Pathology Progression Phases
Infection Window
Pathogen replicates inside body tissue (e.g. liver for malaria, blood cells for dengue). Usually asymptomatic during this window.
Clinical Manifestation
Sudden onset of high fever, severe headache, muscle joints pain, and shivering. Highly infectious to feeding vectors.
Convalescence or Crisis
Antibodies clear the pathogen. If complications develop (e.g. plasma leakage, hemorrhagic shock), intensive care is required.
Introduction
Dengue virus is transmitted through the bites of infected female mosquitoes, principally Aedes aegypti. It is a major public health concern, with over 3.9 billion people in 129 countries at risk of infection. The incidence of dengue has grown dramatically in recent decades due to urbanization, travel, and climate change.
Transmission cycle
The virus is transmitted to humans through the bites of infected female Aedes mosquitoes. After feeding on an infected person, the virus replicates in the mosquito’s midgut before migrating to its salivary glands over a period of 8 to 12 days. Once infective, the mosquito can transmit the virus for the remainder of its lifespan.
Diagnosis and Monitoring
Dengue is diagnosed using blood tests to detect viral RNA (PCR tests) or antibodies (IgM and IgG). Monitoring is critical during the “critical phase,” which begins when the fever starts to subside. Warning signs of severe dengue include severe abdominal pain, persistent vomiting, mucosal bleeding, and rapid drop in blood platelets. Emergency medical care is required immediately if these signs appear.
Diagnostic Symptoms Checklist
- High fever (up to 104°F / 40°C)
- Severe headache
- Pain behind the eyes
- Muscle, bone, and joint pain (hence the name 'breakbone fever')
- Nausea and vomiting
- Skin rash (appearing 2-5 days after onset of fever)
- Mild bleeding (nosebleeds, bleeding gums)
Risk Factors
- •Living in or travelling to tropical and subtropical regions.
- •Prior infection with a different serotype of dengue virus (increases risk of severe dengue).
- •High mosquito population density in urban areas.
Treatment Protocol
There is no specific antiviral treatment for dengue fever. Management focuses on supportive care, including staying hydrated, resting, and using pain relievers like acetaminophen. Avoid aspirin or ibuprofen as they can worsen bleeding risks.
Frequently Asked Questions
Can you get Dengue fever twice?
Yes. There are four distinct serotypes of the dengue virus (DENV-1, DENV-2, DENV-3, and DENV-4). Recovery from one provides lifelong immunity to that specific serotype, but subsequent infections with other serotypes increase the risk of developing severe dengue.
What is severe dengue?
Severe dengue (also known as Dengue Hemorrhagic Fever) is a life-threatening complication characterized by severe abdominal pain, persistent vomiting, rapid breathing, fluid accumulation, mucosal bleeding, and organ impairment.