| Highlight of Dengue prevention 1) Prevent the accumulation of water in your surroundings. 2) Always wear full sleeves, especially during the daytime. 3) Use a mosquito net while sleeping 4) Using repellents containing N N-diethyl 3-methylbenzamide or picardin. 5) Install protective nets on doors and windows |
Dengue Prevention
Dengue Prevention Techniques
Dengue Prevention requires both an individual and community-level approach to become effective.
- Stagnant water is a major breeding spot for dengue mosquitoes, and we should try to prevent water accumulation near our house and also in near by areas. Old rubber tyres, empty cans, and coconut shells can accumulate rainwater and provide breeding spots for these mosquitoes.
- Dengue mosquitoes generally bite in the daytime, and hence wearing full sleeve clothes is important to prevent dengue.
- Use mosquito repellent containing N N diethyl 3 methylbenzamide or picardin.
- Always use a mosquito net while sleeping.
- Also, install protective nets on windows and doors to prevent direct entry of these mosquitoes inside the home.
Dengue Virus
Dengue is a mosquito-borne viral infection that affects humans.
It is also known as ‘Break-bone fever’ because of myalgias ( Muscle pain) and arthralgias ( Joint pain).
It is a single stranded RNA virus which are of four types based on serology – DENV 1,2,3, and 4.
It belongs to the Flaviviridae family.
How Dengue spreads-
Dengue virus spreads through the bite of the Aedes mosquito, particularly Aedes aegypti and Aedes albopictus
Aedes aegypti usually lays eggs in artificial water containers in and around homes.
Adult mosquitoes usually rest inside the home and feed on human blood, especially in the morning and late afternoon.
A mosquito can acquire DENV after biting an infected individual. After this, the virus reaches the midgut of the mosquito and replicates for 7-12 days.
After replication, the virus reaches the salivary gland of the mosquito, and from the gland it is transferred to humans as soon as the mosquito bites other human beings.
How does dengue affect the body?
All four serotypes of dengue, DENV 1,2,3, and 4, can cause disease. Infection with one serotype provides immunity to that serotype, and the person remains susceptible to other serotypes of dengue.
This disease is usually severe in patients with a second infection and in infants with transmitted maternal antibody.
Virus replication increases as soon as it enters the human body.
Systemic vascular leak and coagulopathy are seen in dengue patients, but the actual mechanism is not fully understood yet.
Management of Dengue
Clinical Features of Dengue
Dengue virus symptoms can range from mild fever to severe bleeding and fatality.
Symptoms usually appear after an incubation period of 4 to 7 days.
A) Febrile phase
In this phase, patients can present with-
High-grade fever, headache, retro-orbital pain ( pain located behind the eye socket), malaise (weakness), myalgias ( muscle pain), severe bone and joint pain, Anorexia ( loss of appetite), loss of taste sensation.
Some patients can show a skin rash or skin flushing.
Lymphadenopathy ( Swelling of the lymph nodes), hepatomegaly ( enlarged liver), and hemorrhagic episode such as petechiae or bruising.
B) Critical Phase-
Most patients usually recover from the fever within 3 to 7 days after the onset of the fever.
Some patients don’t recover from fever and get into the critical phase, which is characterized by endothelial dysfunction and transient vascular leak syndrome becomes apparent at this time.
In Vascular leak syndrome, there is usually an increase in haemoconcentration, hypoproteinaemia, pleural effusion, and ascites.
In severe cases, plasma volume starts decreasing, and it can lead to hypovolemic shock, which is known as Dengue shock syndrome.
It is important to properly administer fluids to the patient to prevent any serious complications.
Patients with deteriorating health conditions usually present with lethargy, persistent vomiting, worsening abdominal pain, and increased hepatomegaly.
Hemorrhagic manifestations are more common in adults in comparison to children. Bleeding from gums, epistaxis, gastrointestinal bleeding, and haematuria (bleeding from urine).
C) Recovery phase-
This phase usually begins when the vascular permeability starts decreasing, which usually begins after 24 to 48 hours.
During this phase, fluid absorption improves rapidly, and care should be taken to prevent fluid overload in the patient, as this can lead to respiratory difficulties in the patient.
After 6 to 7 days of illness, a maculopapular rash can appear, typically on the extremities and sometimes on the trunk and face.
The rash blanches or disappears on pressure and may present with intense itching.
Blurred vision and sometimes transient visual loss are also seen in some patients.
Severe clinical features –
Moderate hepatitis is seen commonly in dengue cases, but in some cases, severe hepatitis and acute liver failure can occur.
Renal impairment can be seen in patients if patients get hypovolemic for a longer duration.
Hypoxia or hepatitis can lead to encephalitis.
Myocarditis can also occur in some patients.
Laboratory investigation for dengue-
Early illness – During the first 5 days of infection, laboratory confirmation can be done by virus isolation or on detection of NS1 Antigen by RT-PCR in the blood.
After 5 days of illness IgM antibody detected enzyme enzyme-linked immunosorbent assay (MAC-ELISA) is the most commonly used test to detect dengue.
An Increase in the dengue-specific IgM indicates the chances of acute infection.
Patients who get infected again with dengue often show high levels of IgG.
Treatment of dengue
- No approved medicine has been recognised for the treatment.
- Good supportive care is important for the treatment, and adequate fluid management is the mainstay of the treatment.
- Paracetamol is the most preferred choice of medicine for fever.
- Aspirin and other non-steroidal anti-inflammatory medicines should be completely avoided in this disease.
- Intramuscular injection should be avoided as in this disease, thrombocytopenia and coagulation derangements are common, and injection can lead to bleeding.
- Patient presenting with persistent vomiting, severe abdominal pain, bleeding from mucosa or bleeding in skin or tissue with increasing haemtocrit and drop in platelet count should be managed carefully and may require admission to monitor vital signs and manage accordingly.
- Fluid therapy is important especially in patients with rising haemtocrit.
- For patients who are in shock, adequate fluid management is important because if not managed properly, the risk of organ damage increases.
- Fluid management should be done in such a way that fluid overload is prevented because fluid overload can lead to serious complications and mortality.
- Isotonic crystalloid solution is usually used in fluid management, and in severe cases, colloid solution can be used, or in those patients who do not respond to isotonic crystalloid solution.
- Electrolyte imbalance, metabolic imbalance, and hypoglycemia should be checked and managed properly.
- Platelet infusion is not indicated for mild and moderate thrombocytopenia, and if the patient suffers from severe bleeding, then only transfusion of fresh blood and platelets can be done, but with extreme care to prevent fluid overload.
