Dengue is a common term one can hear in India particularly with the onset of the monsoon. This year also the number of persons diagnosed with Dengue Fever has increased dramatically compared to the last year especially in states like Punjab Gujarat, Tamil Nadu and Kerala. Dengue Fever is emerging as a major public health issue because of the improper water storage practices and changing lifestyles. Many lives are lost every year due to this disease. The Government announces major plans and programmes every year prior to the monsoon to prevent the occurrence of this disease and still the number of cases of Dengue seems to be on the rise. The failure in this regard is mostly because of the ignorance of the general public about their role in preventing this disease. This article is to educate the common man about the dangers of Dengue and things that they can do to prevent this disease from occurring.
What is Dengue?
Dengue is a disease transmitted by the bites of certain types of mosquitoes infected with the Dengue Virus. Dengue is more prevalent in the tropical and sub-tropical regions around the world. The disease manifests in several types ranging from self-limiting mild fever to severe bleeding disorders which could be life threatening. It can present in 3 types, namely :
- Classical Dengue Fever
- Dengue Haemorrhagic Fever without Shock and
- Dengue Shock Syndrome
The progression of the disease depends on the type of presentation. If left untreated, the disease can be lethal. There are no medicines to cure Dengue and an effective vaccine was approved by the World Health Organization in (October 2016 . The patient should take rest and drink more fluids in addition to taking medicines to control the fever. Sever types of Dengue can only be managed at hospitals. More emphasis should be given to the prevention of the disease particularly when many effective preventive measures are available.
Aedes aegypti and Aedes albopictus are the 2 main species of Aedes mosquitoes responsible for the transmission of the disease. Aedes aegypti is a domestic breeder. These mosquitoes are highly susceptible to dengue virus infection and their reproduction. They can be easily identified by the whole stripes on the black body as shown in the picture. Because of these stripes, they are also known as the “Tiger Mosquitoes”.It breeds in artificial water accumulations in and around houses such as water found in discarded tins, broken bottles, pots, coconut shell etc. They bite humans mostly during the day time. Apart from Dengue, these mosquitoes are also responsible for the spread of Chikungunya and Yellow fever.
Aedes mosquitoes are the agents responsible for the transmission of the disease. They become infected when they feed on an infected person’s blood. Transmission of the disease takes place when these infected mosquitoes bites a normal person. Direct transmission of the disease from person to person does not take place.
Dengue virus infected persons can be either asymptomatic or present as any of the 3 clinical types mentioned above. Children, infants and some adults who get infected for the first time may present with just a fever and rash which is usually self-limiting.
Classical Dengue Fever : This is characterised by sudden onset of high-grade fever associated with chills, severe body ache involving the muscles and the joints.Generalised weakness, anorexia, abdominal pain, constipation are the other common symptoms. Rash appears after 2 days of fever and is seen in almost all cases of Dengue fever. Classical Dengue Fever usually subsides within one week after the onset.
Dengue haemorrhagic Fever (DHF): This is a severe type of Dengue Fever and is characterised by symptoms similar to the classical type in the initial phase. Later on, symptoms related to the loss of blood from the blood vessel (as self explained in the term ‘haemorrhagic) happens and this can lead to several complications. Examples of these symptoms include bleeding from oral mucosa, injection sites,reddish rashes spread all over the body, loss of blood in stools etc. Decreased White Blood Cell count and more specifically decreased platelet count is usually seen in this type of Dengue. Severe forms of DHF can result in fluid accumulation in the pleural spaces (pleural effusion), abdominal cavity (ascites). DHF can also affect multiple organs like the Liver, Heart and Brain.
Dengue Shock Syndrome (DSS) : Also known as Severe Dengue, this type is associated with severe bleeding disorders, severe organ impairment, respiratory distress. In simple words, Shock is a clinical state in which there is blood circulatory failure . The blood volume , blood pressure, pulse pressure all decreases in shock. Multiple organ failure occurs as a result of shock. Patients with DHF may progress to DSS.
Diagnosis and Treatment of Dengue Fever depends on the clinical type of the disease. This is a vast topic and I will be writing a separate article on this topic later.
Prevention of Dengue
This can be done by following simple steps. Every individual in the community should understand their responsibilities in preventing this disease. Aedes mosquitoes normally breeds in and around our households in artificial water collections. Some simple measures to prevent these mosquito bites include using mosquito nets, coils, repellant, creams, protective clothes etc. Insecticides can also be used to kill the mosquitoes. More importantly, the individual should make sure that water collections does not occur in their household. They should dispose off the waste properly and look out for possible mosquito breeding containers and destroy them.
I have already written an article on how to get rid of mosquitoes, and I recommend you to go through it.
You should also read about proper waste disposal steps to make more sense on this regard.
Image Credit : James Gathany