Chikungunya Fever Dengue Fever/Dengue Haemorrhagic Fever ...
Dengue fever overview 2013
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Transcript of Dengue fever overview 2013
Dengue Fever
Mahadevappa Hunasikatti MD DPM DCR, FCCP
President, Global Health Care Consultants MD PC2826 Old Lee highway # 250, Fairfax, VA 22031
Tel: 703-573-9212: Fax: [email protected]
Definition:
• Most common arhtropod viral –Arboviral illness in humans.
• 50-100 Millions are affected• 4 types of Flavirus• Its is transmitted by mosqitoes of the genus
Aedes-aegypti
Epidemiology:
• Most are asymptomatic 50-90%• Some result in non-specific febrile illness• Rarely –may result in complex of classic
dengue fever ( DF)• Some-may result in bleeding-Dengue
Hemorrhagic Fever ( DHF).
Spread:
• Epidemic Spread: Isolated event-single viral strain. Infection incidence of 25-50%. Transmission begins in urban centers and then spreads to rest of the country
• Hyper endemic Spread: Continuous circulation of multiple viral serotypes –predominant pattern of global transmission. Antibody prevalence increases with age. Most adults are immune.
Pathophysiology:
• Mosquito borne illness• Serotypes DENV 1-4• Aedes aegypti- is the predominant vector
globally• Others: Aedes albopictus ( tiger mosquito)• Hosts:• Humans are primary reservoir for dengue.
Pathophysiology..
• Patients can remain infectious for 6-7 days
• The viruses replicate in the salivary gland of mosquitos
• Once infected- the dengue has an incubation period of 3-14 days
• Replicate in dendritic cells, hepatocytes and endothelial cells
Clinical Features:
• Recent travel to endemic region• Symptoms that begin more than 2
week after travel from endemic region-is unlikely to be Dengue fever
• Prodrome: Chills• Classic: Fever, chills and severe
aching ot head, back and limbs• Fever last 2-7 days –may be as high as
41 degree celsius
Clinical Features:
• Aches all over the body ( Breakbone syndrome)-Arthralgia, Myalgia
• Headache• Nausea , vomiting• Rash-maculo papular• Weakness• Sore throat• Anorexia
Clinical Features:--
• Bleeding: Petechae, Bleeding gums, epistaxis, and hematuria
• Lymphadenopathy• Saddleback fever: Fever abates for a day only
to return next day• Second rash: later: lasting 1-5 days:
morbilliform, maculopapular , and spares palms and soles.
Clinical Features:---
• Recovery is generally slow –but usually complete recovery takes place.
• At the time of defervescence: Danger!• --This is the time development of dengue
shock or dengue hemorrhagic fever can take place.
Signs to watch for Dengue Hemorrhagic Fever:--
• Abdominal pain• Hypothermia• Thrombocytopenia• Altered mental state• Restlessness
Differential Diagnosis:• Malaria• Ebola virus• Chikungunya fever• West Nile Encephalitis• ITP• Influenza• Hepatitis• Meningitis• Yellow fever• Rocky Mountain Spotted fever• Leptospirosis• Rickettsial infection
Diagnosis:
• Blood-Isolation of virus• Ig G and Ig M titers to dengue virus
antigens• PCR in CSF or Serum • CBC• CMP• Serum patient and albumin• Liver Panel• DIC Panel
Diagnosis Dengue Fever:--
• Characteristics:• -Thrombocytopenia• -Leukopenia• -Moderate AST and ALT elevation
Dengue Hemorrhagic Fever:-
• Increased HCT• Hypoprototeinenia• Increased PT• Increased PTT• Decreased Fibrinogen• Increased Fibrin Split Products• Stool: OB• UA
Dengue Fever—Work Up:--
• Chest X Ray• ABG-in sever cases• CT Scan of Brain-if any altered mental state• Biopsy of skin lesion• EKG-Non-specific
Reportable illness in United States:
• Remember to report to authorities in USA:
• -Demographics • -Travel hisotry• -Date of onset of illness• -Hospitalized or not• -Outcome
Work up…
• Most common electrolyte abnormality: Hyponatremia
• Correct metabolic acidosis• Low Albumin• Increased Transaminases• DIC
Case definition Dengue fever:--
• Serology: IgG or IgM titres• -NS1• Tournquet test: postive• Petechae, echymosis• Purpura• Bleeding from any site• Thrombocytopenia• Plasma leakage-Increased HCT
Case definition; Dengue Shock Fever:--
• Narrow Pulse Pressure: < 20 mm Hg-Elevated Diastolic pressure
• Cool, Clammy skin• Hypotension• Altered Mental state
Treatment of Dengue Fever:---
• Self limited disease –usually• Analgesia: Acetaminophen• Avoid:• -NSAID• -ASPIRIN• Corticosteroids
Treatment of Dengue fever:---
• IV Fluids: NS preferred: Isotonic fluids• Treat any hemorrhage• -PRBC• -Platelet• Bed rest• Treat Shock –asap with adequate fluids
Prevention:
• Mosquito Repellent: DEET: N, N Methylbenzamide
• Protective clothing: Permethrine insecticide impregntion is preferable.
• Mosquito netting: limited value. Aedes are active in day time
• Indoor spray-eliminate mosquito vector
Vaccination:
• No vaccine is currently available
• CDC:• Tel: 1-800-232-4636
Thank You
• If you have any questions feel free to e-mail me: