Transmitted by the bite of the Aedes mosquito, dengue fever, though lethal, can be treated by early medical treatment and consulting the doctor.[break]
According to the World Health Organization, “Some 2.5 billion people – two fifths of the world’s population – are now at risk from dengue. WHO currently estimates there may be 50 million dengue infections worldwide every year.”
Republica caught up with Dr Mukunda Prasad Kafle from Tribhuvan University Teaching Hospital to know the basics about dengue fever.
What is dengue fever?
Dengue is a viral infection. But this viral infection can take severe forms leading to serious infections. Its mortality and morbidity rate is high too. But dengue is simply viral infection.
How is it transmitted?
It’s a virus that’s transferred from humans to mosquitoes and again transferred back to humans. It’s called human to human cycle. The main vector here is the Aedes mosquito. For the infection to have a complete cycle, it should pass through humans and mosquitoes. One stage develops in humans and another stage is developed in mosquitoes and that’s how it gets infectious.
Is it only mosquitoes that transmit dengue?
The virus cycle only develops in human beings and mosquitoes. It’s usually the household mosquitoes that breed in the areas around us. In the Tarai, there are still mosquitoes, and usually the rates of dengue are high between June and November.
What is the lifecycle of the virus in the mosquitoes?
In mosquitoes, the lifecycle of the virus is eight to 12 days. If the mosquitoes die before eight to 12 days, it won’t be able to transmit the virus.
What are the main symptoms of dengue?
The main symptom is fever. But it has three categories on disease manifestation: Dengue fever, Dengue hemorrhagic fever, and dengue shock syndrome. In simple dengue fever, there are syndromes like fever, pain in the eyes, body ache plus there’s a special form called breakbone fever wherein a patient can have severe backache and headache. The patients can feel as if their bones have been fractured.
In dengue hemorrhagic fever, the body’s immune system produces different chemicals called inflammatory mediators. These chemicals leak the capillaries, the smallest blood vessels in the body, which thus makes the fluid inside the blood vessels leak outside the capillaries. This results into lowering the blood pressure, blood platelets, and hemoglobin, which impacts the nutritional transport. There are also bleeding manifestations in this case of dengue.
In case of dengue shock syndrome, there is excessive leakage of the fluid from the capillaries, and the blood pressure is severely low. In medical terms, low blood pressure is called shock.
What are the complications that a patient can have in dengue?
In dengue hemorrhagic fever, the patient may bleed to death [if not treated]. When there is less nutritional supply to different organs, there may be kidney failure, lungs failure, and there can also be bleeding inside the brain, though it may be rare. The patients can also suffer from pneumonia. There can be loss of blood in urine and stool.
When is the right time to get treatment, get blood test and visit a doctor?
The initial three to four days is the asymptomatic period; so even when the mosquito bites, there are no symptoms. Then there is the incubation period, the four to six days period. After that time, the symptoms appear: fever, headache, back ache, throat pain, breakbone fever. It lasts for around three to seven days. Then there might be a remission period of three to four days, and then the fever might reappear. The initial time to treat is that as soon you have fever, you should see the doctor.
Can dengue fever be prevented?
You should avoid mosquito bites. Fill in all the ponds around the houses and spread insecticides. According to literature, mosquitoes breed most in spare tires. Other ways can be using mosquito repellents. Wear full-sleeve clothes. Usually, these [dengue causing] mosquitoes bite you early in the morning or late afternoons.
Is dengue fever a life threatening disease?
It has three different types. You don’t know by clinical symptoms; only when the dengue hemorrhagic fever appears, then you can say that a particular patient has developed it. You should report all syndromes to the doctor. There is no chemical to kill the dengue virus. What we do is support the patient’s basic life system—if the blood pressure falls, we try to raise it; if his hemoglobin level falls, we try to increase that. And we try to avoid secondary complications that may occur. Early treatment depends on getting in touch with a doctor so that he will plan what to do next.
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