HIV and AIDS

Overview

Human Immunodeficiency Virus (HIV) is a virus that attacks the immune system, especially CD4 T lymphocytes.

Without effective treatment, HIV can weaken immune defenses and eventually progress to Acquired Immunodeficiency Syndrome (AIDS).

• HIV: The virus and infection.
• AIDS: The most advanced stage of HIV infection, defined by severe immune damage or certain AIDS-defining conditions.

Important: Having HIV does not mean someone has AIDS. With effective treatment, people with HIV can live long, healthy lives and may never develop AIDS.

HIV vs. AIDS

Feature	HIV	AIDS
Definition	Infection with human immunodeficiency virus	Most advanced stage of HIV infection
Immune function	May be relatively preserved or impaired	Severely compromised
Symptoms	May be absent, mild, or significant	May include serious opportunistic illnesses
Diagnosis	HIV-specific testing	HIV plus AIDS-defining criteria
Treatment	Antiretroviral therapy (ART)	ART plus treatment or prevention of complications

A person with HIV meets AIDS criteria when their CD4 count falls below 200 cells/mm³ or they develop an AIDS-defining illness.

How HIV Affects the Body

1. HIV enters susceptible cells, especially CD4 T lymphocytes.
2. It uses cellular machinery to reproduce.
3. Without treatment, ongoing infection progressively damages immune function.
4. Reduced immune defenses increase vulnerability to opportunistic infections and certain cancers.

Stages of HIV Infection

• Acute HIV Infection: Early period after infection. Some people develop fever, fatigue, rash, sore throat, or swollen lymph nodes; others have no symptoms.
• Chronic HIV Infection: HIV remains active, but symptoms may be absent for years. Treatment can suppress viral replication.
• AIDS: Advanced immune damage associated with high risk of serious complications.

Opportunistic Illnesses

Opportunistic illnesses occur more frequently or more severely when the immune system is weakened.

Examples include:

• Pneumocystis pneumonia (PCP/PJP): Serious fungal lung infection.
• Esophageal candidiasis: Fungal infection affecting the esophagus.
• Toxoplasmosis: Parasitic infection that can affect the brain.
• Tuberculosis: May occur at any HIV stage and can be especially serious with immune suppression.
• Certain cancers: Including Kaposi sarcoma and some lymphomas.

HIV Transmission

HIV spreads through certain body fluids containing infectious virus.

Fluids That Can Transmit HIV

• Blood.
• Semen and pre-seminal fluid.
• Vaginal fluids.
• Rectal fluids.
• Breast milk.

For transmission to occur, these fluids must reach susceptible mucous membranes, damaged tissue, or the bloodstream.

Common Transmission Routes

• Sexual contact involving exposure to infectious fluids.
• Sharing needles, syringes, or other injection equipment.
• Transmission during pregnancy, childbirth, or breastfeeding.
• Occupational blood exposure, such as certain needlestick injuries.

HIV Is Not Transmitted Through

• Hugging, handshakes, or ordinary touching.
• Sharing toilets, utensils, or dishes.
• Sweat, tears, or saliva alone.
• Coughing or sneezing.
• Insect bites.
• Ordinary caregiving without a relevant exposure.

Important: HIV is not an airborne infection. HIV status alone does not require airborne, droplet, or contact isolation.

Testing for HIV

HIV tests look for antibodies, viral antigens, or viral genetic material.

Test	What It Detects	Typical Detection Window After Exposure
Antibody Test	Antibodies produced in response to HIV	23–90 days
Laboratory Antigen/Antibody Test	HIV p24 antigen and antibodies, using blood from a vein	18–45 days
Rapid Fingerstick Antigen/Antibody Test	HIV antigen and antibodies	18–90 days
Nucleic Acid Test (NAT)	HIV genetic material	10–33 days

Window Period

The window period is the interval after infection before a particular test can reliably detect HIV.

• A negative result soon after an exposure does not necessarily exclude infection.
• Follow-up testing may be necessary.
• Positive screening tests require appropriate confirmatory testing.
• HIV testing and interpretation are performed by authorized healthcare professionals.

These typical windows assume the person is not taking antiretroviral medication, which can affect test detection.

HIV Treatment

Antiretroviral Therapy (ART) uses medications to suppress HIV replication.

ART is recommended for everyone diagnosed with HIV.

Effective treatment can:

• Reduce viral load.
• Preserve or restore immune function.
• Prevent progression to AIDS.
• Reduce HIV-related illness and death.
• Prevent sexual transmission when viral suppression is maintained.

Viral Load & CD4 Count

• Viral Load: Amount of HIV in the blood; used to monitor treatment effectiveness.
• CD4 Count: Measure of immune-system status and vulnerability to opportunistic infections.

Undetectable = Untransmittable (U=U)

A person living with HIV who takes ART and maintains a suppressed viral load below 200 copies/mL does not transmit HIV through sex.

This is called Undetectable = Untransmittable (U=U).

U=U specifically refers to sexual transmission. Other routes, including breastfeeding, require separate medical guidance.

Preventing HIV Infection

General Prevention

• Use condoms appropriately to reduce exposure during sex.
• Avoid sharing needles or injection equipment.
• Use sterile equipment for injections and invasive procedures.
• Follow Standard Precautions in healthcare settings.
• Obtain HIV testing and preventive care when appropriate.

Pre-Exposure Prophylaxis (PrEP)

PrEP is medication used by people without HIV to reduce their risk before potential exposure.

• May be taken orally or by scheduled injection.
• Requires appropriate medical assessment and follow-up testing.
• Does not protect against every sexually transmitted infection.

Post-Exposure Prophylaxis (PEP)

PEP is a short course of antiretroviral medication used after a potentially significant HIV exposure.

• Must be started as soon as possible, no later than 72 hours after exposure.
• Typically involves a 28-day medication course.
• Requires prompt medical evaluation.

Healthcare Worker Exposure

Following a possible occupational exposure:

1. Perform immediate first aid appropriate to the exposure, such as washing a needlestick site with soap and water or flushing exposed mucous membranes with water.
2. Report the exposure immediately.
3. Follow the facility’s occupational exposure procedures.
4. Obtain urgent medical evaluation for possible PEP.

Do not delay reporting or evaluation while waiting for information about the source patient’s HIV status.

CNA Considerations

• Use Standard Precautions for all residents.
• Follow facility PPE and sharps-safety procedures.
• Report possible occupational exposures immediately.
• Observe and report new fever, cough, unexplained weight loss, unusual fatigue, mouth lesions, or functional decline.
• Support hydration, nutrition, hygiene, comfort, and prescribed care.
• Do not independently diagnose HIV, interpret test results, or administer HIV medications outside authorized scope.
• Protect confidentiality and treat residents without discrimination.

See Caring for Residents with HIV & AIDS.

Study Notes

• Lymphatic & Immune System
• Standard Precautions
• Transmission-Based Precautions

Clinical Connections

• Standard Precautions: Routine infection prevention applies regardless of known HIV status.
• Chain of Infection: HIV requires specific transmission routes.
• Recognizing Patient Distress: Opportunistic illness can cause serious clinical deterioration.
• Caring for Residents with HIV & AIDS: Covers patient rights, stigma, communication, and individualized care.

Questions

• How does HIV differ from AIDS?
• Which immune cells does HIV primarily affect?
• What are the major stages of HIV infection?
• What body fluids can transmit HIV?
• Why is casual contact not a transmission risk?
• What does the HIV testing window period mean?
• What is the difference between CD4 count and viral load?
• How do PrEP and PEP differ?
• What does U=U mean?
• What actions should a CNA take after a possible occupational exposure?

Sources

• CDC — About HIV
• NIH — Understanding HIV Transmission
• CDC — Getting Tested for HIV
• CDC — Clinical Care of HIV
• NIH — HIV Prevention
• CDC — Clinical Guidance for PEP

Flashcards

What does HIV stand for?01-foundations / diseases-conditions

Answer

Human Immunodeficiency Virus.

What does AIDS stand for?01-foundations / diseases-conditions

Answer

Acquired Immunodeficiency Syndrome.

What is the difference between HIV and AIDS?02-mechanisms / diseases-conditions

Answer

HIV is the infection; AIDS is its most advanced stage.

Which immune cells does HIV primarily attack?01-foundations / diseases-conditions

Answer

CD4 T lymphocytes.

What CD4 count meets an AIDS diagnostic criterion?01-foundations / diseases-conditions

Answer

Below 200 cells/mm³.

Can someone have HIV without developing AIDS?01-foundations / diseases-conditions

Answer

Yes. Effective treatment can prevent progression.

What body fluids can transmit HIV?01-foundations / diseases-conditions

Answer

Blood, semen, vaginal fluids, rectal fluids, and breast milk.

Can HIV spread through hugging or sharing utensils?01-foundations / diseases-conditions

Answer

No. HIV is not transmitted through casual contact.

Is HIV transmitted through the air?01-foundations / diseases-conditions

Answer

No. HIV is not an airborne infection.

What is the HIV testing window period?01-foundations / diseases-conditions

Answer

Time between exposure and when a test can detect infection.

What is antiretroviral therapy (ART)?01-foundations / diseases-conditions

Answer

Medication that suppresses HIV replication.

What does U=U mean?01-foundations / diseases-conditions

Answer

Maintained viral suppression prevents sexual HIV transmission.

What is PrEP?01-foundations / diseases-conditions

Answer

Medication taken before potential HIV exposure to prevent infection.

What is PEP?01-foundations / diseases-conditions

Answer

Medication started after potential HIV exposure to prevent infection.

How soon must HIV PEP be started?03-application / diseases-conditions

Answer

As soon as possible, no later than 72 hours after exposure.

What should a CNA do after a possible HIV needlestick exposure?03-application / diseases-conditions

Answer

Perform appropriate first aid, report immediately, and obtain urgent evaluation.