Dengue Fever Manual

1. Dengue FeverManual Department of Medicine Lahore General Hospital/PGMI Lahore

2. Dengue Fever • Dengue virus • Most prevalent vector-borne viral illness in the world • Main mosquito vector is Aedes Aegypti and Albopictus • Year round transmission

3. Incidence • 50-100 million dengue fever infections per year globally • 500,000 cases of severe dengue, dengue hemorrhagic fever or dengue shock syndrome • 100-200 cases annually in U.S. • Average case fatality 5%

4. Distribution • Endemic in more than 100 tropical and subtropical countries • Pandemic began in Southeast Asia after WW II with subsequent global spread • Several epidemics since 1980s • Distribution is comparable to malaria

5. Virology • Flavivirus family • Small enveloped viruses containing single stranded positive RNA • Four distinct viral serotypes (Den-1, Den-2, Den-3, Den-4)

6. Pathophysiology • Transmitted by the bite of Aedes mosquito (Aedes aegypti and albopictus) • Incubation 3-14 days • Acute illness and viremia 3-7 days • Recovery or progression to leakage phase

7. Clinical Presentation • Spectrum of illness • non-specific febrile illness • classic dengue • dengue hemorrhagic fever • dengue shock syndrome • other (CNS dysfunction, liver failure, myocarditis)

8. The course of dengue illness 3 Phases Febrile Phase Critical Phase Recovery Phase

11. Differential Diagnosis of Dengue Fever

12. D/D of Dengue Fever

13. D/D of Dengue Fever

14. Approach to a Patient with Dengue Fever

15. Approach to a patient with Dengue Fever

16. Treatment Recommendations

17. Step I—Overall assessment History The history should include: – date of onset of fever/illness; – quantity of oral intake; – assessment for warning signs ; – diarrhea; – change in mental state/seizure/dizziness; – urine output (frequency, volume and time of last voiding); – other important relevant histories, such as family or neighborhood dengue, co-existing conditions (e.g. infancy, pregnancy, obesity, diabetes mellitus, hypertension),

18. Step I—Overall assessment Physical examination The physical examination should include: • – assessment of mental state; • – assessment of hydration status; • – assessment of hemodynamic status • – checking for tachypnoea/acidotic breathing/pleural effusion; • – checking for abdominal pain, tenderness/hepatomegaly/ascites; • – examination for rash and bleeding manifestations; • – tourniquet test (repeat if previously negative or if there is no bleeding manifestation).

19. Step I—Overall assessment Investigations: • CBC , PLATELET COUNT, HCT • ELECTROLYTES, CREATININE, BICARBONATE, BSR • LFT’S • URINE C/E • BLOOD GROUP

20. Step II—Diagnosis, assessment of disease phase and severity • On the basis of evaluations of the history, physical examination and/or full blood count and haematocrit, confirm. • The diagnosis as dengue. • assess the phase (febrile, critical or recovery) • Presence of warning signs • The hydration and hemodynamic status o • Needs for admission and/or referral to emergency department.

21. Step II—Diagnosis, assessment of disease phase and severity Hospital Admission Criteria • Warning signs Any of the warning signs if present.

22. Step II—Diagnosis, assessment of disease phase and severity Hospital Admission Criteria

23. Monitoring of Dengue Fever Patients • Feeling of well being • Fever • Pulse pressure, Blood pressure and Heart rate • Vomiting/loose stool and oral intake • Urine output • Blood counts specially HCT

24. Management decisions Depending on the clinical manifestations and other circumstances, • Patients may be sent home (Group A) • Referred for in-hospital management or (Group B) • Require emergency treatment and urgent referral (Group C).

25. Home care for dengue (OPD care - Group A) • Home care card for dengue • Adequate bed rest • Adequate fluid intake (>5 glasses for average-sized adults or accordingly in children) • Milk, fruit juice (caution with diabetes patient) and isotonic electrolyte solution (ORS) and barley/rice water. • - Plain water alone may cause electrolyte imbalance. • Take paracetamol (not more than 8tabs (4 Gm) per day for adults and accordingly in children) • Tepid sponging with water or cold water shower • Look for mosquito breeding places in and around the home and eliminate them

26. Home care for dengue What should be avoided? • • Do not take acetylsalicylic acid (aspirin), mefenemic acid (ponstan), ibuprofen or other non-steroidal anti-inflammatory agents (NSAIDs), or steroids. • • Antibiotics are not required and they are best avoided.

27. Home care for dengue Approach the hospital staff early if • Bleeding • Red spots or patches on the skin • Bleeding from nose or gums • Vomiting blood • Black-colored stools • Heavy menstruation/vaginal bleeding • Frequent vomiting • Severe abdominal pain • Drowsiness, mental confusion or seizures • Pale, cold or clammy hands and feet • Difficulty in breathing

28. In hospital management for dengue (Group B) Compensated shock (systolic pressure) maintained but has signs of reduced perfusion) Fluid resuscitation with isotonic crystalloid 5-10 ml/kg/hr over 1 hour Improvement YES NO Check HCT IV crystalloid 5-7 ml/kg/hr for 1-2 hours, then: HCT or high reduce to 3-5 ml/kg/hr for 2-4 hours; reduce to 2-3 ml/kg/hr for 2-4 hours. HCT If patient continues to improve, fluid can be further reduced. Consider significant occult/overt bleed Administer 2nd bolus of fluid Monitor HCT 6-8 hourly. 10-20 ml/kg/hr for 1 hour Initiate transfusion with fresh whole If the patient is not stable, act according blood to HCT levels: if HCT increases, consider bolus fluid administration or increase fluid administration; if HCT decreases, consider transfusion with Improvement fresh whole transfusion. NO YES Stop at 48 hours. If patient improves, reduce to 7-10 ml/kg/hr for 1-2 hours Then reduce further

29. In Hospital Management of Dengue Fever (Group C – Emergency care)

30. Hypotensive shock I/V fluid 20ml / kg isotonic crystalloid or colloid over 15 min Improvement YES NO Review 1st HCT Crystalloid/colloid 10 ml/kg/hr for 1 hour, then continue with: IV crystalloid 5-7 ml/kg/hr for 1- 2 hours; HCT or high reduce to 3-5 ml/kg/hr for 2-4 hours; HCT reduce to 2-3 ml/kg/hr for 2-4 hours. If patient continues to improve, fluid can be Consider significant occult/overt bleed Administer 2nd bolus fluid (colloid) further reduced. 10-20 ml/kg over ½ to 1 hour Initiate transfusion with fresh whole Monitor HCT 6-hourly. If the patient is not stable, act according to HCT levels: blood if HCT increases, consider bolus fluid administration or increase fluid administration; Improvement if HCT decreases, consider transfusion with fresh whole transfusion. Stop at 48 hours. YES NO Repeat 2nd HCT HCT HCT or high Administer 3rd bolus fluid (colloid) 10-20 ml/kg over 1 hour Improvement YES NO Repeat 3rd HCT

31. Complications of Dengue Fever • Haemorrhagic complications • Fluid overload • Ascites, Pleural effusion, Pulmonary aedema • Metabolic acidosis and electrolyte imbalance • Severe shock • Acute Respiratory Distress Syndrome • Hyperglycaemia and hypoglycaemia • Nosocomial infections • Mycocarditis • Hepatitis

32. Vaccination • No current dengue vaccine • Estimated availability in 5-10 years • Vaccine development is problematic as the vaccine must provide immunity to all 4 serotypes • Lack of dengue animal model • Live attenuated tetravalent vaccines under phase 2 trials • New approaches include infectious clone DNA and naked DNA vaccines

33. Hospital Discharge Criteria

34. Do and don’t of Dengue Fever

35. Prevention Personal: • clothing to reduce exposed skin • insect repellent especially in early morning, late afternoon. Bed netting is of little utility. Environmental: • reduced vector breeding sites • solid waste management • public education

36. Prevention Biological: • Target larval stage of Aedes in large water storage containers • Larvivorous fish (Gambusia), endotoxin producing bacteria (Bacillus), copepod crustaceans (mesocyclops) Chemical: • Insecticide treatment of water containers • Space spraying (thermal fogs)

37. Public Health • Major and escalating global public health problem • Global demographic changes: urbanization and population growth with substandard housing, water, and waster management systems • Deteriorating public health infrastructure with limited resources resulting in “crisis management” not prevention • Increased travel • Lack of effective mosquito control

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