Dengue Fever

What is Dengue fever (DF)?

 Dengue fever is a self-limiting disease and is caused by four distinct types of dengue viruses (Dengue 1-4). All four are transmitted by Aedes mosquito. 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). Rarely the patient suffering from dengue may develop shock, then it is called dengue shock syndrome (DSS). If a person who already has got dengue by one type of virus gets infected by second type of Dengue virus, he/she can get Dengue Hemorrhagic fever with severe shock.

Problem statement

It is a disease which occurs throughout the world except in Europe. It is estimated that every year 2 crore cases of Dengue fever occur in the world. Death rate varies from 5 per 100 cases to 30 per 100 cases. The disease is quite severe in young children as compared to adults. Over the past 10-15 years, next to diarrhoeal disease and acute respiratory infections, dengue has become a leading cause of hospitalization and deaths, among children in the South-East Asian region.

When should Dengue be suspected?

Dengue should be suspected when one has sudden onset of fever. The fever is high, 103-105 degree Fahrenheit or 39-40 degree centigrade. It is accompanied by severe headache (mostly in the forehead), pain behind the eyes, body aches and rash on the skin, nausea or vomiting. The fever lasts for 5-7 days. In some patients fever comes down on 3^rd or 4^th day but comes back. The patient may have only a few of the symptoms listed above.

There are several types of fever, when should dengue be suspected?

The characteristics of dengue that make it different from other causes of fever are the pain behind the eyes, severe pain in the muscles, severe joint pains, and skin rashes. These features make the diagnosis of suspected Dengue likely. Severe body and joint pains produced give rise to the term ?break-bone fever? (Haddi tod Bukhar)

What is the difference between suspected and probable cause of dengue?

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

Can I get dengue from another person?

Dengue does not spread directly from person to person. It only spreads through the bite of an infected mosquito.

Can people be infected with dengue and still do not appear ill?

Yes. There are many people who are infected with the virus and do not suffer from any signs or symptoms of the disease. For every patient with symptoms and signs, there may be 4-5 persons with no symptoms or with very mild symptoms.

Symptoms of the disease

After the mosquito bites the man, dengue signs and symptom appear after 3 to 10 days (commonly 5-6 days).

Symptoms depend upon the type of dengue fever. There are three types of dengue fever-

1. Classical (Simple) dengue fever

2. Dengue hemorrhagic fever (DHF)

3. Dengue Shock Syndrome (DSS)

1. Classical (Simple) Dengue Fever:

• Sudden onset of high fever with feeling of chills (?Thandi Lagna?)
• Severe Headache, Pains in muscles and joints
• Pain behind the eyeballs especially on pressing the eyes or on moving the eyeballs
• Extreme weakness, loss of appetite, feeling of nausea
• Change in taste sensations in mouth
• Pain in abdomen by itself or on touching
• Mild pain in throat
• Patient feels generally depressed and very sick
• Rash on the skin: pinkish red rash appears on the skin in the form of diffuse flushing, mottling or pinhead eruptions on the face, neck and chest. Later on, the rash may become more prominent.
• The entire duration of classical Dengue fever is about 5-7 days.

2. Dengue Hemorrhagic fever (DHF)

It should be suspected if with above mentioned symptoms of Classical ( Simple) Dengue fever, one or more of the following symptoms appear-

• Bleeding (hemorrhagic) manifestations: Bleeding from nose, gums, blood in the stools or in vomiting, bleeding spots on the skin which are seen as dark bluish-black, small or large patches. Flat spots less than 3mm in diameter that are due to the bleeding into the skin, may be seen.
• If a health worker carries out a Tourniquet test, it is positive.
• Certain laboratory investigations carried out on a blood sample also confirm DHF such as platelets below 1 lakh and Hematocrit (PCV) increased by 20 percent or more of base-line value.

3. Dengue Shock Syndrome (DSS)

All symptoms as mentioned above in DHF are present plus the patient also develops a medical condition called ?Shock?. Symptoms of shock in a Dengue Fever case are-

• The person is very restless and the skin feels cold and clammy despite high fever.
• The person may start loosing consciousness.
• If you examine the pulse of the patient, it is weak and rapid. Similarly blood pressure will be low.
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Can dengue fever be treated at home?

If it is classical (simple) Dengue fever, the patient can be managed at home. As it is a self-limiting disease, the treatment is purely supportive and symptomatic.

• Bed rest is advisable during the fever phase.
• Keep the fever low by giving paracetamol tablet or syrup as per health worker?s advice.
• Other medicines such as Aspirin and Brufen should be avoided since they increase the risk of bleeding. The doctors should be very careful when prescribing medicines. Any medicines that decrease platelet count should be avoided.

The patients should drink plenty of water or fluids like shikanji etc. that are available at home and eat nutritious diet. Whenever available, Oral Rehydration Salt (ORS, which is commonly used to treat diarrhea) is preferable.

• It is important to look for danger signs and symptoms and if any of the symptoms indicative of DHS or DSS develop, rush the patient to the nearest hospital at the earliest where appropriate investigations will be carried out and necessary treatment instituted e.g. transfusion of fluids or platelets. Please remember that every patient does not require blood platelet transfusion. Contact the doctor as soon as any or more of these are found.

Please remember, even DHS and DSS can be managed successfully, if a correct diagnosis is made and the treatment is started early The period of shock lasts only 1 or 2 days and most patients respond promptly to close monitoring, oxygen administration and infusion of fluids.

Lab findings

Low WBC count,

Low Platelets,

High PCV or hematocrit ? It  reflects thickness of blood.

Diagnosis is made by IgM ELISA or antigen detection ELISA or RT-PCR during the acute phase.

Dengue hemorrhagic fever/ Dengue shock syndrome

Dengue virus infections cause syndrome of Hemorrhagic fever when the patients are infected second time with a dengue virus which is different from that of the first one. In rare instances first dengue infections lead to a hemorrhagic fever syndrome. The type 1 infection followed by type 2 seems to be more dangerous than type 4 followed by type 2. Type 2 is apparently more dangerous than other types.

Prevention

Prevention of dengue fever is easy and cheap and can be categorized into two types.

• Preventing breeding of Aedes mosquitoes

• Protection from Aedes mosquitoe?s bites

Preventing breeding of aedes mosquitoes

Aedes mosquitoes are easily distinguished by white stripes on a black body. They are sometimes referred to as ?tiger mosquitoes? because of the striped or banded character of their legs. It typically breeds near human habitation, using relatively fresh water from sources such as water jars, flower pots, discarded containers, coconut shells, earthen pots, tree holes and old tires. They are most abundant during the rainy season.

• To prevent the mosquitoes from multiplying, drain out the water from desert coolers/window air coolers (when not in use), tanks, drums, buckets, plastic bags etc. Remove all objects containing (e.g. plant saucers etc.) from the house.
• Don?t allow water to remain stagnant in and around your house. Fill the ditches. Clean the blocked drains.
• Whenever it is not possible to completely drain the water off from room cooler etc., it is advisable to put about 2 tablespoons (30ml0 of petrol or kerosene oil into them for each 100 liters of water. This will prevent mosquito breeding. Repeat it every week.
• You can also put some types of small fish (Gambusia, Lebister) which eat mosquito larvae into these water collections. These fish can be obtained from the local administrative bodies (e.g. Malaria officer?s office in the area).
• Don?t litter garbage and keep the surroundings of your house clean. Don?t allow wild herbs etc to grow around your house (at least in a radius of about 100 meters around your house). They act as hiding and resting places for mosquitoes

Protection from Aedes mosquitoe?s bites

• Wear clothes which cover the body as much as possible. This is more relevant in case of children.
• It is good under to remember that Aedes mosquitoes bite even during daytime and hence you should take precautions against their bite during daytime also. Lastly it is advisable to always keep the patient of Dengue fever under a mosquito net in the first 5-6 days of the illness so that mosquitoes don?t have an access to him/her. This will help in reduction in spread of dengue fever to other persons in the community.
• Use mosquito repellent sprays or liquids to kill or drive away mosquitoes. Use of Googal Smoke is a good indigenous method for getting rid of mosquitoes.

Do inform your local health centre, Panchayat or municipality in case you notice abnormal density of mosquitoes or too many cases of fever are occurring in your area.

If you ever notice that many persons have suffered from an illness which may appear to be dengue fever, please inform this to the local health authorities, at the earliest. This will help in preventing the disease acquiring epidemic proportions.