Dengue, the deadly demon

An acute infectious, eruptive, febrile disease caused by four antigenically related but distinct serotypes of the DENGUE VIRUS. It is transmitted by the bite of infected Aedes mosquitoes, especially A. aegypti. Classical dengue (dengue fever) is self-limiting and characterized by fever, myalgia, headache, and rash. DENGUE HEMORRHAGIC FEVER is a more virulent form of dengue virus infection and a separate clinical entity

Dengue serotypes are maintained in a cycle that involves humans and the Aedes mosquito. However, Aedes aegypti, a domestic, day-biting mosquito that prefers to feed on humans, is the most common Aedes species. Infections produce a spectrum of clinical illness ranging from a nonspecific viral syndrome to severe and fatal hemorrhagic disease. Important risk factors for DHF include the strain of the infecting virus, as well as the age, and especially the prior dengue infection history of the patient.

History of Dengue

The first reported epidemics of DF occurred in 1779-1780 in Asia, Africa, and North America. The near simultaneous occurrence of outbreaks on three continents indicates that these viruses and their mosquito vector have had a worldwide distribution in the tropics for more than 200 years.

During most of this time, DF was considered a mild, nonfatal disease of visitors to the tropics. Generally, there were long intervals (10-40 years) between major epidemics, mainly because the introduction of a new serotype in a susceptible population occurred only if viruses and their mosquito vector could survive.

A pandemic of dengue began in Southeast Asia after World War II and has spread around the globe since then.

How dengue develops?

Dengue fever occurs following the bite of an infected mosquito Aedes aegypti.This type of mosquito has a peculiar white spotted body and legs and is easy to recognize even by laymen.

It breeds in clean water and has a flight range of only 100 – 200 metres.The mosquito gets the Dengue virus after biting a human being infected with dengue virus.

After the entry of the virus in the person, it multiplies in the lymph glands in the body. The symptoms develop when the virus has multiplied in sufficient numbers to cause the symptoms. This happens generally about 4-6 days (average) after getting infected with the virus.

Signs and Symptoms

Fever: Dengue should be suspected with sudden onset of fever. The fever is high 103-105 degrees F or 39-40 degrees C. The fever lasts for 5-7 days. In some patients, fever comes down on 3rd or 4th day but comes back.

Aches and Pains: It is accompanied with severe headache (mostly in the forehead), pain behind the eyes, body aches and pains. Severe muscles and severe joint pains, the severity of the joint pain has given dengue the name "breakbone fever."

Bleeding: Occasionally the patient suffering from dengue may develop bleeding. Common sites for bleeding are nose, gums or skin. Sometimes, the patient may have coffee ground vomiting or black stools. This indicates bleeding in gastro intestinal tracts and it is serious. The patient with dengue who has bleeding has dengue hemorrhagic fever (DHF)

Rashes: Rash on the skin is common in dengue fever. A rash usually appears 3 to 4 days after the start of the fever but it can vary from individual to individual.

Other Signs: Nausea, vomiting, and loss of appetite are common in Dengue fever.

Reduced platelets or an increase in blood haematocrit: If a patient suspected to be having dengue has reduced platelets or an increase in blood haematocrit, and then the patient has probable dengue. (Platelets are cells in blood that help to stop bleeding and Haematocrit indicates the thickness of blood).

Control it before it controls you:

There is no vaccine to prevent dengue but according to WHO vaccine has been developed to prevent dengue fever but it is still under trial. It is not yet available in the market. Scientific progress is likely to help in prevention of dengue fever by vaccination in the years to come. Prevention centers on avoiding mosquito bites in areas where dengue occurs or might occur and eliminating breeding sites.

Drain out the water: Dengue mosquitoes breed in stored, exposed water collections. Favored places for breeding are barrels, drums, jars, pots, buckets, flower vases, plant saucers, tanks, discarded bottles, tins, tyres, water coolers etc.

To prevent the mosquitoes from multiplying, drain out the water from desert coolers/window air coolers (when not in use), tanks, barrels, drums, buckets etc. Remove all objects containing water (e.g. plant saucers etc.) from the house. Collect and destroy discarded containers in which water collects e.g. bottles, plastic bags, tins, used tyres etc.

Cover your body: When outdoors during times that mosquitoes are biting, Wear full sleeves clothes and long dresses to cover as much of your body as possible. Dengue mosquitoes bite during the day time throughout the day. Highest biting intensity is about 2 hours after sunrise and before sunset.

Use repellents Use mosquito coils and electric vapor mats during the daytime also to prevent dengue, be careful in using them in young children and old people, Use mosquito nets to protect children, old people and others who may rest during the day. The effectiveness of these nets can be improved by treating them with permethrin (pyrethroid insecticide). This bed-net is called Insecticide Treated Nets and are widely used in the prevention of malaria.

Some have misconception of getting dengue fever from another person, Dengue does not spread directly from person to person. It is only spread through the bite of an infected mosquito.

The main strategy in the prevention and control of dengue is "source reduction", or prevention of breeding places, mentioned above

Curing Dengue

If you have symptoms of dengue, report to your doctor immediately

At home: Patients should take rest, drink plenty of fluids that are available at home and eat nutritious diet. Whenever available, Oral Rehydration Salt/ORS (commonly used in treating diarrhea) is preferable. Sufficient fluid intake is very important and becomes more important in case DF progresses into DHF or DSS where loss of body fluid / blood is the most salient feature. It is important to look for danger signs and contact the doctor as soon as any one or more of these are found.

Medication: Like most viral diseases there is no specific cure for dengue fever. Antibiotics do not help. Paracetamol (can be purchased without prescription) is the drug of choice to bring down fever and joint pain. Other medicines such as Aspirin and Brufen should be avoided since they can increase the risk of bleeding. Doctors should be very careful when prescribing medicines. Any medicines that decrease platelets should be avoided.

CONSULT YOUR DOCTOR BEFORE TAKING ANY MEDICATIONS.