An introductory how-know of dengue fever.

2. • A debilitating viral disease of the tropics, transmitted by
mosquitoes, and causing sudden fever and acute pains in the
joints.
• Also known as “BREAK-BONE FEVER”.

3. • Genome: RNA virus
• Family: Flaviviridae
• Genus: Flavivirus
• Arbovirus: Viruses transmitted by arthropods.
• Serotypes: There are four forms of this virus; DENV-1, DENV-
2, DENV-3 and DENV-4.

4. • Dengue virus is primarily transmitted by Aedes mosquitoes,
particularly A. aegypti.
Other vector species include
 A. albopictus
 A. polynesiensis
 A. scutellaris

7. • Fever
• Headache
• Pain behind eyes
• Skin rash
• Muscle and joint pain

8. Positive tourniquet test
 To asses fragility of capillary walls
 To identify thrombocytopenia.
 20 or more petechiae per 1 square inch.

9. • Vector bite allows invasion of virus in blood.
• Virus enters WBCs and start reproducing.
• WBC secrete signalling proteins (cytokines, interferons),
responsible for primary symptoms.
• In severe conditions, virus invades body organs (liver & bone
marrow)
• Fluid leakage occurs due to capillary permeability.
• Low blood pressure and dysfunction of bone marrow leading to
decrease platelet count.
• This enhances bleeding and other complications.

10. • Febrile Phase
• Critical Phase
• Recovery Phase

11. Observations include:
• Fever
• Pains
• Vomiting
• Patachea

12. Characterized by;
• Accumulation of fluid in chest and abdomen.
• Depletion of blood from circulation
• Decrease blood supply to vital organs
Critical phase is of two types;
• Dengue Shock Syndrome (low blood pressure)
• Dengue Haemorrhagic Fever (plasma leakage and low platelet
count)

13. This phase involves Reabsorption of fluid
Features are;
• Itching
• Altered consciousness (due to fluid overload)
• Fatigue

14. • Vaccine is introduced but not validated world-wide.
• Primary method is elimination of habitat by pesticides/BCA.
• Supportive treatment include rehydration whether orally or
intravenously. Blood diffusion can be done in severe cases.
• Prevent mosquito bite by;
i. Wearing clothes
ii. Mosquito nettings
iii. Mosquito repellent
• Medication in analgesics i.e. ACETAMINOPHEN.
• Avoid aspirin (analgesic).