Sexually Transmitted Infections: Human Immunodeficiency Virus

Introduction

• Description: Infection by the human immunodeficiency virus (HIV) preferentially involves the immune system and leads to progressive deterioration in immune function. Infection produces a spectrum of disease that progresses from a clinically latent, asymptomatic state to acquired immune deficiency syndrome (AIDS) as a late manifestation. The speed of this progression varies. In untreated patients, the time between infection and the development of AIDS ranges from a few months to 17 years (median, 10 years). Many states have specific laws governing HIV screening, reporting, disclosure, and breach of confidence. All care providers should be familiar with the requirements imposed in their area.

• Prevalence: In 2019 an estimated 34,800 new HIV infections occurred in the United States. More than 1.2 million people in the United States are living with HIV infection, and almost one in eight (12.8%) individuals is unaware of his or her infection.

• Predominant Age: Median age is 35 years; 84% of cases occur at ages 15–44 years. In the United States, Black/African-American women have a 5-fold greater risk than other women of contracting HIV.

• Genetics: No genetic pattern.

Etiology and Pathogenesis

• Causes: Infection with HIV, a retrovirus that preferentially infects helper lymphocytes but may infect macrophages, cells of the central nervous system, and possibly the placenta. Incubation from infection to clinical symptoms ranges from 5 days to 3 months, with an average of 2–4 weeks.

• Risk Factors: Sexual activity (multiple partners or infected partner, 37% of all infections), parenteral exposure to blood (sharing needles, inadvertent needle stick), perinatal exposure of infants. There is no evidence that HIV infection may be transmitted by casual contact, immune globulin preparations, hepatitis B vaccine, or contact with biting insects. HIV infection following donor insemination has been reported.

Signs and Symptoms

• Asymptomatic—some might be asymptomatic or have no recognition of illness.

• Nonspecific symptoms, often mimicking mononucleosis with aseptic meningitis (90%). Febrile pharyngitis is the most common, with fever, sweats, lethargy, arthralgia, myalgia, headache, photophobia, skin rash, and lymphadenopathy lasting up to 2 weeks.

• Signs of loss of immune function—fever, weight loss, malaise, lymphadenopathy, central nervous system dysfunction, abnormal Pap test result, recurrent cervical intraepithelial neoplasia (CIN), oral or vaginal candidiasis. Pneumocystis jirovecii pneumonia is the most common AIDS-defining infection.

• Patients are often diagnosed late in the progression of the disease (up to 40% within 1 year of developing AIDS).

Diagnostic Approach