Answer

Certain groups of people are more at risk from being infected with HIV.

(i) Identify TWO groups of people who are more at risk and for each group, state how infection can be prevented.

homosexual / heterosexual, multiple partners / implied wording;

use condoms ;

intravenous drug users / implied wording;

use sterile needles from needle exchange / don't share needles ;

babies born to women with, AIDS / HIV ;

special arrangements during delivery / don't breast feed ;

AVP (a valid point) ;

max 2 for naming groups    

 [ 4 ]

(ii) Vaccines against viral infections are difficult to develop. Suggest why.

have a high mutation rate ;

contains RNA not DNA as genetic material ;

vaccine made will not be effective against different forms of [a] virus ;

antigen / protein coat changes ;

AVP ;  

[ 2 ]

(iii) SARS (Severe Acute Respiratory Syndrome), a viral infection that affects the respiratory system, was feared as a new Pandemic infection. Suggest what is meant by Pandemic.

an increase / spread / outbreak of cases, across the world

[ 1 ]

(iv) Suggest why it is difficult to control a pandemic infection.

not had chance to develop immunity to it / most people infected with it will

develop disease ;

vaccines not available in advance / AW ;

difficult to diagnose / don't understand how it is transmitted ;

lots of international travelling ;

AVP ;  

[ 2 ]

[Total: 8]