What is Dengue?
Dengue is one of the most common illnesses in humans. It is a flu like illness which is characterized by headache, fever, joint & muscular pain and a characteristic skin rash quite similar to measles. There are four serotypes of dengue virus, all producing a similar clinical symptom; homotypic immunity after infection with one of the serotypes is for life, but heterotypic immunity against other serotypes lasts for a short duration of a few months after infection.
The disease is transmitted by mosquitoes of the genus Aedes (Aedes aegypti & Aedes albopictus) which are widely found in the tropical & subtropical areas around the world.
Features of Dengue
The incubation period of the dengue virus from an infected mosquito bite is usually 2-7 days. Asymptomatic infections are common in all but the disease gets more severe in elderly and infants. A morbiliform rash, which characteristically blanches under pressure, occurs often when the fever is settling.
A more severe illness, called the dengue hemorrhagic fever or dengue shock syndrome, occurs mainly in South East Asian countries. In mild forms of dengue fever, there is thrombocytopenia and haemoconcentration. In the most severe form, after 3-4 days of fever, hypotension, followed by circulatory failure, develops with pleural effusions, ascites, hypoalbuminaemia and features of acute respiratory distress syndrome. Minor or major hemorrhagic signs may occur. The pathogenesis is unclear but pre-existing active or passive immunity to a dengue virus serotype different to the one causing the current infection is a predisposing factor; these heterotypic antibodies are responsible for causing enhanced virus entry and replication in the monocytes. Cytokine release is thought to be the cause of capillary leak causing effusions and disseminated intravascular coagulation may contribute to hemorrhage. Adults rarely have dengue shock syndrome but they have fatal course characterized by elevated liver enzymes, gastrointestinal bleeding and hemostatic abnormalities.
Clinical features of Dengue
- Prognosis: 2 days of persistent fever and malaise
- Acute Onset: Fever, backache, arthalgias, headache, generalized body pains, pain on eye movement, lacrimation, anorexia, nausea, bradycardia, prostration, depression, lymphadenopathy, scleral injection
- Fever: Continuous or prolonged fever with back ache, usually lasting 7-8 days
- Rash: Initial flushing followed by faint muscular rash in 1st 1-2 days. Followed by spread over the rest of the body
- Complications: Minor bleeding from mucosal sites, hepatitis, cerebral hemorrhage or oedema.
Identifying Dengue Fever/Dengue Hemorrhagic Fever (DF/DHF)
Dengue Fever can be defined as an acute febrile illness which lasts for 2-7 days with two or more symptoms of the following manifestations.
- retro-orbital pain
- hemorrhagic manifestations and symptoms (petechiae and positive tourniquet test*)
Dengue Fever in case of children is generally mild. In adults, Dengue Fever may induce severe bone pain and recovery can be associated with prolonged fatigue and depression.
Dengue Haemorrhagic Fever can be categorized as probable case of dengue and hemorrhagic tendency evidenced by one or more of the following:
- Positive tourniquet test
- Petechiae, ecchymosis or purpura
- Bleeding from mucosa (mostly epistaxis or gums), injection sites or other sites
- Haematemesis or melena
* The tourniquet test is performed by inflating a blood pressure cuff to a point mid-way between the systolic and diastolic pressures for a duration of 5 minutes. A test is considered to be positive when 10 or more petechiae per 2.5 cm2 (1 inch) are observed. In DHF, the test gives an accurate and positive result (i.e. >20 petechiae). The test may be negative or mildly positive during the phase of profound shock.
Thrombocytopaenia (platelets 100,000/cu.mm or less) and
- A >20% rise in haemotocrit for age and sex
- A >20% drop in haemotocrit following treatment with
- fluids as compared to baseline
- Signs of plasma leakage (pleural effusion, ascites or hypoproteinaemia).
Dengue Shock Syndrome (DSS) comprises all the above symptoms of DHF plus signs of circulatory failure diagnosed by rapid and weak pulse, narrow pulse pressure (< or equal to 20 mm Hg), hypotension for age, cold & clammy skin followed by restlessness. The above symptoms of DF/DHF/DSS are adequate for concerned doctor to cure the disease. However, for reporting the disease, cases should be classified as suspected DF/DHF/DSS on the basis of above the criteria. Serological evidence would help in categorize them into probable and confirmed cases. Diagnosis of DSS on virological and serological basis is not possible in small hospitals. It is always recommended that blood samples of patients be sent to a laboratory.
There are difficulties that arise in the categorization of the disease. A patient’s disease severity can shift from DHF to DSS, and depending on the stage of the disease which the patient is diagnosed with, a mixed picture is observable. However, till the time the patient evaluation is done systematically, there are no difficulties faced in giving appropriate treatment or in deciding about admission to a hospital or in referring the patients for specialized care.
The course of DF/DHF is unpredictable. Most patients have a febrile phase that lasts 2 -7 days. This is followed by a critical phase which is of about 2-3 days. During this phase, the patient is usually afebrile and develops risk of getting infected with DHF/DSS which may prove fatal if prompt and appropriate treatment is not given. As haemorrhage or shock can occur rapidly, the arrangements for rapid and appropriate treatment should be always available. By doing so, the fatality rate due to DF/DHF can be substantially reduced.
The disease course and duration of DF/DHF is summarized below:
Treatment of DF and DHF
1 Febrile Phase
Distinguishing DF from DHF is not possible in the early febrile phase. Their treatments during the febrile phase remain similar, i.e. symptomatic and supportive:
- Paracetamol (not more than 4 times in 24 hours) according to age for fever above 39 degree Celsius.
What not to do
- Antipyretics like Aspirin or Brufen should be avoided. Aspirin leads to gastritis or bleeding. In children, Reye’s syndrome (encephalopathy) can occur as a serious complication
- Antibiotics should be avoided as these do not help.
- Most recommended is Oral rehderation therapy for patients with moderate dehydration caused by vomiting and high temperature.
- Food should be given according to the appetite of patient.
The dengue patients must be constantly monitored for complications for minimum 2 days after recovery from fever. This is because fatal complications often occur during this phase.
All Patients and households should be educated that severe abdominal pain, black stools, bleeding into the skin or from the nasal mucusa, cold skin and precipitation are danger signs. If any of these signs is observed, the patient should be hospitalized. Detailed information which should be provided to all patients and households by the doctors. The patient who does not have any evidence of complications and who has been afebrile for 2-3 days does not need further observation.
2 Afebrile Phase
(1) Dengue Fever
Symptoms in patients suffering with Dengue Fever after the decline of fever are same as the febrile stage. Most patients show recovery without any complications.
(2) Dengue Hemorrhagic Fever (DHF) I and II
In Dengue Fever, during the course of afebrile phase of DHF I and II, the patient shows the same symptoms as present during the febrile phase. The clinical symptoms plus haemoconcentration or rise in hematocrit with thrombocytopenia are sufficient to have a clinical diagnosis of DHF. During this phase, the patients should be monitored for at least 2-3 days after the decline in temperature, skin rashes, profuse bleeding from nose or gums, blue spots on the skin followed by tarry stools. If any such signs are observable, then the patients should be hospitalized without any delay. Only difference found between the DF and DHF Grade I is the presence of thrombocytopenia and rise in haematocrit (>20%). Patients with DHF Grade I do not usually require intravenous fluid therapy and Oral Rehydration Therapy is sufficient.
DO’S AND DONT’S FOR PATIENTS
If you or any family member is suffering from suspected dengue fever, it is important to keep a careful watch on yourself or the affected person for the next few days as this disease rapidly becomes very serious, leading to a medical emergency. The manifestations associated with Dengue Fever/Dengue Haemorrhagic Fever generally appear between the 3rd and 5th day of illness. Hence ,the patient should be monitored for two days even after the fever disappears.
Global Burden of Dengue: The incidence of dengue has grown dramatically around the world in recent decades. Over 2.5 billion people and over 40% of the world’s population are now at risk from dengue. According to WHO estimates, there may be 50–100 million dengue infections worldwide every year.
Symptoms: The symptoms include high fever, body pain, nausea and skin rashes. The Dengue fever may be asymptomatic. Adults have a mild febrile onset with sudden, abrupt fever, headache, pain behind eyes and muscular & joint pains.
The other type, which is the Dengue Hemorrhagic Fever, is characterized by high fever, damage to lymph and blood vessels, nasal and gum bleeding, liver enlargement, and circulatory system failure. The symptoms may also shift to profuse bleeding, shock, and death. This is called dengue shock syndrome (DSS).
A drop in the platelet count below 100000 per/mm3 is usually diagnosed between 3 and 8th day of illness indicates presence of dengue.
Manifestation of Dengue Infection
All four dengue virus (Den 1, 2, 3 and 4) infections may be asymptomatic or may lead to undifferentiated fever, dengue fever(DF), or dengue haemorrhagic fever (DHF) with plasma leakage that may lead to hypovolemic shock, dengue shock syndrome (DSS).
Management and prevention
Treatment is symptomatic. Aspirin should be avoided due to bleeding risk. Volume replacement and blood transfusions may be indicated in patients with shock. With intensive care support, mortality rates are 1% or less. Corticosteroids are ineffective. No existing antivirals are seen to show any treatment towards dengue virus.
Breeding places of Aedes mosquitoes should be abolished and the adults destroyed by insecticides. There is no licensed vaccine available.
What to do?
- Keep body temperature below 39 degree Celsius. Give the patient paracetamol (not more than four times in 24 hours)
- Consume large amounts of fluids (water, soup, milk, juice) along with the normal diet.
- Complete bed rest is recommended.
- Immediately consult a doctor if the following manifestations appear:
- Red spots or points on the skin;
- Bleeding from the nose or gums;
- Frequent vomiting;
- Vomiting with blood;
- Black stools;
- Constant crying;
- Abdominal pain;
- Excessive thirst (dry mouth);
- Pale, cold or clammy skin;
- Difficulty in breathing.
What not to do?
- Do not wait in case the above symptoms appear. It is important to quickly get treatment in case of these complications.
- Aspirin or Brufen or Ibubrufen should not be taken.
Home Remedies and Ayurvedic Treatment
Neem leaves and Neem Oil act as good purifying agents and should be applied in a damp warm cloth in dosages of between 15 and 60 grams, 2-3 times daily. It should be ensured that usage should be restricted in both males and females seeking pregnancy.
Consumption of liquids should be increased in order to recover loss of fluids. It also helps to bring down body temperature.
Eating solid foods should be avoided until the fever is gone. Solid foods can be replaced by drinking plenty of distilled water and/or juices.
Coriander leaves, taken in the form of a tonic, help reduce the fevers in dengue.
Kakamachi, which is a syrup like product, can be consumed as a soothing, cooling drink that helps expel negative toxins that develop during an attack of dengue from the digestive system and ultimately purify the body. A cup of kakamachi syrup twice daily is the recommended dosage.
Fruits that are rich in vitamin C like amla (embellica officinalis) are highly recommended as vitamin C helps in the better absorption of iron.
Chyavanprash can be consumed as it is an effective immunobooster, blood purifier and blood count increaser.
Hogweed is helpful in bringing down temperature. Hogweed induces plenty of perspiration that flushes out the toxins and brings the fever down.
Powdered Hermal seeds are taken as either an infusion or as a decoctin to treat intermittent and recurrent fevers that are observed with dengue.
Boiled tulsi i.e basil leaves served in a warm drink like tea can help prevent dengue. It is a bitter and pungent herb and has all the properties that strengthen the internal system against fever.
10-15 basil leaves can be chewed twice a day or can be boiled in 200ml water at low temperature. When half the boiled quantity is left, it can be taken 2-3 times a day. This helps strengthen the body’s defense mechanism.
Papaya juice is an effective natural cure for dengue fever. The juice of Papaya leaf is also a sure cure for platelet deficiency
The cassia tree root is used as a tonic for reducing dengue fever.
Chirayata has tremendous medicinal properties that help in the reduction of fevers. It is used for reducing the convulsions that accompany fevers in dengue.
Dhatura is the Ayurvedic version of the belladonna. Its leaves have the power to reduce the seriousness of dengue fevers. However, the dosage must not exceed 2 decigrams or it will show severe negative symptoms.
Indian mallow infusion is used as an efficacious treatment for reducing the dengue fever.
Fenugreek leaves can be consumed as herbal tea in order to reduce fevers. This drink is an effective, soothing and cleansing antioxidant for the human system.
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Davidson’s Principles of Medicine.
Use and Interpretation of tests in infectious diseases – James. B Peter(Speciality Ranbaxy)
Medical Microbiology- C.P Baweja
Virology- Dr. U.C Chaturvedi