Fatal dengue hemorrhagic fever in adults: emphasizing the evolutionary pre-fatal clinical and laboratory manifestations

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

An unusual case of dengue fever in aneurysmal subarachnoid haemorrhage: diagnosis and management nuances

BACKGROUND

Dengue fever is highly prevalent in the Asia-Pacific region. Here we present an unusual case of dengue fever in a patient with a ruptured cerebral aneurysm causing subarachnoid (SAH) and intraventricular haemorrhage (IVH) and discuss the implications of dengue-related thrombopathies on the management of SAH and its complications.

CASE REPORT

A 56-year-old female with a two-day history of high-grade pyrexia and myalgia presented with sudden-onset drowsiness (presenting Glasgow Coma Scale, GCS: E1V1M4). Imaging revealed extensive SAH and IVH due to a ruptured right middle cerebral artery (MCA) aneurysm, with extensive vasospasm. Blood test revealed thrombocytopenia and a positive NS-1 antigen. She subsequently suffered from two episodes of re-rupture of the aneurysm and elevated intracranial pressure which required a decompressive craniectomy in addition to coilingof the MCA aneurysm. Cerebral perfusion and rheology were maintained with the triple-H therapy. Her GCS improved to E4V1M6, but remained aphasic.

DISCUSSIONS

Thrombocytopenia and deranged platelet functions in dengue infection might affect the stability of clot and increase the risk of re-rupture of aneurysm. Immediate securement of the aneurysm was paramount. In cases of severe dengue, plasma leakage could lead to intravascular depletion, and coupled with haemoconcentration and hypotension would further increase the risk for vasospasm.

Dengue overview: An updated systemic review

Dengue is caused by the dengue virus (DENVs) infection and clinical manifestations include dengue fever (DF), dengue hemorrhagic fever (DHF), or dengue shock syndrome (DSS). Due to a lack of antiviral drugs and effective vaccines, several therapeutic and control strategies have been proposed. A systemic literature review was conducted according to PRISMA guidelines to select proper references to give an overview of DENV infection. Results indicate that understanding the virus characteristics and epidemiology are essential to gain the basic and clinical knowledge as well as dengue disseminated pattern and status. Different factors and mechanisms are thought to be involved in the presentation of DHF and DSS, including antibody-dependent enhancement, immune dysregulation, viral virulence, host genetic susceptibility, and preexisting dengue antibodies. This study suggests that dissecting pathogenesis and risk factors as well as developing different types of therapeutic and control strategies against DENV infection are urgently needed.

Mechanism of Immune Evasion in Mosquito-Borne Diseases

In recent decades, mosquito-borne illnesses have emerged as a major health burden in many tropical regions. These diseases, such as malaria, dengue fever, chikungunya, yellow fever, Zika virus infection, Rift Valley fever, Japanese encephalitis, and West Nile virus infection, are transmitted through the bite of infected mosquitoes. These pathogens have been shown to interfere with the host's immune system through adaptive and innate immune mechanisms, as well as the human circulatory system. Crucial immune checkpoints such as antigen presentation, T cell activation, differentiation, and proinflammatory response play a vital role in the host cell's response to pathogenic infection. Furthermore, these immune evasions have the potential to stimulate the human immune system, resulting in other associated non-communicable diseases. This review aims to advance our understanding of mosquito-borne diseases and the immune evasion mechanisms by associated pathogens. Moreover, it highlights the adverse outcomes of mosquito-borne disease.

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

Background

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

Methods

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

Results

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

Conclusions

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

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

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

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

Production, Transmission, Pathogenesis, and Control of Dengue Virus: A Literature-Based Undivided Perspective

Dengue remains one of the most serious and widespread mosquito-borne viral infections in human beings, with serious health problems or even death. About 50 to 100 million people are newly infected annually, with almost 2.5 billion people living at risk and resulting in 20,000 deaths. Dengue virus infection is especially transmitted through bites of Aedes mosquitos, hugely spread in tropical and subtropical environments, mostly found in urban and semiurban areas. Unfortunately, there is no particular therapeutic approach, but prevention, adequate consciousness, detection at earlier stage of viral infection, and appropriate medical care can lower the fatality rates. This review offers a comprehensive view of production, transmission, pathogenesis, and control measures of the dengue virus and its vectors.

Immunopathogenesis of Different Emerging Viral Infections: Evasion, Fatal Mechanism, and Prevention

Different emerging viral infections may emerge in different regions of the world and pose a global pandemic threat with high fatality. Clarification of the immunopathogenesis of different emerging viral infections can provide a plan for the crisis management and prevention of emerging infections. This perspective article describes how an emerging viral infection evolves from microbial mutation, zoonotic and/or vector-borne transmission that progresses to a fatal infection due to overt viremia, tissue-specific cytotropic damage or/and immunopathology. We classified immunopathogenesis of common emerging viral infections into 4 categories: 1) deficient immunity with disseminated viremia (e.g., Ebola); 2) pneumocytotropism with/without later hyperinflammation (e.g., COVID-19); 3) augmented immunopathology (e.g., Hanta); and 4) antibody-dependent enhancement of infection with altered immunity (e.g., Dengue). A practical guide to early blocking of viral evasion, limiting viral load and identifying the fatal mechanism of an emerging viral infection is provided to prevent and reduce the transmission, and to do rapid diagnoses followed by the early treatment of virus neutralization for reduction of morbidity and mortality of an emerging viral infection such as COVID-19.

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.

Predictors and Outcomes of Dengue-Associated Acute Kidney Injury

Dengue viral infections present with a wide clinical spectrum ranging from asymptomatic to severe manifestations with organ involvement. The term "expanded dengue syndrome" has been commonly used to illustrate the unusual or atypical manifestations; acute kidney injury (AKI) is one of the atypical manifestations of this syndrome. The use of heterogeneous criteria to determine the presence of AKI in dengue patients due to the vast diversity in populations led to difficulties in assessing the true incidence of dengue-associated AKI. This review presents a variable, but often high, frequency of dengue-associated AKI among vastly diverse populations with various disease severities. Dengue-associated AKI is not an uncommon complication, and its importance has often been neglected during the management of dengue patients. The risk factors and certain clinical and laboratory findings commonly reported among dengue patients with AKI should be considered to support a timely diagnosis and case management. This review highlights the need for clinicians to be aware of dengue-associated AKI to reduce the morbidity and mortality associated with this common and important tropical disease.

Clinical characteristics and risk factors for intracranial hemorrhage or infarction in patients with dengue

BACKGROUND

Intracranial hemorrhage (ICH) or infarction in dengue cases is rare but very challenging for clinicians. We report these uncommon complications of dengue patients and focused on the significant factors associated with ICH or infarction in dengue patients.

METHODS

This investigation was a retrospective study of 182 adult dengue patients who received brain computed tomography at three Taiwan hospitals during the 2014 and 2015 dengue outbreaks. This included 13 hemorrhage cases, 26 infarction cases and 143 cases without brain infarction or hemorrhage.

RESULTS

Among them, 13 (7.14%) suffered from ICH (6 had subdural hemorrhage, 3 had subarachnoid hemorrhage, 1 had subdural and subarachnoid hemorrhage, and 3 had intracerebral hemorrhage) and 26 (14.3%) had brain infarction. The overall mortality rate was 4/13 (30.8%) in the ICH group and 3/26 (11.5%) in the infarction group. The significant variables from the univariate analysis, including difference between 2014 and 2015, age, history of cerebrovascular accident, bone pain, arthralgia, dizziness, altered consciousness, and a higher Charlson comorbidity score. Multivariate analysis revealed that significant risk factors for ICH/infarction in dengue cases were the year of occurrence, 2014 vs. 2015 (p < 0.0001, OR = 25.027, 95% CI = 8.205-76.336), Charlson score >4 (p = 0.01, OR = 3.764, 95% CI = 1.364-10.386) and altered consciousness (p < 0.0001, OR = 6.3, 95% CI = 2.242-17.7). The factors physicians should notice in dengue endemic regions for brain infarction or ICH include altered consciousness and a Charlson score >4, especially in the year that a higher frequency of infarction/ICH was observed.

Impact of Nutritional Status on the Severity of Dengue Infection Among Pediatric Patients in Southern Thailand

BACKGROUND

Given the lack of specific antiviral drugs and effective vaccine for dengue infection, factors such as host nutritional status that may alter disease progression require investigation. This study examined the relationship between baseline nutritional status and severity of dengue infection in pediatric patients.

METHODS

Data from dengue patients 1-14 years of age treated at four hospitals in southern Thailand (2017-2018) were reviewed. Dengue infection was classified as dengue fever, dengue hemorrhagic fever and dengue shock syndrome. Children's nutritional status was assessed based on international and national growth charts. Binary logistic regression was used to identify factors associated with dengue severity and malnutrition.

RESULTS

Overall, 248, 281 and 43 patients had dengue fever, dengue hemorrhagic fever and dengue shock syndrome, respectively. Overweight was associated with increased risk of dengue severity [odds ratio (OR) = 1.76, 95% confidence interval (CI): 1.13-2.75, P = 0.012; OR = 1.84, 95% CI: 1.09-3.09, P = 0.022, per international and national growth criteria, respectively). Stunting was associated with decreased risk of dengue severity (OR = 0.54, 95% CI: 0.33-0.88, P = 0.013; OR = 0.61, 95% CI: 0.39-0.95, P = 0.030, per international and national growth criteria, respectively). Being overweight was significantly and positively associated with levels of hemoglobin >14 g/dL, hematocrit >42%, hemoconcentration ≥20% and platelet count ≤50,000/mm, whereas being stunted was significantly and negatively associated with levels of hemoglobin >14 g/dL and hematocrit >42%.

CONCLUSIONS

These findings support a hypothesis that malnutrition might influence the severity of dengue infection through host immune response. Overweight children with dengue infections should be closely observed for early signs of severe dengue infection.

Frequency of Iron Uptake Proteins Related Genes Among Klebsiella pneumoniae Isolates

Aims:

The present study aimed to evaluate Iron uptake protein-related genes in clinical and environmental Klebsiella pneumoniae isolates.

Background:

Klebsiella pneumoniae as an opportunistic pathogen cause infections in immunocompromised patients. Iron uptake systems play an important role in the pathogenesis of Klebsiella pneumonia.

Objectives:

This study was designed to investigate the prevalence of iron uptake coding genes among isolates of Klebsiella pneumonia.

Materials and Methods:

A total of 300 isolates of Klebsiella pneumonia including 150 clinical isolates and 150 environmental isolates were selected. Finally, the frequency of iroN, iucD, kfuA,hmuR, and ybt [yHPI] genes were detected by PCR method.

Results:

The frequency of kfuA, iucD, iroN, yHPI in clinical isolates were 33.3%, 16.7%, 24.7%, 15.3%, respectively and these genes among environmental isolates were 20.7%, 6%, 49.3% and 0.7%, respectively. Among the clinical isolates, the most frequency genes were kfuA gene [50 isolates] and after that iroN [37 isolates], iucD [25 isolates] and yHPI [23 isolates], the genes with the most frequency among environmental isolates were iroN gene [74 isolates] and following that kfuA [31 isolates], iucD [9 isolates] and yHPI [1 isolate]. No hmuR positive samples among all clinical or environmental isolates were found.

Conclusion:

The result of this study showed that because of the high frequency of ferric iron system coding gene kfu among clinical isolates, this system might play an important role in the survival of bacteria against its host.

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.

Management of anti-thrombotic therapy in patients with recent percutaneous coronary intervention and acute dengue infection: A case series

There is currently little data regarding the ideal management for a patient who has undergone recent percutaneous coronary intervention (PCI) and subsequently develops dengue fever. Patients with recent PCI are at high risk of stent thrombosis with cessation of dual anti-platelet therapy. On the other hand, patients with dengue viral infection are at high risk of bleeding. Managing patients with recent PCI and dengue involves the delicate balancing of the risk of thrombosis and bleeding. Careful consideration of the timing of coronary intervention and the severity of the dengue infection is required. We describe the management of the anti-thrombotic therapy in three different patients with dengue infection and recent PCI and discuss our approach to managing such patients.

Serum LPS Associated with Hantavirus and Dengue Disease Severity in Barbados

Hantavirus and dengue virus (DENV) infections are caused by RNA viruses which infect immune systems’ cells including monocytes, macrophages and dendritic cells and occur year-round in Barbados. A retrospective serological study (2008–2015) was conducted on hantavirus and dengue patient sera confirmed by IgM and IgG ELISA, NS1 and RT-PCR using Limulus amoebocyte lysate (LAL) kinetic turbidimetric method to determine serum endotoxin levels. Hantavirus patients were categorized into two groups, namely (a) hospitalized and (b) non-hospitalized. Dengue patients were categorized into 3 groups using 2009 WHO dengue guidelines (a) severe dengue (SD), (b) hospitalized non-severe dengue (non-SD) and (c) non-hospitalized non-SD. Statistical analyses were conducted to determine the association of endotoxin levels with hantavirus disease severity based on hospitalization and dengue disease severity. Serum endotoxin levels are associated with hantavirus disease severity and hospitalization and dengue disease severity (p < 0.01). Similar studies have found an association of serum endotoxin levels with dengue disease severity but never with hantavirus infection. Co-detection of hantavirus- and DENV-specific IgM in some patients were observed with elevated serum endotoxin levels. In addition, previous studies observed hantavirus replication in the gut of patients, gastrointestinal tract as a possible entry route of infection and evidence of microbial translocation and its impact on hantavirus disease severity. A significant correlation of serum endotoxin and hantavirus disease severity and hospitalization in hantavirus infected patients is reported for the first time ever. In addition, serum endotoxin levels correlated with dengue disease severity. This study adds further support to the role of endotoxin in both hantavirus and dengue virus infection and disease severity and its role as a possible therapeutic target for viral haemorrhagic fevers (VHFs).

Concurrent infections of dengue virus serotypes in Bali, Indonesia

Objective

To describe cases of dengue virus (DENV) concurrent infections in patients from both local and international traveler visiting Bali, Indonesia.

Results

During a hospital-based study, 260 patients (from 161 local and 99 international traveler patients) were recruited. Among them, 190 were positive by DENV RT-PCR in which eight patients (five local and three international travelers) detected as having concurrent infections by two different DENV serotypes. Among the eight patients, the common dengue symptoms diagnosed were fever, headache, and myalgia. Six cases (75%) were diagnosed with dengue fever (DF) while two cases (25%) manifested with bleeding and were diagnosed with dengue hemorrhagic fever (DHF) grade 1. The DENVs concurrent infections involved all four DENV serotypes known to be circulating in Bali. Although cases of DENV concurrent infections have been implicated with severe manifestation, we observed that most of concurrent infections cases in our study were of mild clinical manifestation, that may be related to the changing of DENV serotype predominance which is occurring in Bali, Indonesia.

Assessment of chemokine and cytokine signatures in patients with dengue infection: A hospital-based study in Kolkata, India

Dengue fever is an acute viral infection transmitted by arthropods but may evolve to severe clinical manifestations. Descriptions of the role of circulating immune modulators such as cytokines or chemokines in dengue immunopathogenesis have largely relied on data from South-east Asia and America, while India is poorly represented. This study characterizes dengue cases from West Bengal, eastern India, with respect to clinical profile and pro-inflammatory and inflammatory cytokines. We evaluated the profile of both inflammatory and anti-inflammatory cytokines (IFNγ, IL6, IL10, IL12 and TGFβ) and chemokines (IL8, CXCL9, CXCL10 and RANTES) in 100 hospitalized NS1/IgM confirmed Dengue patients during the epidemic in West Bengal during 2017. Additionally, all necessary blood investigations of the study subjects were performed. The patients mostly hailed from Kolkata, followed by Nadia, 24 Parganas (North and South), Murshidabad and Midnapore. The most common presentations apart from fever and bodyache were gastrointestinal symptoms. An elevated levels of cytokines IL6 and IL10 chemokine IL8 and CXCL10 along with decreased RANTES were found in the patients with Severe Dengue as compared to mild forms of dengue (p < 0.0001) during 3-6 days of infections. A significant association was obtained between most of cytokine and increased SGPT, haematocrit, albumin and decreased platelet count, whereas a negative correlation with the level of RANTES to haematocrit (r=-0.220 with p = 0.029) was found in severe dengue cases with altered liver function parameters. This is the first study demonstrating cytokine and chemokine association with dengue severity from the eastern part of India. Taken together, this study demonstrated that the altered expression levels of IL6, IL10, IL8, CXCL10 and RANTES had significant associations with dengue severity parameters.

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

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

Seroprevalence of dengue fever and the associated sociodemographic, clinical, and environmental factors in Makkah, Madinah, Jeddah, and Jizan, Kingdom of Saudi Arabia

This study aimed to estimate the seroprevalence of anti-dengue IgG antibodies in Makkah, Al Madinah, Jeddah, and Jizan; and to identify the associated demographic, clinical, and environmental independent risk factors. A community-based household serosurvey conducted between September 20, 2016 and January 31, 2017. A multi-stage stratified cluster sampling was used to select 6596 participants from Makkah, Madinah, Jeddah, and Jizan. Blood samples were drawn from all participants to detect anti-dengue IgG antibodies. A semi-structured questionnaire was used to collect information on demographic, clinical, and environmental data. Multivariate logistic regression was carried out to identify independent risk factors of dengue seropositivity. The dengue seroprevalence (95% confidence intervalI) was 26.7% (25.6%, 27.8%), with the highest (33.6%) and lowest (14.8%) rates in Jizan and Madinah, respectively, and reaching 50% or more in several districts of the four cities. Demographic predictors of seroprevalence included: dwelling in Makkah (odds ratio [OR] = 2.19, p < 0.001) or Jizan (OR = 2.17, p < 0.001); older age (OR = 3.91, p < 0.001 for age>30 years); housing type (OR = 1.84 and 1.82, p < 0.001 for popular and social houses, respectively); and number of household occupants (OR = 0.86 and 0.71 for 6-10 [p = 0.042] and 11-20 [p = 0.002] occupants, respectively). Environmental predictors included the absence of pest control works in residency area (OR = 1.39, p = 0.002), presence of mosquitoes in the home (OR = 1.39, p = 0.001), and absence of awareness campaigns (OR = 1.97, p < 0.001). One in four inhabitants of the Western region of Saudi Arabia was seropositive for the dengue virus. Implementation of behavior-based educational programs is recommended, involving the population in the identification and eradication of vector sources and promoting appropriate behaviors that prevent the spread.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Critical care for dengue in adult patients: an overview of current knowledge and future challenges

PURPOSE OF REVIEW

This review aims to update and summarize the current knowledge about clinical features, management, and risk factors of adult dengue patients requiring intensive care with consequently higher risk of mortality.

RECENT FINDINGS

Increasingly, there are more adult dengue patients who require intensive care. This may be due to a shift in epidemiology of dengue infection from mainly a pediatric disease toward adult disease. In addition, multiorgan dysfunction was observed to be a key risk factor for ICU admission and mortality. This may be due to older adults having preexisting comorbidities that potentially predispose to have multiple severe organ impairment. Interventions remain largely supportive but also require more evidence-based trials and treatment protocols.

SUMMARY

These findings highlight the common clinical manifestations of adult dengue patients and the challenges of clinical management in ICU. Risk factors for prediction of adult dengue patients who require ICU are available, but they lack validation and consistent study design for meta-analysis in future. Early recognition of these risk factors, with close monitoring and prompt clinical management, remains critical to reduce mortality.

Characteristics and predictors for gastrointestinal hemorrhage among adult patients with dengue virus infection: Emphasizing the impact of existing comorbid disease(s)

BACKGROUND

Gastrointestinal (GI) bleeding is a leading cause of death in dengue. This study aims to identify predictors for GI bleeding in adult dengue patients, emphasizing the impact of existing comorbid disease(s).

METHODS

Of 1300 adults with dengue virus infection, 175 (mean age, 56.5±13.7 years) patients with GI bleeding and 1,125 (mean age, 49.2±15.6 years) without GI bleeding (controls) were retrospectively analyzed.

RESULTS

Among 175 patients with GI bleeding, dengue hemorrhagic fever was found in 119 (68%) patients; the median duration from onset dengue illness to GI bleeding was 5 days. Gastric ulcer, erythematous gastritis, duodenal ulcer, erosive gastritis, and hemorrhagic gastritis were found in 52.3%, 33.3%, 28.6%, 28.6%, and 14.3% of 42 patients with GI bleeding who had undergone endoscopic examination, respectively. Overall, nine of the 175 patients with GI bleeding died, giving an in-hospital mortality rate of 5.1%. Multivariate analysis showed age ≥60 years (cases vs. controls: 48% vs. 28.3%) (odds ratio [OR]: 1.663, 95% confidence interval [CI]: 1.128-2.453), end stage renal disease with additional comorbidities (cases vs. controls: 1.7% vs. 0.2%) (OR: 9.405, 95% CI: 1.4-63.198), previous stroke with additional comorbidities (cases vs. controls: 7.4% vs. 0.6%) (OR: 9.772, 95% CI: 3.302-28.918), gum bleeding (cases vs. controls: 27.4% vs. 11.5%) (OR: 1.732, 95% CI: 1.1-2.727), petechiae (cases vs. controls: 56.6% vs. 29.1%) (OR: 2.109, 95% CI: 1.411-3.153), and platelet count <50×109 cells/L (cases vs. controls: 53.1% vs. 25.8%) (OR: 3.419, 95% CI: 2.103-5.558) were independent predictors of GI bleeding in patients with dengue virus infection.

CONCLUSIONS

Our study is the first to disclose that end stage renal disease and previous stroke, with additional comorbidities, were strongly significant associated with the risk of GI bleeding in patients with dengue virus infection. Identification of these risk factors can be incorporated into the patient assessment and management protocol of dengue virus infection to reduce its mortality.

Clinical and Laboratory Profile of Zika and Dengue Infected Patients: Lessons Learned From the Co-circulation of Dengue, Zika and Chikungunya in Brazil

Background: The current triple epidemic caused by dengue, zika and chikungunya constitutes a serious health problem in Brazil. The aim of this study was to investigate acute samples (up to the 7 days of symptoms) from patients presenting acute fever syndrome suspected as arboviral infection and characterize the clinical and laboratorial profile during the co-circulation of dengue, zika and chikungunya in Campo Grande, Mato Grosso do Sul (MS), midwest region of Brazil. Methods: All suspected cases (n=134) were tested by using serological and molecular diagnostic tests including DENV, ZIKV and CHIKV RT-PCR, Dengue nonstructural protein 1 (NS1) antigen capture ELISA, anti- DENV IgM ELISA and anti-CHIKV IgM ELISA. In addition, clinical, hematological and biochemical parameters of infected patients were analyzed. Results: It was observed that 79.1% of the blood samples were confirmed for ZIKV and/or DENV infection Of those, 38.0% patients were DENV monoinfected, 26.8% were ZIKV monoinfected and 13.4% were DENV/ZIKV co-infected. Seven patients presented Chikungunya IgM antibodies indicating a previous CHIKV infection. Common symptoms included fever, rash, arthralgia, myalgia, prostration, headache and conjunctivitis. Statistical analysis showed that pruritus and edema were associated with ZIKV infection while prostration and vomiting were more associated with dengue. Additionally, total protein and ALT levels were significantly different in DENV patients compared to ZIKV ones. Some DENV infected patients as well as co-infected needed hospitalization and venous hydration. Otherwise, most ZIKV infected patients presented mild clinical course. Among the pregnant women studied (n=11), three were ZIKV monoinfected while four were DENV monoinfected and two were DENV-1/ZIKV coinfected. In general, normal birth outcomes were observed except for the death due to respiratory insufficiency of one baby born to a mother coinfected with DENV-1/ZIKV. Conclusions: Herein, we provide evidence of the co-circulation of DENV, ZIKV and CHIKV infections in the Campo Grande, MS, Brazil, with a high frequency of DENV-1/ZIKV coinfection. Laboratorial diagnosis poses a challenge where those arboviruses are endemic and differential diagnosis proved to imperative for cases characterization. The knowledge about disease severity during arbovirus coinfections is still scarce and there are several issues emphasizing the importance of adequate management of patients at risk areas.

Targeted Interventions in Critically Ill Children with Severe Dengue

Background:

The World Health Organization guidelines provide suggestions on early recognition and treatment of severe dengue (SD); however, mortality in this group can be high and is related both to disease severity and the treatment complications.

Subjects and Methods:

In this prospective observational study, we report our results where standard therapy (ST) was enhanced by Intensive Care Unit (ICU) supportive measures that have proven beneficial in other conditions that share similar pathophysiology of capillary leak and fluid overload. These include early albumin for crystalloid-refractory shock, proactive monitoring for symptomatic abdominal compartment syndrome (ACS), application of a high-risk intubation management protocol, and other therapies. We compared outcomes in a matched retrospective cohort who received ST.

Results:

We found improved outcomes using these interventions in patients with the most devastating forms of dengue (ST+ group). We could demonstrate decreased positive fluid balance on days 1–3 and less symptomatic ACS that necessitated invasive percutaneous drainage (7.7% in ST+ group vs. 30% in ST group, P = 0.025). Other benefits in ST+ group included lower intubation and positive pressure ventilation requirements (18.4% in ST+ vs. 53.3% in ST, P = 0.003), lower incidence of major hemorrhage and acute kidney injury, and reduced pediatric ICU stays and mortality (2.6% in ST+ group vs. 26% in ST group, P = 0.004).

Conclusion:

Children with SD with refractory shock are at extremely high mortality risk. We describe the proactive application of several targeted ICU supportive interventions in addition to ST and could show that these interventions resulted in decreased resuscitation morbidity and improved outcomes in SD.

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.

Dengue Virus Serotypes 1 and 2 Responsible for Major Dengue Outbreaks in Nepal: Clinical, Laboratory, and Epidemiological Features

Dengue virus (DENV) is expanding toward previously nonendemic areas. DENV has recently been introduced in Nepal with limited information. We report the clinical features and serotype distribution of DENV in Nepal during the 2010 outbreaks. A total of 1,215 clinical dengue cases at two major hospitals of central and western Nepal were investigated. Demographic, clinical, and laboratory parameters were recorded. Serum specimens were tested for DENV by IgM/IgG enzyme-linked immunosorbent assays (ELISAs) and reverse transcription polymerase chain reaction (RT-PCR). We confirmed DENV infection in 403 (33%) patients from 12 districts with an estimated case fatality rate of 1.5%. DENV infection was more common in adults (87%) and urban settings (74%). We detected all four serotypes but DENV-1 and -2 were mainly responsible for major outbreaks (92%). Overall, 60% of all DENV infections were secondary and 17% were severe dengue; both being more frequent among the DENV-2 infections. Rash, bleeding, abdominal pain, hepatomegaly, elevated liver enzymes, and thrombocytopenia were significantly more common in severe dengue compared with nonsevere infections. We also confirmed the expansion of dengue to hill urban areas (DENV-1 and -2), including the capital Kathmandu (altitude, 1,300 m) though > 90% cases were from southern plains. Differential clinical and laboratory features probably help in clinical decisions. Multiple serotypes circulation and elevated secondary infections pose potential risk of severe outbreaks and deaths in the future. Therefore, a country with recent dengue introduction, like Nepal, urgently requires a systematic surveillance and appropriate control measures in place to respond to any disastrous outbreaks.

Clinical Audit of Dengue Related Deaths in 2011-Mayo Hospital Lahore Pakistan

Background and Objective:

Dengue infection has evolved into an epidemic during last few years in Pakistan and has been associated with poor outcomes. Literature with respect to mortality risk factors in Dengue infection is not sufficient. This compelled us to conduct this study to find out major contributory factors to death in patients with dengue viral infection at one of Asia’s ancient hospital setting with an aim to recognize complications at earliest and improve case management in future.

Methods:

A retrospective observational study of 95 adult dengue deaths was performed at Mayo Hospital Lahore from July 1st 2011 to 31st December 2011 during a major dengue epidemic. Patients who tested positive by dengue IgM in the presence of acute fever fulfilling the World Health Organization criteria for Dengue Fever, Dengue Hemorrhagic Fever or Dengue Shock Syndrome and died within same setting, were included. Data regarding demographic profile, clinical and laboratory parameters along with treatment details were obtained and analysed. All records examined were anonymized.

Results:

Median age was 36 years (range13-80 years) among 95 deaths due to Dengue. Male gender comprised 60 (63.1%). Co-morbidities existed in 74 (77.9%) with hypertension in 21 (22.1%) diabetes in 11 (11.58%), liver disease in 9 (9.47%) and ischemic heart disease in 8(8.4%) cases. Patients presented at second day of fever for admission (range 1-8 days) and death occurred at a median of 4 days (range 30 minutes to 23 days). Hospital stay was for less than a week for seventy nine (83.2%) patients and 16 (16.8%) were admitted for more than 7 days. Critical care was required in 67(71%). Severe hepatitis occurred in 41 (43.1%), acute renal impairment occurred in 32 (33.7%) and disseminated intravascular coagulation in 16 (16.8%). Deaths were due to prolonged shock 49 (51.5%) fluid overload 46 (48.4%) and massive bleeding 18(19%) leading to organ failure.

Conclusion:

Decompensated shock complicated by either massive plasma leakage, frank bleeding, multi organ failure or deranged clotting profile results in enhanced mortality in Dengue infection. Co-morbidities especially Diabetes are poor prognostic factors in predicting Dengue mortality.

Prothrombin Time Prolongation was the Most Important Indicator of Severe Bleeding in Children with Severe Dengue Viral Infection

To determine the indicators of severe bleeding in children with severe dengue viral infection (DVI), the medical records of patients aged <15 years admitted to Songklanagarind Hospital in southern Thailand during 1989-2011 were reviewed. Severe-bleeding DVI was defined as needing blood products transfusion owing to DVI-caused bleeding. Of the 238 children with severe DVI according to the World Health Organization 2009 criteria, 44 (18.5%) had severe bleeding, of whom 28 (63.6%) died. The international normalized ratio (INR) had high correlations with both transaminase enzymes (Spearman correlation, rs = 0.67-0.69, p <0.01). Multivariate analysis found that patients who had dengue haemorrhagic fever (DHF) grade IV, platelets <20 000/mm3 and INR ≥ 1.5 had increased risk of severe bleeding with odds ratios (95% confidence intervals) of 3.4 (1.4, 8.6), 2.6 (1.1, 6.2) and 10.6 (4.0, 28.4), respectively. Blood products should be at hand in severe DHF children with high risk of severe bleeding.

Differences in Mortality and Clinical Manifestations of Dengue Hemorrhagic Fever in Taiwan in Different Years: A Comparison for Cases in 2014 and 2015 Epidemics

People in southern Taiwan experienced two major dengue outbreaks in 2014 and 2015. The mortality and clinical features were very different between these 2 years. Dengue virus serotype 1 (DENV-1) caused epidemic outbreak in 2014 and DENV-2 was predominant in 2015. The characteristics of dengue hemorrhagic fever (DHF) cases in the 2 years was analyzed. We conducted a retrospective chart review to analyze the clinical and laboratory features of 206 adult patients with DHF in southern Taiwan in 2014 and 2015. The mortality rate of DHF cases in 2015 was higher than that of cases in 2014 (38.7% versus 12.4%, P < 0.0001). Compared with cases in 2014, DHF cases in 2015 had more complications, such as gastrointestinal bleeding (78.5% versus 61.9%, P = 0.01), severe hepatitis (30.1% versus 8%, P < 0.0001), and myocarditis (14% versus 0.9%, P < 0.0001). Among the mortality cases, diabetes, chronic renal failure, proton-pump inhibitors using, platelet transfusion, and Charlson comorbidity index score (Charlson score) were also higher in 2015. Multivariate analysis for the mortality cases revealed that the risk factors were Charlson score ≥ 5 (P = 0.02, odds ratio [OR] = 4.07, 95% confidence interval [CI] = 1.244-13.307), severe hepatitis (P < 0.0001, OR = 11.97, 95% CI = 3.831-37.396), and acute renal failure (P < 0.0001, OR = 98.76, 95% CI = 10.847-899.22). DHF cases in 2015 had higher mortality and more complications, such as gastrointestinal bleeding, severe hepatitis, and myocarditis, than in 2014 in southern Taiwan. In the 2-year DHF case series, Charlson score ≥ 5, severe hepatitis, and acute renal failure were independent significant variables for mortality.

Analyses of clinical and laboratory characteristics of dengue adults at their hospital presentations based on the World Health Organization clinical-phase framework: Emphasizing risk of severe dengue in the elderly

BACKGROUND/PURPOSE

Dengue clinically dynamically changes over time; the World Health Organization (WHO) dengue classification framework proposed 3 dengue clinical phases-febrile (days 1-3), critical (days 4-6) and recovery (days ≥7) phases. This study aimed to better understand clinical and laboratory characteristics in adults (≥18 years) suffering dengue in different clinical phases at their hospital presentations.

METHODS

A retrospective analysis of adults suffering dengue between 2008 and 2014.

RESULTS

Of the 669 included dengue adults, 146 (21.8%) were elderly (≥65 years), and 27 (4%) suffered severe dengue. When compared with those in febrile phase, significantly higher incidence of ascites, mucosal bleeding, and/or gastrointestinal bleeding; lower white blood cell (WBC) and platelet counts; higher hematocrit, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) values were found in critical phase. When compared with their younger counterparts, elderly at febrile phase had significantly lower frequencies of bone pain, myalgia, headache and rash; higher frequencies of vomiting, pleural effusion and mucosal bleeding; higher WBC count, AST and ALT levels, and lower platelet count; in critical phase, elderly had significantly higher frequencies of pleural effusion, mucosal bleeding and gum bleeding. Four (0.6%) patients experienced severe dengue in recovery phase. Significantly higher proportions of elderly developed severe dengue in both febrile and critical phases as compared with younger adults.

CONCLUSIONS

Elderly had lower frequency of classical dengue symptoms, yet were at higher risk of development of severe dengue during their early dengue course. A small number of patients developed severe dengue at the WHO-proposed recovery phase.

Risk factors and clinical outcome of profound thrombocytopenia in adult patients with DENV infections

Severe thrombocytopenia is common in dengue virus (DENV) infections. However, studies focusing on the role of profound thrombocytopenia (PT) (nadir platelet counts ≤ 20 000/mm³) in DENV infections are scarce. This study aims to identify the associated features and outcome of DENV patients with PT. It involves 237 adult hospitalized patients who were DENV PCR positive. The presence of comorbidity (AOR = 4.625; 95% CI = 1.113-19.230), higher admission hematocrit (AOR = 1.213; 95% CI = 1.067-1.379), lower admission albumin (AOR = 0.870; 95% CI = 0.766-0.988) and lower admission platelets (AOR = 0.980; 95% CI = 0.969-0.991) was associated with platelets ≤ 20 000/mm³ in multivariate logistic regression. PT was not affected by DENV serotypes, coinfections and secondary DENV infections. Patients with PT had significantly higher risk of experiencing warning signs (AOR = 3.709, 95% CI = 1.089-12.634) and longer hospital stay (AOR = 1.943, 95% CI = 1.010-3.774). However, severe dengue disease, hemorrhagic manifestations and need for intensive care were not significantly associated with PT.

Dengue virus infection increases microglial cell migration

Activated microglial cells are present in dengue virus (DENV)-infected brains; however, the possible effects of DENV on microglia remain unclear. Here, we demonstrated DENV caused infection, including viral entry, RNA replication, viral protein expression, and virus release, in the murine microglial cell line BV2. DENV infection caused an increase in the formation of the multipolar phenotype in vitro and in vivo without affecting cell growth and cytotoxicity. DENV infection considerably increased cell motility and disrupting either actin filaments or clathrin retarded such effect. Increase in cell migration was only occurred by DENV infection following a clathrin-regulated endocytosis of DENV entry. Ultraviolet-inactivated DENV did not affect cell migration, and pharmacologically blocking toll-like receptor (TLR) 3 and TLR3-related signaling pathways reduced the DENV-induced increase in cell migration. These results demonstrate an advanced effect of DENV infection on microglial migration via a mechanism involving viral entry, RNA release, and TLR3 signal activation.

Hepatitis and thrombocytopenia: markers of dengue mortality

Dengue fever is of great concern to public health in India as it contributes significantly to the burden of healthcare. The aim of our study was to measure mortality in dengue and its association with hepatitis and thrombocytopenia. Our study was performed in a tertiary care setting in the state of Kerala in southern India. Adult patients admitted in the year 2013 were included. Among 1308 confirmed dengue patients, the mortality rate was 1.76%. Hepatitis and thrombocytopenia were present in over 80% of all patients, but severe hepatitis was seen in 11.4% and severe thrombocytopenia in 9.3%. These were markers of fatal outcome. Other factors significantly associated with mortality were age >60 years, male sex, diabetes and the presence of any co-morbidity.

A New Look at an Old Disease: Recent Insights into the Global Epidemiology of Dengue

PURPOSE OF REVIEW

By all measures, the morbidity and mortality due to dengue are continuing to worsen worldwide. Although both early and recent studies have demonstrated regional differences in how dengue affects local populations, these findings were to varying extents related to disparate surveillance approaches.

RECENT FINDINGS

Recent studies have broadened the recognized spectrum of disease resulting from DENV infection, particularly in adults, and have also demonstrated new mechanisms of DENV spread both within and between populations. New results regarding the frequency and duration of homo- and heterotypic anti-DENV antibodies have provided important insights relevant to vaccine design and implementation.

SUMMARY

These observations and findings as well as difficulties in comparing the epidemiology of dengue within and between regions of the world underscore the need for population-based dengue surveillance worldwide. Enhanced surveillance should be implemented to complement passive surveillance in countries in the tropics to establish baseline data in order to define affected populations and evaluate the impact of dengue vaccines and novel vector control interventions.

Acute transverse myelitis and subacute thyroiditis associated with dengue viral infection: A case report and literature review

Acute transverse myelitis is a rare manifestation of dengue infection. To the best of our knowledge, only 6 cases of acute transverse myelitis as a manifestation of dengue infection have been reported thus far. The present study described a case of acute transverse myelitis complicated with subacute thyroiditis 6 days after the onset of dengue viral infection. In addition, the available literature was searched to identify similar previous cases. Treatment with intravenous pulse methylprednisolone immunoglobulin plasmapheresis and physiotherapy resulted in partial recovery at 3 months post-infection. In conclusion, the involvement of dengue infection should be considered in patients who develop central nervous system manifestations during or after the recovery period of dengue infection. Furthermore, since methylprednisolone and immunoglobulin are effective during the active phase of the infection, prompt diagnosis and initiation of treatment are crucial.

Bacterial coinfections in dengue virus disease: what we know and what is still obscure about an emerging concern

PURPOSE

Dengue virus is the most frequent arthropod-borne viral infection worldwide. Simultaneously to the growth of its incidence, cases of bacterial coinfection in dengue have been increasingly reported. The clinical course of dual infections may worsen for reciprocal interactions and delays in the diagnosis, so that clinicians should be aware of this eventuality. Therefore, we reviewed literature to provide an overview of the epidemiological, clinical, and physiopathological issues related to bacterial coinfections and bacteremia in dengue.

METHODS

Clinical studies and case reports regarding bacteremia and bacterial coinfections in dengue and the interactions between the pathogens published on PubMed were reviewed.

RESULTS

We found 26 case reports, only 3 studies on concurrent bacteremia and 12 studies reporting data on bacterial coinfections in dengue. According to the three available studies, the 0.18-7 % of dengue infections are accompanied by concurrent bacteremia, while the 14.3-44.4 % of dengue-related deaths seem associated to bacterial coinfections. Comorbidities, advanced age, and more severe dengue manifestations could be risk factors for dual infections. A longer duration of fever and alterations in laboratory parameters such as procalcitonin, hyponatremia, leukocyte count, and renal function tests can raise the suspicion.

CONCLUSIONS

Despite the real burden and consequences of this emerging concern is still not computable accurately due to the lack of a significant number of studies on large cohorts, clinicians need a greater awareness about it to early recognize warning signs, to properly use available diagnostic tools and to readily start antibiotic treatment able to prevent worsening in mortality and morbidity.

Microglia retard dengue virus-induced acute viral encephalitis

Patients with dengue virus (DENV) infection may also present acute viral encephalitis through an unknown mechanism. Here, we report that encephalitic DENV-infected mice exhibited progressive hunchback posture, limbic seizures, limbic weakness, paralysis, and lethality 7 days post-infection. These symptoms were accompanied by CNS inflammation, neurotoxicity, and blood-brain barrier destruction. Microglial cells surrounding the blood vessels and injured hippocampus regions were activated by DENV infection. Pharmacologically depleting microglia unexpectedly increased viral replication, neuropathy, and mortality in DENV-infected mice. In microglia-depleted mice, the DENV infection-mediated expression of antiviral cytokines and the infiltration of CD8-positive cytotoxic T lymphocytes (CTLs) was abolished. DENV infection prompted the antigen-presenting cell-like differentiation of microglia, which in turn stimulated CTL proliferation and activation. These results suggest that microglial cells play a key role in facilitating antiviral immune responses against DENV infection and acute viral encephalitis.

Characteristics and Risk Factors for Fatality in Patients with Dengue Hemorrhagic Fever, Taiwan, 2014

An unprecedented dengue outbreak involving more than 15,000 infections, including 136 dengue hemorrhagic fever (DHF) cases and 20 fatalities, occurred in Taiwan in 2014. The median age of the DHF cases was 71 years (range: 4-92 years) and most of them (N = 100, 73.5%) had comorbidities, of which the majority were hypertension (56%) and diabetes mellitus (DM; 27%). Only approximately half of the DHF cases (59/136) were classified as severe dengue, based on the 2009 WHO-revised dengue classification. The fatality rate for this DHF outbreak was 14.7%. DM (odds ratio [OR] = 3.60, 95% confidence interval [CI] = 1.22-10.63) and presentation with severe plasma leakage (OR = 6.42, 95% CI = 1.76-23.63) were independent risk factors for fatality.

Development of a Simple Clinical Risk Score for Early Prediction of Severe Dengue in Adult Patients

We aimed to develop and validate a risk score to aid in the early identification of laboratory-confirmed dengue patients at high risk of severe dengue (SD) (i.e. severe plasma leakage with shock or respiratory distress, or severe bleeding or organ impairment). We retrospectively analyzed data of 1184 non-SD patients at hospital presentation and 69 SD patients before SD onset. We fit a logistic regression model using 85% of the population and converted the model coefficients to a numeric risk score. Subsequently, we validated the score using the remaining 15% of patients. Using the derivation cohort, two scoring algorithms for predicting SD were developed: models 1 (dengue illness ≤4 days) and 2 (dengue illness >4 days). In model 1, we identified four variables: age ≥65 years, minor gastrointestinal bleeding, leukocytosis, and platelet count ≥100×10⁹ cells/L. Model 1 (ranging from −2 to +6 points) showed good discrimination between SD and non-SD, with an area under the receiver operating characteristic curve (AUC) of 0.848 (95% confidence interval [CI], 0.771–0.924). The optimal cutoff value for model 1 was 1 point, with a sensitivity and specificity for predicting SD of 70.3% and 90.6%, respectively. In model 2 (ranging from 0 to +3 points), significant predictors were age ≥65 years and leukocytosis. Model 2 showed an AUC of 0.859 (95% CI, 0.756–0.963), with an optimal cutoff value of 1 point (sensitivity, 80.3%; specificity, 85.8%). The median interval from hospital presentation to SD was 1 day. This finding underscores the importance of close monitoring, timely resuscitation of shock including intravenous fluid adjustment and early correction of dengue-related complications to prevent the progressive dengue severity. In the validation data, AUCs of 0.904 (95% CI, 0.825–0.983) and 0.917 (95% CI, 0.833–1.0) in models 1 and 2, respectively, were achieved. The observed SD rates (in both cohorts) were <3% for patients with a score <1 point, but >50% for those with a score of ≥2 points, irrespective of the day of illness onset, suggesting that our simple risk score can be easily implemented in resource-limited countries for early prediction of dengue patients at risk of SD provided that they have rapid dengue confirmed tests. For patients with other acute febrile illnesses or bacterial infections usually have SD risk score of >1. Thus, these scoring algorithms cannot totally replace good clinical judgement of the physician, and most importantly, early differentiating dengue from other febrile illnesses is critical for appropriate monitoring and management.

Identifying Adult Dengue Patients at Low Risk for Clinically Significant Bleeding

BACKGROUND

Clinically significant bleeding is important for subsequent optimal case management in dengue patients, but most studies have focused on dengue severity as an outcome. Our study objective was to identify differences in admission parameters between patients who developed clinically significant bleeding and those that did not. We sought to develop a model for discriminating between these patients.

METHODS

We conducted a retrospective study of 4,383 adults aged >18 years who were hospitalized with dengue infection at Tan Tock Seng Hospital, Singapore from 2005 to 2008. Patients were divided into those with clinically significant bleeding (n = 188), and those without (n = 4,195). Demographic, clinical, and laboratory variables on admission were compared between groups to determine factors associated with clinically significant bleeding during hospitalization.

RESULTS

On admission, female gender (p<0.001); temperature >38°C (p<0.001); nausea/vomiting (p = 0.009) and abdominal pain/tenderness (p = 0.005); lower systolic blood pressure (p<0.001); higher pulse rate (p<0.001); increased absolute neutrophil count (ANC; p<0.001); reduced absolute lymphocyte count (ALC; p<0.001), haematocrit percentage (p<0.001) and platelet count (p = 0.04), and increased prothrombin time (p = 0.003) were significantly associated with clinically significant bleeding on univariate analysis. Multivariate analysis showed that independent variables in the final model were female gender (aOR 2.85; 95% CI: 1.9-4.33); temperature >38°C (aOR 1.81; 95% CI: 1.27-2.61), nausea/vomiting (aOR 1.39; 95% CI: 0.94-2.12), ANC (aOR 1.3; 95% CI: 1.15-1.46), ALC (aOR 0.4; 95% CI: 0.25-0.64), hematocrit percentage (aOR 0.96; 95% CI: 0.92-1.002) and platelet count (aOR 0.993; 95% CI: 0.988-0.998). At the cutoff of -3.919, the model achieved an AUC of 0.758 (sensitivity:0.87, specificity: 0.38, PPV: 0.06, NPV: 0.98).

CONCLUSION

Clinical risk factors associated with clinically significant bleeding were identified. This model may be useful to complement clinical judgement in triaging adult dengue patients given the dynamic nature of acute dengue, particularly in pre-identifying those less likely to develop clinically significant bleeding.

Metabolomics-Based Discovery of Small Molecule Biomarkers in Serum Associated with Dengue Virus Infections and Disease Outcomes

BACKGROUND

Epidemic dengue fever (DF) and dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS) are overwhelming public health capacity for diagnosis and clinical care of dengue patients throughout the tropical and subtropical world. The ability to predict severe dengue disease outcomes (DHF/DSS) using acute phase clinical specimens would be of enormous value to physicians and health care workers for appropriate triaging of patients for clinical management. Advances in the field of metabolomics and analytic software provide new opportunities to identify host small molecule biomarkers (SMBs) in acute phase clinical specimens that differentiate dengue disease outcomes.

METHODOLOGY/PRINCIPAL FINDINGS

Exploratory metabolomic studies were conducted to characterize the serum metabolome of patients who experienced different dengue disease outcomes. Serum samples from dengue patients from Nicaragua and Mexico were retrospectively obtained, and hydrophilic interaction liquid chromatography (HILIC)-mass spectrometry (MS) identified small molecule metabolites that were associated with and statistically differentiated DHF/DSS, DF, and non-dengue (ND) diagnosis groups. In the Nicaraguan samples, 191 metabolites differentiated DF from ND outcomes and 83 differentiated DHF/DSS and DF outcomes. In the Mexican samples, 306 metabolites differentiated DF from ND and 37 differentiated DHF/DSS and DF outcomes. The structural identities of 13 metabolites were confirmed using tandem mass spectrometry (MS/MS). Metabolomic analysis of serum samples from patients diagnosed as DF who progressed to DHF/DSS identified 65 metabolites that predicted dengue disease outcomes. Differential perturbation of the serum metabolome was demonstrated following infection with different DENV serotypes and following primary and secondary DENV infections.

CONCLUSIONS/SIGNIFICANCE

These results provide proof-of-concept that a metabolomics approach can be used to identify metabolites or SMBs in serum specimens that are associated with distinct DENV infections and disease outcomes. The differentiating metabolites also provide insights into metabolic pathways and pathogenic and immunologic mechanisms associated with dengue disease severity.

Concurrent infections of dengue viruses serotype 2 and 3 in patient with severe dengue from Jakarta, Indonesia

OBJECTIVE

To describe the clinical manifestation of patient with severe dengue, to identify the serotypes and genotypes of dengue viruses (DENV) which concurrently infecting the patient, and to explore the possible relationship of severe dengue with the concurrent infection of DENV.

METHODS

Dengue diagnosis was performed using NS1 antigen detection and IgG/IgM ELISA. Standard clinical and laboratory examinations were performed to obtain the clinical and hematological data. DENV concurrent infections were detected and confirmed using RT-PCR and DENV Envelope gene sequencing. Phylogenetic analyses were performed to determine the genotypes of the viruses.

RESULTS

The patient was classified as having severe dengue characterized by severe plasma leakage, hemorrhage, and organ damage involving lung, liver, and kidney. Concurrent infection of DENV serotype 2 and 3 was observed. The infecting DENV-2 virus was grouped into Cosmopolitan genotype while DENV-3 virus was classified into Genotype I. Both viruses were closely related to isolates that were endemic in Jakarta. Viremia measurement was conducted and revealed a significantly higher virus titer of DENV-3 compared to DENV-2.

CONCLUSIONS

The occurrence of multi-serotype DENV infections was presented in a patient with severe clinical manifestation in Indonesia. The hyperendemicity of dengue in Indonesia may contribute to the DENV concurrent infections cases and may underlie the severity of the disease.