Dengue Fever Flashcards
What is a single-stranded RNA virus of the genus Flavivirus and has 4 subtypes, making it possibleo be infected four times.
Dengue Fever
What is the common name for Dengue Fever
Breakbone fever
How is dengue fever transmitted?
Aedes aegypti mosquito; mother to child; blood transfusion/organ donation
incubation period for dengue fever
3-14 days; period of illness is 3-7 days.
Who qualifies for dengue fever vaccine?
only given to previously infected sero-confirmed individuals.
what percentage of dengue fever infections present asymptomatically and the person doesnt realize they are infected
75%
what percentage of dengue fever infected patients progress to threatening severe dengue
5%
what are the three phases of dengue fever
febrile
critical
convalescent
how long does the febrile phase of dengue fever last
2-7 days and can be biphasic
signs and sx of dengue fever (febrile phase)
retroorbital pain
muscle, joint, and bone pain
macular/maculopapular rash
(hemo sx- ecchymosis, epistaxis, bleeding gums, hematuria, + TQ test)
how long does critical phase last of dengue fever?
begins at cessation of fever, typically lasts 24-48 hrs.
Why is the “critical phase” of dengue fever go by that name.
most patients clinically improve and move on to recovery/convalescence phase
however, those with substantial plasma leakage develop severe dengue.
signs of severe plasma leakage with dengue fever
pleural effusions or ascites, hypoproteinemia, and hemoconcentration (may appear well despite early shock)
What is “dengue shock syndrome”
once hypotension develops, SBP declines rapidly, and irreversible shock occurs.
(may develop hematemesis, bloody stool, melena)
What happens during convalescent/recovery phase of dengue fever
rash may desquamate and be pruritic
patient begins to absorb extravasated intravenous fluids, pleural, and abdominal effusions.
what are the two hallmarks of severe dengue
infection-induved capillary permeability and disordered/diminished blood clotting.
What are the three main reasons Dengue fever can cause leaky capillaries?
secondary to an immune response to the virus
cells become necrotic, and affect both agulation and fibrinolysis
low platelete count degrates the normal clotting response
What is a positive dengue TQ test
10 or more petechia below AC fossa after an inflated cuff left on arm for 5 min and rested for 2.
*cuff will be inflated between SBP and DBP.
How is dengue diagnosed with lab?
serum obtained early <7 days.
or later in the illnes (greater than 4 days after fever) with ELISA.
Treatment for Dengue
hydration. avoid aspirin and NSAIDS. avoid procedures due to bleeding risk.
acetaminophen for fever.
(maintenance of body fluid volume is critical for severe dengue)
