Question

2. Identify the study design in the following scenarios. Give reasons for your answers.

b. All IDUs in refugee camp X who agreed to participate in the study were screened for HCV infection using anti-HCV test and those who were negative were followed up for a period of 6 months. A standardized questionnaire was used to collect information on the frequency of injections monthly. Similarly, blood samples were also collected monthly to test for HCV seroconversion (i.e. from negative to positive anti-HCV test).

Answer 1

ANSWER 2. b.

HCV is the virus that causes Hepetitis C.

The anti-HCV Test is used to test if a person has developed any antibodies against the Hepatitis C virus. These antibodies are known as anti-HCV since they are released in response to mechanism against the HCV. Thus a person can be screened for the presence of Hepatitis C virus by using this anti-HCV test.

If a person is infected , the anti-HCV test will be positive. However in absense of HCV or if there is not enough HCV - RNA to be screened, the person will show a negative anti-HCV test.

In this case, the refugees were followed up for a period of 6 months in case the virus starts multiplying to generated enough HCV RNA to be screened. This would test for HCV seroconversion (i.e. from negative to positive anti-HCV test) if any. Also, a  standardized questionnaire was used to collect information on the frequency of injections monthly. Similarly, blood samples were also collected monthly to keep a track of the period when the person was tested.