Prognostic values of serum lactate-to-bicarbonate ratio and lactate for predicting 28-day in-hospital mortality in children with dengue shock syndrome

This study aimed to assess the clinical utility of blood lactate-to-bicarbonate (L/B) ratio, as a prognostic factor for 28-day in-hospital mortality in children with dengue shock syndrome (DSS), admitted to the pediatric intensive care unit (PICU). This single-center retrospective study was conducted at a tertiary children hospital in southern Vietnam from 2013 to mid-2022. Prognostic models for DSS mortality were developed, using a predefined set of covariates in the first 24 hours of PICU admission. Area under the curves (AUCs), multivariable logistic and Least Absolute Shrinkage and Selection Operator (LASSO) regressions, bootstrapping and calibration slope were performed. A total of 492 children with DSS and complete clinical and biomarker data were included in the analysis, and 26 (5.3%) patients died. The predictive values for DSS mortality, regarding lactate showing AUC 0.876 (95% CI, 0.807-0.944), and that of L/B ratio 0.867 (95% CI, 0.80-0.934) (P values of both biomarkers < .001). The optimal cutoff point of the L/B ratio was 0.25, while that of lactate was 4.2 mmol/L. The multivariable model showed significant clinical predictors of DSS fatality including severe bleeding, cumulative amount of fluid infused and vasoactive-inotropic score (>30) in the first 24 hours of PICU admission. Combined with the identified clinical predictors, the L/B ratio yielded higher prognostic values (odds ratio [OR] = 8.66, 95% confidence interval [CI], 1.96-38.3; P < .01) than the lactate-based model (OR = 1.35, 95% CI, 1.15-1.58; P < .001). Both the L/B and lactate models showed similarly good performances. Considering that the L/B ratio has a better prognostic value than the lactate model, it may be considered a potential prognostic biomarker in clinical use for predicting 28-day mortality in PICU-admitted children with DSS.

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

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

Serum IL-18 Is a Potential Biomarker for Predicting Severe Dengue Disease Progression

Background. Dengue virus (DENV) infection is the most common arboviral disease that affects tropical and subtropical regions. Based on the clinical hallmarks, the different severities of patients range from mild dengue fever (MDF) to severe dengue diseases (SDDs) and include dengue hemorrhagic fever or dengue shock syndrome. These are commonly associated with cytokine release syndrome (CRS). The types and levels of cytokines/chemokines, which are suppressed or enhanced, are varied, indicating CRS's pathogenic and host defensive effects. Principal Finding. In this study, we created an integrated and precise multiplex panel of cytokine/chemokine assays based on our literature analysis to monitor dengue CRS. A 24-plex panel of cytokines/chemokines was evaluated to measure the plasma levels of targeting factors in dengue patients with an MDF and SDD diagnosis without or with comorbidities. As identified in sixteen kinds of cytokines/chemokines, ten were significantly (P < 0.05) (10/16) increased, one was significantly (P < 0.01) (1/16) decreased, and five were potentially (5/16) altered in all dengue patients (n = 30) in the acute phase of disease onset. Compared to MDF, the levels of IL-8 (CXCL-8) and IL-18 in SDD were markedly (P < 0.05) increased, accompanied by positively increased IL-6 and TNF-α and decreased IFN-γ and RANTES. With comorbidities, SDD significantly (P < 0.01) portrayed elevated IL-18 accompanied by increased IL-6 and decreased IFN-α2 and IL-12. In addition, decreased platelets were significantly (P < 0.05) associated with increased IL-18. Significance. These results demonstrate an efficient panel of dengue cytokine/chemokine assays used to explore the possible level of CRS during the acute phase of disease onset; also, we are the first to report the increase of IL-18 in severe dengue with comorbidity compared to severe dengue without comorbidity and mild dengue.

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

BACKGROUND

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

METHODOLOGY

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

PRINCIPAL FINDINGS

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

CONCLUSION

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

Multi-Tissue Transcriptomic-Informed In Silico Investigation of Drugs for the Treatment of Dengue Fever Disease

Transcriptomics, proteomics and pathogen-host interactomics data are being explored for the in silico–informed selection of drugs, prior to their functional evaluation. The effectiveness of this kind of strategy has been put to the test in the current COVID-19 pandemic, and it has been paying off, leading to a few drugs being rapidly repurposed as treatment against SARS-CoV-2 infection. Several neglected tropical diseases, for which treatment remains unavailable, would benefit from informed in silico investigations of drugs, as performed in this work for Dengue fever disease. We analyzed transcriptomic data in the key tissues of liver, spleen and blood profiles and verified that despite transcriptomic differences due to tissue specialization, the common mechanisms of action, “Adrenergic receptor antagonist”, “ATPase inhibitor”, “NF-kB pathway inhibitor” and “Serotonin receptor antagonist”, were identified as druggable (e.g., oxprenolol, digoxin, auranofin and palonosetron, respectively) to oppose the effects of severe Dengue infection in these tissues. These are good candidates for future functional evaluation and clinical trials.

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

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

Clinical and laboratorial profiles of dengue virus infection in kidney transplant recipients: Report of a single center

Dengue infection (DI) is the most important arboviral infection in the world. The majority of immunocompetent patients will have asymptomatic or mild infections, but the degree of dengue severity in kidney transplant recipients (KTx) is unknown. In this study, we report the clinical profile and outcomes of 39 dengue cases in KTx. From a total of 1,186 KTx outpatients in follow-up we reviewed clinical and laboratory records of 60 (5%) patients admitted with suspected DI initially screened by NS-1, IgM, and when possible, multiplex nested PCR. The prevalence of DI in KTx was 3% (39/1,118), with symptoms leading to hospital admission being fever, myalgia, malaise, and headache. Laboratory tests showed leucopenia, thrombocytopenia, and liver enzyme elevation. DI was confirmed by positivity of NS-1 (33%), IgM (69%), and/or RT-PCR (59%). Twenty-three patients (59%) had dengue with warning signs, and 15% had severe dengue, 2 of them with a fatal course. Acute graft dysfunction occurred in 59% (mean nadir serum creatinine: 2.9 ± 2.6mg/dL), 4 of them requiring dialysis. CMV coinfection diagnosed in 19% of the cases and patients was associated with worse clinical presentation. Our results suggest that KTx with DI presented initial physical and laboratorial profile similar to the general population. However, DI in KTx seems to have a higher risk for graft dysfunction, severe dengue, and death. Because CMV coinfection aggravates the DI clinical presentation and recovery, it must be evaluated in all cases.

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).

Evaluation of biochemical and haematological changes in dengue fever and dengue hemorrhagic fever in Sri Lankan children: a prospective follow up study

BACKGROUND

Series of biochemical and haematological changes occur during the course of dengue infection, which vary depending on the clinical disease. The patterns of change are not well documented and identifying these patterns in children with dengue infection would help to anticipate the progression to different clinical stages thus enabling effective management.

METHODS

A prospective follow up study was conducted during the period of July 2013 - April 2014 at Professorial Pediatric unit, Lady Ridgeway Hospital for Children, Colombo, Sri Lanka. Children (5-12 years) admitted within the first 84 h of fever, with a clinical diagnosis of dengue infection were recruited. Children who became positive for dengue IgM were included in the final analysis. Blood was collected on admission for complete blood count, Alanine aminotransferase, Aspartate aminotransferase, albumin, cholesterol and corrected calcium. These tests were repeated at 12 hourly intervals during the hospital stay.

RESULTS

Data of 130-subjects were analyzed (Dengue fever /Dengue hemorrhagic fever: 100/30). There was a significant difference in the pattern of white cell counts, platelets and haematocrit in the two clinical groups. Both transaminase rose initially in both dengue fever and dengue hemorrhagic fever and a steep rise were seen between 8th and 9th days in hemorrhagic fever. Both albumin and cholesterol decreased significantly at the time of entering into the critical phase. According to Receiver operating characteristic curve analysis, albumin level crossing 37.5g/L (sensitivity 86.7%, specificity 77.8%) and a 0.38 mmol/L reduction in cholesterol level (sensitivity 77.3%, specificity 71.9%) between day 3 and 4 were the best predictors of entering into critical phase. Calcium levels did not show any distinct pattern.

CONCLUSIONS

There is a clear difference in the pattern of change of both hematological and biochemical parameters in dengue fever and dengue hemorrhagic fever. Reduction in albumin and cholesterol levels seen between the completion of day 3 and day 4 were highly valid predictors of entering into critical phase in dengue hemorrhagic fever.

The role of lipids in the inception, maintenance and complications of dengue virus infection

Dengue fever is a viral condition that has become a recurrent issue for public health in tropical countries, common endemic areas. Although viral structure and composition have been widely studied, the infection phenotype in terms of small molecules remains poorly established. This contribution providing a comprehensive overview of the metabolic implications of the virus-host interaction using a lipidomic-based approach through direct-infusion high-resolution mass spectrometry. Our results provide further evidence that lipids are part of both the immune response upon Dengue virus infection and viral infection maintenance mechanism in the organism. Furthermore, the species described herein provide evidence that such lipids may be part of the mechanism that leads to blood-related complications such as hemorrhagic fever, the severe form of the disease.

Early Detection of Plasma Leakage in Dengue Hemorrhagic Fever

Dengue viral infection remains a major public health problem. As many as 400 million people are infected yearly. Even though the vaccine is available, the use of dengue vaccine is still limited due to some concerns. Among patient infected with dengue viral infection, early recognition of the virus and prompt supportive treatment are important to avoid complication and mortality.The clinical spectrum of dengue viral infection is diverse ranging from undifferentiated fever to dengue shock syndrome characterized by plasma leak and hemoconcentration. No specific antiviral therapy is available. Therefore, anticipation of complication should be performed adequately.The most dangerous complication of dengue infection is shock syndrome. Hypothetically the occurrence of shock is a result of secondary viral infection. The manifestation of increased vascular permeability and low intravascular volume lead to the development of shock. In addition to that, another complex mechanism underlies the occurrence of shock such as endothelial dysfunction that could happened abruptly. No specific method exists to identify this condition as early as possible.During dengue infection, fever can be last between 2 and 7 days. The localized plasma leakage could happen and manifested as a pleural effusion fluid accumulation in abdominal cavity or hemoconcentration. This will only last for 48 hours and will be resolved later spontaneously. Severity of leakage varies among patients and the unanticipated of leakage due to failure to recognize and treat this manifestation related to mortality.Most of the fatal cases of dengue are related to late detection of the illness as shown by massive hemorrhage and severe intravascular volume depletion. The role of dendritic cells is as the initiator of immune response that facilitate virus uptake. On the other hand, the non-neutralize cross reactive antibodies will increase virus uptake and resulted in more viral replication. Some studies showed higher NS1 protein were found in patients with more severe disease. In addition to that antibody to NS1 could bind to the endothelial cells and lead to apoptosis of these cells. Both host and viral factors contribute to the severity of the illness.One of the important factors for dengue viral infection is the capacity of clinicians to identify the risk factors for shock. Studies reported that female, infants, elderly, patients with concomitant diseases are prone to have more severe infection. Virus serotype and genetic susceptibility may also contribute but the evidence is still limited. So, those are not sensitive enough be used in clinical setting.Besides those, after the diagnosis of with dengue infection based on WHO criteria and confirmation by serology detection or viral material in the blood, no specific sign and symptoms are available to determine any potential severity. There were studies performed to monitor the plasma leakage using mean arterial blood pressure (MAP) instead of hematocrit values. Rapid intervention can be administered by monitoring MAP to avoid deleterious consequences.The classification of WHO 1997 or 2009 were not able to detect the plasma leakage earlier. Nainggolan et al presented the resulted of their observation among early dengue infection which was the occurrence of gallbladder wall thickening as a manifestation of plasma leakage. Ultrasonographic measurement is valuable and applicable to detect plasma leakage in earlier phase with positive likelihood ratio 2.14 (95% CI 1.12 - 4.12). Similar report from Indonesia also showed the role of ultrasonography in dengue.

Dengue fever. Clinical features of 567 consecutive patients admitted to a tertiary care center in Saudi Arabia

OBJECTIVES

To delineate the clinical features and outcomes of dengue infection and to guide clinician of early diagnosis and identification of risks factors for dengue hemorrhagic fever. Methods: This study is a retrospective cross-sectional. Clinical records of 567 patients with a confirmed diagnosis of dengue infection, admitted to a single hospital in Jeddah, Saudi Arabia, between January 2010 and  June 2014 were reviewed.  Results: Dengue infection was most common in adult males. Sixty-eight percent of infections were in Saudi nationals. In addition to the diagnostic clinical features, leucopenia and thrombocytopenia were typical of dengue infection. Approximately 4.1% of adult patients and 7.1% of pediatric patients developed dengue hemorrhagic fever (DHF). Abdominal pain and vomiting were more common in patients developing DHF. Mean platelet count was lower in adult, but not pediatric patients developing DHF. Peak alanine aminotransferase (ALT) was higher in adult and pediatric patients developing DHF. Three patients died, 2 of them developed DHF. Ninety-eight percent of adult patients and 92% of pediatric patients made a full recovery. Conclusions:   Dengue infection is common in Jeddah.  Abdominal pain and vomiting, thrombocytopenia, and elevated ALT are typical of severe infection, which is more likely to be associated with significant morbidity and mortality.

Chymase Level Is a Predictive Biomarker of Dengue Hemorrhagic Fever in Pediatric and Adult Patients

Background

Most patients with dengue experience mild disease, dengue fever (DF), while few develop the life-threatening diseases dengue hemorrhagic fever (DHF) or dengue shock syndrome (DSS). No laboratory tests predict DHF or DSS. We evaluated whether the serum chymase level can predict DHF or DSS in adult and pediatric patients and the influence of preexisting conditions (PECs) on chymase levels.

Methods

Serum chymase levels were measured in patients presenting with undifferentiated fever to hospitals in Colombo District, Sri Lanka. The value of serum the chymase concentration and clinical signs and symptoms as predictors of DHF and/or DSS was evaluated by multivariate analysis. We assessed the influence of age, PECs, and day after fever onset on the robustness of the chymase level as a biomarker for DHF and/or DSS.

Results

An elevated chymase level in acute phase blood samples was highly indicative of later diagnosis of DHF or DSS for pediatric and adult patients with dengue. No recorded PECs prevented an increase in the chymase level during DHF. However, certain PECs (obesity and cardiac or lung-associated diseases) resulted in a concomitant increase in chymase levels among adult patients with DHF.

Conclusions

These results show that patients with acute dengue who present with high levels of serum chymase consistently are at greater risk of DHF. The chymase level is a robust prognostic biomarker of severe dengue for adult and pediatric patients.

Potential of Nigella sativa seed aqueous extract in ameliorating quinine-induced thrombocytopenia in rats

Dengue infection is rapidly spreading in most of the countries of south Asia. It is of utmost importance to explore the plants with "anti-thrombocytopenic activity" the dreadful response of dengue fever. The present study was conducted to investigate the potential of aqueous extract of Nigella sativa (black cumin) seeds in alleviating the severity of dengue disease by raising the platelet count (PLT). Serum samples of thirty patients with dengue hemorrhagic fever (DHF) were analysed for different biochemical parameters. When compared with control groups, the patients were found with very low PLT count (7.62 fold), reduced antioxidant levels; catalase (1.4 fold), ascorbic acid (1.1 fold), bilirubin (1.06 fold), and severe deficiency of micronutrient concentrations; cobalt (2.27 fold), iron (2.35 fold) and nickel (71.46 fold). Similar parameters were studied in albino rats to observe the changes in serum levels of biochemical markers, after administration of single dose of choloroquine phosphate (IM, 1.5 mL saline). The drug successfully induced thrombocytopenia along with significant decrease in levels of antioxidants and trace metals. Administration of N. sativa aqueous seed extract (15.25 mg/kg/bw) for 12 days resulted in an increase in PLT count (1.59 fold) as compared to control group. N. sativa post-treatment was found effective in elevating the serum levels of catalase, ascorbic acid, and bilirubin (1.06, 1.58 and 0.4 folds respectively). However, the N. sativa pre-treatment was useful in increasing the levels of micronutrients; iron, nickel and cobalt when compared to quinine-induced group. From the above findings it was suggested that N. sativa seed aqueous extract supplementation would be a promising solution for declined PLT count and associated consequences.

Cardio-haemodynamic assessment and venous lactate in severe dengue: Relationship with recurrent shock and respiratory distress

Background

Dengue can cause plasma leakage that may lead to dengue shock syndrome (DSS). In approximately 30% of DSS cases, recurrent episodes of shock occur. These patients have a higher risk of fluid overload, respiratory distress and poor outcomes. We investigated the association of echocardiographically-derived cardiac function and intravascular volume parameters plus lactate levels, with the outcomes of recurrent shock and respiratory distress in severe dengue.

Methods/Principle findings

We performed a prospective observational study in Paediatric and adult ICU, at the Hospital for Tropical Diseases (HTD), Ho Chi Minh City, Vietnam. Patients with dengue were enrolled within 12 hours of admission to paediatric or adult ICU. A haemodynamic assessment and portable echocardiograms were carried out daily for 5 days from enrolment and all interventions recorded.

102 patients were enrolled; 22 patients did not develop DSS, 48 had a single episode of shock and 32 had recurrent shock. Patients with recurrent shock had a higher enrolment pulse than those with 1 episode or no shock (median: 114 vs. 100 vs. 100 b/min, P = 0.002), significantly lower Stroke Volume Index (SVI), (median: 21.6 vs. 22.8 vs. 26.8mls/m², P<0.001) and higher lactate levels (4.2 vs. 2.9 vs. 2.2 mmol/l, P = 0.001). Higher SVI and worse left ventricular function (higher Left Myocardial Performance Index) on study days 3–5 was associated with the secondary endpoint of respiratory distress. There was an association between the total IV fluid administered during the ICU admission and respiratory distress (OR: 1.03, 95% CI 1.01–1.06, P = 0.001). Admission lactate levels predicted patients who subsequently developed recurrent shock (P = 0.004), and correlated positively with the total IV fluid volume received (rho: 0.323, P = 0.001) and also with admission ALT (rho: 0.764, P<0.001) and AST (rho: 0.773, P<0.001).

Conclusions/Significance

Echo-derived intravascular volume assessment and venous lactate levels can help identify dengue patients at high risk of recurrent shock and respiratory distress in ICU. These findings may serve to, not only assist in the management of DSS patients, but also these haemodynamic endpoints could be used in future dengue fluid intervention trials.

Dengue is a viral illness that can lead to severe and potentially fatal complications. The most common complication is fluid leakage from blood vessels, which can cause low blood pressure or dengue shock syndrome (DSS). The majority of patients recover with simple intravenous fluid replacement, however in approximately 30% of DSS cases, recurrent episodes of shock occur, and these patients have a higher risk of fluid overload, respiratory distress and death. We investigated whether using portable echocardiograms (Echo) in the intensive care unit (ICU) to assess cardiac function and intravascular volume parameters as well as blood lactate levels, can help identify these patients. We found patients who developed recurrent shock had higher heart rates and lower Stroke Volume Index (SVI), and higher lactate levels at enrolment than those with 1 episode or no shock. Higher SVI and worse cardiac function after 3 days in ICU was associated with respiratory distress. Admission lactate levels predicted patients who subsequently developed recurrent shock and correlated positively with the total IV fluid volume received. These results demonstrate that Echo-derived intravascular volume assessment and venous lactate levels can help identify dengue patients at high risk of poor outcomes in the ICU, and could assist in the management of severe dengue.

A Cohort Study of Adult Patients with Severe Dengue in Taiwanese Intensive Care Units: The Elderly and APTT Prolongation Matter for Prognosis

Background

There was a large dengue outbreak in Taiwan in 2015, in which the ages of the affected individuals were higher than those in other countries. The aim of this study was to explore the characteristics and prognostic factors for adults with severe dengue in intensive care units (ICUs).

Methods

All adults admitted to ICUs with dengue virus infection (DENV) at a medical center from July 1, 2015 to December 31, 2015 were enrolled. DENV was diagnosed by the presence of serum NS1 antigen, IgM antibodies to dengue virus, or dengue virus RNA by real-time reverse transcriptase polymerase chain reaction. Demographic data, clinical features, and lab data were collected, and a multivariate Cox model was used to identify the predictive factors for in-hospital mortality.

Results

Seventy-five patients admitted to ICUs with laboratory-confirmed DENV were enrolled (mean age 72.3±9.3 years). The most common comorbidities included hypertension (72.0%), diabetes (43.7%), and chronic kidney disease (22.7%). The in-hospital case fatality rate (CFR) was 41.3%. The patients who died were predominantly female, had higher disease severity at ICU admission, shorter ICU/hospital stay, longer initial activated partial thromboplastin time (APTT), and higher initial serum aspartate transaminase levels. Cardiac arrest before ICU admission (hazard ratio [HR]: 6.26 [1.91–20.54]), prolonged APTT (>48 seconds; HR: 3.91 [1.69–9.07]), and the presence of acute kidney injury on admission (HR: 2.48 [1.07–5.74]), were independently associated with in-hospital fatality in the Cox multivariate analysis.

Conclusion

During the 2015 dengue outbreak in Taiwan, the patients with severe dengue in ICUs were characterized by old age, multiple comorbidities, and a high CFR. Organ failure (including cardiac failure, and renal failure) and coagulation disturbance (prolongation of initial APTT) were independent predictive factors for in-hospital fatality.

Severe forms of dengue fever (DF) are usually considered as a pediatric disease in southern Asia and are graded from dengue hemorrhagic fever (DHF) to dengue with shock syndrome (DSS). However, the age of affected individuals is increasing in Singapore, Thailand, Mainland China, Taiwan and many other countries. Limited data are available on the elderly with DF in intensive care units (ICUs). DF in the elderly is an emerging infectious disease and poses a new clinical challenge to physicians. We enrolled the patients with laboratory-confirmed dengue in our ICU during the 2015 dengue outbreak in Taiwan. These patients were characterized by old age, multiple comorbidities, and a high case fatality rate (CFR). All of the patients were classified as severe dengue, and the in-hospital CFR was 41.3%. Renal failure and cardiac arrest were associated with fatality. In addition to organ failure, initial prolonged activated partial thromboplastin time (APTT) in our study was consistent with an independent predictive factor for in-hospital fatality. Previous studies have also reported that prolongation of APTT is a clinical predictor of dengue virus infection (DENV) or DHF. Our results highlight that APTT prolongation may be a prognostic factor in critically ill adults with severe dengue.

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

Background

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

Methodology/Principal Findings

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

Conclusions/Significance

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

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

A Proteomic Approach Identifies Candidate Early Biomarkers to Predict Severe Dengue in Children

BACKGROUND

Severe dengue with severe plasma leakage (SD-SPL) is the most frequent of dengue severe form. Plasma biomarkers for early predictive diagnosis of SD-SPL are required in the primary clinics for the prevention of dengue death.

METHODOLOGY

Among 63 confirmed dengue pediatric patients recruited, hospital based longitudinal study detected six SD-SPL and ten dengue with warning sign (DWS). To identify the specific proteins increased or decreased in the SD-SPL plasma obtained 6-48 hours before the shock compared with the DWS, the isobaric tags for relative and absolute quantification (iTRAQ) technology was performed using four patients each group. Validation was undertaken in 6 SD-SPL and 10 DWS patients.

PRINCIPAL FINDINGS

Nineteen plasma proteins exhibited significantly different relative concentrations (p<0.05), with five over-expressed and fourteen under-expressed in SD-SPL compared with DWS. The individual protein was classified to either blood coagulation, vascular regulation, cellular transport-related processes or immune response. The immunoblot quantification showed angiotensinogen and antithrombin III significantly increased in SD-SPL whole plasma of early stage compared with DWS subjects. Even using this small number of samples, antithrombin III predicted SD-SPL before shock occurrence with accuracy.

CONCLUSION

Proteins identified here may serve as candidate predictive markers to diagnose SD-SPL for timely clinical management. Since the number of subjects are small, so further studies are needed to confirm all these biomarkers.

Host biomarkers are associated with progression to dengue haemorrhagic fever: a nested case-control study

OBJECTIVES

Dengue represents the most important arboviral infection worldwide. Onset of circulatory collapse can be unpredictable. Biomarkers that can identify individuals at risk of plasma leakage may facilitate better triage and clinical management.

DESIGN

Using a nested case-control design, we randomly selected subjects from a prospective cohort study of dengue in Colombia (n=1582). Using serum collected within 96 hours of fever onset, we tested 19 biomarkers by ELISA in cases (developed dengue hemorrhagic fever or dengue shock syndrome (DHF/DSS); n=46), and controls (uncomplicated dengue fever (DF); n=65) and healthy controls (HC); n=15.

RESULTS

Ang-1 levels were lower and angptl3, sKDR, sEng, sICAM-1, CRP, CXCL10/IP-10, IL-18 binding protein, CHI3L1, C5a and Factor D levels were increased in dengue compared to HC. sICAM-1, sEng and CXCL10/IP-10 were further elevated in subjects who subsequently developed DHF/DSS (p=0.008, p=0.028 and p=0.025, respectively). In a logistic regression model, age (odds ratio (OR) (95% CI): 0.95 (0.92-0.98), p=0.001), hyperesthesia/hyperalgesia (OR; 3.8 (1.4-10.4), p=0.008) and elevated sICAM-1 (>298ng/mL: OR; 6.3 (1.5-25.7), p=0.011) at presentation were independently associated with progression to DHF/DSS.

CONCLUSIONS

These results suggest that inflammation and endothelial activation are important pathways in the pathogenesis of dengue and sICAM-1 levels may identify individuals at risk of plasma leakage.

FATAL RHABDOMYOLYSIS IN DENGUE HEMORRHAGIC FEVER: A CASE REPORT

Dengue hemorrhagic fever is caused by dengue virus infection. The classical manifestations consist of fever, thrombocytopenia, and hemoconcentration. However, its unusual complications may be fatal, such as prolong shock, massive bleeding, volume overload, and unusual manifestations, for example, severe rhabdomyolysis. Here we report a case of 17-year old Thai man who was referred to our hospital because of 7-day fever with thrombocytopenia, hemoconcentration and right pleural effusion. The serology tests confirmed to be dengue infection. He developed various complications: severe hepatitis, coagulopathy, and heavy proteinuria; encephalopathy that needed a respiratory ventilator. On day 12 of fever, he had myalgia and passed dark urine. Serum creatinine and serum creatinine phosphokinase (CPK) were found abnormally high. He was diagnosed as severe rhabdomyolysis with acute kidney injury, and immediate hemodialysis was performed. He did not respond to treatment and expired within three hours. Although the mechanism of severe rhabdomyolysis in dengue fever is not clearly known, it may theoretically be proposed such as direct muscle cell injury leading to myositis by dengue virus, myotoxic cytokines which are produced in response to viral infection, dehydration or hypophosphatemia.

Clinico-pathological profile of dengue syndrome: an experience in a tertiary care hospital, Dhaka, Bangladesh

Dengue is the fastest emerging arboviral infection and became a major public health concern in tropical and subtropical countries. Dengue infections can result in a wide spectrum of disease severities ranging between dengue fever (DF) to the life-threatening dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). This study was performed to find out the varied presentations and laboratory findings to put forward an overview about dengue syndrome in Bangladesh, in order to create better awareness and diagnostic skills among the health care providers. This hospital based observational study was conducted in the department of Medicine, Square Hospitals Ltd. during January, 2008 to December, 2010. A total of 262 adult subjects of both sexes having dengue syndrome were included in this study. Dengue syndrome was common in younger age group and the majority (72%) was below 45 years of age. All the patients had fever and the majority had malaise (96%), severe headache (72%) and musculoskeletal pain (65%). Skin rash (47%) was the commonest hemorrhagic manifestation while tourniquet test (49%) and low pulse pressure (37%) were the commonest clinical signs. All had thrombocytopenia (100%) and the majority had leukopenia (84%) and elevated liver transaminase (ALT-74%, AST-88%). Most of the subjects developed anti dengue antibody (IgM-92%, IgG -72%). All subjects survived.

Serum lactate and lactate dehydrogenase as parameters for the prediction of dengue severity

BACKGROUND

Lactate and lactate dehydrogenase (LDH) have been found to be elevated in cardiopulmonary failure, sepsis, shock and hepatic injury. Severe dengue hemorrhagic fever (DHF) patients also develop shock and experience a certain degree of hepatic injury, implicating that serum lactate and LDH may be elevated in Dengue shock syndrome (DSS).

OBJECTIVE

To determine serum lactate and LDH levels in dengue patients to see whether they can be used as predictors of severe dengue cases.

MATERIAL AND METHOD

A cross sectional study was conducted on suspected dengue patients admitted to the dengue ward, Queen Sirikit National Institute of Child Health (QSNICH), between May 2011 and February 2012. Laboratory tests were used to confirm dengue cases in the enrolled patients. Blood for serum lactate was drawn in patients every day after enrollment. Blood for LDH and liver function test (LFT) were drawn 3 times: enrollment day, day of leakage, and discharge day. Lactate and LDH levels are compared among dengue and non-dengue patients. Dengue fever (DF), DHF and DSS patients were classified according to the WHO 1997 dengue classification.

RESULTS

253 patients were enrolled, comprising of 120 DF, 75 DH, 30 DSS, and 28 non-dengue patients. The majority of dengue patients had liver impairment, demonstrated by elevated aspartate aminotransferase (AST) (94.9%) and alanine aminotransferase (ALT) levels (68.6%) while non-dengue patients have minimal elevation. Serum lactate levels were not elevated in the early stages in dengue patients, but were elevated in non-dengue patients. The mean serum lactate levels in DSS patients increased towards the end of febrile phase and reached maximum values on Day 0 (2.2 U/L). On the other hand, serum lactate levels were found to be decreasing in the non-dengue group. The mean serum lactate levels on Day 0 was found to be different in DSS patients (2.26 U/L) compared to DF 1.63 U/L), DHF (1.79 U/L) and non-dengue patients (1.68 U/L) (p < 0.05). Mean serum LDH levels were elevated in the early stages of the disease in all groups of patients, but with different levels. Mean serum LDH levels was 709.2 in DF, 1,873 in DHF, 654.5 in DSS, and 434 IU in non-dengue patients. The mean LDH levels in dengue patients were > 500 IU, while it was < 500 IU in non-dengue patients. The increasing mean levels of LDH towards the end of febrile phase were only seen in DHF and DSS patients, but not in DF and non-dengue patients. The mean levels of LDH on Day 0 in DHF, DSS, DF and non-dengue patients are 1,060.7, 1,180.7, 787.2, and 423.8 IU, respectively.

CONCLUSION

Serum lactate and LDH was found to be elevated in DHF and/or DSS patients. Lactate may be used as a predictor of DSS if the level is > 2 U/L on Day 0. LDH can be used to differentiate patients with or without dengue in the early febrile phase, if the level is > 500 IU. If the level of LDH is increased to approximately 1, 000 IU on Day 0, it may be a predictor of severe dengue infection or DHF and DSS with plasma leakage.

A strong interferon response correlates with a milder dengue clinical condition

BACKGROUND

Type 1 interferon (IFNα/β) has a significant role in establishing protection against virus infections. It has been well documented by in vitro studies that dengue virus (DENV) activates a robust IFNα/β response. However, DENV also induces a down-regulation of the JAK/STAT pathway, inhibiting the induction of interferon regulated genes. As a consequence, the role played by the IFN type 1 response in the protection of dengue patients is not fully understood.

OBJECTIVE

To compare IFN-α levels in dengue patients with dengue fever (DF) or dengue hemorrhagic fever (DHF) undergoing primary or secondary infections.

STUDY DESIGN

Two hundred and four serum samples were analyzed for IFN-α level by cytometric bead array. Patients' clinical condition was assigned following the WHO 1997 criteria and specific IgG and IgM antibodies were measured using commercial assays to determine primary and secondary infections. The infecting serotype was determined by qRT-PCR.

RESULTS AND CONCLUSION

The IFN-α levels were found significantly higher in DF than DHF patients irrespective of the infecting serotype (DENV1 or 2), and were found to decline rapidly at day 3 after fever onset. For DENV2 infections, higher IFN-α level was found during primary than secondary infections. These results suggest that an early strong interferon response correlates with a better clinical condition.

Low levels of antibody-dependent enhancement in vitro using viruses and plasma from dengue patients

Background

The majority of dengue patients infected with any serotype of dengue virus (DENV) are asymptomatic, but the remainder may develop a wide spectrum of clinical symptoms, ranging from mild dengue fever (DF) to severe dengue hemorrhagic fever (DHF). Severe cases occur more often in patients who experience a secondary infection with a different virus serotype. A phenomenon called antibody-dependent enhancement (ADE) has been proposed to explain the onset of these severe cases, but the exact mechanism of ADE remains unclear.

Methodology/Principal Finding

Virus neutralization and ADE assays were performed using ultracentrifugation supernatants of acute-phase sera from patients with secondary infections or human monoclonal antibodies (HuMAbs) as anti-DENV antibodies. Virus sources included infectious serum-derived viruses from the ultracentrifugation precipitates, laboratory-culture adapted DENV, or recombinant DENVs derived from patient sera. In contrast to the high levels of ADE observed with laboratory virus strains, low ADE was observed with autologous patient-derived viruses, when patient sera were used to provide the antibody component in the ADE assays. Similar results were obtained using samples from DF and DHF patients. Recombinant-viruses derived from DHF patients showed only minor differences in neutralization and ADE activity in the presence of HuMAbs or plasma derived from the same DHF patient.

Conclusion/Significance

Serum or plasma taken from patients during the acute phase of a secondary infection showed high levels of ADE, but no neutralization activity, when assayed in the presence of laboratory-adapted virus strains. By contrast, serum or plasma from the same patient showed high levels of neutralization activity but failed to induce significant ADE when the assays were performed with autologous virus. These results demonstrate the significance of the virus source when measuring ADE. They also suggest that repeated passage of DENV in cell culture has endowed it with the capacity to induce high levels of ADE.

Risk factors associated with death in Brazilian children with severe dengue: a case-control study

OBJECTIVE

The purpose of this case-control study was to evaluate risk factors associated with death in children with severe dengue.

METHODS

The clinical condition of hospitalized patients with severe dengue who died (cases, n = 18) was compared with that of hospitalized patients with severe dengue who survived (controls, n = 77). The inclusion criteria for this study were age under 13 years; hospital admission in São Luis, northeastern Brazil; and laboratory-confirmed diagnosis of dengue.

RESULTS

Severe bleeding (hemoptysis), a defining criterion for dengue severity, was the factor most strongly associated with death in our study. We also found that epistaxis and persistent vomiting, both included as warning signs in the World Health Organization (WHO) classification of dengue, were strongly associated with death. No significant association was observed between any of the laboratory findings and death.

CONCLUSIONS

The finding that epistaxis and persistent vomiting were also associated with death in children with severe dengue was unexpected and deserves to be explored in future studies. Because intensive care units are often limited in resource-poor settings, any information that can help to distinguish patients with severe dengue with a higher risk to progress to death may be crucial.

[Biochemical alterations as prediction markers for the severity of illness in dengue fever patients]

INTRODUCTION

Dengue is the most important mosquito-borne infection in the world. There is evidence supporting the use of biochemical alterations as prediction tools for severity of illness in dengue.

OBJECTIVE

To evaluate biochemical alterations as potential prediction markers for severity in dengue.

MATERIALS AND METHODS

This was a case-control study nested in a cohort. We randomly selected 125 severe dengue cases and 120 controls with non-severe dengue for measuring LDH, CK, CRP and albumin serum levels using acute phase sera. To evaluate the predictive value for each biomarker, we established cut-off points with 90% sensitivity in detecting severe cases.

RESULTS

There was association among the CRP levels < 9.8 mg/L (OR=0.04; 95%CI=0.02-0.08; p=0.000), <400 U/L LDH levels (OR=0.49; 95%CI=0.24-1.02; p=0.053) and <4 mg/dl albumin levels (OR=3.46; 95%CI=1.96-6.12; p=0.000) with the severity of dengue. In contrast, the CK levels showed no association with the severity of the disease.

CONCLUSIONS

Our findings suggest an association of CRP, LDH and albumin levels with the severity of dengue. These biochemical tests could be used as predictive tools in the clinical course of the infection.

[Biomarkers for the prognosis of severe dengue]

INTRODUCTION

There are very few strategies for the early detection of the patients who might develop the severe form of the illness.

OBJECTIVE

To evaluate the utility of serum levels of some immune response mediators as early biomarkers for the severe dengue prognosis during the early phase of the illness.

MATERIALS AND METHODS

Using a case-control design nested in a multicenter cohort from the AEDES network (a Colombian multicenter study), we compared TNF a, ST2, TRAIL and IDO levels in samples which were obtained during the early phase of the illness.

RESULTS

ST2, TRAIL and TNF a levels were higher in severe dengue patients compared with uncomplicated patients (p<0.0001), as follows: OR=24.8, CI95%= 6.1- 98.0; OR=18.0, CI95%= 4.6-69.1; OR=NC, CI95%= NC, respectively. We did not find statistically significant differences between IDO levels in severe dengue and uncomplicated dengue (p=1.000, OR=1.0, CI95%= 0.2-6.1).

CONCLUSIONS

In the early phase of the dengue infection (96 hours), ST2, TRAIL and TNF a quantifications could contribute to the prediction of complications of the illness.

Dengue virus enhances thrombomodulin and ICAM-1 expression through the macrophage migration inhibitory factor induction of the MAPK and PI3K signaling pathways

Dengue virus (DV) infections cause mild dengue fever (DF) or severe life-threatening dengue hemorrhagic fever (DHF). The mechanisms that cause hemorrhage in DV infections remain poorly understood. Thrombomodulin (TM) is a glycoprotein expressed on the surface of vascular endothelial cells that plays an important role in the thrombin-mediated activation of protein C. Prior studies have shown that the serum levels of soluble TM (sTM) and macrophage migration inhibitory factor (MIF) are significantly increased in DHF patients compared to levels in DF patients or normal controls. In this study, we investigated how MIF and sTM concentrations are enhanced in the plasma of DHF patients and the potential effect of MIF on coagulation through its influence on two factors: thrombomodulin (TM) and intercellular adhesion molecule-1 (ICAM-1) in endothelial cells and monocytes. Recombinant human macrophage migration inhibitory factor (rMIF) was used to treat monocytic THP-1 cells and endothelial HMEC-1 cells or primary HUVEC cells. The subsequent expression of TM and ICAM-1 was assessed by immunofluorescent staining and flow cytometry analysis. Additionally, the co-incubation of THP-1 cells with various cell signaling pathway inhibitors was used to determine the pathways through which MIF mediated its effect. The data provided evidence that severe DV infections induce MIF expression, which in turn stimulates monocytes or endothelial cells to express TM and ICAM-1 via the Erk, JNK MAPK and the PI3K signaling pathways, supporting the idea that MIF may play an important role as a regulator of coagulation.

Identification of dengue virus in Aedes mosquitoes and patients' sera from Si Sa Ket Province, Thailand

Dengue fever (DF), dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS) are the re-emerging infectious diseases caused by dengue (DEN) virus, transmitted by Aedes mosquito. There are more than 100,000 cases of dengue infection and more than 100 deaths annually in Thailand. Virological surveillance for DEN viruses is used as an early warning system to predict outbreaks. The seroprevalence of infection and serotypes of DEN virus in 116 pediatric patients at Si Sa Ket Province, Thailand were analyzed during June to September 2004. At the same period, Aedes mosquitoes were caught from patients' and their neighbors' houses, from control houses, located in villages with no report of dengue infection during the previous 3 years. The majority of DHF cases were secondary infections of DEN-2 and DEN-4 serotypes. Of the 1,652 Aedes mosquitoes collected 1,583 were Ae. aegypti and 69 Ae. albopictus. Ten mosquitoes from each house were pooled and dengue viruses were determined using RT-PCR assay; only 1 positive pooled was found. Although the dengue infection rate in the field caught mosquitoes was low, the existing dengue virus control program in transmission areas by aerial spraying to destroy the larva breeding sites should be continued.

Clinicohematological profile and platelet trends in children with dengue during 2010 epidemic in north India

OBJECTIVE

To study the clinicohematological profile and the platelet trends in children presenting with dengue infection during the 2010 dengue epidemic in north India and to compare the it with previous epidemics.

METHODS

This retrospective study was carried out in a tertiary care hospital of North India. Of the 219 children admitted from August 2010 through November 2010 with suspected dengue infection, 135 were IgM positive and were included in the final analysis.

RESULTS

These children were further categorized as dengue fever (8%), dengue hemorrhagic fever (51%) and dengue shock syndrome (42%). The mean age (± SD) of children were 8.3 ± 3.5 y with male: female ratio 1.32. Mean duration of fever (±SD) was 6.3 d ± 3.7 d. The clinical features included fever (100%), headache (63%), abdominal pain (71%), petechia (35.5%), rash (26.6%) and bleeding manifestations (48.8%). On examination, Hess test (33.3%), signs of fluid retention (23%), pallor (13.3%),signs of circulatory failure (43%), hepatomegaly (31.1%) and splenomegaly (27%) were positive. Laboratory investigations revealed mean (±SD) hemoglobin 11.5 g/dl (±1.7), hematocrit 36.1(±5.5), leucocyte count 7,551/mm(3) and platelet count 38,800 mm(3) on day of admission. A total of 92.6% of children had thrombocytopenia and 19.2% had abnormal leucocyte count. Deranged liver function tests were observed in 48 children. The mean (±SD) of hospitalization and platelet recovery were 4.2 ± 2.3 d and 3.6 ± 1.3 d respectively and did not vary according to disease category (P > 0.05). Bleeding manifestations were not related to platelet count (P > 0.05). There was no statistical difference in the demographic, clinical or laboratory observations according to disease category (P > 0.05). A total of 24 children had evidence of other co-infections and four had atypical complications. Dengue 2 virus was the strain reported in most of the cases.

CONCLUSIONS

This study showed shift to higher age of presentation, more number of dengue hemorrhagic fever and associated co-infections in children. The complications and mortality was low and platelet recovery time was not influenced by disease category.

Discovery proteomics and nonparametric modeling pipeline in the development of a candidate biomarker panel for dengue hemorrhagic fever

Secondary dengue viral infection can produce capillary leakage associated with increased mortality known as dengue hemorrhagic fever (DHF). Because the mortality of DHF can be reduced by early detection and intensive support, improved methods for its detection are needed. We applied multidimensional protein profiling to predict outcomes in a prospective dengue surveillance study in South America. Plasma samples taken from initial clinical presentation of acute dengue infection were subjected to proteomics analyses using ELISA and a recently developed biofluid analysis platform. Demographics, clinical laboratory measurements, nine cytokines, and 419 plasma proteins collected at the time of initial presentation were compared between the DF and DHF outcomes. Here, the subject's gender, clinical parameters, two cytokines, and 42 proteins discriminated between the outcomes. These factors were reduced by multivariate adaptive regression splines (MARS) that a highly accurate classification model based on eight discriminant features with an area under the receiver operator curve (AUC) of 0.999. Model analysis indicated that the feature-outcome relationship were nonlinear. Although this DHF risk model will need validation in a larger cohort, we conclude that approaches to develop predictive biomarker models for disease outcome will need to incorporate nonparametric modeling approaches.

First report of sylvatic DENV-2-associated dengue hemorrhagic fever in West Africa

Dengue virus (DENV) circulates in human and sylvatic cycles. Sylvatic strains are both ecologically and evolutionarily distinct from endemic viruses. Although sylvatic dengue cycles occur in West African countries and Malaysia, only a few cases of mild human disease caused by sylvatic strains and one single case of dengue hemorrhagic fever in Malaysia have been reported. Here we report a case of dengue hemorrhagic fever (DHF) with thrombocytopenia (13000/µl), a raised hematocrit (32% above baseline) and mucosal bleeding in a 27-year-old male returning to Spain in November 2009 after visiting his home country Guinea Bissau. Sylvatic DENV-2 West African lineage was isolated from blood and sera. This is the first case of DHF associated with sylvatic DENV-2 in Africa and the second case worldwide of DHF caused by a sylvatic strain.

Clinical profile of dengue haemorrhagic fever from Jan 2009 to Dec 2009 in and around Aurangabad

In present study 890 serum samples suspected of dengue fever on clinical grounds were received in department of Microbiology. Out of these 249 cases showed thrombocytopenia (platelet count < 1 lakh/cumm) and were subjected to rapid dengue serological test as well as IgM capture ELISA. 11(4%) cases were diagnosed as primary dengue infection (only IgM positive) by rapid dengue IgG/IgM bispot immunocomb test. There were 123(49%) cases with only IgG positive suggesting secondary/past dengue infection. Both IgM and IgG were seen in 24(10%) cases. Number of cases negative for both IgM and IgG were 91(37%). IgM positive cases were confirmed by IgM capture ELISA. Classical dengue fever (DF) was noted in 168 (67%) patients and dengue hemorrhagic fever (DHF) in 81(33%) cases. Common clinical presentations of DHF were fever 78 (96%), body-ache 74 (91%), arthralgia 74 (91%), retro-orbital pain 65 (80%), abdominal pain 07 (09%). Bleeding manifestation were in the form of petechiae, melena, epistaxis, hematuria, hemoptysis, hematemesis, bleeding gums and conjunctival hemorrhages. Out of 81 DHS patients 13 (16%) patients had platelet count between 50,000 and 1 lakh. 68 (84%) patients had platelet count below 50,000. Majority of these patients 47 (58%) had platelet below 20000 and were IgG positive. Thrombocytopenia correlated well with bleeding manifestations in our patients. In an epidemic setting if the patients present with fever, vomiting, musculoskeletal pain and bleeding along with low platelet count a strong possibility of DHF/DSS should be kept.

Both viremia and cytokine levels associate with the lack of severe disease in secondary dengue 1 infection among adult Chinese patients

Secondary dengue infections are frequently associated with increased risk for dengue hemorrhagic fever and dengue shock syndrome. Surprisingly, we observed no dengue hemorrhagic fever cases among 353 hospitalized dengue-infected patients including 212 with primary, and 141 with secondary dengue 1 infection in China. To explore virological and immunological mechanisms which may account for this unexpected clinical observation, we assessed dengue viremia, type I interferon and inflammatory cytokine levels in these patients. While the levels of viremia and inflammatory cytokines are indistinguishable between primary and secondary infections, IFNα levels are significantly higher in primary than that in secondary infection. However, IFNα levels are positively correlated with dengue viremia levels (p<0.0001), but negatively correlated with the platelet counts (p<0.0001) and serum ALT levels (p = 0.0003). These results provide direct in vivo evidence that clinical dengue disease severity is affected by both viral and human immune factors.

The early whole-blood transcriptional signature of dengue virus and features associated with progression to dengue shock syndrome in Vietnamese children and young adults

Dengue is a pantropic public health problem. In children, dengue shock syndrome (DSS) is the most common life-threatening complication. The ability to predict which patients may develop DSS may improve triage and treatment. To this end, we conducted a nested case-control comparison of the early host transcriptional features in 24 DSS patients and 56 sex-, age-, and virus serotype-matched uncomplicated (UC) dengue patients. In the first instance, we defined the "early dengue" profile. The transcriptional signature in acute rather than convalescent samples (≤72 h post-illness onset) was defined by an overabundance of interferon-inducible transcripts (31% of the 551 overabundant transcripts) and canonical gene ontology terms that included the following: response to virus, immune response, innate immune response, and inflammatory response. Pathway and network analyses identified STAT1, STAT2, STAT3, IRF7, IRF9, IRF1, CEBPB, and SP1 as key transcriptional factors mediating the early response. Strikingly, the only difference in the transcriptional signatures of early DSS and UC dengue cases was the greater abundance of several neutrophil-associated transcripts in patients who progressed to DSS, a finding supported by higher plasma concentrations of several canonical proteins associated with neutrophil degranulation (bactericidal/permeability-increasing protein [BPI], elastase 2 [ELA2], and defensin 1 alpha [DEF1A]). Elevated levels of neutrophil-associated transcripts were independent of the neutrophil count and also of the genotype of the infecting virus, as genome-length sequences of dengue virus serotype 1 (DENV-1) (n = 15) and DENV-2 (n = 3) sampled from DSS patients were phylogenetically indistinguishable from those sampled from uncomplicated dengue patients (32 DENV-1 and 9 DENV-2 sequences). Collectively, these data suggest a hitherto unrecognized association between neutrophil activation, pathogenesis, and the development of DSS and point to future strategies for guiding prognosis.

Dengue virus-induced hemorrhage in a nonhuman primate model

Lack of a dengue hemorrhagic animal model recapitulating human dengue virus infection has been a significant impediment in advancing our understanding of the early events involved in the pathogenesis of dengue disease. In efforts to address this issue, a group of rhesus macaques were intravenously infected with dengue virus serotype 2 (strain 16 681) at 1 x 10(7) PFU/animal. A classic dengue hemorrhage developed 3 to 5 days after infection in 6 of 6 animals. Blood chemistry appeared to be normal with exception of creatine phosphokinase, which peaked at 7 days after infection. A modest thrombocytopenia and noticeable neutropenia concomitant with slight decrease of hemoglobin and hematocrit were registered. In addition, the concentration of D-dimer was elevated significantly. Viremia peaked at 3 to 5 days after infection followed by an inverse relationship between T and B lymphocytes and a bimodal pattern for platelet-monocytes and platelet-neutrophil aggregates. Dengue virus containing platelets engulfed by monocytes was noted at 8 or 9 days after infection. Thus, rhesus macaques inoculated intravenously with a high dose of dengue virus produced dengue hemorrhage, which may provide a unique platform to define the early events in dengue virus infection and help identify which blood components contribute to the pathogenesis of dengue disease.

Laboratory predictors of dengue shock syndrome during the febrile stage

The clinical manifestations of dengue hemorrhagic fever (DHF) consist of three successive stages: febrile, toxic and convalescent. The toxic stage is the critical period, which may manifestas circulatory disturbance or even profound shock in some patients. We attempted to determine predictors for the risk of dengue shock syndrome (DSS) during the febrile stage. One hundred one children with acute febrile illness were enrolled in the study, with a mean age of 11 years old. The diagnosis included dengue fever (DF) 21 cases, DHF grade I 30 cases, DHF grade II 33 cases, DHF grades III and IV 10 cases; children with other febrile illnesses (OFI) 7 cases were used as controls. Complete blood counts, coagulation tests, von Willebrand factor antigens (VWF:Ag) and ristocetin cofactor activity (VWF:Rcof) were determined daily during hospitalization and 2-4 weeks after discharge from the hospital. The results revealed any one of the following abnormal laboratory findings during the febrile stage served as a predictor for risk of DSS: increase in hematocrit > 25%, a platelet count < 40,000/microl, an activated partial thromboplastin time >44 seconds, a prothrombin time >14 seconds, a thrombin time >16 seconds or a VWF:Ag or VWF:Rcof > 210%. The relative risk ranged from 4.8 to 10.9. Simple laboratory investigations with complete blood count, coagulation test or the more sophisticated von Willebrand factor, are helpful in predicting the risk for DSS during the febrile stage.

Electrolyte disturbances and abnormal urine analysis in children with dengue infection

Serum electrolytes and urine analysis results were retrospectively reviewed in children with either dengue fever (DF) or dengue hemorrhagic fever (DHF). Children who had positive serology for dengue infection and serum electrolytes determined before starting intravenous fluid were included in the study. During the years 2004-2007, 73 DF patients, age 9.29 +/- 3.62 years, and 77 DHF patients, age 10.04 +/- 3.64 years were enrolled in the study. The patients were admitted to the hospital on average on days 4.12 +/- 1.1 and 4.25 +/- 1.4 of febrile illness for DF and DHF, respectively. The prevalence of hyponatremia in patients with DF was 61% and DHF was 72% (p = 0.149). The mean serum sodium levels in patients with DF and DHF were 133.5 +/- 3.52 and 133.5 +/- 3.20 mEq/l (p = 0.938), respectively. The prevalence of hyponatremia in patients with mild (grade I), moderate (grade II) and severe (grade III-IV) DHF were 70, 77, and 78% (p = 0.729), respectively, and the mean serum sodium levels were 134.1 +/- 3.05, 132.9 +/- 3.33, and 132.5 +/- 3.28 (p = 0.189), respectively. The prevalence of hypokalemia in patients with DF was 14% and 17% in patients with DHF (p = 0.588). A high urine specific gravity reflecting dehydration was found in 63% of patients with DF and 60% of patients with DHF (p = 0.77). The prevalences of hematuria in patients with DF and DHF were 18% and 27% (p = 0.182), respectively and proteinuria were 15% and 27% (p = 0.072), respectively. The prevalences of hematuria and proteinuria were not different among patients with mild, moderate and severe DHF. No patients had gross hematuria or developed acute renal failure requiring dialysis. Mild hyponatremia is a common electrolyte disturbance and renal involvement is mild in patients with DF and DHF.

Modification of the cytoprotective protein C pathway during Dengue virus infection of human endothelial vascular cells

Dengue fever (DF) is the most prevalent arthropod-borne viral disease of humans. No safe vaccine is available, there is no experimental animal model and no specific treatment (antiviral) for Dengue virus (DV) infection exists. The pathogenic mechanisms of the severe forms of the disease, such as Dengue shock syndrome (DSS) and Dengue haemorrhagic fever (DHF), in which endothelial damage is the pathognomonic sign, are not fully understood. Clinical observations have revealed significant abnormalities in the coagulation and inflammation systems, with increased levels of soluble thrombomodulin (sTM) in the plasma of patients with DHF/DSS (grade III or IV). Blood sTM was proposed as an early predictor of DSS during the febrile stage. However, the role of the DV in endothelial injury during DSS is unclear. Here, we present novel insights into the participation of DV in the downregulation of the thrombomodulin-thrombin-protein C complex formation at the endothelial surface, with a reduction in activated protein C (APC). APC is the most important vasoprotective protein because it downregulates thrombin generation (by the inactivation of procoagulant factors Va and VIIIa) and has anti-inflammatory, antiapoptotic, and barrier protection properties. These biological functions of APC are associated with the endothelial protein C receptor (EPCR) and protease-activated receptor 1 (PAR-1) signalling pathways, which link the coagulation-inflammation responses. We found alterations in the antithrombotic and cytoprotective protein C pathways during DV infection of human endothelial vascular cells, which may explain the vasculopathy observed during DHF/DSS. Clarification of the basic principles that underlie these processes has important implications for the design of new therapeutic strategies for DHF/DSS.

An open pilot study of the efficacy and safety of Polygeline in adult subjects with dengue haemorrhagic fever

AIM

To observe the efficacy and safety of Polygeline colloid (Haemaccel) in adults with stage I - II of dengue haemorrhagic fever (DHF).

METHODS

An open, non-comparative clinical trial. The subjects were male or female between 17 - 55 years old, who fulfilled the criteria of stage I or II of DHF according to WHO and selected with consecutive sampling. Fluid treatments were given following this protocol: polygeline i.v. infusion: 500 ml over first 6 hours and continued with 500 ml for the next 18 hours, and maintained to 1000 mL/24 hours from day-2 until maximum day-5. Ringer's lactate infusion: 1000 mL/18 hours from the first day to maximum day-5, as maintenance. Efficacy and safety of polygeline colloid were evaluated using initial stabilization of haematocrite level, measured as percentage of clinical trial subject who has stabilization of haemodynamic status based on serial haematocrite levels examinations, total parenteral fluid required and length of hospitalization. Statisticial analysis was done using ANOVA test and post hoc analysis using Turkey test.

RESULTS

There were 43 subjects who completely participated in this study and included in analysis. From baseline levels, haematocrite decreased in first 6 hours during fluid treatment. This decrement persisted in 48 hours of observation. Statistical analysis with ANOVA test showed the significant differences of haematocrite level during observation (Sum of square between groups 495 and within group 4845, p= 0.000). Post hoc analysis with Turkey test showed significant differences of haematocrite level from baseline level to 48, 72 and 96 hours during observation periods.

CONCLUSION

This pilot study showed that polygeline colloid was a safe initial fluid treatment and can be used for maintaining fluid adequacy in adults with stage I-II of DHF.

Differential expression of aldolase, alpha tubulin and thioredoxin peroxidase in peripheral blood mononuclear cells from dengue fever and dengue hemorrhagic fever patients

We determined the differential expression levels of proteins in peripheral blood mononuclear cells of patients with dengue fever (DF) and dengue hemorrhagic fever (DHF). Proteins were subjected to two-dimensional electrophoresis, mass spectrometry and Western blot analysis. We identified 8 proteins that were 2-fold or more up-regulated in patients compared to healthy control, three of which, aldolase, thioredoxin peroxidase and alpha tubulin, were related to dengue infection. Both thioredoxin peroxidase and alpha tubulin were over-expressed 4.9 and 3.3 times respectively in DHF compared to DF patients while aldolase was up-regulated 2.2 times in DF compared to DHF patients. Alpha tubulin and thioredoxin peroxidase have the potential to be utilized as biomarkers for DHF.

The 2006 dengue outbreak in Delhi, India

Dengue is a worldwide condition spread throughout the tropical and subtropical zones between 30 degrees north and 40 degrees south. It is endemic in South East Asia, the pacific, East and West Africa, the Caribbean and the Americas. Dengue outbreaks are occurring almost every three yearly in Delhi for the last 12 years. The latest outbreak was in the year 2006, which started late in August, peaked in the month of October and lasted till late November. We describe here the clinical, hematological and biochemical data of 70 patients of dengue fever diagnosed as per WHO criteria in Lok Nayak Hospital, New Delhi during this outbreak. Hematological parameters were estimated by automated counter and dengue serology was done by capture ELISA technique. The results displayed widespread effect of dengue fever on hematological and biochemical profile. Some of our patients also had atypical dengue manifestations. These results suggest that dengue fever is a major public health problem which can lead to significant morbidity and can even be fatal at times. All efforts should be made to prevent it.

Serum ferritin levels in children with dengue infection

The purpose of this study was to evaluate the levels of ferritin, an acute-phase reactant, in predicting the risk of dengue hemorrhagic fever (DHF) in patients with dengue infection. One hundred seventy-seven Thai children (100 males, 77 females) 4-16 years old (median age 11 years) with DF (n = 44) and DHF (n = 133) were enrolled in the study. All patients had serologic confirmation of dengue infection. Each had a venous blood sample drawn daily during hospitalization and at the outpatient clinic 2-4 weeks after discharge from the hospital, to determine serum ferritin levels. The median serum ferritin levels (ng/ml) in children with DHF (Day 2, 974; Day 3, 624; Day 4, 1,136; Day 5, 1,912; Day 6, 2, 105; Day 7, 1,840; Day 8, 1,478 and Day 9, 1,144 of illness) were higher than those with DF (Day 2, 25.4; Day 3, 45.6; Day 4, 655; Day 5, 1,050; Day 6, 1,075; Day 7, 615; Day 8, 764 and Day 9, 600 of illness) with p-values of 0.013, 0.001 and 0.013 on Days 5, 6 and 7 of illness, respectively. A cutoff level of serum ferritin of 1,200 ng/ml was used to calculate sensitivity and specificity for DHF. The results reveal the sensitivities on Days 5, 6 and 7 of illness were 81.5, 84.4 and 89.9%, respectively, and the specificities were 42.4, 39.0 and 36.4%, respectively. High serum ferritin levels > or = 1,200 ng/ml may be a predictor of dengue hemorrhagic fever.

Desialylation of plasma proteins in severe dengue infection: possible role of oxidative stress

Oxidative stress in dengue infection has been suggested. This study was carried out to explore the plasma protein oxidation and its sialic acid content in dengue infection. Thirty-two dengue hemorrhagic fever (DHF), 25 dengue shock syndrome (DSS), 29 dengue fever (DF), and 63 healthy controls were included in this study. The extent of carbonylation, sulphydryl content, and desialylation of plasma protein was estimated in acute phase sample. Significantly higher levels of protein carbonyls and lower levels of sialic acid and sulphydryl groups were found in DHF and DSS compared with DF using one-way analysis of variance. Regression analysis showed that desialylation is dependent on protein carbonyls in DHF/DSS. This study indicates that, in dengue infection, plasma proteins undergo increased levels of desialylation, which can be attributed to the oxidative stress. Future studies on sialylation status of endothelium and platelets can show light into the pathogenesis of the dengue infection.

Humoral immune response of dengue hemorrhagic fever cases in children from Tegucigalpa, Honduras

The humoral immune response in Honduran dengue hemorrhagic fever (DHF) hospitalized pediatric cases from the epidemics of 2004 and 2005 was studied in sera collected from 5 to 7 days of fever onset. A total of 145 cases were included in the study: 40 classified as primary with DHF Grade I or II and 86 classified as secondary; from them, 73 were DHF Grade I or II and 13 were dengue shock syndrome (DSS) Grade III or IV. The highest number of primary cases was found in children < 1 year of age. The highest number of secondary cases was observed in children between 5 and 10 years of age. The IgA values showed a statistically significant difference between primary and secondary groups. The relationship between antibody responses and severity grade is discussed. This is the first study related to the humoral immune response and severity grade in DHF cases in Honduran children.

Blood zinc levels and clinical severity of dengue hemorrhagic fever in children

The aims of the study were to investigate the relationship between blood zinc levels and the severity of DHF. A cross-sectional study was conducted involving 51 children at Budhi Asih Hospital, Jakarta, from March to May, 2005. Blood zinc levels were measured with a colorimeter using 5-BR-PAPS. The diagnosis and grading of DHF was determined according to WHO criteria. On analyzing the data, z test, ANNOVA, chi-square, linear regression and coefficient of correlation, were applied appropriately with p < or = 0.05. Forty-five samples were obtained consisting of 15 boys and 30 girls, age 75 +/- 35 months, body mass index of 15.1 +/- 3.2, pre-admission fever for 4.4 +/- 1.6 days, a hematocrit of 38.4 +/- 5.1%, a thrombocyte count of 77,200 +/- 32,100/dl, and a zinc level of 6.4 +/- 6.3 micromol/l, of with 34 had low and 11 were high zinc level cases (cutoff point: 9.18 micromol/l). The clinical severity in the low and high zinc groups were not significantly different. The blood zinc level in DHF grade 4 was not significantly lower than in the other three grades (p>0.05). The numbers of lymphocytes in the four grades were significantly different (p<0.01), between the low and high zinc groups (p<0.05). The association between lymphocytes and zinc levels showed a linear regression of Yc: 42.04+1.30X, p<0.05 and a coefficient correlation of r: 0.47. Therefore, no association was found between zinc levels and clinical severity of DHF in children.

Early predictors of haemorrhage in acute febrile syndrome patients from Bucaramanga, Colombia: a dengue endemic area

INTRODUCTION

Spontaneous haemorrhage is an important cause of hospitalisation in dengue patients. Early predictors of these complications could help to make opportune decisions.

METHODS

We prospectively evaluated 51 febrile patients (without previous spontaneous haemorrhage), including 32 cases of dengue fever. Initial evaluation was performed during the first 96 hours after the onset of fever and included complete blood cell count and coagulation tests. Participants were followed-up daily until the seventh day of the disease.

RESULTS

Overall, 15 patients developed spontaneous haemorrhage during the follow-up. Tourniquet test and dengue infection were not associated with haemorrhage (p-value is greater than 0.2). In a logistic regression analysis, platelet count (odds-ratio [OR] 0.78; 95 percent confidence interval [CI] 0.65-0.94) and partial thromboplastin time (OR 1.78; 95 percent CI 1.06-2.99) were independently associated with spontaneous haemorrhage.

CONCLUSION

Early alterations in platelet count and coagulation test could predict spontaneous bleeding in the acute febrile syndrome.

Biochemical alterations as markers of dengue hemorrhagic fever

We evaluated biochemical alterations as predictors of dengue hemorrhagic fever (DHF). Patients with confirmed infection with dengue virus were prospectively evaluated for the first seven days of disease to determine their final clinical outcome. Serum samples taken 48-96 hours after onset of fever were used for biochemical tests. Of 199 patients, 30 developed DHF. Cases of DHF had higher levels of lactate dehydrogenase (LDH), creatine kinase (CK), and aspartate aminotransferase, and lower levels of albumin, total cholesterol, and triglycerides. Multivariate analysis showed that early alterations of CK (hazard ratio [HR] = 6.98, 95% confidence interval [CI] = 2.34-20.85, P = 0.001), LDH (HR = 3.19, 95% CI = 1.01-10.12, P < 0.05), and albumin (HR = 2.54, 95% CI = 1.09-5.92, P = 0.03) were associated with DHF. Triglyceride levels > 160 mg/dL were negatively associated with developing DHF (HR = 0.07, 95% CI = 0.01-0.59, P = 0.01). Early alterations of biochemical markers can predict DHF in patients with acute fever caused by dengue.

[Predictors of spontaneous bleeding in dengue patients: a systematic review of the literature]

Spontaneous bleeding is a frequent complication in dengue patients and it is associated with increased mortality. In order to identify predictors of spontaneous hemorrhages in dengue, a systematic revision of literature was performed using the data base of PubMed. The available data has been obtained from cross sectional, cases and controls and retrospective cohort studies. In these studies, thrombocytopenia and alterations of coagulation mechanisms have been the variables more frequently associated to bleeding in dengue. Other manifestations like tourniquet test, changes of blood pressure, pleural effusion and hepatic alterations, among others, have also been suggested as potential predictors of spontaneous hemorrhages. In this article, available evidence is discussed and the author suggests evaluating these results in prospective cohort studies.