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 selflimited 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,immunemediated 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.

Modeling and Forecasting Malaria and Dengue Hemorrhagic Fever Incidence and Prevalence in Northern Thailand

Malaria and dengue hemorrhagic fever （DHF） are infectious diseases prevalent in many tropical countries, including Thailand. Thailand is located geographically in a tropical zone and the transmission of malaria and DHF is common, particularly in the upper Northern region of the country. The objective of this study is to identify the patterns of hospital-diagnosed Malaria and DHF incidences by using the previous monthly or quarterly periods of incidences occurring in the upper Northern region of Thailand. The authors use additive plus multiplicative regression models to describe these patterns. The models can be used to forecast malaria and DHF incidences, thus predicting where epidemics are likely to occur. This information can be used to prevent disease outbreaks occurring. Graphical displays showing district and period effects are presented. The results of this study show that historical malaria and DHF incidence rates can be used to provide a useful model for forecasting future epidemics. The graphical display shows the improvement of risk prediction brought about by model. The model, even if based purely on statistical data analysis, can provide a useful basis for allocation of resources for disease prevention.

Predictors of hemorrhagic manifestations in dengue:A prospective observational study from the Hadoti region of Rajasthan

Objective:To study the laboratory and clinical predictors of hemorrhagic manifestations in dengue virus-infected patients.Methods:This was a single-center hospital-based prospective observational study.200 Dengue seropositive patients were included in the study.A detailed clinical examination was done and comprehensive laboratory investigations were done.These parameters were compared between patients with and without hemorrhagic manifestations.Results:Out of the 200 patients,47(23.5%)had bleeding.64.5%Patients were males and 76.0%were under the age of 40 years.The most common presenting symptoms were fever(100.0%)followed by myalgia(77.0%),nausea and vomiting(56.0%).Leukocytosis,neutrophilia,thrombocytopenia,hyperbilirubinemia,transaminitis,decreased serum albumins,and raised D-dimer can serve as hematological,biochemical,and coagulation predictors of hemorrhagic manifestations for dengue.Conclusions:Dengue is a tropical infection with various complications.Bleeding complications are one of them.Laboratory parameters like white blood cells,platelets,bilirubin level,liver enzymes,and D-dimer can help to identify patients at risk for bleeding.Early identification and appropriate management can save a lot of resources and lives.

Progress towards understanding the pathogenesis of dengue hemorrhagic fever

Dengue virus(DENV) is a mosquito-borne virus belonging to the Flaviviridae family. There are 4 serotypes of DENV that cause human disease through transmission by mosquito vectors. DENV infection results in a broad spectrum of clinical symptoms, ranging from mild fever to dengue hemorrhagic fever(DHF), the latter of which can progress to dengue shock syndrome(DSS) and death. Researchers have made unremitting efforts over the last half-century to understand DHF pathogenesis. DHF is probably caused by multiple factors, such as virus-specific antibodies, viral antigens and host immune responses. This review summarizes the current progress of studies on DHF pathogenesis, which may provide important information for achieving effective control of dengue in the future.

Pituitary apoplexy secondary to dengue fever-induced-thrombocytopenia:A case report and review of literature

Rationale:Pituitary apoplexy(PA)is a rare endocrine emergency that requires prompt diagnosis and management.Dengue fever-induced-thrombocytopenia may rarely predispose to PA.Patient’s Concern:A 58-year-old male patient having known pituitary macroadenoma presented to the emergency department with fever,a sudden onset severe headache,and altered sensorium.Diagnosis:Pituitary apoplexy caused by dengue fever-induced-thrombocytopenia.Interventions:Conservative management with fluids,mannitol,dexamethasone and symptomatic treatment.Outcomes:The patient responded well to the treatment and was discharged uneventfully.Lessons:Although dengue hemorrhagic fever is a rare cause of pituitary apoplexy,it should be considered if a patient presents with headache and altered sensorium,and prompt initiation of treatment is crucial to prevent fatality and neuro-ophthalmic deficits.

Dengue fever leading to acute dengue hemorrhagic leukoencephalitis:A case report

Rationale:Dengue fever is a prevalent tropical infectious disease that has a broad panorama of presentations from mild febrile illness to life-threatening manifestations in the form of dengue hemorrhagic fever and dengue shock syndrome.Patient’s concerns:A 20-year-old male presented with a 2-day history of fever,multiple episodes of vomiting,and altered sensorium.Diagnosis:Dengue fever leading to acute hemorrhagic leukoencephalitis.Interventions:Multiple transfusions of single donor platelets,intravenous methylprednisolone,intravenous immunoglobulin,anti-seizure prophylaxis,and broad-spectrum antibiotics.Outcomes:Repeat brain magnetic resonance imaging showed resolution of lesions.The patient was subsequently discharged from the hospital in a healthy state.Lessons:This report helps us to gain a better understanding of the patient’s presentation,which will help to improve the timely recognition and prevention of this rare devastating presentation.

Molecular surveillance of dengue virus in Bahia State, Brazil

Dengue is an important emerging viruses, posing a threat to one-third of the global human population. In 2002, the introduction of DENV-3 in the state of Bahia produced massive epidemic (about 35,000 cases detected) and the first cases of dengue hemorrhagic fever. To understand the nature of the virus circulating at Bahia, E/NS1 sequence was determined for 31 DENV viruses isolated in Bahia during the 2006 and 2007 transmission season, from patients presenting with different degrees of severity. The carboxi-terminal region of the E gene (220 nt) of 31 viruses, isolated from dengue patients with clinical diagnosis of dengue infection were used to determine the genetic variability of dengue 2 (DENV-2) and dengue 3 (DENV-3). Sequence data were used in phylogenetic comparisons with global samples of DENV-2 and DENV-3. DENV-2 sample grouped in the South East Indian genotype, while DENV-3 samples were grouped within Indian genotype. This study is the first report on Bahia isolates during two transmission seasons. Our data confirms reports from other parts of Brazil and different countries showing the DENV-3 (geno-type III) strains circulating in the Americas are closely related, and cluster within the genotype that has been associated with DHF epidemics in different conti-nents.