Understanding HIV and AIDS: Pathophysiology, Diagnosis, and Management

AIDS-Defining Conditions

An individual is diagnosed with AIDS if they manifest one or more of the following opportunistic conditions:

• Esophageal, bronchi, trachea, or lung candidiasis.
• Kaposi’s sarcoma or Burkitt’s lymphoma.
• Pneumocystis jirovecii pneumonia (PJP).
• Mycobacterium tuberculosis at any site.
• Wasting syndrome (extreme weight loss and muscle wasting).
• Chronic Herpes simplex ulcers (lasting more than one month).

Exam Tip: Interpreting Lab Trends If a patient's $CD4^+$ count is steadily decreasing, it indicates a poor prognosis or medication resistance. Furthermore, a normal $CD4:CD8$ ratio is $2:1$; a ratio of less than $1$ indicates severe disease manifestation.

Diagnostic Evaluation

The diagnostic process for HIV follows a specific sequence to ensure accuracy and avoid false positives.

1. Screening: The initial test is typically an ELISA (Enzyme-Linked Immunosorbent Assay) to detect HIV antibodies.
2. Confirmation: If the ELISA is positive, a confirmatory test such as a Western blot or IFA (Indirect Immunofluorescence Assay) must be performed.
3. Viral Load: Once the diagnosis is confirmed via Western blot, clinicians conduct viral load testing to measure the amount of virus in the blood.

Laboratory monitoring also includes a Complete Blood Count (CBC) to check for anemia, leukopenia, or thrombocytopenia (low platelet count).

Highly Active Antiretroviral Therapy (HAART)

Because HIV mutates rapidly, a single medication is rarely effective. Instead, clinicians use Highly Active Antiretroviral Therapy (HAART), which combines three to four different medications to reduce the risk of drug resistance, minimize adverse effects, and lower required dosages.

Key Medication Classes

Clinical Note: Zidovudine (NRTI) Zidovudine is a widely used NRTI that prevents the integration of viral RNA into host DNA. However, nurses must monitor for a major complication: bone marrow suppression.

Nursing Management and Patient Teaching

Nursing care focuses on preventing opportunistic infections, managing nutrition, and ensuring medication adherence.

Infection Prevention

Patients with HIV are immunocompromised and must take precautions to avoid infections that a healthy person might easily fight off:

• Dietary Safety: Avoid raw or undercooked foods (meat, fish, eggs) and unwashed fruits or vegetables.
• Environmental Safety: Patients should avoid cleaning pet litter boxes to reduce the risk of toxoplasmosis.
• Blood Safety: Because HIV is blood-borne, HIV-positive individuals are ineligible to donate blood.

Nutritional Management

For patients experiencing wasting syndrome, nurses should implement a nutritional plan consisting of at least six small, high-protein feedings per day to combat muscle wasting and weight loss.

Prevention of Transmission and Postexposure Prophylaxis (PEP)

• General Prevention: Consistent condom use is the most effective method for preventing STIs during sexual activity.
• Herpes Simplex Virus (HSV): Patients with genital lesions must abstain from sexual activity during active outbreaks. Note that HSV can enter a dormant (remission) stage, but the condition remains chronic and transmissible.
• Postexposure Prophylaxis (PEP): In the event of an exposure (such as a needle-stick injury), PEP must be started within 72 hours. A common regimen includes Tenofovir and Zidovudine.

Critical Thinking: The $CD4^+$ Connection If a patient's $CD4^+$ count drops significantly between visits (e.g., from 250 to 150), the nurse should consider three possibilities: the infection is becoming more severe, the viral load is increasing, or the patient is not adhering to their medication regimen.