4%) belonged to 21–40 year age group. Hepatic (96.8%) followed by hematological (79.2%) involvement were the most common findings. CNS involvement observed among 27%. Survival to hospital discharge was 78.9%. Respiratory and gastrointestinal system involvement was associated with increased mortality. Acute respiratory distress syndrome (ARDS), acute kidney injury (AKI) and shock were the clinical syndromes associated with mortality. Serum lactate, aspartate transaminase (AST) and alanine transaminase (ALT) were significantly elevated among non survivors. Significant difference in sequential organ failure assessment (SOFA) and acute physiology and chronic health evaluation (APACHE) scores was also observed among survivors and non survivors.

Conclusion

Organ system involvement and higher disease severity scores are strong predictors of mortality. High index of suspicion for atypical manifestations of dengue is warranted.

How to cite this article

Padyana M, Karanth S, Vaidya S, Gopaldas JA. Clinical Profile and Outcome of Dengue Fever in Multidisciplinary Intensive Care Unit of a Tertiary Level Hospital in India. Indian J Crit Care Med 2019;23(6):270–273.

Prognostic Factors in Adult Patients with Dengue: Developing Risk Scoring Models and Emphasizing Factors Associated with Death ≤7 Days after Illness Onset and ≤3 Days after Presentation

Dengue is a mosquito-borne viral disease that is a threat to global health. However, information relating to mortality ≤7 days after dengue onset and ≤3 days after presentation is limited. We retrospectively analyzed 1086 adults with dengue during a 12-year period. Three scoring models were established: model-1 (death ≤3 days after presentation), model-2 (death ≤7 days after illness onset), and model-3 (overall fatality). In total, 39 patients with fatal dengue were identified, of which 17 and 14 patients died ≤7 days after illness onset and ≤3 days after presentation, respectively. In model-1 (range: 0‒4 points), gastrointestinal bleeding ≤72 h after presentation, thrombocytopenia (<50 × 10⁸ cells/L) at presentation, and acute kidney injury after hospitalization, using a cutoff level of 2 points, exhibited good discrimination (area under the receiver curve (AUC): 0.975) between survivors and non-survivors. In model-2, the significant predictors were gastrointestinal bleeding ≤72 h after presentation, and hemoconcentration and leukocytosis after hospitalization. Model-2 (range: 0⁻4 points) showed an AUC of 0.974, with a cutoff value of 2 points. The independent factors in model-2 were the predictors of overall mortality (model-3), which include thrombocytopenia (<50 × 10⁸ cells/L) at presentation. Using a cutoff value of 2 points, model-3 (range: 0⁻7 points) revealed an excellent discrimination between survivors and non-survivors (AUC: 0.963).

Comorbidities increase in-hospital mortality in dengue patients in Brazil

Dengue remains an unmet public health burden. We determined risk factors for dengue in-hospital mortality in Brazil. Of 326,380 hospitalised dengue cases in 9-45-year-old individuals, there were 971 deaths. Risk of dying was 11-times higher in the presence of underlying common comorbidities (renal, infectious, pulmonary disease and diabetes), similar to the risk of dying from severe dengue and much higher with the combination. Ensuring access to integrated dengue preventative measures in individuals aged ≥ 9 years including those with comorbidities may help achieve the WHO objective of 50% reduction in mortality and 25% reduction in morbidity due to dengue by 2020.

Prediction of mortality in severe dengue cases

BACKGROUND

Increasing incidence of dengue cases in Malaysia over the last few years has been paralleled by increased deaths. Mortality prediction models will therefore be useful in clinical management. The aim of this study is to identify factors at diagnosis of severe dengue that predicts mortality and assess predictive models based on these identified factors.

METHOD

This is a retrospective cohort study of confirmed severe dengue patients that were admitted in 2014 to Hospital Kuala Lumpur. Data on baseline characteristics, clinical parameters, and laboratory findings at diagnosis of severe dengue were collected. The outcome of interest is death among patients diagnosed with severe dengue.

RESULTS

There were 199 patients with severe dengue included in the study. Multivariate analysis found lethargy, OR 3.84 (95% CI 1.23-12.03); bleeding, OR 8.88 (95% CI 2.91-27.15); pulse rate, OR 1.04 (95% CI 1.01-1.07); serum bicarbonate, OR 0.79 (95% CI 0.70-0.89) and serum lactate OR 1.27 (95% CI 1.09-1.47), to be statistically significant predictors of death. The regression equation to our model with the highest AUROC, 83.5 (95% CI 72.4-94.6), is: Log odds of death amongst severe dengue cases = - 1.021 - 0.220(Serum bicarbonate) + 0.001(ALT) + 0.067(Age) - 0.190(Gender).

CONCLUSION

This study showed that a large proportion of severe dengue occurred early, whilst patients were still febrile. The best prediction model to predict death at recognition of severe dengue is a model that incorporates serum bicarbonate and ALT levels.

Dengue in Araraquara, state of São Paulo: epidemiology, climate and Aedes aegypti infestation

OBJECTIVE

To describe the epidemiology of dengue in a medium-sized city in the state of São Paulo.

METHODS

Data, such as circulating serotypes, severe cases and deaths, age group, sex, among others, were obtained on reported and confirmed dengue cases in Araraquara, state of São Paulo, between 1991 and 2015. Climatic and infestation data were also analyzed. These variables were evaluated descriptively, using statistical measures such as frequencies, averages, minimum and maximum. Dengue incidence rates were calculated according to month, year, age and sex, and time series of dengue cases, infestation, and climatic variables.

RESULTS

Approximately 16,500 cases of dengue fever were reported between 1991 and 2015. The highest number of reports was recorded in 2015 (7,811 cases). In general, the age group with the highest number of reports is between 20 and 59 years old. The highest incidences, generally between March and May, occurred after the increase in rainfall and infestation in January.

CONCLUSIONS

Increased levels of infestation due to rainfall are reflected in incidence rates of the disease. It is fundamental to know the epidemiology of dengue in medium-sized cities. Such information can be extended to diseases such as Zika and Chikungunya, which are transmitted by the same vector and were reported in the city. The intensification of surveillance efforts in periods before epidemics could be a strategy to be considered to control the viral spread.

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.