Cytomegalovirus Ileocolitis and Kaposi Sarcoma in HIV/AIDS

Introduction

An unusual outbreak of Kaposi sarcoma (KS) and Pneumocystis carinii pneumonia among young homosexual men was first reported by the Centers for Disease Control and Prevention (CDC) in 1981. By the end of 1982, the term acquired immune deficiency syndrome (AIDS) was born. In 1983, two research groups published their findings of the retrovirus thought to be responsible for AIDS. Initially referred to as human T-lymphotrophic virus III and lymphadenopathy-associated virus, it turned out both researchers were dealing with the same virus, renamed human immunodeficiency virus (HIV) in 1986.

AIDS and HIV are global pandemics. By the end of 2011, the World Health Organization estimated that 34 million people were living with HIV. This number varies from country to country, with African nations being the most severely affected; 4.9% of the African population is living with HIV. More than 2.5 million new cases of HIV were diagnosed in 2011, and the World Health Organization estimates that 1.7 million people worldwide succumbed to AIDS-related illnesses in 2011. Heterosexual spread is the most common mode of transmission, although in the Western world, homosexual men are still the most frequently affected.

HIV infections and the syndrome of AIDS are big public health problems in the United States. The CDC estimated that in the United States in 2010 there were 47,500 new HIV infections and that 872,990 people were living with HIV. The CDC also reported that in the United States in 2010, a total of 32,052 people were diagnosed with AIDS and 487,692 people were living with AIDS. The number of AIDS-related deaths in the United States in 2010 was 15,529, and the estimated total AIDS-related deaths through 2010 was more than 636,048. Gay and bisexual persons and men who have sex with men are the most frequently affected individuals in the United States. White men having sex with men account for 11,200 of the new infections, followed by black men having sex with men at 10,600.

HIV is spread through exposure to infected blood (transfusions, needle sticks, or needle sharing), sexual contact (including oral, vaginal, and anal sex), and transmission from pregnant mothers to fetuses. The risk varies depending on the type of exposure and the surrounding circumstances. Direct exposures to infected blood or needle sticks still carry the highest risk. Varying sexual acts carry differing risks of infection, with receptive anal intercourse having the highest risk. The rectum is a well vascularized organ with fragile mucosa, allowing for easier transmission of the virus. Multiple publications have shown that the presence of other sexually transmitted diseases increases the risk of HIV transmission.

Primary HIV infection often presents with a short flu-like illness that lasts around 14 days. This illness is accompanied by fever, malaise, and lymphadenopathy. Seroconversion, the period when antibodies are produced by the body’s immune system, occurs in 4 to 10 weeks in most patients but can take up to 6 months. In this “window” period, antibody tests may give false-negative responses. Rapid antibody tests are available and used for point of care tests to aid in the diagnosis of HIV infection. The Food and Drug Administration has recently approved the use of a rapid in-home test for this purpose. Further testing is required to confirm the diagnosis, and a negative result may not be reliable in the “window” period. The enzyme-linked immunosorbent assay tests the patient’s serum against a plate of HIV antigens. If antibodies are present, the test is confirmed via Western blot. The current immunoassay for detection of HIV is in its fourth generation. It uses a synthetic peptide or recombinant protein antigens that are designed to detect immunoglobulin (Ig)M and IgG antibodies and p24 antigen. A positive result is tested to differentiate HIV-1 antibodies from HIV-2 antibodies. Patients with a positive result from this second test should be considered positive to either HIV-1 or HIV-2 and should seek medical care for further testing for viral load and resistance assays.

The introduction of antiretroviral therapy, more commonly referred to as highly active antiretroviral therapy (HAART), has helped improve the outcomes of patients infected with HIV. HAART medication is made up of three categories of drugs: protease inhibitors, non-nucleoside reverse transcriptase inhibitors, and nucleoside reverse transcriptase inhibitors. The combination of these drugs has allowed patients to live longer, increasing life expectancy from months to decades. A recent study from the HIV Prevention Trials Network confirmed that HAART therapy can reduce the risk of sexual transmission of HIV from one partner who is infected with HIV to his or her noninfected partner by 96%.