B20 Human immunodeficiency virus [HIV] disease

Name of the Condition

• Human immunodeficiency virus [HIV] disease

Summary

Human immunodeficiency virus [HIV] disease is a chronic viral infection that targets the immune system, specifically CD4+ T cells, leading to progressive immunodeficiency. The condition progresses through distinct stages, from acute infection to clinical latency and eventually acquired immunodeficiency syndrome (AIDS) if untreated. HIV infection can be managed with antiretroviral therapy (ART), which suppresses viral replication and preserves immune function, reducing the risk of opportunistic infections and improving long-term outcomes.

Causes

HIV disease is caused by the human immunodeficiency virus (HIV), a retrovirus that infects and destroys CD4+ T lymphocytes, critical components of the immune system. Transmission occurs through contact with infected bodily fluids, including blood, semen, vaginal fluids, rectal fluids, and breast milk. Common routes of transmission include unprotected sexual intercourse, sharing of contaminated needles or syringes, perinatal exposure during childbirth or breastfeeding, and less commonly, transfusion of infected blood products (now rare in regions with screening protocols).

Risk Factors

• Unprotected sexual activity with an HIV-positive partner or multiple partners.
• Injection drug use with shared needles or syringes.
• Having a sexually transmitted infection (STI), which can increase susceptibility.
• Perinatal exposure during pregnancy, childbirth, or breastfeeding without preventive measures.
• Occupational exposure to infected blood or bodily fluids (e.g., healthcare workers).

Symptoms

• Acute HIV infection may present with flu-like symptoms (fever, fatigue, sore throat, rash) 2–4 weeks post-exposure.
• Asymptomatic or mild symptoms during the clinical latency stage, which can last years.
• Advanced disease (AIDS) may cause persistent fever, night sweats, unexplained weight loss, chronic diarrhea, and opportunistic infections (e.g., Pneumocystis pneumonia, candidiasis).

Diagnosis

Diagnosis involves laboratory testing, starting with an HIV antibody/antigen test to detect viral markers. Confirmatory testing (e.g., Western blot or nucleic acid test) is performed if initial results are positive. CD4+ T cell counts and viral load measurements are used to assess disease progression and guide treatment. Routine screening is recommended for high-risk individuals and during prenatal care.

Treatment Options

Antiretroviral therapy (ART) is the standard treatment, combining multiple drugs to suppress viral replication. ART is recommended for all HIV-positive individuals, regardless of CD4 count, to maintain immune function and prevent transmission. Treatment is lifelong and requires adherence to prevent drug resistance. Supportive care, including prophylaxis for opportunistic infections, is provided based on immune status.

Prognosis and Follow-Up

With consistent ART, HIV disease has a near-normal life expectancy. Regular follow-up includes monitoring CD4 counts, viral load, and screening for comorbidities (e.g., cardiovascular disease, liver disease). Adherence to treatment and lifestyle modifications (e.g., avoiding substance use) improve outcomes. Untreated HIV progresses to AIDS, with increased mortality from opportunistic infections or malignancies.

Complications

• Opportunistic infections (e.g., tuberculosis, cryptococcal meningitis).
• Malignancies (e.g., Kaposi sarcoma, non-Hodgkin lymphoma).
• Neurocognitive disorders (e.g., HIV-associated dementia).
• Cardiovascular, renal, and metabolic complications (e.g., dyslipidemia, insulin resistance).

Lifestyle & Prevention

• Consistent condom use during sexual activity.
• Pre-exposure prophylaxis (PrEP) for high-risk individuals.
• Avoiding sharing needles; using sterile equipment.
• Routine HIV testing for early detection.
• Breastfeeding avoidance in HIV-positive mothers in regions with safe alternatives.

When to Seek Professional Help

Seek care if experiencing flu-like symptoms after potential exposure, or if diagnosed with HIV to initiate ART promptly. Immediate medical attention is needed for severe symptoms (e.g., high fever, persistent diarrhea, neurological changes) or suspected opportunistic infections.

Tips for Medical Coders

Document the stage of HIV disease (e.g., asymptomatic, symptomatic, AIDS-defining illness) and any associated conditions (e.g., opportunistic infections, malignancies) to support accurate coding. Ensure documentation reflects the patient’s current clinical status and treatment, as this impacts code assignment. Note that B20 is used for HIV disease regardless of CD4 count or viral load, but associated conditions may require additional codes.