Dengue Fever: The Mosquito’s Wrath

Dengue is a viral infection which is caused by flavivirus. It is mostly common in tropical and subtropical climatic conditions. Dengue is transmitted by day time biting mosquitoes. Individuals are infective with dengue fever during the first 3 days of the illness, while mosquitoes become infective about 2 weeks after feeding on the infected person and remain infective for the rest of their lives. In patients with severe dengue, the following may be present : 

• Prolonged prothrombin time 
• Decreased fibrinogen
• Hypoprotienemia
• Prolonged activated partial thromboplastin time 

Common Symptoms And Signs Of Dengue Fever

Many people experience no signs and symptoms of it. When symptoms do occur, usually begins four to ten days after being bitten by an infected mosquito. 

• Symptoms :
  • Prodromal symptoms like malaise, headache and myalgia. 
  • Acute onset – High grade fever, headache, chills, retrobulbar pain, red  eyes, lacrimation, GI symptoms, cough, sore throat, bradycardia and break-bone fever.
  • Types of Fever – Continuous or double peak with break on 4th days and usually lasts for 7-8 days.
  • Rashes – A scarlet morbilliform rash which blanches on pressure, develops gradually over dorsum of hands, feets, legs , spreads   upwards.
  • Convalescence is slow.
    
• Signs :
  • Suffused face, redness of eyes.
  • Abdominal tenderness
  • Lymphadenopathy
  • Pharyngeal congestion

Severe Dengue 

It happens when blood vessels become damaged and leaky. It leads to the number of clot-forming cells in your bloodstream drops. Warning signs of severe dengue can develop quickly. It may include severe stomach pain, bleeding from gums, blood in the urine and stools, persistent vomiting, difficult breathing, fatigue and restlessness. It is a life threatening emergency. It requires immediate medical attention. 

Investigations In Dengue Fever

The diagnosis is easy in an endemic area when a patient has the characteristic symptoms and signs. Tests used to detect the virus, viral nucleic acid, antigens a combination thereof : 

Demonstration of a great change in reciprocal IgM antibody titers to one or more virus antigens in paired serum samples. Detection of viral genomic sequence in autopsy tissue via reverse – transcriptase polymerase chain reaction. Immunohistochemistry may also be done for antigen detection in tissue samples. The following lab tests should also be performed under the case of dengue fever : 

• CBC count 
• Liver Panel
• Serum protein and albumin level
• Metabolic panel
• Coagulation panel

Imaging study includes chest cardiography, CT scan to detect intracranial bleeding , Ultrasonography to detect fluid in the chest or abdominal cavities.

Dengue Fever In children 

Children spend a significant amount of time outside the house or in a playzone. These areas might serve as a breeding ground for mosquitoes. Children have less severe dengue symptoms as compared to adults. Here are few possible signs of it in infants –

• Most common a skin rash
• Decreased body temperature
• Daily vomiting
• Irritability
• High temperature
• Nose and gum bleeding
• Lots many tears

Prevention is always preferable to treatment, especially in the case of children. Prevention includes use of anti – mosquito products, cleanliness in the surrounding environment and maintaining proper hygiene. 

Treatment And Management 

There is no known specific treatment of dengue fever. While recovering from dengue fever, drink plenty of fluids. Fluid replacement, blood transfusion and vasopressors are indicated in haemorrhagic variety and dengue shock treatment. Mild cases recover spontaneously. Mortality is high in dengue shock syndrome in spite of treatment. In case of fever, pain relievers including aspirin, ibuprofen, should be completely avoided. These pain relievers can increase the risk of dengue fever bleeding complications.

In case of severe dengue fever, supportive care in the hospital is needed. Blood pressure monitoring should be done. Oxygenation therapy should be used to improve oxygenation. 

Prevention And Control 

•  When cleaning your house, use cleaning solutions and other deterrents to prevent mosquitoes from entering the house. 
• Wear protective clothes like full shirts and long pants. The less exposed skin you have, the lower your chances of getting bitten.
• Avoidance and eradication of mosquito vectors.
• During an epidemic, fumigation of insecticide by road vehicles in the areas affected. 
• Removal of breeding sites/containers.
• Avoid the use of stored water and try to use piped water.
• Avoid smells that attract mosquitoes.
• Sleep under a mosquito net.
• Use mosquito repellent creams. 
• Refrain from breeding grounds. 
• Stay in well-screened houses.
•  Keep your wet garbage separate and throw it in a wet bin.
• Change your hand towels after a day’s use.
• Time your outings. 
• No effective vaccine available.