1. Dengue .

2. Dengue fever (DF)
Is an acute febrile viral illness presenting with headache , bone or joint and muscular pains , rash and leukopenia caused by arthropod – borne viruses.
Dengue hemorrhagic fever ( DHF ) : -
Is characterized by four major manifestations :
High grade fever ,
hemorrhagic phenomenon
Hepatomegaly
Signs of circulatory failure
Dengue shock syndrome (DSS ) : -
Hypovolemic shock resulting from plasma leakage

3. Dengue
Dengue is mosquito-borne infection transmitted by the bite of an Aedes mosquito
Symptoms appear 3-14 days after the infective bite.
Symptoms range from a mild fever to high fever, with severe headache, pain behind the eyes, muscle and joint pain, and rash.

4. Epidemiological features
Agent factors:
Agent: The dengue viruses are arthropod-borne viruses of the Flavivirus genus, within the family Flaviviridae. There are four serologically distinct dengue virus serotypes (DEN-1, DEN-2; DEN-3 and DEN-4)
Reservoir of infection: Humans are the main amplifying host of the virus.
Host factors: All ages and both sexes are susceptible to dengue fever.

5. Cont..
Environmental factors: Start during rainy season when the breeding of the vector mosquito is generally abundant.
Modes of transmission
It is transmitted by the bite of an infected female Aedes species mosquito. Worldwide, Aedes aegypti, a day-biting species, is the major vector for human-to-human transmission .
Incubation period: days

6. Clinical features (three forms): - Classical dengue fever
Symptoms of typical uncomplicated (classic) dengue usually start with fever within 4 to 7 days after bite by an infected mosquito and include
High fever, up to 105ºF
Severe headache
Retro-orbital (behind the eye) pain
Severe joint and muscle pain
Nausea and vomiting
Rash: may appear over most of the body 3 to 4 days after the fever begins, and then subsides after 1 to 2 days.
Prolonged fatigue and depression are typical symptoms during the recovery phase.

7. Dengue hemorrhagic fever
Fever: acute onset, high, continuous, and lasting for 2-7 days.
Marked damage to blood and lymph vessels
Bleeding from the nose, gums, or under the skin, causing purplish bruises.
Haemorrhagic manifestation including petechia, purpura, ecchymosis, epistaxis, gum bleeding, haematemesis and malena
The liver is often enlarged. This form of dengue disease can cause death.

8. Grading of severity of DHF
Grade I: the only haemorrhagic manifestation is a positive tourniquet test.
Grade II: Patients with spontaneous bleeding
Grade III: Circulatory failure manifested by rapid and weak pulse, low blood pressure, with presence of cold and clammy skin and restlessness.
Grade IV: Profound shock with undetectable blood pressure and pulse

9. Dengue shock syndrome-
The most severe form of dengue disease, include all of the symptoms of classic dengue and dengue hemorrhagic fever, plus
Massive bleeding
Shock
This form of the disease usually occurs in children (sometimes adults) experiencing their second dengue infection. It is sometimes fatal, especially in children and young adults.

10. Diagnosis From symptoms. Positive tourniquet test.
Blood test: Thrombocytopenia
Haemoconcentration, haemotocrit increased by 20%.
During 3-7 days of illness, the virus can be isolated from blood/serum. From 8th day, specific antibodies can be detected by serological tests.

11. Clinical criteria to hospitalize with DF
Severe abdominal pain
Passage of black stool
Bleeding into the skin or from the nose or gums
Sweating
Cold skin

12. It is important to maintain hydration. Avoid aspirin.
Treatment
The management of dengue fever is symptomatic and supportive, including careful management of fever, bed rest, fluid balance, electrolytes and clotting parameters, is crucial for the case management of dengue hemorrhagic fever.
It is important to maintain hydration. Avoid aspirin.
Dengue haemorrhagic fever is a potentially lethal complication, affecting mainly children. Early clinical diagnosis and careful clinical management by experienced physicians and nurses increase survival of patients.

13. particularly early morning and late afternoon.
Prevention
Personal protective measures are aimed at preventing mosquito bites during the day,
particularly early morning and late afternoon.
use personal insect repellents
use insecticide mats to kill mosquitoes
screen living and sleeping areas
wear long, loose clothing when outdoors
spray indoors in dark places (eg.behind cupboards, under beds)

14. throwing out rubbish that collects water
Cont..
The best form to control is to get rid of dengue mosquito breeding sites around the home.
Dengue mosquitoes breed in containers that hold water.
These include buckets, tyres, pot plant bases
Roof guttering, rainwater tanks are also potential breeding sites.
Recommendations to control breeding include:
tipping out containers which can hold water
storing containers in a dry place
throwing out rubbish that collects water