Question

The Varicella zoster virus (VZV) causes chickenpox and shingles, which are skin infections. While chickenpox is most common in children and is characterized by red itchy blisters, shingles occur only in people who have previously been infected with chickenpox and most commonly in adults over the age of 50. Shingles can cause severe lesions of the skin, eyes, and mucous membranes that can last for more than a month.

Which of the following statements best explains why some adults develop shingles after having chickenpox?

A. Everyone is born with the shingles virus, but chickenpox infection causes the shingles virus to switch from the latent lysogenic cycle to the active lytic reproductive cycle.

B. Varicella zoster virus (VZV) can switch from a dormant lysogenic cycle to an active lytic cycle, reactivating after many years of dormant.

C. Varicella zoster virus (VZV) can switch from a dormant latent-lytic cycle to an active lysogenic cycle, reactivating after many years of dormant.

D. Varicella zoster virus (VZV) can mutate over time, resulting in a new disease in people who have previously been infected with chickenpox.

The Varicella zoster virus (VZV) causes chickenpox and shingles, which are skin infections. While chickenpox is most common in children and is characterized by red itchy blisters, shingles occur only in people who have previously been infected with chickenpox and most commonly in adults over the age of 50. Shingles can cause severe lesions of the skin, eyes, and mucous membranes that can last for more than a month.

Which of the following statements best explains why some adults develop shingles after having chickenpox?

A. Everyone is born with the shingles virus, but chickenpox infection causes the shingles virus to switch from the latent lysogenic cycle to the active lytic reproductive cycle.

B. Varicella zoster virus (VZV) can switch from a dormant lysogenic cycle to an active lytic cycle, reactivating after many years of dormant.

C. Varicella zoster virus (VZV) can switch from a dormant latent-lytic cycle to an active lysogenic cycle, reactivating after many years of dormant.

D. Varicella zoster virus (VZV) can mutate over time, resulting in a new disease in people who have previously been infected with chickenpox.

Answer 1

The key to understanding this question is to remember the difference between the latent and lytic cycles of a virus.

Complete step-by-step Answer: Option B is correct because the Varicella zoster virus (VZV) has the ability to establish a latent infection in the nerve cells of the body after an initial chickenpox infection. This means that the virus remains dormant or inactive within the nerve cells without causing any symptoms. However, under certain circumstances, such as ageing or a weakened immune system, the virus can reactivate and enter an active lytic cycle, resulting in shingles.

The lytic cycle is the virus's replication cycle, where it actively produces new viral particles and causes damage to the host cells. This is what leads to the characteristic symptoms of shingles, including painful skin lesions, rash, and nerve pain.

Option A is incorrect because everyone is not born with a version of the shingles virus. The VZV is acquired through chickenpox infection.

Option C is incorrect because the term "latent-lytic cycle" is not a recognized term in virology. The correct terms are latent lysogenic cycle and active lytic cycle.

Option D is incorrect because VZV does not typically mutate to cause shingles. Reactivation of the dormant virus is the primary cause of shingles.

Hence the Correct Answer is Option B

Note: Shingles can be a very painful and incapacitating condition, particularly in older people. However, there are antiviral medications that can help reduce the severity of symptoms and shorten the duration of the infection. The chickenpox vaccine can also help reduce the risk of developing shingles later in life.