The Global Burden of Acquired Immune Deficiency Syndrome ( AIDS ) in Tuberculosis Infected Patients and Related Financial Aspects

The acquired immune deficiency syndrome (AIDS) is an infectious disease caused by human immunodeficiency virus (HIV). Approximately about 37 million people are infected by this virus with the rate of 1.2 million deaths per year. The mortality rate is high among HIV infected patients in the first 6 months of treatment.1 Immune deficient cases are at the high risk of any opportunistic infection. AIDS has been closely linked with tuberculosis (TB) disease, so almost one third of total mortality is related to this co-infection. In this regard, tuberculosis is used as a diagnostic index for AIDS.2 AIDS is not only associated with high mortality and morbidity, but it affects social life with related stresses and anxieties.3 Considering vast influence of HIV-TB over peoples’ lives, the present study aimed to estimate direct global burden of HIV infection on the patients with TB in a one-year period in 2014.

The disability-adjusted life year (DALY) was considered for calculating disease burden.The DALY index is equal summation of 2 components called years of lost life (YLL) and years lost due to disability (YLD). 9

DALY=YLL+YLD
(1) The YLL comes from number of deaths (N) and related lost lives (L) and the YLD comes from the number of infected patients (I) and the time during which they were infected (d) and lost their usual abilities considering disability weight (DW).

YLL = N×L
(2) (3) According to Global Burden of Disease (GBD) report, HIV disability weight was equal to 0.153. 10The economic burden was calculated by using GDP per capita. 4,6conomic Burden = DALY×GDP (4) The total number of newly diagnosed HIV infected patients was 1 502 600 worldwide with the average of 14,310 new cases per country in 2014.The total number of HIV-TB co-infected patients was 1 097 014 in the world with the average of 6377 per country in 2014.Almost 73% of new HIV patients were also infected with TB in 2014.Out of total 21 440 237 HIV-TB adjusted lost years, 167 843 years were related to disability and 21 272 394 years were related to mortality in 2014.The average lost years were 52 938 per country.Total financial loss was more than 70 billion USD worldwide with the average of 173 million USD per country.The first 10 countries with maximum burden were South Africa, Nigeria, Mozambique, India,   1.
In a study by Winter et al in 2018, it was shown than the TB susceptibility was in relationship with HIV infection.
HIV infection is considered as a risk factor for latent TB.The early diagnosis of HIV infection is essential for the proper treatment of HIV-TB infected patients. 11The study of Lawn et al demonstrated that HIV-TB incidence was approximately equal to 1.37 million worldwide in 2007.This co-infection included almost 15% of total global TB cases.It also encompassed 23% of total HIV related mortalities.Moreover, multidrug resistance was further seen in HIV-TB infected patients.One fourth of the world HIV-TB cases have been located in Africa with higher incidence in sub-Saharan region. 12An updated report of global HIV-TB burden in 2014 is provided in Table 1.
In a survey on HIV infection by Dieleman for the years 1995-2015, middle income countries spent more on TB related health programs and had fastest per capita growth in comparison with high and low income countries. 13In a study by Filha et al on direct and indirect costs of TB-HIV infections, indirect costs were more than half of the total costs.The costs for TB-HIV infected patients were almost 8.5 times more than those for TB infected patients. 14herefore the total cost of HIV-TB co-infection is more than what was reported as direct cost in this study.
Due to the lack of data associated with economy and health in some countries, the global burden was much lower than the actual burden in calculation.In our calculations, we did not add TB disability weight because we tried to estimate HIV infection burden in TB infected subjects with a focus on HIV.However, even these underestimated values of burden were quite significant and no case could be ignored.More than 99% of lost years caused by HIV-TB co-infection were coinfection-related deaths; therefore, TB screening is strongly recommended in all new HIV cases to reduce related deaths.

doi 10 .
15171/ijbsm.2018.25The Global Burden of Acquired Immune Deficiency Syndrome (AIDS) in Tuberculosis Infected Patients and Related Financial Aspects

Table 1 .
Global HIV-TB Burden in 2014

Table 1 .
ContinuedInternational Journal of Basic Science in Medicine.Volume 3, Issue 4, 2018 GDP, gross domestic production; YLL, years of life lost; YLD, years lived with disability.