Who is Afraid of Dengue Fever

8/14/2019 Who is Afraid of Dengue Fever

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PUBLIC ENEMY NO. 1

Dengue Haemorrhagic Fever

Dr. SOMESH MEHROTRA

Critical care Specialist

Siddhi Vinayak HospitalBareilly , UP, india

9837000048


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To fight- you should know the enemy inside out


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Four lives of Dengue virus Family flaviviridae .

has four serovars.den1-den2,den3and den4

Infection with one serotype confers long term immunity tothat serotpt only


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Efficient vector susceptible to Dengue virus.

Bites many human for a single meal in day time.

Urban dweller


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Global problem

Recognized in the Philippines in 1953.


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Transmission of Dengue Viruses

Viruses are transmitted from humans to

mosquitoes to humans

Next generation of mosquitoes

Human are the main amplifying hosts

Monkeys can also be reservoirs

The virus circulates in the blood approx.

at the time of fever


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OUT BREAK

-PART I

(Two important epidemiological patterns)

DHF/DSS in where multiple dengue

serotypes are endemic.

Sporadic cases or small outbreaks in urban

areas that steadily.increase in size

Pattern of epidemic activity every 2-5 years.


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OUT BREAKPART - II

A second pattern

Low endemicity

Multiple Dengue serotypes

Relatively low rates of infections


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Pathology

At autopsy Frequency of Hemorrhage

Skin and subcutaneous tissue


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Liver

There is focal necrosis of hepatic cells,

swelling.


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Kidney

Immune-complex type of

glomerulonephritis which resolves

completely in 3 weeks Perivascular Oedema

Sderum complement, immunoglobulin and

fibrinogen.


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Bone marrow

Depression of all haematopoietic cells was

observed, which would rapidly improve as

fever subsided.


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Pathogenesis of DHF/DSS

Vascular permeability. Disorder in haemostasis

(Haemoconcentration, ( Vascular changes,

low pulse pressure. Thrombocytopenia andSign of shock.) coagulopathy.)

of the complement system of C3 and C5 levels.

Platelet defects both qualitative and quantitative.


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Secondary Infections

Enhancement of virus replication in

macrophages by heterotypic antibodies.

Cross-reactive but not neutralizing

antibodies.

Cross-reactive CD4+ and CD8 + cytotoxic

lymphocytes.

Cross Reaction


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Case Definitions

Probable Dengue Fever

An acute febrile illness with two or more of the following :

headache

retro-orbital pain myalgia rash

heamorrhagic manifestations

leukopenia

and

supportive serology : antibody titre >1280, a comparable IgG ELISA titre, or a positiveIgM antibody test

Or occurrence at the same location and time as other confirmed cases of dengue

fever.


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Case Difination

Confirmed dengue fever Isolation of the dengue virus from serum or autopsy; or

A fourfold or greater change in rciprocal IgG or IgM antibody titresto one or more dengue virus antigens in paried serum samples; or

Dengue virus antigen in autopsy tissue, serum or C.S.F. samples byimmunohistochemistry, immunofluorescence or ELISA; or

Dengue virus genomic sequences in autopsy tissue serum or C.S.F.

samples by PCR.


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Case definition

Dengue haemorrhagic feverAll of the following must be present

Fever, or history of acute fever, lasting 2-7 days occasionally biphasic.

Haemorrhagic tendencies(at least one of--)

Tourniquest test

1. Petechiae, ecchymoses,purpura2. Bleeding-mucosa,git,injection site

3. Haemetemesis, malena

Thrombocytopenia (100000 cells per mm3 or less).

Evidence of plasma leakage due to increased vascular permeability,manifested by at least one of the following.

1. A rise in PCV equal to or greater then.2. A drop in the haematocrit following volume-replacement treatmentequal to or greater than 20% of baseline;

3. Signs of plasma leakage such as pleural effusion, ascities andhypoproteinaemia.


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Case Definition for Dengue

Shock SyndromeAll four points of DHF and ;

Rapid and weak pulse.

Narrow pulse pressure(< 20mm Hg

(2.7KPa))

or manifested by :

Hypotension for age.

Cold, clammy skin and restlessness.


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Drugs for dengue


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Grading severity of DHF

Grade I : Fever + non-specific cc + tourniquet test and/or easybruising.

Grade II: Spontaneous bleeding.

..DSS..

Grade III : Circulatory failure i.e. a rapid, week pulse and narrowingof pulse pressure or hypotension, + cold, clammy skin andrestlessness.

Grade IV: Profound shock with undetectable blood pressure or pulse.


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Indications for hospitalization

for bolus intravenous fluid therapy may be

necessary where significant dehydration

(>10% of normal body weight) hasoccurred and rapid volume expansion is

needed. Signs of significant dehydration

include :


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Tachychardia

Ivreased capillary refill time (>2s)

Cool, mottled or pale skin

Diminished peripheral pulses

Changes in metal status

Oliguria

Sudden rise in haematocrit or continuously elevated

haematocrit despite administration of fluids

Narrowing of pulse pressure (


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DHF-treatment

# ORS

Hyperpyrexia

Day of judgment;is the day of

defervescence


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DSS- continued replacement

Plasma loss may continue for 24-48 hrs

CVP measurement

Reabsorption of extravasated plasma=pcv

falls

Blood transfusion


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Unusual manifestations of

dengue haemorrhagic fever Acute hepatic failure

Maintainance of consciousness even in

presence of severe shock


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Criteria for discharging inpatients

Absence of fever for at least 24 hours.

Return of appetite.

Visible clinical improvement. Good urine out put.

Stable haematocrit.

Passing of at least 2 days after recovery from

shock.

No respiratory distress from pleural effusion orascites.

Platelet count of more then 1 lakh per mm

3

.


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Chikungunya; that which bends up Is the little sister clinically

Joint pains are the major feature of both acute andchronic phase

Ankle & wrist Intense pain caused by the pressure on wrist is

diagnostic Lymphopenia, thrombocytopenia,hepatitis

High viremia causes direct man to mantransmission

World wide 2 million cases


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. Perils of platelet transfusion

Nu. & condition of pl.extract.

Fever, spelnomeghaly,drugs,DIC, Alloimmunization-from wbc,rbcs in

pl.extractirradation by ultraviolet B helps

TRAP study-apherisis ???#

Refractoriness


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Who is Afraid of Dengue Fever

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