Setting the Scene
In order to quantify the HIV/TB epidemic, and understand how it affects our country and its people, scientists need to research the number of people who have tested positive or may have died from AIDS and/or TB-related diseases.
One can almost draw a parallel between the importance of voluntary counselling and testing (VCT) and the importance of epidemic statistics; VCT reflects the progression of the disease (where you are at) and statistics inform the epidemic’s trends and evolution.
Thus scientists look at the many medical and social impacts of the epidemic. Among others, researchers would look at how many people have received VCT; how many people are taking antiretroviral (ARV) and/or TB medication and how many child-headed households there are, per health district.
Thus the records collated will include the number of people living with HIV/TB, the number of new infections, and the number of people who have died of AIDS and/or TB.
Reports of ‘actual cases’ indicate each positive HIV/TB test which has been recorded. Unfortunately, there are many cases which go unreported and therefore this data reflects the ‘minimum’ number of people infected, and can’t be viewed as an accurate reflection of the actual number of people infected.
Surveys, on the other hand, give the estimated number of people living with HIV and/or TB, as well as other statistics and are based on a number of initial hypotheses.
Prevalence
‘Prevalence’ is given as a percentage of a population. For the purpose of producing a national or international HIV and TB prevalence figures, researchers include the ‘prevailing’ number of people living with HIV and TB, at a given point in time – irrespective of whether or not they have full-blown AIDS.
Incidence
‘Incidence’ refers to the number of new HIV and TB infections in the population at a given point in time. People who were infected before that time period, will not be included in the count.