Monday, December 14, 2009

Let’s break down a CRNE style question

1. A Hepatitis A virus outbreak has occurred at the cafeteria of a large high school. Public health nurses have been immunizing students that ate there with Hepatitis A Immune globulin. This works by:

a. Stimulating the body to produce antibodies to attack the Hepatitis A virus

b. Causes the immune system to release memory B cells to attack the Hepatitis A virus

c. Antibodies in the Immune globulin attack the hepatitis A virus

d. Stimulates the body to release IgA antibodies

Reflective Points

This question is really trying to determine if you understand what Hepatitis A immune globulin is and how it works. So let’s analyze the options:

a. This sounds like a good option, as it is antibodies that attack the virus, however we know that it takes about two week to get an adequate immune response against a foreign agent. But, if it takes two week to build up an immune response this will not protect the students who were potentially exposed the Hepatitis A virus.

b. Memory B cells only develop if a person is naturally exposed to Hepatitis A or if immunized against Hepatitis A in the past, so this is not the correct response

c. Hepatitis A Immune globulin consists of preformed antibodies (grown in culture media) that are ready to attack Hepatitis A. So, this sounds like the right answer so far, but let’s take a look at the last option.

d. This is the weakest option. It’s a bit vague compared to option A and C but could refer to either.

Hope this helps you to analyze the questions and answers on the CRNE.
For more practice with this enroll in our CRNE review workshops.
Next sesion is January 9-10, 2010 in Vancouver.
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