Dengue with who guidelines
- 1. Dengue infection ReviseD Who guiDelines 2009
- 2. Dengue viral infection ● The most rapidly spreading mosquito-borne viral disease in the world ● Dengue virus : 4 serotypes : DEN1, DEN2,DEN3, and DEN4 Family Flaviviridae Genus Flavivirus Single stranded RNA virus ● “Asian” genotypes of DEN-2 and DEN-3 : frequently associated with severe disease accompanying secondary dengue infections
- 4. Average annual number of DF and DHF cases reported to WHO, and of countries reporting dengue, 1955–2007
- 5. Dengue Virus Infection ● Immunity : long lasting in same serotype, partial and transient to other serotypes ● Primary infection, secondary infection ● Greater risk of serious symptoms in secondary infection • Plasma leakage distinguishes dengue fever from dengue hemorrhagic fever • Plasma leakage,hemoconcentration and abnormalities in homeostasis characterize severe dengue
- 6. Dengue Virus Infection: Clinical Syndromes ● Undifferentiated fever ● Dengue fever: fever, headache, muscle pain, nausea/vomiting, rash ● DHF ● DSS Gr I, II Plasma leakage Gr III, IV
- 7. Definition of Dengue Hemorrhagic Fever 4 necessary criteria: • Fever, or recent history of acute fever • Hemorrhagic manifestations ● Low platelet count (100,000/mm3 or less) ● Objective evidence of “leaky capillaries” elevated hematocrit (20% or more over baseline) pleural or other effusions Fall in hematocrit >20% after I.V Fluids
- 8. Definition of Dengue Shock Syndrone 4 criteria for DHF ● Evidence of circulatory failure manifested indirectly by all of the following: Rapid and weak pulse Narrow pulse pressure (< 20 mm Hg) OR hypotension for age Cold, clammy skin and altered mental status ● Frank shock is direct evidence of circulatory failure
- 9. WHO classification ● Undifferentiated fever ● Dengue fever (DF) ● Dengue haemorrhagic fever (DHF) 4 severity grades grades III and IV : dengue shock syndrome (DSS) ● Currently the classification into DF/DHF/DSS continues to be widely used
- 11. ● patients with non-severe dengue patients with warning signs patients without warning signs ● “dengue is one disease entity with different clinical presentations and often with unpredictable clinical evolution and outcome”
- 13. Vectors ● Aedes aegypti Stegomyia aegypti (formerly Aedes aegypti)
- 14. Dengue ● incubation period of 4-10 days ● wide spectrum of illness (most, asymptomatic or subclinical) ● Primary infection : induce lifelong protective immunity to the infecting serotype ● Individuals suffering an infection are protected from clinical illness with a different serotype within 2-3 months of the primary infection ● no long-term cross-protective immunity
- 15. Risk factors (determine the severity of disease and secondary infection) ● Age ● Ethnicity ● Possibly chronic diseases (bronchial asthma, sickle cell anemia and DM) ● Young children (less able to compensate for capillary leakage and are consequently at greater risk of dengue shock) ● Secondary heterotypic infection as risk factor for severe dengue
- 16. The course of dengue illness
- 17. Febrile phase ● High-grade fever, 2–7 days ● facial flushing, skin erythema, body ache, myalgia, arthralgia, headache and N/V ● Indistinguishable between severe and non-severe dengue cases ● Monitoring for warning signs ● Mild hemorrhagic manifestations : petechiae and mucosal membrane bleeding (e.g. nose and gums) ● Liver often enlarged and tender after a few days of fever ● The earliest abnormality in CBC : progressive decrease in WBC
- 18. The course of dengue illness Dengue: Guidelines for diagnosis, treatment, prevention and control. WHO 2009
- 19. Critical phase ● Day 3–7 of illness ● Progressive leukopenia rapid ↓platelet count plasma leakage ● Patients without ↑capillary permeability will improve ● Patients with ↑capillary permeability : worse, lose plasma volume ● The degree of increase above the baseline HCT reflects severity of plasma leakage • Shock-WBC may increase in patients with severe bleeding
- 20. The course of dengue illness Dengue: Guidelines for diagnosis, treatment, prevention and control. WHO 2009
- 21. Recovery phase ● Gradual reabsorption of extravascular compartment fluid takes place in the following 48–72 hours ● Well-being improves, appetite returns, GI symptoms abate, hemodynamic status stabilizes and diuresis ensues ● Rash : “isles of white in the sea of red” Some may experience generalized pruritus ● Hct stabilizes or lower due to the dilutional effect of reabsorbed fluid ● WBC usually rise soon after defervescence but the recovery of platelet count is typically later than that of WBC
- 22. Febrile, critical and recovery phases in dengue Febrile phase Dehydration; high fever may cause neurological disturbances and febrile seizures in young children Critical phase Shock from plasma leakage; severe hemorrhage; organ impairment Recovery phase Hypervolemia (only if iv fluid therapy has been excessive and/or has extended into this period)
- 23. Severe dengue ● Fever of 2–7 days plus any of the following Evidence of plasma leakage : high or progressively rising Hct pleural effusions or ascites circulatory compromise or shock (tachycardia, cold and clammy extremities, capillary refill time > 3 seconds, weak or undetectable pulse, narrow PP or, in late shock, unrecordable BP) Significant bleeding Altered level of consciousness (lethargy or restlessness, coma, convulsions) Severe GI involvement (persistent vomiting, increasing or intense abdominal pain, jaundice) Severe organ impairment (acute liver failure, ARF, encephalopathy or encephalitis, or other unusual manifestations, cardiomyopathy)
- 24. Diagnosis of Dengue Infection ● Antibody detection Hemagglutination Inhibition (HAI) ELISA (IgG/IgM) Rapid test (IgG/IgM) ● Antigen detection NS1 & E/M antigen ● RNA detection PCR ● Viral isolation
- 25. Diagnosis • Approximate time-line of primary and secondary dengue virus infections and the diagnostic methods that can be used to detect infection
- 26. Interpretation of dengue diagnostic tests
- 27. Primary Infection ● NS1 antigen : Day 1 after onset of fever and up to day 9 ● IgM antibody : Day 5 of infection, sometimes as early as Day 3 IgM levels : peak in 2 weeks, followed by a 2 week rapid decay Undetectable 2 to 3 months after infection ● Low levels of IgG are detected in the early convalescent phase, not during the acute phase
- 28. Secondary Infection ● NS1 antigen : day 1 after onset of fever and up to day 9 ● IgM response is more varied ● Usually preceded by IgG and appears quite late during the febrile phase ● Minority of patients will show no detectable levels of IgM ● May not be produced until 20 days after onset of infection ● High levels of IgG are detectable during the acute phase ● Persist for 30-40 days then decline to levels found in primary or past infection
- 29. Atypical neurological manifestations of dengue ● Neurologic abnormalities : uncommon during dengue fever ● DHF, encephalopathy is well recognized, from several factors cerebral anoxia cerebral edema cerebral hemorrhage hyponatremia toxicity secondary to liver failure ● Studies in southeast Asia, encephalopathy associated with classic DF can occur in up to half of the cases
- 30. Atypical gastrointestinal manifestations of dengue • Hepatitis Hepatomegaly, jaundice and raised aminotransferase levels (AST>ALT) caused by the dengue virus and ⁄or Hypoxia and tissue ischemia in cases of shock • Fulminant hepatic failure Severe hepatic dysfunction (ALT and AST >10x normal) was seen with DHF associated with spontaneous bleeding tendencies tends to occur more often in DHF or DSS compared to classic dengue infections • Acalculous cholecystitis • Acute pancreatitis
- 31. Atypical cardiovascular manifestations of dengue fever ● uncommon ● Cardiac rhythm disorders : atrioventricular blocks atrial fibrillation sinus node dysfunction ectopic ventricular beats ● Most are asymptomatic, benign self limiting course with resolution of infection ● Attributed to viral myocarditis
- 32. Atypical respiratory manifestations of dengue ● ARDS ● Pulmonary hemorrhage : thrombocytopenia, changes in vascular permeability, platelet dysfunction
- 33. Dengue myositis ● Dengue fever : break bone fever, severe muscle, joint and bone pain ● Acute benign myositis : elevated SGOT, SGPT, and CPK ● Dengue virus infection may also cause persisting, severe, myositis for weeks
- 34. Lymphoreticular complications of dengue ● Dengue virus antigen is found predominantly in cells of the spleen, thymus and lymph nodes ● DHF, lymphadenopathy is observed in half of the cases ● Splenomegaly is rarely observed ● Splenic rupture and lymph node infarction in DHF are rare
- 35. Management of dengue infection
- 36. A stepwise approach to the management of dengue Step I. Overall assessment History : symptoms, past medical and family history Physical examination : full physical and mental assessment Investigation : routine laboratory and dengue-specific laboratory Step II. Diagnosis, assessment of disease phase and severity Step III. Management Disease notification Management decisions. Depending on the clinical manifestations and other circumstances, patients may: – be sent home (Group A); – be referred for in-hospital management (Group B); – require emergency treatment and urgent referral (Group C).
- 38. Groups A-Patients who are sent home • Encourage plenty of oral fluids • Inform about the warning signs • Paracetamol for high fever. Never aspirin,ibuprofen or other NSAIDS
- 40. Group B-In Patient Hospital Management
- 41. Algorithm for fluid management in compensated shock Compensated shock (SBP maintained but has signs of reduced perfusion) Fluid resuscitation with isotonic crystalloid 5–10 ml/kg/hr over 1 hour Improvement NO YES Check HCT IV crystalloid 5–7 ml/kg/hr for 1–2 HCT↑ or high HCT↓ hours, then: reduce to 3–5 ml/kg/hr for 2–4 hours; Administer 2nd bolus of fluid Consider significant reduce to 2–3 ml/kg/hr for 2–4 hours. 10–20 ml/kg/hr for 1 hour occult/overt bleed Initiate transfusion If patient continues to improve, fluid can be Improvement with fresh whole further reduced. blood Monitor HCT 6–8 hourly. YES NO If the patient is not stable, act according to HCT levels: If patient improves, if HCT ↑, consider bolus fluid administration reduce to 7–10 ml/kg/hr or increase fluid administration; for 1–2 hours if HCT ↓, consider transfusion with fresh Then reduce further whole transfusion. Stop at 48 hours.
- 42. Algorithm for fluid management in hypotensive shock Hypotensive shock Fluid resuscitation with 20 ml/kg isotonic crystalloid or colloid over 15 minutes. Try to obtain a HCT level before fluid resuscitation Improvement YES NO Review 1st HCT Crystalloid/colloid 10 ml/kg/hr for 1 hour, HCT↓ then continue with: HCT↑ or high IV crystalloid 5–7 ml/kg/hr for 1– 2 hours; Administer 2nd bolus fluid (colloid) Consider significant reduce to 3–5 ml/kg/hr for 2–4 hours; 10–20 ml/kg over ½-1 hour occult/overt bleed reduce to 2–3 ml/kg/hr for 2–4 hours. Initiate transfusion with Improvement fresh whole blood If patient continues to improve, fluid can be further reduced. YES NO Monitor HCT 6-hourly. Repeat 2nd HCT If the patient is not stable, act according HCT↑ or high HCT↓ to HCT levels: if HCT ↑, consider bolus fluid administration Administer 3rd bolus fluid (colloid) or increase fluid administration; 10–20 ml/kg over 1 hour if HCT ↓, consider transfusion with fresh whole transfusion. Improvement Stop at 48 hours. YES NO Repeat 3rd HCT
- 43. Treatment of hemorrhagic complications ● Mucosal bleeding : if patient remains stable with fluid resuscitation/replacement, considered as minor ● Bleeding improves rapidly during recovery phase ● Patients with profound thrombocytopenia : strict bed rest and protect from trauma not give i.m injections (avoid hematoma) prophylactic platelet transfusions for severe thrombocytopaenia in hemodynamically stable patients not shown to be effective and not necessary
- 44. Management of Dengue Infection ● No hemorrhagic manifestations and patient is well- hydrated: home treatment ● Hemorrhagic manifestations or hydration borderline: outpatient observation center or hospitalization ● Warning signs (even without profound shock) or DSS: hospitalize
- 45. Treatment of Dengue Fever ● Fluids ● Rest ● Antipyretics (avoid aspirin and NSAIDs) ● Monitor blood pressure, hematocrit, platelet count, level of consciousness
Editor's Notes
- #7: - Grade I มีไข้และมีอาการร่วมอื่นๆแต่ไม่จำเพาะ แต่เมื่อทำ tourniquet test จะให้ผล positive - Grade II อาการเหมือน grade I แต่ที่เพิ่มเติมคือ พบเลือดออกเป็นจุดเลือดใต้ผิวหนัง - Grade III ระบบไหลเวียนโลหิตเริ่มล้มเหลวเกิดอาการช็อค ชีพจรเร็ว เบา pulse pressure แคบ ความดันโลหิตต่ำ ริมฝีปากเขียว ตัวเย็น กระสับกระส่าย - Grade IV แสดงอาการช็อครุนแรง ความดันโลหิตและชีพจรวัดไม่ได้
- #8: 21
- #9: 22
- #10: - Grade I มีไข้และมีอาการร่วมอื่นๆแต่ไม่จำเพาะ แต่เมื่อทำ tourniquet test จะให้ผล positive - Grade II อาการเหมือน grade I แต่ที่เพิ่มเติมคือ พบเลือดออกเป็นจุดเลือดใต้ผิวหนัง - Grade III ระบบไหลเวียนโลหิตเริ่มล้มเหลวเกิดอาการช็อค ชีพจรเร็ว เบา pulse pressure แคบ ความดันโลหิตต่ำ ริมฝีปากเขียว ตัวเย็น กระสับกระส่าย - Grade IV แสดงอาการช็อครุนแรง ความดันโลหิตและชีพจรวัดไม่ได้
- #27: dengue infection is defined as primary if IgM/IgG OD ratio > 1.2 (using pt’s sera at 1/100 dilution) or 1.4 (using pt’s sera at 1/20 dilutions) secondary if ratio <1.2 or 1.4 Ratios : vary between lab