Dengue fever Flashcards
What is Dengue fever?
Dengue fever is a viral infection caused by the dengue virus, which can progress to viral haemorrhagic fever.
Examples include yellow fever, Lassa fever, and Ebola.
What type of virus causes Dengue fever?
Dengue fever is caused by an RNA virus of the genus Flavivirus.
How is Dengue fever transmitted?
Dengue fever is transmitted by the Aedes aegypti mosquito.
What is the incubation period for Dengue fever?
The incubation period for Dengue fever is approximately 7 days.
What are the clinical features of Dengue fever?
Clinical features include:
* Fever
* Headache (often retro-orbital)
* Myalgia (muscle pain)
* Bone pain
* Arthralgia (‘break-bone fever’)
* Pleuritic pain
* Facial flushing
* Maculopapular rash
* Haemorrhagic manifestations (e.g., positive tourniquet test, petechiae, purpura/ecchymosis, epistaxis)
What are the warning signs of Dengue fever?
Warning signs include:
* Abdominal pain
* Hepatomegaly (enlarged liver)
* Persistent vomiting
* Clinical fluid accumulation (e.g., ascites, pleural effusion)
What is Severe Dengue (Dengue haemorrhagic fever)?
Severe dengue is a form of disseminated intravascular coagulation (DIC), resulting in thrombocytopenia and spontaneous bleeding.
What is Dengue shock syndrome (DSS)?
Around 20-30% of patients with severe dengue develop Dengue shock syndrome (DSS).
What are the common blood investigations for Dengue fever?
Common findings in blood tests include:
* Leukopenia (low white blood cell count)
* Thrombocytopenia (low platelet count)
* Raised aminotransferases (liver enzymes)
What are the diagnostic tests for Dengue fever?
Diagnostic tests include:
* Serology (to detect antibodies)
* Nucleic acid amplification tests (for viral RNA)
* NS1 antigen test
What is the treatment for Dengue fever?
Treatment is entirely symptomatic, including:
* Fluid resuscitation
* Blood transfusion (if needed)
There are no antivirals currently available for treatment.
