Incidence and Clinical Outcome of Acute Liver Failure Caused by Dengue in a Hospital for Tropical Diseases, Thailand

Gastrointestinal Manifestations and Prognostic Factors for Severe Dengue in Thai Children

Dengue infection poses a significant public health challenge in tropical countries. In Thailand, children ages 5-14 years are among the groups with the highest incidence of dengue. This study aimed to determine the prevalence of gastrointestinal (GI) manifestations in children with dengue infection and assess prognostic factors for severe dengue. We reviewed the medical records of children ages 0-14 years who were hospitalized with a diagnosis of dengue infection between 2019 and 2022 at Charoenkrung Pracharak Hospital in Bangkok, Thailand. Dengue severity was classified according to the 2009 WHO dengue guidelines. Clinical manifestations and laboratory data were analyzed for their association with severe dengue using a logistic regression model. The study included 556 dengue cases, with 48 cases (8.6%) classified as severe dengue. The mean age (SD) of patients was 9.9 (3.7) years. The most common GI symptoms were anorexia (91.7%) and vomiting (57.6%) followed by abdominal pain (38.3%), and diarrhea (33.3%). GI bleeding was found in 3.2% of patients. Hepatomegaly and ascites were found in 20.9% and 2.9% of patients, respectively. Acute liver failure and acalculous cholecystitis were found in 0.4% and 0.2% of patients, respectively. Children younger than 5 years of age exhibited a lower prevalence of vomiting and abdominal pain compared with older children, making the diagnosis of dengue more challenging. Vomiting, ascites, aspartate aminotransferase >450 U/L, and serum albumin <3.5 g/dL were significantly associated with severe dengue infection. Children with dengue infection presenting any of these factors should be closely monitored for severe dengue.

Role of Plasma Exchange and Combining Therapies in Dengue-Associated Acute Liver Failure: A Systematic Review of Individual Cases

Background/Aims

Dengue-associated acute liver failure (ALF) poses a significant risk for mortality, especially in regions lacking access to liver transplantation. Although Plasma Exchange (PLEX) is recognized as a potential therapeutic intervention for dengue-associated ALF, data on its efficacy remain limited. This systematic review aimed to comprehensively examine the literature on PLEX and other combination therapies for dengue-associated ALF. It focused on assessing their effectiveness, safety profile, and potential implications for therapeutic interventions.

Methods

In this study, we conducted a systematic review to assess the efficacy and safety of PLEX and other combination therapies in patients with dengue-associated ALF. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses criteria were used to search the PubMed, Scopus, Embase, Ovid, and Google Scholar databases. Studies published in English between 2019 and May 2024 were included. The titles and abstracts were reviewed for discrepancies, and any differences were resolved through discussion.

Results

Among the 713 studies assessed for review, 9 met the eligibility criteria. Studies have demonstrated that PLEX, both alone and in combination with other therapies, such as continuous renal replacement therapy (CRRT), improves liver function, survival rates, and neurological outcomes in patients with dengue virus. Both high- and low-volume plasma exchanges were effective.

Conclusion

This systematic review highlights the beneficial role of PLEX and the potential benefits of combination therapies in the treatment of rare and severe forms of dengue-associated ALF. However, given the limited sample sizes and the necessity for well-designed studies, further investigations are needed to determine the optimal volume of PLEX and the efficacy of additional therapeutic strategies.

Predicting the risk of mortality in children with dengue-induced hepatitis admitted to the paediatric intensive care unit

BACKGROUND

Dengue-associated acute liver failure (PALF) accounts for a high mortality rate in children admitted to the pediatric intensive care unit (PICU). To date, there is a lack of data on clinical algorithms for estimating the risk of mortality in pediatric patients with dengue-induced severe hepatitis (DISH).

AIM

To determine the prevalence of PALF and identify the predictors of mortality among patients with DISH.

METHODS

This single-institution retrospective study was performed at a tertiary pediatric hospital in Vietnam between 2013 and 2022. The primary outcome was in-hospital mortality in pediatric patients with DISH, which was defined as either aspartate aminotransferase > 350 IU/L or alanine aminotransferase > 400 IU/L. Prognostic models for estimating the risk of death among patients with DISH were developed using a predefined set of clinical covariables and hepatic biomarkers on PICU admission and during the first 72 hours of admission. Area under the curve, multivariable logistic regression, and multiple imputation using the chained equation for missing values were performed. Backward stepwise model selection based on the Akaike information criterion was employed. Bootstrapping, calibration slope, and Brier score were used to assess the final models.

RESULTS

A total of 459 children with DISH were included in the analysis. The median patient age was 7.7 years (interquartile range: 4.3-10.1 years). The prevalence of dengue-associated PALF in children with DISH was 18.3%. Thirty-nine DISH patients developing PALF (8.5%) died. Hepatic biomarkers, including the international normalized ratio (INR) ≥ 2.11 and total serum bilirubin (≥ 1.7 mg/dL), showed high predictive values for mortality (all P values < 0.001). Multivariable models showed the significant clinical predictors of death from dengue-induced PALF in patients with DISH, including reduced level of consciousness (pain and unresponsive levels on the Alert, Verbal, Pain, Unresponsive scale), high vasoactive-inotropic score (> 30), and elevated levels of blood lactate, INR, and serum bilirubin. The final prognostic model demonstrated high discrimination, Brier score, and an acceptable calibration slope.

CONCLUSION

The prevalence of PALF in children with DISH is 18.3%. We developed robust prognostic models to estimate the risk of death in hospitalized children with severe dengue-induced hepatitis.

Validation of prognostic scores for predicting acute liver failure and in-hospital death in patients with dengue-induced severe hepatitis

BACKGROUND

Acute liver failure (ALF) in dengue is rare but fatal. Early identification of patients who are at risk of ALF is the key strategy to improve survival.

AIM

To validate prognostic scores for predicting ALF and in-hospital mortality in dengue-induced severe hepatitis (DISH).

METHODS

We retrospectively reviewed 2532 dengue patients over a period of 16 years (2007-2022). Patients with DISH, defined as transaminases > 10 times the normal reference level and DISH with subsequent ALF, were included. Univariate regression analysis was used to identify factors associated with outcomes. Youden's index in conjunction with receiver operating characteristic (ROC) analysis was used to determine optimal cut-off values for prognostic scores in predicting ALF and in-hospital death. Area under the ROC (AUROC) curve values were compared using paired data nonparametric ROC curve estimation.

RESULTS

Of 193 DISH patients, 20 developed ALF (0.79%), with a mortality rate of 60.0%. International normalized ratio, bilirubin, albumin, and creatinine were independent predictors associated with ALF and death. Prognostic scores showed excellent performance: Model for end-stage liver disease (MELD) score ≥ 15 predicted ALF (AUROC 0.917, sensitivity 90.0%, specificity 88.4%) and ≥ 18 predicted death (AUROC 0.823, sensitivity 86.9%, specificity 89.1%); easy albumin-bilirubin (ALBI) score ≥ -30 predicted ALF and death (ALF: AUROC 0.835, sensitivity80.0%, specificity 72.2%; death: AUROC 0.808, sensitivity 76.9%, specificity 69.3%); ALBI score ≥ -2 predicted ALF and death (ALF: AUROC 0.806, sensitivity 80.0%, specificity 77.4%; death: AUROC 0.799, sensitivity 76.9%, specificity 74.3%). Platelet-ALBI score also showed good performance in predicting ALF and death (AUROC = 0.786 and 0.699, respectively). MELD and EZ-ALBI scores had similar performance in predicting ALF (Z = 1.688, P = 0.091) and death (Z = 0.322, P = 0.747).

CONCLUSION

MELD score is the best predictor of ALF and death in DISH patients. EZ-ALBI score, a simpler yet effective score, shows promise as an alternative prognostic tool in dengue patients.

Incidence of acute liver failure and its associated mortality in patients with dengue infection: A systematic review and meta-analysis

Acute liver failure (ALF) is a devastating consequence of dengue infection. This systematic review and meta-analysis assessed the incidence of ALF in dengue infection and its associated mortality. We systematically searched the EMBASE and MEDLINE databases from inception to December 2023 for observational studies reporting ALF incidence and mortality in dengue patients. Twenty-one studies encompassing 26,839 dengue-infected patients were included. Meta-analysis revealed a pooled incidence of ALF in cases of general dengue infection of 2.0 % (95 % CI, 1.2-3.0 %), with 1.2 % (95 % CI, 0.6-2.1 %) in adults and 5.0 % (95 % CI, 1.5-10.2 %) in children. ALF incidence was 17.3 % (95 % CI, 6.5 %-31.5 %) in severe dengue and 7.4 % (95 % CI, 0.8-18.5 %) in dengue shock syndrome. The pooled mortality rate of dengue-associated ALF was 47.0 % (95 % CI, 32.9-61.2 %). These findings underscore the detrimental impact of dengue infection on the development of the relatively uncommon, albeit life-threatening, condition of ALF.

Liver involvement in dengue: A systematic review

Liver involvement is an unusual yet frequently overlooked dengue complication. Pivotal for an efficient clinical management, the early diagnosis of dengue-associated liver involvement relies on an accurate description of its clinical and biological characteristics, its prognosis factors, its association with severe dengue and its clinical management. We conducted a systematic review by searching PubMed and Web of Science databases for original case reports, cohort and cross-sectional studies reporting the clinical and/or biological features of dengue-associated liver involvement. The study was registered in PROSPERO (CRD42021262657). Of the 2552 articles identified, 167 were included. Dengue-associated liver involvement was characterised by clinical features including abdominal pain, hepatomegaly, jaundice, nausea/vomiting, and an echogenic liver exhibiting hepatocellular necrosis and minimal inflammation. Elevated Aspartate Aminotransferase and Alanine Aminotransferase but also elevated bilirubin, Alkaline Phosphatase, gamma-glutamyl transferase, increased International Normalised Ratio, creatinine and creatine kinase, lower albumin and prolonged prothrombin and activated partial thromboplastin time were prevalent in dengue-associated liver involvement. Cardiovascular and haematological systems were frequently affected, translating in a strong association with severe dengue. Liver involvement was more common in males and older adults. It was associated with dengue virus serotype-2 and secondary infections. Early paracetamol intake increased the risk of liver involvement, which clinical management was mostly conservative. In conclusion, this systematic review demonstrates that early monitoring of transaminases, clinical assessment, and ultrasound examination allow an efficient diagnosis of dengue-associated liver involvement, enabling the early identification and management of severe dengue.

A curious case of expanded dengue syndrome

Dengue fever (DF) primarily presents with fever, headache, malaise, bleeding manifestations and haemoconcentration. World Health Organization (WHO) classifies DF according to levels of severity: (a) without warning signs; (b) with warning signs, such as abdominal pain, persistent vomiting, fluid accumulation, mucosal bleeding, lethargy, liver enlargement, increasing haematocrit and thrombocytopenia; and (c) severe dengue with severe plasma leakage, severe bleeding or organ failure. Atypical clinical presentations of DF are defined as expanded dengue syndrome: this includes renal, cardiac, hepatic or cerebral damage. We report such a severe case where a young man developed acute kidney injury, acute fulminant liver failure and acute pancreatitis secondary to DF, but recovered.

Viral hepatitis-induced acute liver failure

Viral hepatitis-induced acute liver failure (ALF) is a preventable cause for liver-related mortality worldwide. Viruses are the most common cause for ALF in developing nations in contrast to the west, where acetaminophen is largely responsible. Viruses may be hepatotropic or affect the liver secondary to a systemic infection. In tropical countries, infections such as leptospirosis, scrub typhus and malaria can mimic the symptoms of ALF. Differentiating these ALF mimics is crucial because they require etiology-specific therapy. Treatment of viral hepatitis-induced ALF is two-pronged and directed towards providing supportive care to prevent organ failures and antiviral drugs for some viruses. Liver transplantation (LT) is an effective modality for patients deteriorating despite adequate supportive care. Early referral and correct identification of patients who require a transplant are important. Liver support devices and plasma exchange have evolved into "bridging modalities" for LT. Preventive strategies such as hand hygiene, use of clean and potable water and inclusion of vaccines against viral hepatitis in the national program are simple yet very effective methods focusing on the preventive aspect of this disease.

Dengue-related acute liver failure-A scoping review

Infection by dengue virus is common in tropical countries. Hepatic involvement in dengue can range from asymptomatic elevation of transaminases to life-threatening acute liver failure (ALF). Dengue-related ALF (DALF) is responsible for significant morbidity and mortality, especially in Southeast Asia. However, there is a scarcity of literature on DALF, necessitating a thorough examination of its clinical determinants and management strategies. All relevant studies related to DALF were reviewed until December 2023. Case reports, case series and studies reporting ALF in dengue infection were included. Demographics, clinical profiles, management and outcomes of DALF cases were analyzed, which revealed a predominance of DALF incidence in pediatric patients (1.1% to 15.8%) and an upward trend over the years, particularly in India. The proportion of ALF cases attributable to dengue was also higher among pediatric ALF patients (6.7% to 34.3%). Age ≤ 40 years, persistent nausea, vomiting and elevated serum bilirubin and alkaline phosphatase (ALP) with aspartate aminotransferase (AST) > 1000 IU/mL within the first five days of illness, more than 10% of atypical lymphocytes in peripheral blood, platelet count of < 50,000/cu·mm, severe hepatitis at presentation and baseline model for end-stage liver disease (MELD) > 15 were the risk factors for the development of DALF. Histopathological features of DALF included multi-lobular hepatic necrosis, steatosis and occasional cholestasis. Mortality in DALF ranged from 0% to 80%; admission pH and lactate strongly predicted mortality, while mortality was found to be significantly higher in patients with cirrhosis. N-Acetyl cysteine (NAC) has been used as a treatment modality with varying results. There is limited evidence regarding the use of extra-corporeal support systems, while candidate selection for liver transplantation (LT) in DALF remains poorly defined.

Severe dengue infection unmasking drug-induced liver injury: Successful management with N-acetylcysteine

Key Clinical Message

Clinicians in tuberculosis and dengue endemic regions should have heightened vigilance for drug-induced liver injury (DILI) overlapping with active infections, enabling prompt recognition and life-saving conservative management.

Abstract

Severe dengue and drug-induced liver injury (DILI) are significant independent risk factors for acute liver failure. The co-occurrence of these conditions significantly complicates clinical management. Here, we describe the case of a 21-year-old Nepali female who developed acute liver failure during antitubercular therapy (ATT). The patient, presenting with fever and nausea after 3 weeks of ATT, subsequently received a diagnosis of severe dengue. Laboratory evidence indicated markedly elevated transaminases (AST 4335 U/L, ALT 1958 U/L), total bilirubin (72 μmol/L), and INR (>5). Prompt discontinuation of first-line ATT, initiation of a modified ATT regimen, and N-acetylcysteine (NAC) infusion facilitated the patient's recovery after a week of intensive care. This case underscores the potential for synergistic hepatotoxicity in regions where multiple endemic illnesses coincide. Early recognition of DILI, cessation of offending agents, and comprehensive intensive care are crucial interventions. While the definitive efficacy of NAC remains under investigation, its timely administration in these complex cases warrants exploration for its potential lifesaving benefits.

Associations of obesity and dengue-associated mortality, acute liver failure and mechanical ventilation in children with dengue shock syndrome

Dengue-associated complications, including dengue shock syndrome, severe respiratory distress, and pediatric acute liver failure (PALF), are associated with high mortality rates in patients with dengue. There is increasing prevalence of overweight and obesity among children worldwide. Obesity may activate inflammatory mediators, leading to increased capillary permeability and plasma leakage in patients with dengue. Several studies have shown a correlation between obesity and DSS, but did not include dengue fatality or PALF. Therefore, we hypothesized possible associations between obesity and critical dengue-associated clinical outcomes among PICU-admitted children with DSS, including dengue-related mortality, mechanical ventilation (MV) requirements, and dengue-associated PALF. The nutritional status of the participants was assessed using World Health Organization growth charts. A total of 858 participants with complete nutritional data were enrolled in this study. Obesity was significantly associated with risk of severe respiratory failure and MV support (odds ratio = 2.3, 95% CI: 1.31-4.06, P < .01); however, it was not associated with dengue-associated mortality or acute liver failure. Obese pediatric patients with DSS should be closely monitored for severe respiratory distress and the need for high-flow oxygenation support, particularly MV, soon after hospitalization.

Acute liver failure in low-income and middle-income countries

Acute liver failure is a rare condition involving the rapid development, progression, and worsening of liver dysfunction, characterised by coagulopathy and encephalopathy, and has a high mortality unless liver transplantation is performed. Population-based studies are scarce, and most published data are from high-income countries, where the main cause of acute liver failure is paracetamol overdose. This Review provides an overview of the scanty literature on acute liver failure in low-income and middle-income countries, where patients are often admitted to primary care hospitals and viral hepatitis (especially hepatitis E), tropical infections (eg, dengue), traditional medicines, and drugs (especially anti-tuberculosis drugs) have an important role. We discuss incidence, cause, occurrence in children and pregnant women, prognostic factors and scores, treatment, and mortality. To conclude, we advocate for international collaboration, the establishment of central registries for the condition, and better diagnostics.

Combined Therapeutic Plasma Exchange and Continuous Renal Replacement Therapy in Children With Dengue-Associated Acute Liver Failure and Shock Syndrome: Single-Center Cohort From Vietnam

OBJECTIVES

Pediatric acute liver failure (PALF) is a fatal complication in patients with severe dengue. To date, clinical data on the combination of therapeutic plasma exchange (TPE) and continuous renal replacement therapy (CRRT) for managing dengue-associated PALF concomitant with shock syndrome are limited.

DESIGN

Retrospective cohort study (January 2013 to June 2022).

PATIENTS

Thirty-four children.

SETTING

PICU of tertiary Children's Hospital No. 2 in Vietnam.

INTERVENTIONS

We assessed a before-versus-after practice change at our center of using combined TPE and CRRT (2018 to 2022) versus CRRT alone (2013 to 2017) in managing children with dengue-associated acute liver failure and shock syndrome. Clinical and laboratory data were reviewed from PICU admission, before and 24 h after CRRT and TPE treatments. The main study outcomes were 28-day in-hospital mortality, hemodynamics, clinical hepatoencephalopathy, and liver function normalization.

MEASUREMENTS AND MAIN RESULTS

A total of 34 children with a median age of 10 years (interquartile range: 7-11 yr) underwent standard-volume TPE and/or CRRT treatments. Combined TPE and CRRT ( n = 19), versus CRRT alone ( n = 15), was associated with lower proportion of mortality 7 of 19 (37%) versus 13 of 15 (87%), difference 50% (95% CI, 22-78; p < 0.01). Use of combined TPE and CRRT was associated with substantial advancements in clinical hepatoencephalopathy, liver transaminases, coagulation profiles, and blood lactate and ammonia levels (all p values < 0.001).

CONCLUSIONS

In our experience of children with dengue-associated PALF and shock syndrome, combined use of TPE and CRRT, versus CRRT alone, is associated with better outcomes. Such combination intervention was associated with normalization of liver function, neurological status, and biochemistry. In our center we continue to use combined TPE and CRRT rather than CRRT alone.

Unforeseen complications: a case of dengue shock syndrome presenting with multi-organ dysfunction in a subtropical region

OVERVIEW

Dengue fever, a viral illness transmitted by the Aedes mosquito, is capable of causing a range of serious complications, including fulminant hepatic failure, renal dysfunction, encephalitis, encephalopathy, neuromuscular and ophthalmic disorders, seizures, and cardiomyopathy.

CASE DESCRIPTION

This report details the case of a 30-year-old lactating woman with no notable medical history who presented to the emergency department with symptoms of high-grade fever, altered mental status, and seizures. Upon imaging, bilateral infarcts in the thalami and cerebellar hemispheres were observed, consistent with cerebellitis and dengue encephalitis.

PATIENT TREATMENT AND OUTCOME

The patient was admitted to the intensive care unit and received appropriate treatment. Following a critical phase and successful patient stabilization, she was transferred to a high dependency unit for a week before being discharged with recommendations for follow-up care.

CONCLUSION

This case illustrates the broad spectrum of complications that can arise as a result of dengue infection and the importance of timely diagnosis and management in improving patient outcomes. Further investigation is required to better understand the mechanisms underlying these complications and to formulate specific guidelines for the prevention and treatment of dengue shock syndrome.

Prognostic Scores in Acute Liver Failure Due to Viral Hepatitis

Viral infections are among the major causes of acute liver failure (ALF) worldwide. While the role of agents such as hepatitis A, B, C, D and E viruses in precipitating ALF are well known, improvements in serological assays have led to the detection of viral agents such as Epstein Barr virus, cytomegalovirus etc. as atypical causes of ALF. Despite the plethora of literature available on viral hepatitis and ALF, there is very limited large-scale epidemiologic data on the prevalence, risk factors of progression and outcomes in ALF of viral causes. This is important as viral infections remain the leading cause of ALF in the East and in developing countries, while the impact of viral ALF in the West has largely been ameliorated by effective vaccination and sanitization programs. This review focuses specifically on the available prognostic scores that aid in the management of ALF of viral etiologies while also briefly reviewing the current literature on newer viral agents known to cause ALF, risk factors of progression, outcomes and how management algorithms can be developed by incorporation of prognostic scoring systems for referral and transplant listing.

Alpha-mangostin inhibits viral replication and suppresses nuclear factor kappa B (NF-κB)-mediated inflammation in dengue virus infection

Severe dengue virus (DENV) infection results from viral replication and dysregulated host immune response, which trigger massive cytokine production/cytokine storm. The result is severe vascular leakage, hemorrhagic diathesis, and organ dysfunction. Subsequent to previously proposing that an ideal drug for treatment of DENV infection should efficiently inhibit both virus production and cytokine storm, we discovered that α-mangostin (α-MG) from the pericarp of the mangosteen fruit could inhibit both DENV infection and cytokine/chemokine production. In this study, we investigated the molecular mechanisms underlying the antiviral and anti-inflammatory effects of α-MG. Time-of-drug-addition and time-of-drug-elimination studies suggested that α-MG inhibits the replication step of the DENV life cycle. α-MG inhibited polymerization activity of RNA-dependent RNA polymerase (RdRp) with IC50 values of 16.50 μM and significantly reduced viral RNA and protein syntheses, and virion production. Antiviral and cytokine/chemokine gene expression profiles of α-MG-treated DENV-2-infected cells were investigated by polymerase chain reaction array. α-MG suppressed the expression of 37 antiviral and cytokine/chemokine genes that relate to the NF-κB signaling pathway. Immunofluorescence and immunoblot analyses revealed that α-MG inhibits NF-κB nuclear translocation in DENV-2-infected cells in association with reduced RANTES, IP-10, TNF-α, and IL-6 production. These results suggest α-MG as a potential treatment for DENV infection.

Epidemiology of liver failure in Asia-Pacific region

The global burden of deaths caused by liver failure is substantial. The Asia-Pacific region is home to more than half of the global population and accounted for 62.6% of global deaths because of liver diseases in 2015. The aetiology of liver failure varies in different countries at different times. Viruses (Hepatitis A, B and E), drugs (herbs and anti-tuberculous drugs), toxins (alcohol use) and autoimmune flares are mainly responsible of majority of liver failure in individuals with normal liver (acute liver failure; ALF); else these may precipitate liver failure in those with chronic liver disease (acute-on-chronic liver failure; ACLF). Concomitant increases in alcohol misuse and metabolic syndrome in recent years are concerning. Ongoing efforts to address liver failure-related morbidity and mortality require accurate contemporary estimates of epidemiology and outcomes. In light of the ever-changing nature of liver disease epidemiology, accurate estimates for the burden of liver failure across the countries are vital for setting clinical, research and policy priorities. In this review, we aimed to describe the current as well as changing epidemiological trends of common liver failure syndromes, ALF and ACLF in the Asia-Pacific region.

Dengue and COVID-19: two sides of the same coin

BACKGROUND

Many countries in Asia and Latin America are currently facing a double burden of outbreaks due to dengue and COVID-19. Here we discuss the similarities and differences between the two infections so that lessons learnt so far from studying both infections will be helpful in further understanding their immunopathogenesis and to develop therapeutic interventions.

MAIN BODY

Although the entry routes of the SARS-CoV-2 and the dengue virus (DENV) are different, both infections result in a systemic infection, with some similar clinical presentations such as fever, headache, myalgia and gastrointestinal symptoms. However, while dengue is usually associated with a tendency to bleed, development of micro and macrothrombi is a hallmark of severe COVID-19. Apart from the initial similarities in the clinical presentation, there are further similarities between such as risk factors for development of severe illness, cytokine storms, endothelial dysfunction and multi-organ failure. Both infections are characterised by a delayed and impaired type I IFN response and a proinflammatory immune response. Furthermore, while high levels of potent neutralising antibodies are associated with protection, poorly neutralising and cross-reactive antibodies have been proposed to lead to immunopathology by different mechanisms, associated with an exaggerated plasmablast response. The virus specific T cell responses are also shown to be delayed in those who develop severe illness, while varying degrees of endothelial dysfunction leads to increased vascular permeability and coagulation abnormalities.

CONCLUSION

While there are many similarities between dengue and SARS-CoV-2 infection, there are also key differences especially in long-term disease sequelae. Therefore, it would be important to study the parallels between the immunopathogenesis of both infections for development of more effective vaccines and therapeutic interventions.

Risk Factors for Mortality in Patients with Dengue: A Systematic Review and Meta-Analysis

OBJECTIVE

To investigate risk factors for mortality in dengue.

METHODS

Systematic review and meta-analysis searching MEDLINE, Embase, SciELO, LILACS Bireme, and OpenGrey to identify eligible observational studies of patients with dengue, of both genders, aged 14 years or older, that analyzed risk factors associated with mortality and reported adjusted risk measures with their respective confidence intervals (CIs). We estimated the pooled weighted mean difference and 95% CIs with a DerSimonian and Laird random-effects model. Methodological quality was assessed using the Newcastle-Ottawa Scale.

RESULTS

Of 1,170 citations reviewed, 18 papers, with a total of 25,851 patients, were included in the systematic review and 12 in the meta-analysis. Severe hepatitis (OR 29.222, 95% CI: 3.876-220.314), dengue shock syndrome (OR 23.575, 95% CI 3.664-151.702), altered mental status (OR 3.76, 95% CI 1.67-8.42), diabetes mellitus (OR 3.698, 95% CI 1.196-11.433), and higher pulse rate (OR 1.039, 95% CI 1.011-1.067) are associated with mortality in patients with dengue. All studies included were classified as having a high quality.

CONCLUSIONS

Proper identification and management of these risk factors should be considered to improve patient outcomes and reduce the hidden burden of this neglected tropical disease. Future well-designed studies are needed to investigate the association of other clinical, radiological, and laboratorial findings with mortality in dengue, as well as to develop prognostic models based on the risk factors found in our study.

Dengue hemorrhagic fever and the liver

Dengue hemorrhagic fever (DHF) is one of the most rapidly emerging infections of tropical and subtropical regions worldwide. It affects more rural and urban areas due to many factors, including climate change. Although most people with dengue viral infection are asymptomatic, approximately 25% experience a self-limited febrile illness with mild to moderate biochemical abnormalities. Severe dengue diseases develop in a small proportion of these patients, and the common organ involvement is the liver. The hepatocellular injury was found in 60%-90% of DHF patients manifested as hepatomegaly, jaundice, elevated aminotransferase enzymes, and critical condition as an acute liver failure (ALF). Even the incidence of ALF in DHF is very low (0.31%-1.1%), but it is associated with a relatively high mortality rate (20%-68.3%). The pathophysiology of liver injury in DHF included the direct cytopathic effect of the DENV causing hepatocytes apoptosis, immune-mediated hepatocyte injury induced hepatitis, and cytokine storm. Hepatic hypoperfusion is another contributing factor in dengue shock syndrome. The reduction of morbidity and mortality in DHF with liver involvement is dependent on the early detection of warning signs before the development of ALF.

Dengue hemorrhagic fever and cardiac involvement

Dengue viral infection (DVI) is one of the world’s most significant viral infections spreading. Most of the patients have been asymptomatic, with relatively benign clinical manifestations and outcomes. However, a small number of patients have progressed to severe dengue diseases, including hemorrhage, multi-organ impairment, and increased vascular leakage causing hypovolemic shock, which can cause cardiovascular collapse and death. Numerous lines of evidence have demonstrated that DVI could also cause cardiac dysfunction, arrhythmias, and severe myocarditis. The treatment for dengue hemorrhagic fever (DHF) patients remains symptomatic and supportive, with close monitoring of hemodynamic status. The contributory role of cardiac dysfunction in DHF patients has potentially critical implications on the management. This review will address the current knowledge of cardiac involvement in DHF patients and the management strategy to reduce the fatality outcome.

Prevalence and clinical manifestations of dengue in older patients in Bangkok Hospital for Tropical Diseases, Thailand

BACKGROUND

The global incidence of dengue has increased with the ageing population. We examined the prevalence, clinical manifestations and risk factors associated with dengue severity among older patients.

METHODS

A retrospective cohort study was conducted at a hospital in Thailand from 2013 to 2018. Data were collected from patient records. Older patients were those aged ≥60 y, whereas adult patients were aged at least 18 y but younger than 60 y.

RESULTS

In total, 1822 patients were included in the study. The prevalence of older dengue was 7.96%. Older dengue patients were at a higher risk of developing dengue haemorrhagic fever (DHF) than adult dengue patients (40.69% vs 30.71%). Haematuria was significantly more frequent in older patients (24.82% vs 3.58%), whereas other clinical manifestations had similar frequencies between the groups. Multivariate logistic regression indicated that hypertension (adjusted OR [aOR]=3.549, 95% CI 1.498 to 8.407) and abdominal pain (aOR=10.904, 95% CI 1.037 to 114.710) were significantly associated with DHF among older patients.

CONCLUSIONS

Dengue is common in older adults, who also have a higher incidence of developing DHF. Older patients with dengue and comorbid hypertension and abdominal pain should be monitored for their increasing risk of DHF.

Clinical Outcomes of Children Diagnosed Dengue-Associated Acute Liver Failure with or without N-Acetylcysteine Treatment: A Retrospective Cohort Study

OBJECTIVES

N-acetylcysteine (NAC) has been shown to prevent hepatic damage and improve microcirculatory blood flow and oxygen delivery to the tissue. Previous studies have proposed the benefit of NAC in dengue-associated acute liver failure (ALF). However, most studies are descriptive and lack comparison between groups. We aimed to compare the ALF resolution rate and mortality rate of those who received and did not receive NAC treatment.

METHODS

A retrospective cohort study was conducted among children aged <15 years who were diagnosed with dengue-associated ALF at a tertiary hospital in Thailand, between January 2002 and July 2019. Demographic and clinical information were collected. Main outcomes were ALF resolution and mortality rate.

RESULTS

Thirty-three patients were included of which 16 received NAC treatment (48.5%). Mean ages were 8.5 years (SD 3.7) and mean onset of ALF was 6.3 days (SD 1.6) after onset of fever. The grading of hepatic encephalopathy (HE) and organ failure was not significantly different between the two groups. In the NAC group, 13/16 children were prescribed 100 mg/kg/day of NAC until INR <2 without HE or <1.5 with HE. NAC was initiated 1.1 days (SD 0.3) after the ALF diagnosis. The NAC group showed a higher rate of ALF resolution (75% vs. 53% in the non-NAC group, p = 0.34) with a lower mortality rate (31% vs. 53%, p = 0.36). Side effects of NAC were not found.

CONCLUSION

NAC may be beneficial in dengue-associated pediatric ALF. Further well-designed randomized control trials should be carried out.

Crocetin Improves Dengue Virus-Induced Liver Injury

Dengue virus (DENV) infection is one of the most widespread mosquito-borne viral infections. Liver injury is commonly observed in severe DENV infection, and the present study aimed to examine the efficacy of crocetin treatment in an immunocompetent mouse model of DENV infection exhibiting liver injury. The efficacy of crocetin treatment in DENV-induced liver injury was assessed via both transaminase levels and histopathology analysis. A real-time polymerase chain reaction array was then used to describe the expression of 84 apoptosis-related genes. Using real-time RT-PCR and Western blot analysis, the gene expressions of host factors were investigated. Additionally, the effect of crocetin in NF-kB signaling during DENV infection was studied. We did not observe any significant reduction in virus production when DENV-infected mice were treated with crocetin. However, DENV-infected mice treated with crocetin showed reduced DENV-induced apoptosis. The real-time polymerase chain reaction array revealed pro-inflammatory cytokine expressions to be significantly reduced in the crocetin-treated DENV-infected mice. We also found that crocetin could effectively modulate antioxidant status in DENV-infected mice. Moreover, crocetin demonstrated the ability to reduce the nuclear translocation of NF-kB in DENV-infected mice. Our results suggest that crocetin treatment does not inhibit DENV replication in the liver of DENV-infected mice; however, we did find that crocetin improves host responses that reduce liver injury.

Dengue hepatitis with acute liver failure: Clinical, biochemical, histopathological characteristics and predictors of outcome

BACKGROUND

Hepatitis infection from non-hepatotropic viruses such as dengue virus (DENV) is increasing worldwide. There is increasing recognition of the changing epidemiology and atypical presentations of DENV infection including acute liver failure (ALF). There is paucity of data regarding incidence, disease characteristics, and markers of prognosis in patients who develop DENV-related ALF.

METHODS

We aimed to study the incidence, clinical features, laboratory characteristics, and determinants of outcome in patients of DENV presenting with ALF. We reviewed all patients with DENV infection and focused on DENV-related ALF from 2014 to 2017. Diagnosis of DENV and ALF was confirmed by serological tests and standard criteria, respectively.

RESULTS

Thirty-six patients (20 men, mean age 32.3) developed ALF among 10 108 patients with DENV infection (0.35%). Twenty-one patients died (58.3%). Although bilirubin, aspartate and alanine aminotransferase, and international normalized ratio were markedly elevated in all patients with DENV ALF, there was no statistically significant difference between survivors and non-survivors. Lactate levels, pH at admission, and model for end-stage liver disease (MELD) score were the only predictors of mortality. Lactate levels were significantly higher in non-survivors (11.5 ± 4.2 mmol/L) than survivors (6.3 ± 3.6 mmol/L) (P < 0.001). MELD score in non-survivors (26.7 ± 10.2) was significantly higher than in survivors (20 ± 7.2) (P = 0.039). Receiver operator characteristic curve showed lactate or pH to be a superior prognostic marker than MELD with an area under the curve of 0.80, 0.79, and 0.70, respectively.

CONCLUSION

Dengue hepatitis progressed to ALF in 0.35%. Development of ALF was associated with a high mortality (> 50%). Lactate level, pH, and MELD score at admission were significant determinants of outcome.

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

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

Dengue

Mortality from severe dengue is low, but the economic and resource burden on health services remains substantial in endemic settings. Unfortunately, progress towards development of effective therapeutics has been slow, despite notable advances in the understanding of disease pathogenesis and considerable investment in antiviral drug discovery. For decades antibody-dependent enhancement has been the prevalent model to explain dengue pathogenesis, but it was only recently demonstrated in vivo and in clinical studies. At present, the current mainstay of management for most symptomatic dengue patients remains careful observation and prompt but judicious use of intravenous hydration therapy for those with substantial vascular leakage. Various new promising technologies for diagnosis of dengue are currently in the pipeline. New sample-in, answer-out nucleic acid amplification technologies for point-of-care use are being developed to improve performance over current technologies, with the potential to test for multiple pathogens using a single specimen. The search for biomarkers that reliably predict development of severe dengue among symptomatic individuals is also a major focus of current research efforts. The first dengue vaccine was licensed in 2015 but its performance depends on serostatus. There is an urgent need to identify correlates of both vaccine protection and disease enhancement. A crucial assessment of vector control tools should guide a research agenda for determining the most effective interventions, and how to best combine state-of-the-art vector control with vaccination.

Unusual manifestations of visceral leishmaniasis in children: a case series and its spatial dispersion in the western region of São Paulo state, Brazil

Background

Visceral leishmaniasis (VL) is becoming endemic in São Paulo state, in the southeastern region of Brazil. Unusual manifestations with non-specific signs and symptoms may make diagnosis difficult and delay treatment, increasing the risk of severity and death, particularly in new endemic areas. There are few studies on patients with these characteristics in Brazil. We describe a case series of unusual manifestations of VL in children and its spatial dispersion in the western region of São Paulo state.

Cases presentation

From 2009 to 2014, five clinical cases involving children treated in the Regional Hospital of Presidente Prudente (RH) were selected. Two patients had multiple relapses requiring liposomal amphotericin B; one patient had VL-cytomegalovirus-dengue co-infection and liver injury; one patient was diagnosed with X-linked agammaglobulinemia, a primary immunodeficiency; and one patient was diagnosed with VL-human immunodeficiency virus/acquired immunodeficiency syndrome (VL-HIV/AIDS) co-infection. Primary or secondary immunodeficiencies were found in four children, and associated viral infections were found in three children. Three patients were referred from other hospitals to RH. With regard to the geographic spread of VL, more cases were found in the northern area, in the epicenter of the infection where the first cases were registered, flowing south; a spatial-temporal occurrence was found.

Conclusions

Primary and secondary immunodeficiencies and viral co-infectious should be considered among unusual manifestations of VL, especially in those with multiple relapses. Spatial-temporal occurrence was found. Thus, integrated actions and effective monitoring of the disease are needed to complement curative practices to stem the tide of the epidemic.

Validation of Serum Aminotransferases Levels to Define Severe Dengue Fever in Children

PURPOSE

We aimed to study the pattern of liver-injury in children with dengue fever (DF) and validate serum aminotransferase ≥1,000 IU/L as a marker of severe DF.

METHODS

Children admitted with DF were included. DF was defined by presence of clinical criteria and positive serological or antigen tests in absence of other etiology. DF severity was graded as dengue without or with warning signs and severe dengue. Liver-injury was defined as alanine aminotransferase (ALT) more than twice the upper limit of normal (boys, 30 IU/L; girls, 21 IU/L).

RESULTS

Of 372 children with DF, 144 (38.7%) had liver-injury. Risk of liver-injury and aminotransferase levels increased with DF severity (p<0.001). Recommended ALT and aspartate aminotransferase (AST) cut-off at ≥1,000 IU/L had sensitivity 4.8% (5/105), specificity 99.3% (265/267) for detection of severe DF. In children with ALT and AST <1,000 IU/L (n=365), the area under receiver operating curves for prediction for severe DF, were 0.651 (95% confidence interval [CI], 0.588-0.714; p<0.001) for ALT and 0.647 (95% CI, 0.582-0.712; p<0.001) for AST. Serum ALT at 376 IU/L and AST at 635 IU/L had sensitivity and specificity comparable to ≥1,000 IU/L for defining severe DF.

CONCLUSION

Liver-injury is common in DF. The ALT and AST levels increase with DF severity. ALT and AST levels of ≥1,000 IU/L could be lowered to 376 IU/L and 635 IU/L respectively for defining severe DF.

Serum metabolome changes in adult patients with severe dengue in the critical and recovery phases of dengue infection

Dengue virus (DENV) is the most prevalent arbovirus leading to an estimated 100 million symptomatic dengue infections every year. DENV can cause a spectrum of clinical manifestations, ranging from mild dengue fever (DF) to more life threatening forms such as dengue hemorrhagic fever (DHF). The clinical symptoms of DHF become evident typically at the critical phase of infection (5-7 days after onset of fever), yet the mechanisms that trigger transition from DF to DHF are not well understood. We performed a mass spectrometry-based metabolomic profiling of sera from adult DF and DHF patients at the critical and recovery phases of infection. There were 29 differentially expressed metabolites identified between DF and DHF at the critical phase. These include bile acids, purines, acylcarnitines, phospholipids, and amino acids. Bile acids were observed up to 5 fold higher levels among DHF compared to DF patients and were significantly correlated to the higher levels of aspartate transaminase (AST) and alanine transaminase (ALT), suggestive of liver injury among DHF. Uric acid, the most abundant antioxidant in the blood, was observed to be 1.5 fold lower among DHF compared to DF patients. This could result in decreased capacity of endogenous antioxidant defense and elevated oxidative stress among DHF patients. In the recovery phase, the levels of eight metabolites were still significantly higher or lower among DHF patients, including chenodeoxyglycocholic acid, one of the bile acids observed at the critical phase. This indicates potential prolonged adverse impact on the liver due to DENV infection in DHF patients. Our study identified altered metabolic pathways linked to DHF in the critical and recovery phases of dengue infection and provided insights into the different host and DENV interactions between DF and DHF. The results advance our understanding on the mechanisms of DHF pathogenesis, alluding to possible novel therapeutic targets to dengue management.

Dengue fatal cases present virus-specific HMGB1 response in peripheral organs

Dengue is an important infectious disease that presents high incidence and yields a relevant number of fatal cases (about 20,000) every year worldwide. Despite its epidemiological relevance, there are many knowledge gaps concerning dengue pathogenesis, especially with regards to the circumstances that drive a mild clinical course to a severe disease. In this work, we investigated the participation of high mobility group box 1 (HMGB1), an important modulator of inflammation, in dengue fatal cases. Histopathological and ultrastructural analyses revealed that liver, lung and heart post-mortem samples were marked by tissue abnormalities, such as necrosis and apoptotic cell death. These observations go in line with an HMGB1-mediated response and raised concerns regarding the participation of this cytokine in promoting/perpetuating inflammation in severe dengue. Further experiments of immunohistochemistry (IHC) showed increased expression of cytoplasmic HMGB1 in dengue-extracted tissues when compared to non-dengue controls. Co-staining of DENV RNA and HMGB1 in the host cell cytoplasm, as found by in situ hybridization and IHC, confirmed the virus specific induction of the HMGB1-mediated response in these peripheral tissues. This report brings the first in-situ evidence of the participation of HMGB1 in severe dengue and highlights novel considerations in the development of dengue immunopathogenesis.

Dengue

Dengue is one of the most important mosquito-borne viral infections caused by single-stranded RNA virus that are transmitted by the Aedes aegypti and Aedes albopictus mosquito species. Dengue is endemic in over 140 countries in Asia, the USA, the Eastern Mediterranean, and Africa. The World Health Organization (WHO) estimated that there are more than 2.5 billion people—mainly occurs in children living in tropical and subtropical countries—at risk of dengue infection with one or more dengue viruses. There are estimated nearly 100 million symptomatic dengue infections occurring worldwide annually, nearly 75% in Asia and the Western Pacific region [1]. During the past decades, the outbreaks of dengue infection have been reported throughout the world with increased severity. Ecologic and demographic changes are considered to be the contributing factors to the emergence of dengue infection in the past decades. Dengue has expanded into new countries and into urban settings associated with increased distribution of A. aegypti, population growth, urbanization, development of slums, migration of population, movement of dengue virus by infected travelers, trade development, and improved diagnostic capabilities in medical practice [2, 3]. Increased transmission of dengue virus in tropical urban areas has been created by substandard housing and crowding as well as deterioration in water, sewer, and waste management systems, all of which are intimately associated with unplanned urbanization [4–7]. So it is likely that dengue will expand its geographic reach and become an increasing burden on health resources in affected areas during the next decade. An effective vector-control management is the only means to reduce dengue infection in endemic areas. Because vector control has achieved only limited success so far in reducing the transmission of dengue, the usage of effective dengue vaccine in target population along with the preventive measures already used such as raising public awareness may be the means to effectively control of this disease in endemic area [8].