Dengue the deadly virus – a simple reminder

By Vashni Benjamin
According to the Epidemiology Unit of the Ministry of Health of Sri Lanka, there have been 15,748 dengue-related deaths reported as at April 2019 in the country. Despite years of awareness, the dengue menace is yet to be curbed in the country.

In 2017, the first quarter of the year saw 45,701 dengue-related deaths with the number dropping to 17,766 in the first quarter of 2018. Though data reported by the Epidemiology Unit has shown a drop in the number of dengue-related deaths, the problem is far from being solved.

Unlike malaria, another mosquito-borne disease that was eradicated from the country in 2016, dengue is a virus that is constantly evolving. Moreover, the Aedes aegypti and Aedes albopictus mosquitoes that carry this virus are becoming highly adaptable to any environment, with incidents of them breeding even in brackish water being reported from various parts of the country. The fact that there is no specific antibiotic or vaccine available to treat this virus makes it all the more harder to prevent.

The Sunday Morning Brunch thought it essential to go back to the basics to remind us all about this deadly virus that still claims the lives of thousands. For this purpose, we spoke to private practitioner Dr. Yasantha Ariyaratne.

What is Dengue?

The dengue fever is caused by a virus of the ribonucleic acid (RNA) category. The disease is often carried by mosquitoes of the Aedes aegypti and Aedes albopictus varieties and spreads when one is bitten by a mosquito carrying the virus.

Identifying these mosquitoes is important. Firstly, these mosquitoes are primarily day-biters, so try to avoid getting bitten by mosquitoes during the day. The Aedes aegypti mosquito is usually a small, dark insect with distinct white markings on its legs.

The females, who are generally the carriers of the virus, are larger than the males and can be identified by small silver-tipped palps. The Aedes albopictus can be identified by its black and white striped legs and small black and white body.

We then questioned if it was true that contracting dengue once can provide one with lifelong immunity thereafter, to which he replied that the dengue virus can occur in four different serotypes: DEN-1, DEN- 2, DEN- 3, and DEN- 4. While contracting one of these varieties may provide the patient with immunity to that particular type, it is still likely that they may contract another form of the dengue fever.

When a patient who has recovered from one of the serotypes contracts it from another strain, it is possible for them to develop complications.

Common symptoms

Dengue is often accompanied by many flu-like symptoms. Diagnosis is recommended for sudden high fever accompanied by two or more of symptoms which are sudden high fever, severe headache, pain behind the eyes, nausea, vomiting, swollen glands, muscle and joint pains, and rash – bright red patches that often appear first on the lower limbs and chest.

It is important to allow the patient plenty of rest and ensure that they take plenty of fluids. While Paracetamol can be used to relieve fever and muscle or joint pain, it is advised to avoid non-steroidal anti-inflammatory drugs (NSAIDs) such as Aspirin.

Complications that can arise

Dengue haemorrhagic fever (DHF) is a complication that can arise in severe cases. This condition can be caused by various reasons such as fluid accumulation, respiratory distress, or organ impairment. Though it is not very common, when contracted, it can be life-threatening, especially for children.

It can usually be identified by the following symptoms that will accompany continuous high fever. Prompt medical care is advised if the following symptoms persist within three to seven days of the initial symptoms showing up.

  • Severe and continuous pain in abdomen
  • Bleeding from the nose, mouth, and gums, or skin bruising
  •  Persistent vomiting with or without blood
  •  Rapid breathing
  •  Black stools like coal tar
  •  Excessive thirst (dry mouth)
  •  Pale, cold skin
  •  Restlessness or sleepiness

Dengue shock syndrome (DSS) is a condition caused as a result of intensifying DHF. It mostly affects children under 10 and is life-threatening. Cold, clammy skin and a weak pulse accompanied by the symptoms of DHF are symptoms that help identify this condition.

Protecting ourselves from contracting dengue

Taking steps to ensure that you are not bitten by a dengue carrier mosquito is the best method of personal protection. Dengue mosquitoes are primarily day-biters, but are also active at night if there is enough light. The following are some steps that can help you avoid being bitten.

  • Using mosquito repellents – these provide protection both indoors and outdoors. Make sure that the repellent you use is non-toxic and environment-friendly. Caution is advised when applying repellent, especially with small children. Natural oils such as eucalyptus, lemon grass, or citronella also provide adequate protection
  • Using mosquito traps or nets
  • Secure windows and other holes around the house that may allow easy access for mosquitoes
  • Wear the right clothing – longer pants and sleeves reduce the risk of being bitten. Mosquitoes are more attracted to darker colours. Therefore, wear light-coloured clothing as much as possible. Use repellent patches or apply repellent to areas that are left uncovered.

However, in order to curb the problem in the long run, steps must be taken to address the issue at its root. More attention must be paid to the environment and how it facilitates the breeding of these mosquitoes.

Eliminating breeding sites of mosquitoes, which is very often fresh water that is stagnant, is essential and unfortunately cannot be accomplished without the cooperation of the country’s people and public services. Proper garbage disposal and waste management can be the first step towards the right direction.

Some simple steps that can be taken to eliminate mosquito breeding sites at your homes are:

  •  Get rid of any containers – plastic cups, flower pots, broken bottles, etc. – that are likely to collect water or store them upside down if necessary for later use
  •  Properly dispose of old unused tires
  •  Periodically clean roof gutters
  •  Change water in birdbaths at least once a week
  •  If you have ponds, make sure to use proper larvicide treatments or grow larvae eating fish such as guppies and goldfish
  •  Keep water drains clean
  •  The fogging treatment also helps control adult mosquitoes

“Though the trend shows little sign of declining, disease management continues to improve,” stated Dr. Ariyaratne, adding: “Dengue is a debilitating and often fatal illness.

Like an epidemic, it affects both the country’s economy and society’s wellbeing as a whole. Therefore, it is important that we build a community that stands strong in its campaign of dengue prevention to truly curb this problem.”