Consider the following statements regarding dengue virus : 1. It has four distinct serotypes. 2. Infection with any one serotype confers lifelong immunity for that virus serotype. 3. Secondary infection with dengue serotype 2 leads to severe form of dengue. Which of the statements given above are correct?
Dengue Virus Serotypes Overview
The dengue virus exists in four distinct serotypes: DENV-1, DENV-2, DENV-3, and DENV-4. Understanding these serotypes is crucial for studying dengue epidemiology and disease progression.
Dengue Serotype Immunity
Following an initial infection with one specific dengue serotype, an individual typically develops lifelong immunity against that particular serotype. However, this immunity does not extend to the other three serotypes, leaving the person susceptible to reinfection.
Secondary Dengue Infection Severity
A secondary dengue infection, which occurs when a person is infected with a different serotype after a previous infection, carries a higher risk of developing severe dengue symptoms. Studies often indicate that secondary infections involving certain serotypes, such as DENV-2, are associated with increased severity, potentially leading to severe dengue manifestations like dengue hemorrhagic fever and dengue shock syndrome.
Conclusion on Dengue Statements
Based on the established knowledge of dengue virus characteristics:
- Statement 1 is correct as there are indeed four serotypes.
- Statement 2 is correct because immunity is serotype-specific and lifelong for that type.
- Statement 3 is correct as secondary infections, especially with specific serotypes like DENV-2, are linked to severe forms of the disease.
Therefore, all three statements are correct.
Important Questions from Infectious Disease Control & Prevention
As per the Open Vial Policy, partially used multidose vials of which of the following vaccines can be used over more than one immunization session?
1. BCG vaccine
2. DPT vaccine
3. Hepatitis B vaccine
4. Measles vaccine
Select the correct answer using the code given below.
Consider the following statements regarding dengue :
1. The mosquito becomes infective after an extrinsic incubation period of 8-10 days.
2. Once it becomes infective, the mosquito remains infective for life.
3. The genital tract of the mosquito does not get infected.
Which of the statements given above are correct?
Consider the following statements about Kyasanur Forest Disease (KFD) :
1. It is transmitted by ticks.
2. It was originally called 'pig disease' because of the association with dead pigs.
3. It was first recognized in Karnataka State.
How many of the statements given above are correct?
- In countries with low levels of measles transmission, what should be the appropriate age for starting immuni-zation with measles-containing vaccine (MCV)?
- Monkeypox, a viral zoonotic disease, is caused by
