Infective period of Aedes mosquito in dengue?

RUHS, Jaipur, PB B.Sc Nursing Entrance-2018

Applied Microbiology & Infection control

Easy

Appeared in: RUHS, Jaipur, PB B.Sc Nursing Entrance-2018

Explanation

'Till death' because once an Aedes mosquito becomes infectious with the dengue virus, it remains capable of transmitting the virus for the rest of its life.
This lifelong infectivity begins after the virus completes its extrinsic incubation period (EIP) of about 8-10 days within the mosquito.
During this infective period, every subsequent blood meal the mosquito takes can lead to the transmission of the dengue virus to a susceptible human.

Option A: A period of 1-2 days is too short for the dengue virus to replicate sufficiently and migrate to the mosquito's salivary glands to make it infectious.
Option B: This is a classic distractor. The 8-10 day period represents the extrinsic incubation period (EIP), which is the time required for the mosquito to become infectious after biting an infected person. It is not the duration of the infective period itself.
Option C: The mosquito does not lose its infectivity after a single transmission. It can infect multiple individuals during its lifespan.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Dengue virus transmission cycle and vector infectivity as background academic context rather than a clinical decision trigger.
Understanding the mosquito's lifelong infectivity underscores the importance of vector control measures like eliminating breeding sites (stagnant water), using mosquito nets, and applying repellents.
Nurses must educate patients with dengue to protect themselves from mosquito bites during the first week of illness (viremic phase) to prevent further spread of the virus in the community.
What if? If the mosquito's infective period was only for a few days, vector control efforts might be focused only on short-term, immediate measures. However, because it's lifelong, sustained, long-term control strategies are essential to manage dengue outbreaks.

How to Approach the Question

First, identify the key terms in the question: 'Infective period' and 'Aedes mosquito' in the context of 'dengue'.
The question asks for the duration the mosquito can transmit the disease, not how long it takes to become infectious.
Recall the dengue transmission cycle. A mosquito bites an infected person and ingests the virus.
Differentiate between the 'extrinsic incubation period' (the time for the virus to develop in the mosquito, ~8-10 days) and the 'infective period' (the time the mosquito can transmit the virus).
Evaluate the options: '8-10 days' is the incubation period. 'Till death' correctly describes the duration of infectivity once the incubation is complete.

Concept Tested & Keywords

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