Dengue

1. Dengue Varun S CRRI SRM MCH& RC

2. SYNOPSIS • INTRODUCTION • Microbiology • Classical features of dengue fever • Phases of dengue • Febrile phase • Critical phase • Recovery phase • Severe dengue • Laboratory diagnosis • Grouping and Stepwise management

3. ARTHROPOD BORNE VIRAL DISEASE MOST IMPORTANT EMERGING ARTHROPOD BORNE DISEASE OF TROPICAL AND SUBTROPIC REGIONS Self-limiting disease

4. Microbiology • Flaviviridae • Arthropod – Mosquito – Aedesaegypti and Aedesalbopictus

5. DENGUE VIRUS • 4 Serotypes: • 1, 2, 3, 4 • RAINY SEASONS

6. TRANSMISSION

7. Latest problem statement

8. OLD CLASSIFICATION Dengue Classical dengue/without haemorrhage Dengue hemorrhagic fever With shock (DSS) Without shock

9. DENGUE- NEW WARNING SIGNS NEGATIVEPOSITIVE Coexisting conditions & DENGUE WITH WARNING SIGNSSEVERE DENGUE Social circumstances DENGUE WITHOUT WARNING SIGNS

10. Classical dengue fever • Incubation period: 3 to 10 days • Clinical features: • Chills • High fever • Intense headache • Muscle and joint pains • Eye symptoms: • Retro-orbital pain • Photophobia

11. Other symptoms include: • Extreme weakness • Anorexia • Constipation • Altered taste sensation • Colicky pain • Abdominal tenderness • Sorethroat • General depression

12. FEVER 39 TO 40 CENTIGRADE Biphasic type of fever Lasts for 5 to 7 days

13. RASH • Morbiliform rash • Diffuse, flushing, mottling of fleeting pin-point eruptions on the face, neck and chest during the first half of the febrile phase and a conspicuous rash that may be scarlatiniform on 3rd or 4th day

14. The case fatality low, infection with one dengue serotype gives immunity against that particular serotype and partial protection against others.

15. Phases of dengue • FEBRILE PHASE • CRITICAL PHASE • RECOVERY PHASE • SEVERE DENGUE

18. Febrile phase • Incubation – 4 to 6 days • Clinical features: • Increased fever • Facial flushing • Headache • Anorexia • Vomiting • Maculopapular rash less common

19. DF or DHF? • Rising haematocrit • Marked thrombocytopenia

20. WHY THROMBOCYTOPENIA? • 1. BONE MARROW SUPPRESSION • (WANG EL AL) VIRUS SPECIFIC ANTIBODY • ANTIPLATELET ANTIBODIES

21. CRITICAL PHASE • 24-48 hours • Around the time of defervesence • Temperature decreases to 37.5 to 38 centigrade • Shock from plasma leakage • Severe hemorrhage • Organ impairment • Pleural effusion • Ascites Degree of plasma leakage SHOCK When the critical volume of plasma is lost through leakage

22. Prolonged shock Constant hypoperfusion Progressive organ impairment Metabolic acidosis DIC SEVERE HEMMORHAGE The other reason for severe hemorrhage with updated sources in VASCULITIS AND LOSS FOR VASCULAR INTEGERITY

23. CONTRARY • NON SEVERE DENGUE / DENGUE WITHOUT WARNING SIGNS

24. Warning signs • Abdominal pain or tenderness • Persistent vomiting • Clinical fluid accumulation • Mucosal bleed • Lethargy, restlessness • Liver enlargement >2cm • Laboratory: Increase in HCT concurrent with rapid decrease in PLATELET COUNT

25. DENGUE WARNING SIGNS NEGATIVEPOSITIVE Coexisting conditions & DENGUE WITH WARNING SIGNSSEVERE DENGUE Social circumstances DENGUE WITHOUT WARNING SIGNS

26. Recovery phase Critical phase Gradual reabsorption of extravascular compartment fluid in the next 48 to 72 hours General wellbeing improves Appetite returns to normal GI symptoms abate Hemodynamic status stabilizes and diuresis ensues HAEMATOCRIT STABILIZES OR MAY BE LOWER DUE TO THE DILUTIONAL EFFECT OF REABSORBED FLUID

27. SEVERE DENGUE Plasma leakage Severe bleeding Severe organ impairment Dengue shock with or without respiratory distress or fluid accumulation IF HYPOVOLEMIA WORSENS Results in shock

28. Organ impairment • Myocardial damage • Hepatic dysfunction • Renal dysfunction : • Proteinuria • Haematuria • Pyuria • Rhabdomyolysis • CNS manifestations such as encephalopathy

29. DENGUE INCOGNITO • Compensatory mechanisms during the initial stage of shock • Normal systolic blood pressure also produces tachycardia and peripheral vasoconstriction with reduced skin perfusion resulting in cold extremities and delayed capillary refilling time • Shock  if pulse pressure <20 mm of Hg

30. Tourniquet test • Rumpel-leede capillary fragility test • Thrombocytopenia • >20 petechiae/square onch

31. Laboratory diagnosis • Leucopenia (<5000/cu mm) • Thrombocytopenia (<50,000) • Elevated liver enzymes (AST or ALT >1000) • Isolation of virus from the blood (within first 5 days of onset of clinical features) • Serum NS1 antigen – highly specific & positive early • CARD TEST • Rising viral antibody titers- HI, CF, NT, MAC-ELISA • CXR- pleural effusion & USG ABD- Ascites & GB thickening

32. A stepwise approach to the management of dengue • Step I. Overall assessment • History, including information on symptoms, past medical and family history • Physical examination, including full physical and mental assessment • Investigation, including 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).

33. GROUP A CRITERIA LABORATORY • No warning signs • Able to tolerate adequate volume of oral fluids • Pass urine once every 6 hours • FBC • PCV

34. Group A management • Adequate bed rest • Adequate fluid intake • Paracetamol 4grams max./day • Patients with stable HCT can be sent home • MONITORING: • Daily review of the disease progression • Decreasing WBC & Platelets • Defervesence • Warning signs • Written advice about the management

35. GROUP B CRITERIA LABORATORY TESTS • Coexisting conditions such as pregnancy, infancy, old age, diabetes, renal failure • Social circumstances such as living alone/ living far from hospital • Full blood count • Haematocrit

36. Group B management • Encourage oral fluids • Not tolerated start IVF – 0.9% Saline or LR • MONITOR: • Temperature pattern • I/O • Warning signs • PCV, WBC & PC • Warning signs– proceed to compensated shock management protocol

37. Compensated shock Fluid resuscitation with isotonic crystalloid 5 to 10 ml/kg/hr over 1 hour NO YES IMPROVEMENT Check HCT • IV crystalloid 5-7 ml/kg/hr for 1-2 hours, then; • Reduce to 3 to 5 ml/kg/hr for 2 to 4 hours • Reduce to 2 to 3 ml/kg/hr for 2 to 4 hours. • If the patient continues to improve, fluid can be reduces. • Monitor haematocrit 6 to 8 hourly. • If the patient is not stable, act according to PCV levels, • If PCV increases, consider bolus fluid administration or increase fluid administration • If PCV decreases, consider transfusion with fresh whole blood PCV PCV Consider significant occult/overt bleed and initiate transfusion 2nd bolus of fluid 10-20 ml/kg/hr for 1hr IMPROVEMENT NO YES 7-10ml/kg/hr for 1-2 hours

38. Calculation of total intravenous fluid infusion Body weight Total fluid requirement _______________________________________________________ 0-10 kg 100ml/kg >10-20kg 1000ml + 50ml/kg for each kg >10kg >20 1500ml + 20ml/kg for each kg >20kg

39. GROUP C (HYPOTENSIVE SHOCK) CRITERIA LABORATORY TESTS • Severe plasma leakage with shock • And or fluid accumulation with respiratory distress • Severe bleeding • Severe organ impairment • Full blood count • Haematocrit • Other organ function tests as indicated

40. Compensated shock Fluid resuscitation with isotonic crystalloid 5 to 10 ml/kg/hr over 1 hour NO YES IMPROVEMENT Check HCT • IV crystalloid 5-7 ml/kg/hr for 1-2 hours, then; • Reduce to 3 to 5 ml/kg/hr for 2 to 4 hours • Reduce to 2 to 3 ml/kg/hr for 2 to 4 hours. • If the patient continues to improve, fluid can be reduces. • Monitor haematocrit 6 to 8 hourly. • If the patient is not stable, act according to HCT levels, • If HCT increases, consider bolus fluid administration or increase fluid administration • If HCT decreases, consider transfusion with fresh whole blood PCV PCV Consider significant occult/overt bleed and initiate transfusion 2nd bolus of fluid (colloid) 10-20 ml/kg/hr for 1hr IMPROVEMENT NO Repeat 2nd PCV YES PCV PCV 7-10ml/kg/hr for 1-2 hours 3rd bolus of fluid (colloid) 10-20 ml/kg/hr for 1hr IMPROVEMENT Repeat 3rd PCV NO YES

41. HEMORRHAGIC COMPLICATIONS • Mucosal bleeds  stable?  minor • Profound thrombocytopenia  strict bed rest no IM injections

42. Patients who are at high risk of major bleeding • Prolonged/refractory shock • Hypotensive shock • Renal/liver failure • Severe persistent metabolic acidosis • NSAIDs • Preexisting peptic ulcer disease • Anticoagulant therapy • Any form of trauma

43. Action plan for treatment of hemorrhagic complications • 5 to 10 ml/kg of fresh Packed cells or 10-20ml/kg of fresh whole blood • Platelet transfusion

44. Treatment complications • Fluid overload • ARDS • Metabolic acidosis

45. Dengue vaccine • French drug makers- Sanofi is making trials of dengue vaccine. Not yet effective. • Trials not conclusive. Maybe ready 2015

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