2. EPIDEMIOLOGY
• Dengue is the most rapidly spreading
mosquito-borne viral disease in the world
• Increase in incidence by over 30-fold in
the last 50 years
• Currently endemic in all continents except
Europe
3. ETIOLOGY
THE VIRUS
• DEN- family flaviviridae
genus flavivirus
• Has four distinct serotypes (DEN1 – 4)
• DEN-2 and DEN-3 cause severe disease
• Cleaved by host and viral proteases into 3
structural proteins and 7 nonstructural
proteins(NS)
4. THE VECTOR
• Transmitted by infected Aedes
mosquitoes
• Highly urbanized,
fresh water,
day feeding mosquito
5. THE HOST
• Humans are the primary host of the virus
• Severity depends upon factors like
gender,secondary infection,age and
chronic diseases (sickle cell anemia,
asthma , DM)
• Vertical transmission and through infected
blood products +
10. • Specific antibodies start appearing
around day 5 of illness.
• Infection with one serotype gives lifelong
immunity to that type, but only short term
protection against the other three.
• Secondary infection with DEN-2, DEN-3
is associated with dengue haemorrhagic
fever.
11. CLINICAL MANIFESTATIONS
• Multisystem disease with a wide clinical
spectrum
• Incubation period – 4 to 10 days
• Illness begins abruptly following the
IP,divided into three phases
FEBRILE CRITICAL RECOVERY
12. FEBRILE PHASE
• High grade fever lasting for 2-7 days
• Accompanied by facial
flushing,rash,myalgia,arthralgia,headache,
nausea,vomiting,anorexia,sore
throat,injected pharynx and conjunctiva.
• Petechiae,epistaxis,gum bleed may be
seen.
13. CRITICAL PHASE
• Usually occurs on days 3-6 of the illness
• Lasts for 24-48 hours
• Progressive leukopenia,increasing
hematocrit levels,decrease in platelet
count precede plasma leakage
Ascites Pleural effusion Shock
14. • Prolonged shock leads to DIC which
leads to severe haemorrhage
-Decrease in hematocrit
-GI bleeding usually
• Organ hypoperfusion can lead to
hepatitis,myocarditis,encephalitis
15. RECOVERY PHASE
• Reabsorption of the fluid from
extravascular compartment occurs
• General well-being improves,appetite
returns,hemodynamic status
stabilizes,urine output becomes normal,GI
symptoms abate
• Generalized pruritus,bradycardia ++
18. DENGUE CASE
PROBABLE DENGUE
(live in/travel to endemic area+fever+any of the following
two criteria :
rash,nausea/vomiting,aches,positive tourniquet
test,leukopenia,any warning sign)
WARNING SIGNS
NEGATIVE POSITIVE
DENGUE WITH SEVERE
WARNING SIGNS DENGUE
DENGUE
WITHOUT
WARNING
SIGNS
20. SEVERE DENGUE
FEVER OF 2-7 DAYS PLUS ANY OF THE
FOLLOWING FEATURES :
1.EVIDENCE OF PLASMA LEAKAGE
2.SIGNIFICANT BLEEDING
3.ALTERED LEVEL OF CONSCIOUSNESS
4.SEVERE GI INVOLVEMENT
5.SEVERE ORGAN INVOLVEMENT
24. MANAGEMENT
• HISTORY – Time of fever
onset,associated symptoms,warning
signs,urine output,family or
neighbourhood dengue
• PHYSICAL EXAMINATION – Assess
hydration,hemodynamic status,tender
abdomen,ascites,hepatomegaly,pleural
efffusion,bleeding manifestations,mental
state,tourniquet test
25. • INVESTIGATIONS – CBP with HCT,other
organ function tests as
indicated(USG,CXR,LFT,RFT,PT APTT
INR,BLOOD GLUCOSE,SERUM
ELECTROLYTES,ABG)
• SPECIFIC DIAGNOSTIC TESTS –
NS1 Ag detection
IgM IgG detection
Viral isolation
PCR to detect viral genome
33. DISCHARGE CRITERIA
• No fever for 48hours
• Improvement in general well-
being,appetite,U/O,hemodynamic status
• Increasing platelet count
• Stable HCT without IVF
34. D/D
• CONDITIONS THAT MIMIC FEBRILE PHASE :
Influenza,
measles,
chikungunya,
scarlet fever,
meningococcal infection,
drug reactions,
G.E
acute mosquito transmitted disease characterized by
fever, headache, muscle, joint pains, rash, nausea and vomiting.
Global case load of about 50 million annually ……endemic in all states except extreme north and the north east….cyclical trends with high epidemic years and non epidemic years
Dengue fever virus is an ss rna virus…transmitted by arthropods hence also called arbovirus….asian genotypes ….viralgenome cleaved into capsid membrane envelope
Prinicpally aedes aegyptyi..also albopictus polynesiensis scutellaris(stegomyia family)……….good vector coz its highly anthropophilic(close proximity to humans)
Mechanism explain….extrinsic ip of 8-12 days females-more severe
ENHANCING ANTIBODIES ARE CONCENTRATION DEPENDENT AND SEROTYPE INDEPEMNDENT
Coincident with the disappearance of virus and antigens
Difficult to differentiate between dengue and non dengue fever in this phase.Positive tourniquet test during this phase increases probability of dengue
Around the time of defervescence
GI BLEEDING USUALLY
Over 48 to 72 hours…no excess iv fluids .islets of white in sea of red rash
CNS , GI MANIFESTATIONS
SHOULD BE CONSIDERED WHEN THE PERSON IS FROM AN AREA AT DENGUE RISK
ACC TO NVBDCP……..DHF GRADE 3 AND 4 IS DSS
TO ESTABLISH BASELINE HCT…>20% rise……as early as day 1….igm varies….at around 5 days……nvbdcp using macelisa…HEMAGG INHIBITION METHOD
MONITOR PERIPHERAL PERFUSION,VITALS,URINE OUTPUT,HCT,BLOOD GLUCOSE,OTHER ORGAN FUNCTIONS
GROUP CRITERIA INCLUDE
5-10 ML OF PACKED CELLS./10-20 ML OF FRESH WHOLE BLOOD…………correct the electrolyte dist,acid base imbalances