Dengue, also known as breakbone fever, is a fast emerging viral disease in many parts of the world. This mosquito-borne viral infection not only flourishes in urban areas, suburbs, and the countryside, but also affects more affluent neighbourhoods in tropical and subtropical countries causing a severe flu-like illness and sometimes lethal complications in its victims.
History of the disease
The first record of a case of probable dengue fever was in a Chinese medical encyclopaedia from the Jin dynasty (265-420 AD). But the dengue epidemics that occurred simultaneously in Asia, Africa and North America in the 1780s are the first recognised dengue epidemics in the history. This was right after dengue was named as a disease in 1779. Since then, the Dengue virus has spread worldwide, predominating in the tropics and subtropics.
According to WHO statistics, each year, up to 400 million people get infected with dengue. Approximately 100 million people get sick from infection and 22,000 die from its complications. Sri Lanka itself has been affected by dengue fever epidemics for over two decades, the latest being in 2017 during which a total of 186,101 suspected cases and 440 deaths occurred.
Types of Dengue
Dengue fever is known to be caused by 4 types of viruses; DENV-1, DENV-2, DENV-3, DENV-4 of the same genus; genus Flavivirus. This virus is transmitted from one host to the next by mosquitoes of Aedes spp. Aedes aegypti being the most common vector. Once an infected person is bitten by a mosquito, the virus enters and multiplies within the salivary glands of the mosquito which then will be released into the blood of another individual by bitting. Once infected by one type of dengue virus, a person develops immunity to that particular virus type for life which sadly will not come handy during an infection by another type of dengue virus.
There is also a possibility of a single individual being infected by all four different types of dengue viruses within a lifetime. It is ironic how the smallest of microorganisms with the aid of the smallest of Arthropods has managed to bring the whole world to its knees over the decades.
Dengue being a painful, debilitating disease, begins to show symptoms 4-6 days after infection which would last for about 10 days. Common symptoms include; (can present without any symptom as well)
- Sudden high fever
- Severe headaches
- Pain behind the eyes
- Severe joint and muscle pain
- Nausea and/or vomiting
- Skin rash which appears 2-5 days after onset of fever
- Mild bleeding such as nose bleed, bleeding gums or easy bruising.
Sometimes symptoms are mild and can be mistaken for those of the flu or another viral infection. Along the course of the disease patient can develop some serious complications.
Dengue hemorrhagic fever
Dengue haemorrhagic fever, a type of dengue fever which is characterised by high fever, damage to lymph and blood vessels, bleeding from nose and gums, enlargement of the liver and fluid leakage from blood vessels into the tissues. The symptoms may progress to shock, cardivascular failure and death. This is called Dengue shock syndrome (DSS). People with weakened immune systems as well as those with a second or subsequent dengue infections are believed to be at greater risk for developing dengue haemorrhagic fever.
Diagnosis of Dengue
For diagnosis of dengue fever in a suspected individual, We can use their signs and symptoms with physical examination. it can always be aided with testing patients blood to check for the virus or its antigens and antibodies. ( Antigen test should done with in 48 hours of the having fever, but not very early or very late)
As the causative agent of Dengue is a virus, there is no specific treatment or cure for this disease. If a patient is tested positive for dengue virus, that person is instructed to use antipyretics but only acetaminophen E.g paracetomol. ALWAYS avoid Non Steroidal Anti Inflammatory Drugs (NSAIDs) such as ibuprofen, which could worsen the disease and can lead to fatal complications.
As for any other disease, the patients are also encouraged to rest while consuming a healthy meal recommended by the doctor in order to make the recovery fast. The fluid intake should be supervised by a medical officer. (Avoid having dark color drinks like Cola, Dark color fruit juices)
How to prevent?
The main reason for the spread of Dengue virus resulting in epidemics is the action of its vector; the mosquitoes. Therefore the key to prevent further loss of lives due to dengue is to reduce the mosquito population. This can be done by getting rid of places where mosquitoes can breed, which is any place where water can accumulate, like old tyres, cans, flower pots, bird baths etc.
Other than this, steps should be taken to protect oneself individually such as using mosquito repellents, using mosquito nets, wearing long sleeved clothes when stepping outdoors etc.
In a world where new discoveries come to light every minute, where today’s technology outsmarts yesterday’s, where mankind takes a step forward each and everyday, it is tragic how still waters keep on breeding death. For this reason the world has to be made aware of this plight and its consequences, so that we can unite as one to rid the world of this debilitating malady.
Rtr. Sanduni Wijeratne