Dengue Fever

Information about Dengue Fever

Published on January 17, 2010

Author: alauddinsarwar



Slide 1: Aedes aegypti Mosquito DENGUE FEVER By: DR. MUHAMMAD ALAUDDIN SARWAR MEDICAL OFFICER SINDH GOVERNMENT QATAR HOSPITAL KARACHI. World Distribution of Dengue 1999 : World Distribution of Dengue 1999 Slide 3: GLOBAL STATUS • New infections annually: 50 million • Deaths: 24,000 annually • People at risk: 2.5-3 billion • Hospitalized cases: 500 000/year (90% of those affected are children) • Disease burden: 465,000 Disability Adjusted Life Years (DALY) Slide 4: DENGUE OUT BREAK IN SOUTH EAST ASIA IN 2005 Slide 5: DENGUE OUT BREAK IN PAKISTAN (2006) Slide 6: Manifestation Of Dengue Virus Infections A) Undifferentiated Fever : A) Undifferentiated Fever May be the most common manifestation of dengue Prospective study found that 87% of students infected were either asymptomatic or only mildly symptomatic Other prospective studies including all age- groups also demonstrate silent transmission DS Burke, et al. A prospective study of dengue infections in Bangkok. Am J Trop Med Hyg 1988; 38:172-80. 2A) Clinical Characteristicsof Dengue Fever : 2A) Clinical Characteristicsof Dengue Fever Fever Headache Muscle and joint pain Nausea/vomiting Rash Hemorrhagic manifestations 2B)Hemorrhagic Manifestationsof Dengue : 2B)Hemorrhagic Manifestationsof Dengue Skin hemorrhages: petechiae, purpura, ecchymoses Gingival bleeding Nasal bleeding Gastro-intestinal bleeding: hematemesis, melena, hematochezia Hematuria Increased menstrual flow C1) Clinical Case Definition forDengue Hemorrhagic Fever : C1) Clinical Case Definition forDengue Hemorrhagic Fever 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) low albumin pleural or other effusions 4 Necessary Criteria: Four Grades of DHF : Four Grades of DHF Grade 1 Fever and nonspecific constitutional symptoms Positive tourniquet test is only hemorrhagic manifestation Grade 2 Grade 1 manifestations + spontaneous bleeding Grade 3 Signs of circulatory failure (rapid/weak pulse, narrow pulse pressure, hypotension, cold/clammy skin) Grade 4 Profound shock (undetectable pulse and BP) Danger Signs inDengue Hemorrhagic Fever : Danger Signs inDengue Hemorrhagic Fever Abdominal pain - intense and sustained Persistent vomiting Abrupt change from fever to hypothermia, with sweating and prostration Restlessness or somnolence Martínez Torres E. Salud Pública Mex 37 (supl):29-44, 1995. Slide 13: Warning Signs for Dengue Shock C2) Clinical Case Definition for Dengue Shock Syndrome : C2) Clinical Case Definition for Dengue Shock Syndrome 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 Unusual Presentationsof Severe Dengue Fever : Unusual Presentationsof Severe Dengue Fever Encephalopathy Hepatic damage Cardiomyopathy Severe gastrointestinal hemorrhage Risk Factors Reported for DHF : Risk Factors Reported for DHF Virus strain Pre-existing anti-dengue antibody previous infection maternal antibodies in infants Host genetics Age Risk Factors for DHF (continued) : Risk Factors for DHF (continued) Higher risk in secondary infections Higher risk in locations with two or more serotypes circulating simultaneously at high levels (hyperendemic transmission) Increased Probability of DHF : Increased Probability of DHF Hyperendemicity Increased circulation of viruses Increased probability of secondary infection Increased probability of occurrence of virulent strains Increased probability of immune enhancement Increased probability of DHF Gubler & Trent, 1994 Viral Risk Factorsfor DHF Pathogenesis : Viral Risk Factorsfor DHF Pathogenesis Virus strain (genotype) Epidemic potential: viremia level, infectivity Virus serotype DHF risk is greatest for DEN-2, followed by DEN-3, DEN-4 and DEN-1 Clinical Evaluation in Dengue Fever : Clinical Evaluation in Dengue Fever Blood pressure Evidence of bleeding in skin or other sites Hydration status Evidence of increased vascular permeability-- pleural effusions, ascites Tourniquet test Petechiae : Petechiae Slide 22: Vaughn DW, Green S, Kalayanarooj S, et al. Dengue in the early febrile phase: viremia and antibody responses. J Infect Dis 1997; 176:322-30. Pleural Effusion Index Tourniquet Test : Tourniquet Test Inflate blood pressure cuff to a point midway between systolic and diastolic pressure for 5 minutes Positive test: 20 or more petechiae per 1 inch2 (6.25 cm2) Pan American Health Organization: Dengue and Dengue Hemorrhagic Fever: Guidelines for Prevention and Control. PAHO: Washington, D.C., 1994: 12. Positive Tourniquet Test : Positive Tourniquet Test Laboratory Testsin Dengue Fever : Laboratory Testsin Dengue Fever Clinical laboratory tests CBC--WBC, platelets, hematocrit Albumin Liver function tests Urine--check for microscopic hematuria Dengue-specific tests Virus isolation Serology Laboratory Methods for Dengue Diagnosis : Laboratory Methods for Dengue Diagnosis Virus isolation to determine serotype of the infecting virus IgM ELISA test for serologic diagnosis Temperature, Virus Positivity and Anti-Dengue IgM , by Fever Day : Temperature, Virus Positivity and Anti-Dengue IgM , by Fever Day Dengue IgM Mean Max. Temperature Virus Adapted from Figure 1 in Vaughn et al., J Infect Dis, 1997; 176:322-30. Fever Day Percent Virus Positive -4 -3 -2 -1 0 1 2 3 4 5 6 39.5 39.0 38.5 38.0 37.5 37.0 Temperature (degrees Celsius) Dengue IgM (EIA units) Outpatient Triage : Outpatient Triage 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 Patient Follow-Up : Patient Follow-Up Patients treated at home Instruction regarding danger signs Consider repeat clinical evaluation Patients with bleeding manifestations Serial hematocrits and platelets at least daily until temperature normal for 1 to 2 days All patients If blood sample taken in first 5 days after onset, need convalescent sample between days 6 - 30 All hospitalized patients need samples on admission and at discharge or death Treatment of Dengue Fever& DHF I & II : Treatment of Dengue Fever& DHF I & II Fluids Rest Antipyretics (avoid aspirin and non-steroidal anti-inflammatory drugs) Monitor blood pressure, hematocrit, platelet count, level of consciousness Slide 31: Treatment of DHF III & IV All above treatment + – In case of severe bleeding, give fresh whole blood 20 ml/kg as a bolus – Give platelet rich plasma transfusion exceptionally when platelet counts are below 5,000–10,000/ mm3 . – After blood transfusion, continue fluid therapy at 10 ml/kg/h and reduce it stepwise to bring it down to 3 ml/kg/h and maintain it for 24-48 hrs Slide 32: 1 unit of RD(Random Donor) Plt. (50ml) per 10 Kg body weight.---- expected to increas the Plt. Count 5000-10000/uL. (If No splenomegaly, Fever or DIC) Alloimmunized (who have received multiple transfusions and thus sensitized) may have little or no increase in the count. They can be best served by SDAP(Single Donor Apheresis Platelets) as 1 SDAP unit(150ml)=6 RD units Evaluation of Refractoriness of RD units Treatment of DHF III & IV Appropriate if CCI is 10X10 9 /ml in 1 hr post transfusion sample and/or CCI is 7.5X10 9/ml in 18-24 hr post transfusion sample. Treatment of Dengue Fever : Treatment of Dengue Fever Raw papaya leaves, 2 pcs just cleaned and pound and squeeze with filter cloth. You will only get one tablespoon per leaf. So two tablespoon per serving once a day. Do not boil or cook or rinse with hot water, it will loose its strength. Only the leafy part and no stem or sap. It is very bitter and you have to swallow it like Won Low Kat. But it works. Papaya Juice vs. Dengue ? Source: from Indonesia March 2005 Indications for Hospital Discharge : Indications for Hospital Discharge Absence of fever for 24 hours (without anti-fever therapy) and return of appetite Visible improvement in clinical picture Stable hematocrit 3 days after recovery from shock Platelets  50,000/mm3 No respiratory distress from pleural effusions/ascites Pan American Health Organization: Dengue and Dengue Hemorrhagic Fever: Guidelines for Prevention and Control. PAHO: Washington, D.C., 1994: 69. Common Misconceptions aboutDengue Hemorrhagic Fever : Common Misconceptions aboutDengue Hemorrhagic Fever Dengue + bleeding = DHF Need 4 WHO criteria, capillary permeability DHF kills only by hemorrhage Patient dies as a result of shock Poor management turns dengue into DHF Poorly managed dengue can be more severe, but DHF is a distinct condition, which even well-treated patients may develop Positive tourniquet test = DHF Tourniquet test is a nonspecific indicator of capillary fragility More Common Misconceptions about Dengue Hemorrhagic Fever : More Common Misconceptions about Dengue Hemorrhagic Fever DHF is a pediatric disease All age groups are involved in the Americas DHF is a problem of low income families All socioeconomic groups are affected Tourists will certainly get DHF with a second infection Tourists are at low risk to acquire DHF Dengue Vaccine? : Dengue Vaccine? No licensed vaccine at present Effective vaccine must be tetravalent Field testing of an attenuated tetravalent vaccine currently underway Effective, safe and affordable vaccine will not be available in the immediate future Prevention : Prevention The main tactic used in fighting Dengue is eradicating the mosquito. Public spraying for mosquitoes is the most important aspect of this approach. Personal prevention involces the use of mosquito nets, repellents, cover exposed skin, use of DEET-impregnated bednets, and avoiding endemic areas. CONTACT : CONTACT [email protected] [email protected] THANK YOU

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