Question 1

How is dengue transmitted?

Accepted Answer

Dengue is transmitted by the bite of infected Aedes mosquitoes, primarily Aedes aegypti, found in tropical and subtropical urban areas. The mosquito becomes infected when it bites a dengue patient and can then transmit the virus to others. Dengue is not transmitted person-to-person — contact with an infected person cannot spread dengue.

Question 2

What are the symptoms of dengue?

Accepted Answer

Dengue causes sudden high fever (39-40 C), severe headache, pain behind the eyes, muscle and joint pains ("breakbone fever"), rash, nausea and vomiting lasting 2-7 days. Around 70-80% of infections are asymptomatic or mild. In a minority, particularly during second infections with a different serotype, severe dengue develops with plasma leakage, severe bleeding and organ impairment.

Question 3

Is there a vaccine for dengue?

Accepted Answer

Two dengue vaccines are licensed. Dengvaxia (Sanofi) is WHO-recommended only for individuals with prior dengue infection (seropositive) because it increases severe dengue risk in dengue-naive people — a critical public health lesson. Qdenga (TAK-003, Takeda) received regulatory approval in 2023 and appears effective regardless of prior dengue status, representing a significant advance.

Question 4

Why is dengue spreading to new areas?

Accepted Answer

Three drivers: climate change extends suitable Aedes mosquito habitat to higher latitudes and altitudes; rapid urbanisation creates more breeding sites; and international travel moves the virus between regions. Southern Europe (Italy, France, Spain) now reports autochthonous dengue cases with increasing frequency. ECDC tracks this expansion as a growing climate-health risk.

Question 5

What is severe dengue and how is it managed?

Accepted Answer

Severe dengue occurs in a minority of cases — characterised by plasma leakage (causing shock), severe bleeding and acute organ impairment. The case-fatality rate without treatment exceeds 2.5%. Management is supportive: careful fluid replacement, close monitoring of haematocrit and platelets, and prompt escalation. Warning signs (abdominal pain, persistent vomiting, rapid bleeding, restlessness) must trigger immediate clinical assessment.

Question 6

How is dengue treated?

Accepted Answer

There is no specific antiviral treatment. Management is supportive: oral or intravenous rehydration, paracetamol for fever (NSAIDs avoided due to bleeding risk), and monitoring for warning signs of severe dengue. Rest and avoiding mosquito bites prevent further spread. Hospitalisation is required for severe dengue.

Question 7

What is Wolbachia biocontrol?

Accepted Answer

The World Mosquito Program introduces Wolbachia bacteria — naturally found in many insects but not Aedes — into Aedes aegypti mosquitoes, reducing their capacity to transmit dengue. Released mosquitoes spread Wolbachia through the population within months. A Phase III randomised trial in Yogyakarta, Indonesia showed 77.1% reduction in dengue incidence and 86% reduction in hospitalisations. This approach is now deployed in multiple countries across Latin America and Asia-Pacific.

Question 8

Why was 2024 a record year for dengue?

Accepted Answer

The Americas reported over 12.9 million dengue cases in 2024 — more than double the previous annual record — driven by: El Nino conditions producing warmer, wetter weather expanding mosquito populations; urban growth; reduced vector control during COVID-19; and circulation of DENV-3 in populations with waning cross-immunity. Brazil was particularly severely affected, overwhelming health systems in multiple states.

Question 9

How does climate change affect dengue?

Accepted Answer

Dengue is highly climate-sensitive: higher temperatures accelerate viral replication within mosquitoes and shorten the incubation period; warmer winters allow Aedes to survive year-round in new areas; and changes in rainfall patterns alter breeding conditions. Climate projections consistently show dengue expanding into higher latitudes and altitudes, bringing it to regions with no prior population immunity.

Question 10

What are the four dengue serotypes and why do they matter?

Accepted Answer

Dengue exists as four serotypes (DENV-1 to DENV-4). Infection with one confers lifelong immunity to that serotype but only partial, temporary cross-immunity to others. A second infection with a different serotype is associated with higher severe dengue risk through antibody-dependent enhancement (ADE), in which prior antibodies paradoxically enhance uptake of the second serotype into immune cells. This is why dengue vaccine design is complex.

Question 11

What is the WHO Global Strategy for Dengue Prevention and Control?

Accepted Answer

WHO's Global Strategy for Dengue Prevention and Control 2012-2020 (and successor frameworks) addresses accurate clinical management, integrated vector management, sustainable vector control research, training and capacity building, and vaccine implementation. WHO's Global Dengue Programme coordinates surveillance, technical support and research collaboration across endemic countries.

Question 12

How does GMJ News cover dengue?

Accepted Answer

GMJ News follows WHO and PAHO dengue surveillance, vaccine trials (TAK-003, Wolbachia studies), and dengue as a case study of climate-health links. While Georgia is not endemic, the expansion of Aedes albopictus into the Caucasus region and dengue importation by returning travellers are of growing public health relevance covered in GMJ News.

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