Dengue fever is an acute febrile disease, endemic in tropics, caused by four closely related Dengue viruses 1,2,3,4. It is transmitted to humans by the Aedes Aegypti mosquito, which unlike malaria causing mosquito Anopheles feeds only during the day. The disease is now spreading internationally. Dengue is not contagious. It spreads only through the bite of an infected mosquito.
Infection by one serotype leads to lifelong immunity to particular serotype but immunity to other serotype is incomplete. Infection by another serotype i.e. secondary infection can lead to severe dengue fever chronic disease such as bronchial asthma and diabetes are also an additional risk factor for severe dengue fever.
Dengue and the risk factors in Children:
- Children are at higher risk for severe dengue fever.
- Age-specific severe dengue is seen in bimodal fashion with severe cases peaking at 7 months of age and again at 3- 5 years of age.
- Severe dengue occurs in infants exclusively during primary dengue infection born to dengue-immune mother
- Children who are 3-5 yrs old suffer from severe dengue following secondary infection.
Signs and Symptoms associated with Dengue:
After an incubation period ( 5+/-2 days) dengue infection manifests from asymptomatic infection to mild undifferentiated fever, classical dengue fever, to severe dengue.
- Classical dengue fever – presents as high fever, headache, retro-orbital pain, photophobia, backache, myalgia, arthralgia.(break bone fever).
- Undifferentiated dengue fever– more common presentation of dengue in the child, fever with erythematous rash, with/without mild respiratory symptom.
- Severe dengue– present with swelling of the body, a collection of fluid in abdomen, chest, bleeding, hypotension.
Stages of Dengue Infection:
There are 3 stages of dengue fever:-
1st Febrile phase– fever last for 2-7 day
- Defervescence occurs between 3-7 days of illness (mostly after 4 th day).
- Most patients recover well.
- some may start showing signs of plasma leakage.
2nd stage critical phase – from 4th -7th day of illness.
- Children who deteriorate show warning signs – these are intense pain in the abdomen, persistent vomiting, mucosal bleed, lethargy, restlessness
- Children may also show signs of hepatomegaly, hemoconcentration with rapid fall in platelet count.
- In case of improper treatment-severe dengue ensures.
3rd stage recovery phase– from 8th to 10th day of illness.
– After successful treatment, gradual reabsorption of leaked fluid occurs.
- Gradual well being improves, hemodynamic condition stabilizes and diuresis ensues.
– In simple dengue, fever child recovers in a week, but in complicated situations, severe dengue may take up to two weeks for complete recovery.