COMMUNITY DENGUE FEVER FOR COMMUNITY STUDENTS PPT

COMMUNITY TOPIC

1. DENGUE FEVER

2. Dengue fever Dengue fever is an acute febrile illness caused by viruses belonging to the flaviviridae family and is characterized by biphasic fever, myalgia , arthralgia and rash Dengue hemorrhagic fever is characterized by abnormalities in hemostasis and by marked leakage of plasma from the capillaries; may lead to shock (dengue shock syndrome)

3. Epidemiology Dengue viruses are arboviruses that belong to the flaviviridae family Reservoir of infection – man, mosquito Vector – Aedes aegypti mosquito Incubation period – 8-10 days Mode of transmission – by bite of female Aedes mosquito. Transmission occurs in cycle, man-mosquito-man It bites the patient at daytime during viremia and sucks the infected blood. Virus multiplies in salivary gland of mosquito. After 8-10 days infection is transmitted to other person by bite of infected mosquito

4. Pathophysiology Classical benign form is termed as dengue fever. Most s erious forms are dengue hemorrhagic fever and dengue shock syndrome. Main pathophysiological changes in DHF and DSS : Increased vascular permeability that give rise to loss of plasma from vascular compartment leading to hemoconcentration , low pulse pressure and other signs of shock It will lead to thrombocytopenia, vascular changes and coagulopathy

5. Clinical features Dengue fever Sudden onset of moderate to high fever Bradycardia Chills Intense headache Muscle and joint pain with restriction of movement Retro orbital pain on movement of eye and photophobia within 24 hours Other features like extreme weakness, anorexia, vomiting, constipation, sore throat, abdominal discomfort, flushing of skin, skin rashes in upper limbs and trunk within 3-4 days after onset of fever Complicated with convulsion, tonsilitis , rhinitis, diarrhea, pharyngitis Generally recovers within 7 days

6. Dengue hemorrhagic fever High continuous fever, epigastric discomfort, abdominal pain and palpable liver Moderate to severe thrombocytopenia, petechia , purpura , ecchymosis present on extremities, axillae , face and palate Prolonged bleeding occurs at needle prick and venipuncture site Complicated with circulatory failure and shock Febrile convulsions in infants Epistaxis , gum bleeding, hemetemesis , malena , hepatitis, encephalitis, glomerulonephritis

7. 3. Dengue shock syndrome After 2-7 days of fever Cold congested skin, rapid and weak pulse, lethargy, restless, acute abdominal pain Hypotension, reduced pulse pressure Hepatitis, encephalitis, glomerulonephritis

8. Diagnosis History, physical examination Positive tourniquet test – appropriate sized cuff is applied to the arm, and inflated between systolic and diastolic BP for 5 min. Test is positive if there are more than 20 petechia / square inch X ray: pleural effusion Blood examination : increased hematocrit , thrombocytopenia, prolonged PT, APTT, hyponatremia , Increased SGPT, hypoproteinemia Stool for occult blood V irus isolation IgM antibody estimation

9. Treatment Symptomatic treatment: bed rest, antipyretics, analgesics ( salicylates must be avoided because it may precipitate bleeding tendency and metabolic acidosis) Oral fluid intake with ORS or fruit juice are preferred to plain water (100-150 ml/kg) Monitor vital signs Treat fluid and electrolyte imbalance, adequate nutrition Blood, FFP, platelet transfusion is needed in severe hemorrhagic manifestations Shock is managed by IVF Children without hypotension: RL 7 ml/kg/hr Children with hypotension: RL 10-20 ml/kg/hr or bolus Discharged when temperature become normal for atleast 24 hrs, urine output normal, improved appetite, no respiratory distress, stable hematocrit and platelet count

10. Prevention Prevention of mosquito breeding in stored water and killing larva Personal protective measures (mosquito net) Isolation of patient during first few days of illness under bed nets

11. Complications DHF/DSS is complicated with intracranial bleeding, encephalopathy, convulsions, renal failure, hemolytic uremic syndrome, hepatic failure and iatrogenic problems like sepsis, pulmonary edema, overhydration and electrolyte imbalance