Viral Zoonoses II Flashcards
How are arboviruses transmitted?
Saliva of arthropods in contact with blood
Person to person
Family flaviviridae
Zikv, yellow, west nile, dengue
Which dengue serotype predisposes one to DHF?
Serotype 2
DNV-5 is similar to
DNV-2
Primary vector for dengue
Aedes aegypti
Dengue characteristics
Enveloped (+) ssRNA
3 categories of symptomatic dengue virus
- Undifferentiated fever
- Dengue fever (breakbone fever)
- DHF
Which grades of DHF causes DSS?
3 and 4
Characterized by plasma leakage, changes in hemoconcentration and abnormalities in homeostasis
DHF
Increased circulation of virus will lead to
Increased probability of occurence of virulent strain
Increased probability of secondary infection
Increased probability of immune enhancement leading to increase in DHF
Stages of dengue
Febrile
Critical
Recovery
Severe Dengue
Marked by increase in capillary permeability > increase in hematocrit, Temperature drops to 37.5-38°, shock, severe organ impairment (hepa, encepha, endocarditis)
Criticsl phase dengue
Shock in dengue leads to
Subnormal body temp
Metabolic acidosis
DIC
Severe Hemmorhage
sore throat, injected pharynx and conjunctival injection, enlarged and tender liver, hemmorhagic signs (petechiae, vaginal bleeding), decrease in WBC, high grade fever
Febrile illness
WBC may start to rise but recovery of platelet count is lesser. Pulmonary edema and CHF due to excessive IV fluid therapy
Recovery phase
Plasma leakage, severe bleeding, severe organ impairment, hypovolemia, tachycardia, shock, peripheral vasoconstriction
Severe dengue
How will you know if a patient is in shock?
Pulse pressure is less than 20 mmHg Cold extremities Delayed capillary refill Rapid pulse rate Hypotension complicated with major bleeding Associated with prolonged shock
T or F: severe dengue has enough coagulation abnormalities to result to major bleeding
False
Most deaths of dengue virus is due t
Profound shock
T or F: dengue virus replicates in salivary glands
True
5 criteria in diagnosign dengue
Hydration status Blood pressure Evidence of bleeding in skin and other parts Increased vascular permeability Tourniquet test
Positive torniquet test
20 or more petechiae per inch2
When is leukopenia observed in dengue
Near end of febrile illness
