Dengue fever
Why in news:
- The recent surge in dengue cases globally, including in new regions has been alarming and poses significant global health challenges.
- The WHO forecasts the possibility of recordlevel cases this year due to global warming favouring diseasetransmitting mosquitoes.
About Dengue fever:
- Dengue (break-bone fever) is a viral infection that spreads from mosquitoes to people.
- It is more common in tropical and subtropical climates.
- Most people who get dengue won’t have symptoms.
- But for those that do, the most common symptoms are high fever, headache, body aches, nausea and rash.
- In severe cases, dengue can be fatal.
- Dengue is treated with pain medicine as there is no specific treatment currently.
Symptoms:
- Most people with dengue have mild or no symptoms and will get better in 1–2 weeks.
- Rarely, dengue can be severe and lead to death.
- If symptoms occur, they usually begin 4–10 days after infection and last for 2–7 days.
Symptoms may include:
- high fever (40°C/104°F)
- severe headache
- pain behind the eyes
- muscle and joint pains
- nausea
- vomiting
- swollen glands
- rash
- Individuals who are infected for the second time are at greater risk of severe dengue.
Diagnostics and treatment:
- Most cases of dengue fever can be treated at home with pain medicine.
- Preventing mosquito bites is the best way to avoid getting dengue.
- There is no specific treatment for dengue. The focus is on treating pain symptoms.
- Acetaminophen (paracetamol) is often used to control pain.
- Non-steroidal anti-inflammatory drugs like ibuprofen and aspirin are avoided as they can increase the risk of bleeding.
- There is a vaccine called Dengvaxia for people who have had dengue at least once and live in places where the disease is common.
- For people with severe dengue, hospitalization is often needed.
Transmission:
Transmission through the mosquito bite:
- The virus is transmitted to humans through the bites of infected female mosquitoes, primarily the Aedes aegypti
- Other species within the Aedes genus can also act as vectors, but their contribution is secondary to Aedes aegypti.
Human-to-mosquito transmission:
- Mosquitoes can become infected by people who are viremic with DENV.
- This can be someone who has a symptomatic dengue infection, someone who is yet to have a symptomatic infection (they are pre-symptomatic), but also people who show no signs of illness as well (they are asymptomatic).
- Human-to-mosquito transmission can occur up to 2 days before someone shows symptoms of the illness, and up to 2 days after the fever has resolved.
Maternal transmission:
- The primary mode of transmission of DENV between humans involves mosquito vectors.
- There is evidence however, of the possibility of maternal transmission (from a pregnant mother to her baby)
Syllabus: Prelims
