Dengue fever Flashcards
infection overview
- Mosquito-borne tropical disease caused by the Dengue virus
- Commonest arbovirus
how many serotypes
4
patient risk factors
- Living or traveling in Africa, Asia, India
- Infants and young children (more common in well nourished children)
- Female
- High BMI
- Viral load
- Polymorphisms in particular genes
pathogen
dengue virus
Patient symptoms
- Fever
- Back pain
- Headache
- Rash
symptoms
dependent on if its the first infection or a re-infection
first infection symptoms
ranges from asymptomatic to non-specific febrile illness (classic dengue)
- Last 1-5 days
- Supportive treatment only
Re-infection with different serotype symptoms
- Antibody dependent enhancement
o Dengue haemorrhage fever (children, hyperendemic areas)
o Dengue shock syndrome
mechanism of infection
- Mosquito bites and passes virus via salvia
- Virus binds to enter WBC and replicates inside the cells
- WBC responds by releasing cytokines and interferons which cause fever and flu-like symptoms
diagnosis
- Virus isolation in Cell cultures
- Nucleic acid detection by PCR
- Viral antigen and antibody detection- ELISA
prevention
Based on control of and protection from the bites of the mosquito that transmits it.
- Eliminating habitats- getting rid of open sources of water or using insecticides
- Nets
- Vaccine
vaccines are recommended to those who
have had prior dengue infection to prevent severe symptoms if re-infected
Treatment
- No antiviral drugs for dengue
- Maintain proper fluid balance is important- IV hydration (1 or 2 days)
- Treatment depends on the symptoms
Outcome of infection
- Recovery takes 2-7 days
o Most recover without ongoing problems - Can develop into dengue haemorrhagic fever
- Dengue shock
dengue haemorrhagic fever
resulting in bleeding, low levels of blood platelets and blood plasma leakage
Dengue shock
when dangerously low blood plasma