Manual of Clinical Nutrition Management III- 46 Copyright © 2013 Compass Group, Inc.
HIV INFECTION AND AIDS
Discussion
The human immunodeficiency virus (HIV) is a retrovirus that is transmitted through contact with blood or
body fluids (semen, vaginal secretions, or breast milk) from an infected person (1). This virus attacks helper T
lymphocytes in the blood, often referred to as CD4+ T cells. The systematic destruction of these cells weakens
the body’s immune system, which increases the host’s vulnerability to opportunistic infections. Acquired
immunodeficiency syndrome (AIDS) is a specific stage of HIV infection in which the progression of the virus
has advanced and the immune system becomes compromised. Due to effective primary prevention and the
life-prolonging effects of antiretroviral therapies (ARTs), the number of reported HIV and AIDS cases has
leveled off at less than 1% of the global population, according to the 2008 Report on the Global AIDS Epidemic
(1,2). In the United States, prevalence rates increased between 2003 and 2006 as a result of improved survival
and efforts to encourage testing and awareness of HIV infection status (1,3,4). Recent data on HIV infection in
the United States indicate that more than two thirds of HIV-infected people are between 25 and 49 years of
age, while one quarter of infected people are older than 50 years, and 5% of infected people are between 13
and 24 years of age (5). The most vulnerable groups at risk for infection are ethnic minorities, women,
children, and adolescents (1).
Overview and Classification of AIDS
The Centers for Disease Control and Prevention (CDC) defines AIDS by the following criteria (6):
a positive antibody test for HIV, and
a CD4 count less than 200/mm^3 or less than 14% of the total white blood cell count, or
a clinical diagnosis of one of the 25 AIDS-defining diseases (7)
In addition to the CDC system, the World Health Organization Clinical Staging and Disease Classification
System can be used readily in resource-constrained settings without access to CD4 cell count measurements
or other diagnostic and laboratory testing methods (8).
A variety of metabolic and physiologic changes are caused by the effect of HIV on the immune system (1).
As a result, persons with HIV infection or AIDS are susceptible to disorders, including opportunistic
infections, wasting syndrome, neurological dysfunctions, and gastrointestinal ailments, that challenge their
nutritional status and quality of life (9). When AIDS is advanced, it increases the patient’s susceptibility to
neoplasms such as Kaposi sarcoma and non-Hodgkin lymphoma (9). The CD4 cell count is used as a marker of
HIV disease progression. The HIV viral load, which is expressed as copies of HIV ribonucleic acid per milliliter
of blood, is used to evaluate the amount of virus in the body (9). The viral load test reflects the level of active
virus replication throughout the body and is used for evaluating the efficacy of HIV therapies, predicting the
progression of HIV infection to AIDS, and assessing the efficacy of new antiviral medications (9). As the viral
load increases, the risk for clinical deterioration also increases (7,9). Although a person at the onset of HIV
infection may be asymptomatic, the HIV is not dormant; rather, the virus is actively reproducing. In addition
to decreasing CD4 counts, symptoms of HIV disease progression include fatigue, weight loss, body
composition changes, and diarrhea. Other signs of disease progression are associated with opportunistic
symptoms and include night sweats, mouth sores, rashes, and fever (9). Highly active antiretroviral therapy
(HAART), which is a combination therapy consisting of several antiretroviral drugs, is effective in reducing
and controlling viral burden and improving immune function. The use of HAART has dramatically reduced the
mortality rate of HIV-infected persons and the incidence of AIDS wasting syndrome (10). However, the long-
term use of HAART has increased the prevalence of complications such as insulin resistance, diabetes,
cardiovascular disease, renal disease, cancers, neurologic disease, and bone density loss (1,9).
Nutritional Implications of HIV and AIDS
The impact of nutrition on HIV and AIDS is significant and multi-factorial (1,9). The HIV infection promotes a
vicious cycle, as the infection can cause malnutrition, which exacerbates immune dysfunctions and thus
increases the vulnerability to opportunistic infections (1,9). The HIV infection and its treatments may initiate a
complex dysregulation of the metabolism associated with changes in nutritional status, such as energy
expenditure, lipid metabolism, hormonal balances, and immune function (1,11-14). Even in well-nourished
individuals, the hormonal response to infection can lead to changes in hormonal sensitivity (eg, insulin,
growth hormone, and sex hormones), tissue catabolism, and a reduction in appetite and food intake (1,9). Poor
nutritional status, including both undernutrition and overnutrition, can affect immune function independent
of HIV infection (1). Reducing or eliminating malnutrition has the potential to significantly slow the