HIV Epidemiology

Introduction and Goals
Identifying and understanding the risk factors associated with HIV acquisition and transmission, and the development and progression of AIDS in men, women, and adolescents are critical aspects in the fight against this disease. Using epidemiological methods, NIAID-supported investigators are able to address key scientific questions by studying and comparing the effects of HIV in different human populations. Scientific findings gathered from these epidemiological studies help to provide insight on how to prevent the spread of HIV and also improve the quality of life for those already infected.


Clinical Trials and Cohort Studies
One major area of investigation involves studying the patterns of use and the efficacy/effectiveness of therapies in clinical trials and in cohort studies. The dramatic impact of highly active antiretroviral therapy (HAART) on HIV infection has prompted researchers to study the long-term clinical course of HIV infection in persons using HAART. While to date there have been no signs of a decrease in the effectiveness of HAART therapy, widespread drug resistance remains a concern. Furthermore, as people living with HIV continue to live longer, many of these immunocompromised individuals, who will naturally have a higher prevalence of other disease risk factors due to age, may develop other life threatening morbidities, such as heart disease or cancer, at a younger age than their HIV-negative peers. These types of scientific questions are now being investigated through epidemiological research.


International Research
Internationally, research opportunities have been expanding and accelerating in parts of the world that have been severely affected by the epidemic, including Africa, Asia and the Caribbean. Research has expanded as a result of dramatic cost reductions of HAART in many countries and the introduction of the Presidents Emergency Plan for HIV/AIDS Relief (PEPFAR), aimed at expanding access of antiretroviral therapy worldwide. The global availability of HAART has opened doors for studying the best use of therapy in different populations, which is important given that therapeutic regimens for HIV may differ in populations due to other health stressors such as other infectious diseases and nutritional deficits. Research on the availability, use and success of HAART in developing economy nations is now underway and additional research in these settings is being planned.


Goals of NIAID’s HIV/AIDS epidemiology research

• Identifying the proportion of the population affected by HIV and the rate at which new infections are occurring, as well as developing profiles on vital baseline information for HIV-infected populations and populations at risk, in order to evaluate vaccine efficacy and therapeutic clinical trials


• Describing the changing manifestations of the clinical and laboratory course of HIV infection, the changing frequency with which various complications occur, and the impact of therapy on modulating changes in HIV-related survival and clinical outcomes


• Investigating the clinical course of HIV infection among persons with other co-morbidities (i.e., HBV, HCV, tuberculosis, malaria, heart disease, diabetes) to better understand the natural and treated history of the disease in those with other chronic conditions


• Evaluating the patterns of adherence to HAART in populations around the world, the predictors of disease progression, and the efficacy of HAART in populations exposed to a variety of other concomitant infections and under nutritional and other health stressors


• Studying the biological, clinical, and epidemiological characteristics of people who are at high risk for HIV infection but do not become infected and those who are long-term non-progressors.

Source: National Institutes of Health