DENGUE FEVER
Dengue fever is a viral illness transmitted primarily by the bite of infected Aedes aegypti mosquitoes, which are most active in the early morning and late afternoon. Common symptoms include a sudden high fever, severe headache, joint and muscle pain, nausea, and a skin rash.
Cause: Four distinct serotypes of the dengue virus.
Transmission: Mosquito bites; it is not spread person to person like the flu.
Incubation period:
The incubation period typically ranges from 4 to 10 days following the bite of an infected mosquito. While most infections remain asymptomatic, symptomatic cases commonly present with high-grade fever, severe headache, retro-orbital pain, myalgia, arthralgia, vomiting, and abdominal pain. Haemorrhagic manifestations such as petechiae, haematemesis, and haematochezia occur mainly in severe forms of the disease.
With appropriate clinical management, the overall case fatality rate is less than 1%.
Symptoms of Dengue Fever
Most cases are mild or asymptomatic, but flu-like symptoms can last for 2 to 7 days.
Sudden high fever (up to 40 degrees Celsius/104 degrees Fahrenheit)
Severe headache and pain behind the eyes
Severe muscle and joint pains (sometimes called “breakbone fever”)
Nausea, vomiting, and a noticeable rash
Warning Signs of Severe Dengue
In rare cases, the illness can progress to severe dengue (including dengue haemorrhagic fever). This requires immediate medical attention and is characterised by:
Severe abdominal pain
Rapid breathing and fatigue
Bleeding gums or nosebleeds
Blood in vomit or stool
Mode of transmission: It is mainly transmitted to humans through the bite of an infected Aedes mosquito (Ae. aegypti or Ae. albopictus). Humans are the main carriers of the dengue virus.
Suspected case: Any person with acute febrile illness of 2-7 days’ duration with 2 or more of the following: headache, retro-orbital pain, myalgia, arthralgia, rash, haemorrhagic manifestations, and leucopenia.
Confirmed case: A suspected case with laboratory confirmation (positive IgM antibody, fourfold or greater rise in IgG antibody titres, positive PCR or viral isolation).
Dengue Shock Syndrome
All the above criteria, plus evidence of circulatory failure manifested by rapid and weak pulse and narrow pulse pressure (≤ 20 mm Hg) or hypotension for age, cold, clammy skin and altered mental status.
Treatment & Management
There is no specific antiviral medication for dengue fever. Treatment focuses on managing symptoms:
Hydration: Drink plenty of fluids to prevent dehydration.
Pain Relief: Use acetaminophen/paracetamol for fever and pain. Avoid ibuprofen, aspirin, and naproxen, as they can increase the risk of bleeding.
Rest: Plenty of rest is recommended for recovery.
Prevention of Dengue fever
Prevention primarily focuses on avoiding mosquito bites and controlling breeding grounds:
Eliminate Standing Water: Empty containers, tyres, and pots that collect water, as these are ideal breeding grounds for mosquitoes.
Vector Control: Use window screens, wear protective clothing, and apply mosquito repellents (such as those containing DEET).
Vaccines: In some endemic areas and countries, vaccination (like Dengvaxia or Qdenga) is available for individuals who have previously been infected with dengue.
Sources:
CDC
WHO
