Maximum infectivity of chickenpox is during:

AIIMS Delhi NO-2016

Applied Microbiology & Infection control (E5)

Easy

Appeared in: AIIMS Delhi NO-2016

Explanation

Chickenpox is highly contagious, with the period of communicability starting 1 to 2 days before the rash (vesicles) appears.
Infectivity continues for 4 to 7 days after the rash onset, lasting until all the characteristic 'dew-drop' vesicles have fully crusted over.
The option '6 days after appearing vesicles' falls squarely within this peak infectious period, as the patient would still have active, fluid-filled vesicles capable of transmitting the virus.
The virus is transmitted through direct contact with the vesicular fluid, as well as through airborne droplets from the respiratory tract.

Option A: This is too early. While the incubation period is long (10-21 days), a person only becomes infectious 1-2 days before the rash appears, not 6 days before.
Option C: By 2 weeks (14 days) after the vesicles appear, almost all lesions have typically crusted over, and the person is no longer considered infectious.
Option D: This is long after the infectious period has ended. Once vesicles have disappeared (crusted and fallen off), the person is not contagious.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Period of communicability for chickenpox (varicella) as background academic context rather than a clinical decision trigger.
Understanding the period of communicability is critical for nurses to implement appropriate infection control measures, primarily Airborne and Contact Precautions, to prevent nosocomial (hospital-acquired) outbreaks.
Patient education is a key nursing role. Nurses must advise patients and families to isolate the infected individual until all lesions have crusted to prevent spread in the community, especially to high-risk individuals (e.g., pregnant women, immunocompromised persons).
What if? If a pregnant healthcare worker without immunity is exposed to a patient with chickenpox, she should receive Varicella-Zoster Immunoglobulin (VZIG) as soon as possible (ideally within 72 hours) to prevent or attenuate the infection, which could otherwise lead to congenital varicella syndrome in the fetus.

How to Approach the Question

First, identify the core of the question, which is about the 'maximum infectivity' of 'chickenpox'.
This is a factual recall question requiring knowledge of communicable diseases.
Recall the timeline of a chickenpox infection. The key is knowing when the virus can be transmitted to others.
Remember that infectivity starts before the rash is visible and continues as long as there are fluid-filled vesicles.
Evaluate each option against this timeline: '6 days before' is too early. '2 weeks after' is too late. '6 days after' falls within the vesicular stage before all lesions have crusted, making it the most infectious period among the choices.

Concept Tested & Keywords

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