The usefulness of clinical-practice-based laboratory data in facilitating the diagnosis of dengue illness

Coagulation abnormalities in Dengue fever infection: A systematic review and meta-analysis

BACKGROUND

Coagulation mechanisms are reported to be affected in dengue illness and evidenced by prolonged activated partial thromboplastin time (APTT) and prothrombin time (PT). The main aim of this systematic review and meta-analysis is to determine the magnitude of coagulation abnormalities among patients with dengue fever infection.

METHOD

This systematic review and meta-analysis were conducted per the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline. The Joana Brigg's Institute (JBI) critical appraisal checklist was used for quality appraisal. STATA version 11 software was used for meta-analysis. The magnitude of coagulation abnormalities among dengue fever patients was determined by using a random-effects model. Subgroup and sensitivity analysis were performed to investigate the possible source of heterogeneity. Egger weighted regression tests were used to check the presence of publication bias among the included articles.

RESULT

Forty-two studies with a total of 12,221 dengue fever patients were eligible for meta-analysis in this study. Of which 22, 15, and 26 studies were used to determine the magnitude of prolonged APTT, PT, and thrombocytopenia, respectively. The magnitude of prolonged APTT and PT among patients with dengue fever infection were 42.91% (95% CI: 30.95, 54.87) I2 = 99.1% and 16.48% (95% CI: 10.95, 22.01) I2 = 97.0%, respectively. Besides, the magnitude of thrombocytopenia among dengue fever patients was 70.29% (95% CI: 62.69, 77.89) I2 = 99.3%. The magnitude of prolonged APTT in children and adults was 51.21% (95% CI: 24.54, 77.89) and 44.89% (95% CI: 28.32, 61.45), respectively. Similarly, the overall magnitude of prolonged PT in children and adults were 13.40% (95% CI: 6.09, 20.71) and 18.73% (95% CI: 7.49, 29.96), respectively.

CONCLUSION

The result of this study showed that there is a high magnitude of prolonged APTT and PT in dengue fever patients. Therefore, screening and early correction of coagulation abnormalities may be helpful to reduce further complications in those patients.

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.

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).

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Clinical features and dynamic ordinary laboratory tests differentiating dengue fever from other febrile illnesses in children

BACKGROUND

Dengue fever is not easily to be diagnosed before presentation of the classic symptoms. The study aimed to investigate the clinical features and dynamic laboratory tests in pediatric patients to facilitate dengue diagnosis.

METHODS

This retrospective study examined the medical records of all pediatric patients who were clinically suspected to have dengue from June to December 2014. Laboratory-positive dengue cases were confirmed by detecting non-structural protein NS1, reverse transcription-polymerase chain reaction of dengue virus, and dengue-specific IgM seroconversion.

RESULTS

Of the 317 pediatric cases clinically suspected of dengue, 205 were laboratory-positive and 112 were laboratory-negative. In laboratory-positive cases, the most common clinical manifestation was skin rash in 156 (76.1%). Leukopenia occurred on days 1-5; thrombocytopenia, on days 2-7; prolonged activated partial thromboplastin time (aPTT), on days 1-4; and elevated transaminase levels, on days 3-11; and low CRP, on days 0-14. The specificity and positive predictive value (PPV) of combining of rash, itching and petechiae increased up to 100%. The PPV of combining of leukopenia, thrombocytopenia, and elevated transaminase levels reached 100% on day 2 as well as days 6-8.

CONCLUSION

Leukopenia, thrombocytopenia, elevated aPTT, elevated transaminase levels, and low CRP could be used to differentiate dengue fever from other febrile illnesses. During dengue epidemics, combinations of the symptoms and laboratory findings are helpful to physicians for accurate diagnosis of dengue fever.

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.

Dengue fever in a south Asian metropolis: a report on 219 cases

BACKGROUND AND OBJECTIVES

Yearly epidemics of Dengue fever occur post-monsoon in India's capital, Delhi. A prospective observational study was conducted during the outbreak months to understand the epidemiology and outcome of this infection and its economic impact.

MATERIALS AND METHODS

Febrile hospitalized (n=219) patients with dengue fever diagnosed by a combination of MAC-ELISA, GAC-ELISA and NS1Antigen-ELISA were enrolled. Epidemiologic (including economic) parameters, clinical, radiological and laboratory manifestations were noted and patients followed up over the period of hospital stay. Patient management means and outcome were recorded and analysed.

RESULTS

As per WHO-2009, 153 (69.9%) and 27 (12.3%) patients were classified as dengue with warning signs and Severe Dengue respectively while according to WHO-1997 guidelines 39 (17.8%) and 18 (8.2%) patients were classified as DHF and DSS respectively. 216 patients were from the city while three were travellers; hospitalization was more frequent among the young and male gender. Fever, vomiting, aches and abdominal pain were the most common troublesome manifestations; classical dengue triad was present in 55 (25.1%) patients; hemorrhagic, neurologic and mucocutaneous manifestations were present in 44 (20.1%), 8 (3.7%) and 70 (32%) patients. Ascitis, pleural effusion, and Gall bladder wall oedema was found in 53 (24.2%), 31 (14.1%) and 45 (20.5%) patients respectively. Mortality was 1.4% (3 deaths); in addition there was an intra-uterine fetal death; mean expenditure per patient during the illness was US$ 377.25.

CONCLUSION

Dengue virus infection results in immense morbidity and substantial mortality.

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.

Maintenance of demographic and hematological profiles in a long-lasting dengue fever outbreak: implications for management

Background

Dengue fever (DF) outbreaks present regionally specific epidemiological and clinical characteristics. In certain medium-sized cities (100 000–250 000 inhabitants) of São Paulo State, Brazil, and after reaching an incidence of 150 cases/100 000 inhabitants (“epidemiological threshold”), clinical diagnosis indicated dengue virus (DENV) infection. During this period, other seasonally infectious diseases with symptoms and physical signs mimicking DF can simultaneously occur, with the consequential overcrowding of health care facilities as the principal drawbacks. Confirmation of clinical diagnosis of DF with serological tests may help in avoiding faulty diagnosis in patients, who might later undergo dengue hemorrhagic fever (DHF) and the dengue-shock syndrome (DSS). Furthermore, demographic and hematological profiles of patients are useful in detecting specific early characteristics associated to DF, DHF and DSS.

Methods

From March to June, 2007, 456 patients from Marilia in northwest São Paulo State who had only been diagnosed for DF by clinical criteria, underwent serologic testing for non-structural 1 (NS1) DENV antigens. Individual results were used in comparative analysis according to demographic (gender, age) and hematological (leukocyte and platelet counts, percentage of atypical lymphocytes) profiles. Temporal patterns were evaluated by subdividing data according to time of initial attendance, using recorded variables as predictors of DENV infection in logistic regression models and ROC curves.

Results

Serologic DENV detection was positive in 70.6 % of the patients. Lower leukocyte and platelet counts were the most important factors in predicting DENV infection (respective medians DENV + = 3 715 cells/ml and DENV- = 6 760 cells/ml, and DENV + = 134 896 cells/ml and DENV- = 223 872 cells/ml). Furthermore, all demographic and hematological profiles presented a conservative temporal pattern throughout this long-lasting outbreak.

Conclusions

As consistency throughout the epidemic facilitated defining the conservation pattern throughout the early stages, this was useful for improving management during the remaining period.

Electronic supplementary material

The online version of this article (doi:10.1186/s40249-016-0177-y) contains supplementary material, which is available to authorized users.

Viral Hemorrhagic Fever Diagnostics

There are 4 families of viruses that cause viral hemorrhagic fever (VHF), including Filoviridae. Ebola virus is one virus within the family Filoviridae and the cause of the current outbreak of VHF in West Africa. VHF-endemic areas are found throughout the world, yet traditional diagnosis of VHF has been performed in large reference laboratories centered in Europe and the United States. The large amount of capital needed, as well as highly trained and skilled personnel, has limited the availability of diagnostics in endemic areas except in conjunction with governmental and nongovernmental entities. However, rapid diagnosis of VHF is essential to efforts that will limit outbreaks. In addition, increased global travel suggests VHF diagnoses may be made outside of the endemic areas. Thus, understanding how to diagnose VHF is imperative for laboratories worldwide. This article reviews traditional and current diagnostic modalities for VHF.

Thrombocytopenia in Dengue: Interrelationship between Virus and the Imbalance between Coagulation and Fibrinolysis and Inflammatory Mediators

Dengue is an infectious disease caused by dengue virus (DENV). In general, dengue is a self-limiting acute febrile illness followed by a phase of critical defervescence, in which patients may improve or progress to a severe form. Severe illness is characterized by hemodynamic disturbances, increased vascular permeability, hypovolemia, hypotension, and shock. Thrombocytopenia and platelet dysfunction are common in both cases and are related to the clinical outcome. Different mechanisms have been hypothesized to explain DENV-associated thrombocytopenia, including the suppression of bone marrow and the peripheral destruction of platelets. Studies have shown DENV-infected hematopoietic progenitors or bone marrow stromal cells. Moreover, anti-platelet antibodies would be involved in peripheral platelet destruction as platelets interact with endothelial cells, immune cells, and/or DENV. It is not yet clear whether platelets play a role in the viral spread. Here, we focus on the mechanisms of thrombocytopenia and platelet dysfunction in DENV infection. Because platelets participate in the inflammatory and immune response by promoting cytokine, chemokine, and inflammatory mediator secretion, their relevance as "immune-like effector cells" will be discussed. Finally, an implication for platelets in plasma leakage will be also regarded, as thrombocytopenia is associated with clinical outcome and higher mortality.