Dengue Flashcards
Acute febrile illness with no focus of infection
Dengue
Dengue incubation period
2-7days
Fever pattern in Dengue
Biphasic
No. Sero types of dengue
4
Principal vector of dengue
Aedes aegypti
Pathogenesis theories (2) of DHF in guazon
- Macrophage/monocytes infection
Most dangerous serotype more prone to producing DHF
Serotype 2
DHF patho genesis
Previous infections with heterogous dengue virus serotype produces nonprotective antiviral antibodies resulting to enhanced infection
Risk factors for induction of vascular permeability and shock
(7)
- Presence of enhancing and nonneutralizing antibodies (trans placental maternal antibody in less than 9 months old, antibody from previous infection
- Age: dec susceptibility after 12 years
- Females more affected
- Whites more than blacks
- Malnutrition protective
- Infecting serotype 2
- Sequence 1 followed by serotype 2
Pathogenesis of dengue shock syndrome
Increased vascular permeability
Typical/ Break-bone fever symptoms
Fever headache retro-orbital pain back pain severe myalgia
Initial symptoms 6
1 maculopapular rash 2 lymphadenopathy 3 anorexia 4 nausea and vomiting 5 palatal vesicles 6 scleral injection
Rash of dengue
Maculopapular
CBC FINDINGS
Leukopenia
Thrombocytopenia
Elevated hematocrit
Serum transaminases
Ast or ALt > 1000 in severe dengue
Chest X-ray
Watch out for pleural effusion
Serology options recovery and acute phase
- Recovery- igM Elisa or paired serology
2. Acute- antigen-detection Elisa or RT-PCR
Antigen determination of dengue during the first 3-4 days
NS-1 antigen
+ tourniquet test
BP cuff inflated midway systolic and diastolic for 5 minutes
> 20 petechiae in a square inch 1.5 inches fr color aspect of the antecubital fossa
WHO Classification of Probable Dengue 7
1. Lives in/traveled to dengue endemic area 2 FEVER plus 2 of the following - nausea and vomiting - rashes/body aches -leukopenia -positive tourniquet test -any warning signs
Warning signs 7
1 Abdominal tenderness 2 Persistent vomiting 3 bleeding in mucous membranes 4 fluid collection evaluated clinically 5 lethargy restlessness 6 hepatomegaly > 2 cm 7 increase in HCT with rapid decrease in platelets
Severe dengue
3
1 Severe plasma leakage leading to shock, fluid accumulation respiratory distress 2 Severe bleeding 3 Severe organ involvement ast/alt >1000 Impaired consciousness Cvs and others
Dengue without warning signs treatment
- Bed rest
- Sufficient fluid intake
- Paracetamol as needed
Signs of progressing disease
1 defervescence
2 improving WBC count
3 warning signs
