Dengue Fever: What We Need to Know

The weather during the transition period from January to March is erratic. It is likely to increase the risk of dengue fever which we must look out for. Dengue fever is caused by a virus transmitted into human body through the infected Aedes aegypti mosquito bites.

There are 3 phases of dengue fever, namely:  

Febrile Phase
The initial phase of a dengue fever is called the febrile phase. In this phase, the patient will experience a sudden high fever up to 40oC for 2-5 days. It is usually followed by skin rashes on the face and other body parts, body and muscle soreness, and headache.

The required tests for this phase are:
- Dengue NS1 Antigen test, it is useful to early detect the virus infection during the 1-3 days onset of the fever. The early dengue detection is important to determine the immediate monitoring and supporting therapies to decrease the risk of complication such as dengue hemorrhagic fever and dengue shock syndrome.
- Anti-Dengue IgG & IgM test, it is carried out at the end of febrile phase, generally within the 3-4 days onset of the fever. This test is useful to know whether the patient is having the primary dengue fever (the first dengue fever) or the secondary dengue fever (recurrent dengue fever).
- Thrombocyte and hematocrit tests, these tests should be regularly taken as the patient is susceptible to enter the critical phase on the 5th day.

Critical Phase
After experiencing the febrile phase, patient usually enters the critical phase of dengue fever on the 5th day. This phase usually outwits the patient. The patient tends to feel better and is able to do their activities since their body temperature decreases to the normal temperature of 37oC.

If the patient goes untreated in this phase, their thrombocyte will continuously decrease and later may result in undetected internal bleeding. Therefore, the patient must seek for immediate medical assistance during this phase as this critical phase only lasts for 24-38 hours. During this phase, the patient is at risk of experiencing leaking veins. Usually it is indicated by constant vomiting, nose bleeding, etc.
Hematologic test must be carried out in this phase to observe the amount of thrombocyte and hematocrit of the patient.

Convalescence Phase
After surviving the critical phase, the patient will again experience a fever. However, body temperature rise is normal during the convalescence phase. During this phase, the hematologic test must be carried out to observe whether the amount of thrombocyte and hematocrit has returned to normal.

An early and precise diagnosis is very important to manage the dengue fever patients. It may prevent the complications such as dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS).