The farmers pray for the rains. The fields are grateful for the wet season. Likewise, disease-carrying creatures are feasting as well.
Mosquitos and other quite harmful insects find new opportunities to multiply during the rainy seasons.
As water has begun to stand in different places beginning from derelict ditches, ponds, abandoned water reservoirs, pools, even the decorative flower vases of our homes, to air-conditioners, egg shells, coconut shells, rejected tyres among others — these small, rejected but dangerous collections of water are creating a highly suitable bleeding environment for the very well known Aedes mosquitoes.
Consequently this uncontrollable breeding is again creating a horror of the late rainy season – the dengue fever!
What is Dengue?
Dengue is an acute viral febrile illness, which is transported mainly by Aedes mosquito.
Here’s the cause of dengue:
Dengue is caused by the so-called “Dengue” virus, which is a member of Flavivirus group.
It has 4 serotypes these types are Den – 1, Den – 2, Den – 3 and Den – 4. Any one of these 4 types may cause Dengue fever.
If any person is infected by any type of these virus, then the person develop life-long protection against that particular type.
At the same time the person also develops protection against other types for 7 – 8 months.
But if the person is infected by other types of virus beyond this time limit then the disease may become dangerous, which is known as “Dengue haemorrhagic fever”.
Dengue fever is more common in late July in our country and gradually increases its incidence for the next 2 -3 months.
How does Dengue spread?
This viral disease is transmitted from one infected person to another healthy person by Aedes aegypti and/or Aedes albopictus species of Aedes genus of mosquito.
Only when a Dengue infected Aedes mosquito bites a healthy person then he also becomes infected by Dengue virus.
This Aedes species of mosquitoes are comparatively larger than the other species of mosquitoes. They are easily distinguished by white stripes on a black body for that reason this type of mosquito also called ‘Tiger mosquito”.
It usually breeds in artificial accumulations of water in and around human dwellings, such as water found in discarded cans, broken bottles, fire buckets, flower pots, coconut shells, earthen pots, tree holes and the like.
They are most abundant during rainy seasons. The female type of Aedes mosquito are fearless biters and they bite chiefly daring the day.
Signs and symptoms of Dengue you should look out for
Generally all the physical sign, symptom and alteration of all the biochemical events in the human body produced by Dengue virus are collectively called “Dengue syndrome”. For the better management purpose this Dengue syndrome is further divided into three group. These groups are
- Classical Dengue fever
- Dengue haemorrhagic fever and
- Dengue Shock syndrome.
According to the importance, these all types of Dengue syndrome are further divided into two phase. Such as:
Febrile Phase: This phase usually present for 2 – 7 days. This disease is usually diagnosed in this phase by the following criteria. Such as sudden onset of continuous fever plus two or more of the following features.
- Severe headache.
- Retro orbital pain
- Severe muscular pain/Joint pain/Back pain
- Haemorrhagic manifestation
- Nausea/Vomiting/Abdominal pain
- Decrease the total count of leukocyte in blood
Plus high index of suspension based on period, population and place. But in this phase the other cause of fever such as Malaria, typhoid etc. is excluded mainly by proper history taking from the patient and laboratory investigations.
In addition to above symptoms, there are different types of rash present at different durations of the disease may be present in affected human body in 80 cases, m first 1 – 2 days the rashes may be diffuse flushing, mottling or fleeting pinpoint eruptions appear mainly on the skin of face, neck & chest.
In 3rd to 4th day the rash may be maculopapular or scantunts form rash like that of the found in measles. In 5th to 6th day appear confluence rash all over the body.
Critical Phase: It is very crucial phase for the Dengue patient. Though the Dengue fever can’t be differentiated from the other two types of Dengue Syndrome at febrile phase, the complication of Dengue hemorrhagic fever and Dengue shock syndrome can early be detected by proper clinical examination of the patient as well as laboratory investigation. In this phase the following clinical features may be either alone on in combination. Such as.
– Positive tourniquet test
– Petechiae/ecchymosis/purpura (bleeding from skin) and Mucosal bleeding: Such as bleeding from nose and mouth
– Uncontrolled bleeding from injection or other site
– Vomiting of blood, passage of blackish soft tar like foul smelling stool. Bleeding with micturition
– Bleeding through the vagina
– Decrease the blood platelet count < 100000/Cu.mm of blood
Plus evidence of Plasma leakage through the capillary vessels due to increased capillary permeability manifested by one or more of the following
– A ³ 20% rise in haematocrit for Age or Sex
– A ³ 20% drop in haematocrit following treatment with fluids as compared to baseline
– Accumulation of fluid materials at abdomen or chest
– Decreased serum sodium I on concentration, although there is no significant change at this phase in classical Dengue fever.
According to the severity. Dengue haemorrhagic fever can be divided into further 4 grades.
Grade – 1 There is no visible bleeding manifestation
Grade – 2 There is spontaneous bleeding manufestation at any site of the body
Grade – 3 In addition to the above problem, there is gradual declination of blood pressure
Grade – 4 Blood pressure can’t be recorded.
The grade 3 & grade 4 are collectively called “Dengue Sheet syndrome”.
In addition to the above all clinical manifestations the Dengue patient may present only with undifferentiated viral fever or with serious complication of Dengue fever such as “Fulminant hepatic failure” or unconsciousness due to “Encephalitis” Though such serious complications in Dengue fever are rare.
Laboratory Test :
For diagnosis of Dengue physician’s clinical suspicion is enough. But for monitoring the prognosis of the disease, some laboratory tests arc important. As there is no significant biochemical changes appear in Dengue on first three days. So it is better to done the laboratory test after 3 day of the dengue fever for confirmation of diagnosis.
The baseline laboratory test for dengue fever is complete blood count including platelet count as well as blood hematocrit or PCV. In addition to above tests total leucocyte count is also important.
Because when the leukocyte count < 5000/cu.mm of blood then the patient is going to critical phase of the disease from febrile phase at anytime within 24 hours. It is better to do the platelet count as well as PCV once daily to see the prognosis of the disease.
In addition to above laboratory tests, for confirmation of diagnosis of Dengue, it is better to detect the Dengue virus or antibody against Dengue virus in the blood. But the virus must be detected in the blood at early stage of febrile phase of the disease.
In addition to above tests. Some times some special investigations are performed for early detection of complication or prevention of complication. Such investigations are like Chest X-ray to detect accumulation of fluid materials at chest.
Ultrasonography of abdomen to detect accumulation of water at abdomen. In case of sever’s disease to detect the functional capability of the various organs of the body, there is requirement of some highly specialized investigations such as Serum albumin, liver function tests to see the liver condition, scrum electrolytes & carmine to see kidney condition etc.
What should be done :
– Proper Bed rest is required,
– In febrile phase only paracetamol tablet may be taken to reduce the body temperature, But the dosage frequency should not be more than 4 times in a day. In adult & older patient half tablet (1 tab = 500 mg) per dose is enough. In case of children if age is more than 5 years the 1/4th of a tablet per dose is enough but if the age is less than 5 year’s then 1/8th of a tablet per dose in sufficient.
– Tepid sponging with water at room temperature is proved to be good to reduce the fever.
– If fever is associated with profuse and frequent vomiting then the patient should be given plenty of water as well as liquid diet (such as normal saline, fruit juice, Dub water (etc.) to correct the water loss from the body,
– The patient should be properly observed for 48 hours after subsidence of fever for early detection of complication of Dengue syndrome.
– If the following symptom such as severe abdominal pain, passage of blackish, soft, foul smelling tarry stool, passage of blood through the vagina, vomiting of blood, bleeding from nose or gum, cold clammy skin of leg and hand present alone or in combination, then the patient must be referred to hospital for proper management under evaluation.
– In case of infant and children. If there is a febrile convulsion or even there is a history of febrile convulsion, then the patient must be referred to hospital for better management.
– In case of Grade – ii, iii and iv Dengue haemorrhagic fever proper fluid therapy is required both through the mouth and intravenous route to maintain the fluid & electrolyte balance of the body In ease of intravenous-fluid normal saline is proved to be better than others.
We must remember that in case of Dengue haemorrhagic fever and Dengue shock syndrome, death rate is consequently 10 – 12 per cent and 40 per cent. But by proper treatment this rate can be reduced to less than 2.
– If platelet count in patient in blood is less than 10,000/cu.mm of blood, then the platelet concentrate is required to prevent and reduce the uncontrolled, spontaneous bleeding.
If the platelet concentrate is not available then the fresh blood may be given in lieu of platelet concentrate.
– In case of Dengue shock syndrome If oxygen can be given then the death rate can be reduced mostly.
– If Dengue fever is associated with other concomitant diseases such as Diabetes mellitus. Appendicitis, Myocardial infarction then the patient must be admitted in hospital for proper & better management.
What should not to be done :
– Aspirin and other NSAIDs should not be used in Dengue to reduce the fever. Because they can cause a dangerous condition called “Reye’s syndrome” in children,
They can also cause gastric irritation as well as bleeding from stomach, that may complicate the Dengue fever.
– Any antibiotic should not be used, because the use of antibiotic may complicate the Dengue fever more.
– In case of Dengue shock syndrome, the use of Dopamine to increase blood pressure is not successful.
– To reduce the capillary lick the use of corticosteroid and carbazochrome is proved to be a failure.
– To reduce the uncontrolled bleeding the use of various antifibrinolytic such as aminocaproic acid proved to be unsuccessful.
As there is no specific treatment for dengue, it is better to take measures for prevention of the disease rather than curative treatment.
It is the first step in case of prevention to control Aedes mosquito which transmit and thereby spreading the disease. This mosquito can be controlled mainly by three methods. Such as:
(a) Environmental Control : The environment should be cleaned up and get rid of water holding containers such as discarded tins, empty pots, broken bottles, coconut shells and similar other collections of water. If water holding is required then water holding container must be covered with various lids. And proper care must be taken so that water accumulation in unwanted places should not last for 5 days.
(b) Chemical Control : In recent years there are various chemical materials found in the market such as: Malathion Fenthion etc. The use of such chemicals is very helpful to reduce and control the both adult mosquito and mosquito larva.
(c) To protect the human body from the mosquito bite : By the use of various materials such as spray, mat, mosquito net etc. the human body can be protected from mosquito bite.
In addition by the use of mosquito net for the Dengue patient is helpful to prevent spreading of Dengue from a diseased a person to healthy person.
As Aedes mosquito bite mainly in the morning and late evening. So it is better to use mosquito net during sleep not only at night but also in both morning and late evening to protect the human body from mosquito bite.
While there are many methods of mosquito control, experts now recommended an “Integrated approach” that is an approach which avoids the excessive use of any one method (e. g. insecticides) but tries to combine one or more methods with a view to obtaining maximum results with minimum input and also to prevent environmental pollution with toxic chemicals and development of insecticide resistance.
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Rappler. (2017). What are the common rainy season diseases?. [online] Available at: https://www.rappler.com/move-ph/issues/disasters/102032-rainy-season-diseases-signs-prevention [Accessed 11 Sep. 2017].
Jha, D. (2017). Why dengue is now an all-season threat – Times of India. [online] The Times of India. Available at: http://timesofindia.indiatimes.com/life-style/health-fitness/health-news/why-dengue-is-now-an-all-season-threat/articleshow/58140823.cms [Accessed 11 Sep. 2017].